Thread: My problems with infinity, the multi-verse & current scientific understanding.

A problem I have had for a while (or rather one of those seriously neurotic brain aneurysm you get from contemplating a puzzle for far too long) Is how Infinity is interpreted.

Infinity, which I hear way too often in the scientific community is an impossibility It exists only on the chalkboard, Often to make the math work or as a place holder for "I do not know."

Take for example a gravitational singularity, it is often interpreted as an "infinitely small point of time, space, and matter." which is, true on the chalk board. However in reality it has size. Now what that size is, a pea, a grain of sand, even the size of a quark or smaller, It still has size, thus is not truly infinite.

This also expands to the large as well such as universal scale. Known universe is about 46billion(i think, current estimates) light years across. However its often hypothesized the true size is "infinite" which is, again an impossibility. Perhaps it extends in the trillions, or quadrillions or larger in size. I do not know, however "infinite" is not possible because there is at some point an end.

This brings me to my issues with the multi-verse, which I have always had an issue with but could not quite place my finger on until recently. I am willing to concede of the possibility of a multi-verse in some form(grudgingly)

However the current accepted idea is pretty much any action committed causes a multiverse. Current models basically state that if I flip a coin, and it comes up heads. In another universe, the coin will come up tails.

Ask yourself, how did this universe come into play, was my flip of the coin what caused it? No, that would be magic. This is how it would happen. 13.7 billion years ago, another universe was formed along side ours. Absolutely everything was the same, our star formed the same way, planet, solar system, in fact the entire universe in every intricate way was exactly the same to ours except for me and 1 coin being flipped. 13.7 billion years of perfection and I screw it up with a quarter.

Now, there is also an "infinite" number of universes for every other possible action or non-action committed by everything else within our universe spawning an infinite number of universes and so on and so forth.

It is an impossibility, a multi-verse could exist, however i dont subscribe to the multi-earth theory for this reason. Something which goes against the current scientific trend I have scene on the acceptance.

I understand on quantum mechanics, quarks do fly in and out of our universe and into another, however the infinity principal must be taken into consideration, there is a limit (it might be vastly huge) I do not know yet a limit there must be.

Please, someone help me with my current train of thought. Am I missing something?

Please forgive me and my grammar as I am very new to any sort of forum discussions.

I think the issue with infinity is that in some ways (in my understanding) is that yes its a stand-in for "idk" but it also means that there are an infinite amount of possibilities in the universe. Seeing as how we are so tiny comparatively to what we have discovered is the universe, im not sure that we have the ability to perceive and understand certain things right now.

However, the way I have tried to think about its is that there is a possibility that the only way that infinity is able to exist is in a loop. If everything is infinitely small it can also be infinitely huge at the same time. As for the multi-verse maybe the things we do not know for sure about black holes, worm holes and such hold the key the answer to that question. More research dedicated to the singularity and the exploration beyond the event horizon is needed.

Originally Posted by GoldenRatio

A problem I have had for a while (or rather one of those seriously neurotic brain aneurysm you get from contemplating a puzzle for far too long) Is how Infinity is interpreted.

Infinity, which I hear way too often in the scientific community is an impossibility It exists only on the chalkboard, Often to make the math work or as a place holder for "I do not know."

Take for example a gravitational singularity, it is often interpreted as an "infinitely small point of time, space, and matter." which is, true on the chalk board. However in reality it has size. Now what that size is, a pea, a grain of sand, even the size of a quark or smaller, It still has size, thus is not truly infinite.

This also expands to the large as well such as universal scale. Known universe is about 46billion(i think, current estimates) light years across. However its often hypothesized the true size is "infinite" which is, again an impossibility. Perhaps it extends in the trillions, or quadrillions or larger in size. I do not know, however "infinite" is not possible because there is at some point an end.

Just a few points:
1. There are an array of different types of mathematical infinities. Infinity in the context of an unending 'physical' singular universe literally means 'without end'. It might not sit neatly in our perception but it needs to be taken literally when used in that context. It is an incorrect assumption (mathematically and physically) to think that at some point there is an end to an infinite universe.
2. A singularity should also be taken literally. It is a mathematical notion. The question we are facing is whether a mathematical singularity can actually 'exists' in our universe. So for those that believe it can't, then a very small volume such as that defined by the Planck volume is taken as the universal limit to 'smallness'.

I know they may strike a chord with what is perceived as a reality, but when used by scientists as a descriptor, they need to be taken literally. :-))

PS One of the problems and pitfalls of not understanding the 'exactness' of these notions is that it is easy to fly off on a tangent assuming that what these terms really meant was somewhat different. Now that physics is getting to the pointy end of the big questions, it is essential that the bounds of physics are correctly defined. It is Ok to question whether the terms 'singularity and infinite' can apply within the context of our universe, but it is a mistake to incorrectly apply definitions used in this context.

Originally Posted by Lestrange217

I think the issue with infinity is that in some ways (in my understanding) is that yes its a stand-in for "idk"

Whut?

but it also means that there are an infinite amount of possibilities in the universe

Really?

However, the way I have tried to think about its is that there is a possibility that the only way that infinity is able to exist is in a loop.

Huh?

If everything is infinitely small it can also be infinitely huge at the same time

Why do think this?

As for the multi-verse maybe the things we do not know for sure about black holes, worm holes and such hold the key the answer to that question. More research dedicated to the singularity and the exploration beyond the event horizon is needed.

This appears ¹ to be flailing about. Why do think they "hold the key"? What do you mean by "exploration beyond the event horizon is needed"?

1 I say it this way due to John Galt's thread here.

OK maybe I should have explained that I am just trying to exercise some imagination. I am new to these topics and wanted to explore. I apologize as you seem to be knowledgeable in this subject, I meant no offense. I in no way wanted to seem like i was any sort of expert just wanting to follow, learn, think out loud in a way.

Trying to explore as much as I can about the universe and how it works.

Originally Posted by Lestrange217

OK maybe I should have explained that I am just trying to exercise some imagination. I am new to these topics and wanted to explore. I apologize as you seem to be knowledgeable in this subject, I meant no offense. I in no way wanted to seem like i was any sort of expert just wanting to follow, learn, think out loud in a way.

Trying to explore as much as I can about the universe and how it works.

No offence taken, it's just that unsupported statements aren't really useful.
Exploration is great, but explaining the thinking behind whatever you're thinking helps everyone - if you're wrong we get to see why you think that way and then sort out the "problem", if you're right we get to learn why - an "answer" on its own doesn't advance things much.

Originally Posted by GoldenRatio

AInfinity, which I hear way too often in the scientific community is an impossibility

You don't know that.

It exists only on the chalkboard, Often to make the math work or as a place holder for "I do not know."

Sometimes it indicates an unknown. Not always.

Take for example a gravitational singularity, it is often interpreted as an "infinitely small point of time, space, and matter." which is, true on the chalk board. However in reality it has size. Now what that size is, a pea, a grain of sand, even the size of a quark or smaller, It still has size, thus is not truly infinite.

Our current theories say that a gravitationally singularity is infinitely small and, therefore, infinitely dense. I don;t think anyone thinks that reflects reality. But currently we don't have a theory that tells what really happens. So you may be right but that is just speculation, not science.

This also expands to the large as well such as universal scale. Known universe is about 46billion(i think, current estimates) light years across. However its often hypothesized the true size is "infinite" which is, again an impossibility.

It is not impossible. It may be infinite, it may not.

however "infinite" is not possible because there is at some point an end.

This is the logical fallacy known as "begging the question".

Why is there an end at some point?
Because the universe is finite.
How do you know the universe is finite?
Because there is an end at some point.
... Repeat.

Again, it may be infinite or it may not. The fact you do not believe infinite is possible is irrelevant. I have seen people argue that the universe is infinite because "it is impossible" that it is finite. Meh.

However the current accepted idea is pretty much any action committed causes a multiverse. Current models basically state that if I flip a coin, and it comes up heads. In another universe, the coin will come up tails.

This is not "the current accepted idea"; this is the Many Worlds interpretation of quantum theory. It is a philosophical position, rather than science. And has nothing to do with multiverse theories - which are probably better described as hypotheses or speculations anyway.

I understand on quantum mechanics, quarks do fly in and out of our universe and into another

I have never heard that. Do you have a reference?

, however the infinity principal must be taken into consideration, there is a limit (it might be vastly huge) I do not know yet a limit there must be.

Why?

Please, someone help me with my current train of thought. Am I missing something?

I would recommend reading some more detailed and accurate descriptions of modern science. You seem to have picked up a few misunderstandings from pop. sci. articles or maybe TV documentaries - in general, they are a truly terrible source of information.

Also, you need to learn to be more open minded. Dismissing something as "impossible" based purely on your instinct or "common sense" is going to get in the way of learning.

Originally Posted by GoldenRatio

Infinity, which I hear way too often in the scientific community is an impossibility It exists only on the chalkboard.

Don't worry, you're not alone on this. I've seen comments by plenty of mathematicians and physicists that express doubts about the existence of actual infinities. As an abstract concept, no problem; as something that can actually occur in nature...? The mind boggles.

Originally Posted by Zwirko

Don't worry, you're not alone on this. I've seen comments by plenty of mathematicians and physicists that express doubts about the existence of actual infinities.

Argumentum ad populum, argument from incredulity and argumentum ab auctoritate all in one. Impressive!

Strange, you really need to quit throwing around accusations of logical fallacies, because you rarely seem to know what they actually mean.

1) If I had said: "Actual infinites are impossible. Dr. X, Y and Z said so", that'd be an argument containing a logical fallacy (argumentum ab auctoritate).
2) If I had said: "Actual infinites are impossible because I can't wrap my head around the concept", that'd be an argument containing a logical fallacy (argument from incredulity).
3) If I had said: "Actual infinites are impossible because I've seen this argument made many times", that'd be an argument containing a logical fallacy (argumentum ad populum).

The brief points I made were:


1) The OP is not alone in his opinon. He's in good company.
2) I have doubts that actual infinites exist in nature. (For the record, I have no idea if they actaully do or do not).
3) The topic of infinity is mind-boggling, an actual infinity doubly so.


Three facts. Three observations. Not a logical fallacy in sight.




The existence of actual infinities is an open question. It has no conclusive answer. I made no argument for either case.

Oh good grief. It was a joke.

[QUOTE=Strange;505088]

Originally Posted by GoldenRatio

AInfinity, which I hear way too often in the scientific community is an impossibility

You don't know that.

Agreed, I also do not know if any other intellegent species exist within the universe beside us. However im strongly inclined to believe we are not alone.

Our current theories say that a gravitationally singularity is infinitely small and, therefore, infinitely dense. I don;t think anyone thinks that reflects reality. But currently we don't have a theory that tells what really happens. So you may be right but that is just speculation, not science.

If it was infinitely dense, then it would be logical to assume all matter in the universe would be orbiting & falling into the singularity. There would be no limit on its density thus no limit on its gravitational pull. Without a limit, all matter would disappear.

I understand on quantum mechanics, quarks do fly in and out of our universe and into another

I have never heard that. Do you have a reference?

I will work on a source later.



Lets try to think about every bit of matter in the known universe, every single atom. Lets say there is another universe to correspond for every atom known in ours. Then another universe for every atom within these other universes, to whatever power you want to take it. No matter how far you decide to go, you have not reached infinity you are not even close, you are not even in the ballpark. That is the problem with infinity. There is no end.

I guess impossible was a bit harsh. Lets say i believe there is an infinitely shrinking probability that infinity exists .

"Everything that has a beginning, has an end. Neo"

Originally Posted by Strange

Oh good grief. It was a joke.

It wasn't very funny.

2/10. Would not recommend.

Originally Posted by GoldenRatio

If it was infinitely dense, then it would be logical to assume all matter in the universe would be orbiting & falling into the singularity. There would be no limit on its density thus no limit on its gravitational pull. Without a limit, all matter would disappear.

Except that gravity only depends on the mass, not the density. A black hole has no more gravitational pull (at a given distance) than any other body of the same mass. For example, if the sun turned into a black hole, the Earth would continue in its orbit unchanged (just darker and colder).

Originally Posted by Strange

Except that gravity only depends on the mass, not the density.

Just a small note here - the above is correct outside a gravitating mass, but not in its interior; the interior metric depends on all the little bits and ends such as densities, fluxes, stresses etc etc.

Originally Posted by Strange

Our current theories say that a gravitationally singularity is infinitely small and, therefore, infinitely dense. I don;t think anyone thinks that reflects reality. But currently we don't have a theory that tells what really happens. So you may be right but that is just speculation, not science.


It is not impossible. It may be infinite, it may not.














I would recommend reading some more detailed and accurate descriptions of modern science. You seem to have picked up a few misunderstandings from pop. sci. articles or maybe TV documentaries - in general, they are a truly terrible source of information.

Also, you need to learn to be more open minded. Dismissing something as "impossible" based purely on your instinct or "common sense" is going to get in the way of learning.

I'm also interested in whether my concept of infinity is wrong, or skewed in some way, because I have picked up simplistic ideas from sources such as popular science articles.
My understanding is that examples of infinity, in the real physical Universe, do not exist and given that, apparently, it is not even considered scientifically correct to draw conclusions, by extrapolating from one concrete example, I find it difficult to grasp why a Universe that is infinite in extent should be considered a distinct possibility.
I'm also puzzled by the view,expressed above, that altho' nobody believes an infinitely small singularity "reflects reality" it is very possible an infinitely large object, such as the Universe, can exist.

Originally Posted by Halliday

My understanding is that examples of infinity, in the real physical Universe, do not exist

Well, if the universe is infinite, then there would be several such examples. So the inability to point to an example now doesn't tell you anything. It is like saying that we have only seen white swans and therefore there is no such thing as a black swan. Until you find a black swan.

I find it difficult to grasp why a Universe that is infinite in extent should be considered a distinct possibility.

Because nothing says it is impossible and it is one possible solution to the Einstein Field Equations that (apparently) describe the universe.

I'm also puzzled by the view,expressed above, that altho' nobody believes an infinitely small singularity "reflects reality" it is very possible an infinitely large object, such as the Universe, can exist.

Infinite density seems physically implausible. But maybe it is an accurate description. There is nothing implausible about an infinite universe.

Originally Posted by Halliday

Originally Posted by Strange

Our current theories say that a gravitationally singularity is infinitely small and, therefore, infinitely dense. I don;t think anyone thinks that reflects reality. But currently we don't have a theory that tells what really happens. So you may be right but that is just speculation, not science.


It is not impossible. It may be infinite, it may not.














I would recommend reading some more detailed and accurate descriptions of modern science. You seem to have picked up a few misunderstandings from pop. sci. articles or maybe TV documentaries - in general, they are a truly terrible source of information.

Also, you need to learn to be more open minded. Dismissing something as "impossible" based purely on your instinct or "common sense" is going to get in the way of learning.

I'm also interested in whether my concept of infinity is wrong, or skewed in some way, because I have picked up simplistic ideas from sources such as popular science articles.
My understanding is that examples of infinity, in the real physical Universe, do not exist and given that, apparently, it is not even considered scientifically correct to draw conclusions, by extrapolating from one concrete example, I find it difficult to grasp why a Universe that is infinite in extent should be considered a distinct possibility.
I'm also puzzled by the view,expressed above, that altho' nobody believes an infinitely small singularity "reflects reality" it is very possible an infinitely large object, such as the Universe, can exist.

Another way to look at this is universes are finite and are created in an infinite setting. Universes are not closed and are fed by the infinite setting. A universe can exist infinitely or it can return to the infinite setting depending on the dynamics of the universe. Because the universes are finite similarities can reoccur without creating the need for infinite possibilities.

Jim Colyer
The theory that our universe may be one of an infinite number of universes has gained popularity. The idea was put forth by Alan Guth (gooth) at Sanford University in 1979. Two Russian cosmologists, Andrei Linde and Alexander Vilenkin, also take the theory seriously. According to multiverse theory, there are countless Big Bangs before and after ours. New universes are always coming into existence. Big Bangs are caused by "repulsive gravity" as energy and space-time move outward. Expansion begins with inflation, a period during which universes expand faster than light. If we could turn off all stars and galaxies, we would see a sea of radiation left over from our own Big Bang. In fact, the COBE and WMAP spacecrafts have detected and mapped this cosmic background radiation.

Alan Guth put the multiverse idea on the shelf for a while. Linde continued to publish. Multiverse proponents contend that "eternal inflation" and dark energy point to a multiverse. Each universe has a different value of dark energy. String theory, too, lends credence to a multiverse. String theory suggests that there may be more dimensions than height, width and depth. At least that is what Guth and Linde think. There may be exact duplicates of ourselves in parallel universes. Naturally, there are scoffers, scientists who believe the multiverse is science fiction. Still, there are those who think the multiverse may be the next Copernican Revolution.

Max Tegmark is a Swedish cosmologist at MIT. He thinks there are at least 4 different kinds of parallel universes and has published articles about them. High-level physics can be pretty speculative.

Originally Posted by Dywyddyr

Exploration is great, but explaining the thinking behind whatever you're thinking helps everyone - if you're wrong we get to see why you think that way and then sort out the "problem", if you're right we get to learn why - an "answer" on its own doesn't advance things much.

42.

Originally Posted by Jim Colyer

Jim Colyer
The theory that our universe may be one of an infinite number of universes has gained popularity. The idea was put forth by Alan Guth (gooth) at Sanford University in 1979. Two Russian cosmologists, Andrei Linde and Alexander Vilenkin, also take the theory seriously. According to multiverse theory, there are countless Big Bangs before and after ours. New universes are always coming into existence. Big Bangs are caused by "repulsive gravity" as energy and space-time move outward. Expansion begins with inflation, a period during which universes expand faster than light. If we could turn off all stars and galaxies, we would see a sea of radiation left over from our own Big Bang. In fact, the COBE and WMAP spacecrafts have detected and mapped this cosmic background radiation.

Alan Guth put the multiverse idea on the shelf for a while. Linde continued to publish. Multiverse proponents contend that "eternal inflation" and dark energy point to a multiverse. Each universe has a different value of dark energy. String theory, too, lends credence to a multiverse. String theory suggests that there may be more dimensions than height, width and depth. At least that is what Guth and Linde think. There may be exact duplicates of ourselves in parallel universes. Naturally, there are scoffers, scientists who believe the multiverse is science fiction. Still, there are those who think the multiverse may be the next Copernican Revolution.

Max Tegmark is a Swedish cosmologist at MIT. He thinks there are at least 4 different kinds of parallel universes and has published articles about them. High-level physics can be pretty speculative.

The background radiation formula must be on a sliding scale. When the math came out before the proof I believe background radiation was thought to be 10K and was adjusted when it was found to be 3K. At the time the universe was believed to be 8 billion years old. As the age of the universe changes and gets older the background radiation formula must have to change with it. Supernovas, gamma ray bursts, and colliding galaxies must also affect the background radiation equation. Copernicus was a visionary but waited until he was dying to present his findings. History does not like to move more than one day at a time as it would too quickly disrupt the balance of power if forced to jump ahead. We are so over populated there might be a chance for a Copernicus and a Kepler to exist in the same era.

Pure psychoceramicism.

Originally Posted by PhDemon

psychoceramicism.

Originally Posted by Markus Hanke

Originally Posted by PhDemon

psychoceramicism.

Pottery à la crack.

Originally Posted by Markus Hanke

Originally Posted by PhDemon

psychoceramicism.

Josiah S. Carberry - Wikipedia, the free encyclopedia

Originally Posted by PhDemon

Josiah S. Carberry - Wikipedia, the free encyclopedia

I must admit that I hadn't heard of that one before...it's brilliant though

The more I read about infinity the more wacky it seems. I've just been informed that the sum of all natural numbers is -1/12.

infinity... Perhaps there is no such thing as nothing

What do you mean? I'm not sure what your point is. What has infinity got to do with the existence of nothing?

Originally Posted by PhDemon

What do you mean? I'm not sure what your point is. What has infinity got to do with the existence of nothing?

Well if there is no such thing as nothing wouldn't that mean infinity is the norm?

I suppose I mean this... if there is such a thing as nothing than that would suggest the "end" of matter or energy or whatever. meaning there could not be infinity because there would be an end point, but what if there is no such thing as nothing... meaning you can always have things smaller (or larger as it may be) that would lend itself to the concept of infinity because there is never an endpoint...

get it?

No, the existence of "nothing" says nothing (pun intended) about the possibility of infinity. If there is such a thing as nothing there could still be infinity as you have only an "end point" at one end. For example there are an infinite number of positive integers (starting from "nothing" but with no end).

Originally Posted by PhDemon

No, the existence of "nothing" says nothing (pun intended) about the possibility of infinity. If there is such a thing as nothing there could still be infinity as you have only an "end point" at one end. For example there are an infinite number of positive integers (starting from "nothing" but with no end).

in this instance of Positive intergers 0 doesn't have to be the starting point. Isn't 0 basically shrodinger's cat being something and nothing at the same time? it's a place holder it may as well be X

Who says there has to be a starting point? "no such thing as nothing" means there as always been (existence, energy, whatever) so there is no starting point... infinity in both directions not just one

I now have no idea what you are on about. Zero as Schrodingers cat? Zero is something and nothing? These make zero sense to me. Infinite in both directions not just one? Something is either infinite or it isn't...

Originally Posted by PhDemon

Something is either infinite or it isn't...

You're the one that wrote that there had to be a starting point... I was illustrating that that is not the case.
My over all point is that perhaps everything is infinite not having a starting or ending point.

Maybe you have another haughty post you could post to me...

Originally Posted by grmpysmrf

You're the one that wrote that there had to be a starting point

Try reading what was written.

Originally Posted by grmpysmrf

Originally Posted by PhDemon

Something is either infinite or it isn't...

You're the one that wrote that there had to be a starting point... I was illustrating that that is not the case.
My over all point is that perhaps everything is infinite not having a starting or ending point.

Maybe you have another haughty post you could post to me...

No I didn't say that at all. I said that the existence of nothing didn't exclude the possibility of infinity.

There was nothing haughty in my post. I simply pointed out your reasoning was unclear and didn't make sense to me. If you want to discuss ideas you need to a) learn to express yourself more clearly, b) actually read the responses you get and respond to what is written not what you think is written and c) develop a much thicker skin. As it is you seem to think any response that isn't a glowing endorsement is "haughty" so I'll leave you to it. Good luck.

Originally Posted by PhDemon

Originally Posted by grmpysmrf

Originally Posted by PhDemon

Something is either infinite or it isn't...

You're the one that wrote that there had to be a starting point... I was illustrating that that is not the case.
My over all point is that perhaps everything is infinite not having a starting or ending point.

Maybe you have another haughty post you could post to me...

No I didn't say that at all. I said that the existence of nothing didn't exclude the possibility of infinity.

There was nothing haughty in my post. I simply pointed out your reasoning was unclear and didn't make sense to me. If you want to discuss ideas you need to a) learn to express yourself more clearly, b) actually read the responses you get and respond to what is written not what you think is written and c) develop a much thicker skin. As it is you seem to think any response that isn't a glowing endorsement is "haughty" so I'll leave you to it. Good luck.

My point and reasoning prior being zero isn't nothing, it's a place holder. You seem to want it to be nothing so you have a starting point for infinity in your positive integer example. understand? The reasoning behind it being that there is something and nothing at the same time? just like the cat is alive and dead at the same time...

I clearly don't have the background as you. you obviously don't see yourself as being haughty, but that in itself doesn't keep you from being such. If I understand what you have written differently than what you intended, I'd say the problem is with your presentation of the information. Just as you have suggested I need to express myself more clearly, I'm thinking that suggestion apply equally to your posts

I wan't looking for an endorsement. I was presenting an idea, and you decided to be condescending.
I'm sure you're just living out some "so this is what it feels like to be a popular varsity jock" fantasy.
I suppose it's working for you. congratulations.

Originally Posted by grmpysmrf

My over all point is that perhaps everything is infinite not having a starting or ending point.

I see two problems with this :

1. The existence of event horizons - once geodesics cross horizons, they effectively terminate there as the region beyond the horizon is not causally connected to the rest of the universe. So not everything is infinite.
2. Infinity does not imply that there is no starting or ending point. We can have a universe that starts with a Big Bang, and then expands forever

Originally Posted by grmpysmrf

infinity... Perhaps there is no such thing as nothing

I also struggle with this.

The definition of nothing to me is that literally 'nothing can be said about it'. You cannot even put a placeholder such as 0 in this context as there is 'nothing' to relate to that placeholder. GR doesn't exist in this context. QM doesn't exist in this context etc. Space doesn't exist, time doesn't exist, the mind doesn't exist, thoughts don't exist, things don't exist etc.).

Clearly vacuum space, energy configurations and spacetime properties are a 'something' as opposed to a 'nothing' (zilch, nada). Existence of 'something' therefore requires a context for it to 'actually exist' in my opinion no matter the transient nature of that existence, whether fleeting or permanent. Yes you can transform much of this away, but at the end of it all you are still left with a something.

In the context of this universe which to me clearly is 'something' then I prefer to avoid that condundrum by at least recognising the context should possess a 'placeholder' in its definition such as a 0 so that we can then at least assess our universe using our current best theories such as QM and GR to see whether it may arise from an initial causal state and potentially be an open or closed system or whether the universe is and has always been infinite in extent with no initial causal state at all.

I therefore tend to use a spectrum of extremes between at least a fundamental notion of 'something' on one end (I will star with a 0 as a fundamental beginning state as opposed to a nothing) and extend it to infinity on the other end to ensure the system I am investigating is all encompassing. I can then safely proceed with my investigations dabbling with closed systems inside this context and investigate whether these closed systems are truly isolated in their context.

Infinity actually is an exciting prospect as it allows for a single infinite classical causal universe from an initial state or an infinite array of classical 'causal' universes arising from an infinite array of initial conditions. I am very slow at following others into the QM multiverse area however as I would like to exhaust possibilities in this one before jumping ship.....but to be fair I have been seduced lately by Steinhardt and Turoks cyclic universe...and it is difficult to reject KJW's logic (but it is nice to be a thorn in his side occassionally /tic).. :-))

PS grmpysmrf your initial post probably threw a wobbly to the audience as the Schrodingers cat example relates to the phenomenon know as entanglement which relates to notions of a classical reality or not as opposed to the question of existence or not.....but I get where you were coming from.

Originally Posted by Markus Hanke

Originally Posted by grmpysmrf

My over all point is that perhaps everything is infinite not having a starting or ending point.

I see two problems with this :

1. The existence of event horizons - once geodesics cross horizons, they effectively terminate there as the region beyond the horizon is not causally connected to the rest of the universe. So not everything is infinite.
2. Infinity does not imply that there is no starting or ending point. We can have a universe that starts with a Big Bang, and then expands forever

I must say you are talking above my head now. Not condescendingly either. It seemed straight forward I just don't understand what those words mean put together like that.

If I am understanding you right I think you said this...

event horizons are not connected with the rest of the universe so once a particle crosses it that particle it ceases to exists...

if that's what your saying, I ask how can the event horizon be in space and not a part of the universe? Also, another scientist (a plumber as I think I recall) has challenged Hawking and has said information is not lost in a black hole (what the event horizon leads to. I state for my clarification not yours) it is just mixed about so it is unrecognizable but the information is still there. So I would present that it's not ceasing to exist it's still there it's just looks different. It's undying/infinite

and then #2

We can have a universe that starts with a Big Bang, and then expands forever

is it really "starting?" Maybe all of that energy/information has been there for a forever amount of time and has just changed shape... big bang wasn't the start of anything. just the natural progression of what "is"

Thanks for indulging my post.

Originally Posted by grmpysmrf

just like the cat is alive and dead at the same time...

No it's not.

Originally Posted by Implicate Order

Originally Posted by grmpysmrf

infinity... Perhaps there is no such thing as nothing

I also struggle with this.

The definition of nothing to me is that literally 'nothing can be said about it'. You cannot even put a placeholder such as 0 in this context as there is 'nothing' to relate to that placeholder. GR doesn't exist in this context. QM doesn't exist in this context etc. Space doesn't exist, time doesn't exist, the mind doesn't exist, thoughts don't exist, things don't exist etc.).

Clearly vacuum space, energy configurations and spacetime properties are a 'something' as opposed to a 'nothing' (zilch, nada). Existence of 'something' therefore requires a context for it to 'actually exist' in my opinion no matter the transient nature of that existence, whether fleeting or permanent. Yes you can transform much of this away, but at the end of it all you are still left with a something.

In the context of this universe which to me clearly is 'something' then I prefer to avoid that condundrum by at least recognising the context should possess a 'placeholder' in its definition such as a 0 so that we can then at least assess our universe using our current best theories such as QM and GR to see whether it may arise from an initial causal state and potentially be an open or closed system or whether the universe is and has always been infinite in extent with no initial causal state at all.

I therefore tend to use a spectrum of extremes between at least a fundamental notion of 'something' on one end (I will star with a 0 as a fundamental beginning state as opposed to a nothing) and extend it to infinity on the other end to ensure the system I am investigating is all encompassing. I can then safely proceed with my investigations dabbling with closed systems inside this context and investigate whether these closed systems are truly isolated in their context.

Infinity actually is an exciting prospect as it allows for a single infinite classical causal universe from an initial state or an infinite array of classical 'causal' universes arising from an infinite array of initial conditions. I am very slow at following others into the QM multiverse area however as I would like to exhaust possibilities in this one before jumping ship.....but to be fair I have been seduced lately by Steinhardt and Turoks cyclic universe..... :-))

He he, Thanks for the post sir/madam. I had to read it several times to try and get all of it

Clearly vacuum space, energy configurations and spacetime properties are a 'something' as opposed to a 'nothing' (zilch, nada). Existence of 'something' therefore requires a context for it to 'actually exist' in my opinion no matter the transient nature of that existence, whether fleeting or permanent. Yes you can transform much of this away, but at the end of it all you are still left with a something.

Jesus, man that's much more profound than how I stumbled on this idea... if you hold your hands apart about 2 inches (we'll say two inches two inches is good) from each other it looks like there is nothing between them, but science tells us that that is not true, there are a gazillion jillion molecules bouncing around between them. So, even though it looks like nothing, there is actually something.

It used to be the smallest things thought were molecules, but then we found atoms (Ha! I say "we" like I was there. ) and then Atoms were the smallest things thought, but then we found protons an neutrons and those now are the smallest things known, but now string theory comes along and now they think perhaps there are strings/filaments inside the protons and neutrons that are the smallest things known and that's not even touching on the other sub atomic particles...

reversely isn't it strange how solar systems look like ridiculously over sized molecules? So perhaps there's a state of matter/existence that makes our stars look ridiculously small... and a state of matter above that that makes those stars look ridiculously small. no matter which way you go big or small you always have something. it's infinite

Perhaps space is like that... I think it's said there is like 1 molecule or atom (i don't remember which) every three miles in space. maybe that's not true maybe there are a gazillion jillion tinier things that we just haven't been able to see yet... just like the "nothing" that exists between our hands when we hold them close to each other but not touch.

So really no matter how you look at it there is always something. The big bang was't the start of anything because all that stuff has always been there

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

just like the cat is alive and dead at the same time...

No it's not.

take it up with schrodinger

Originally Posted by grmpysmrf

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

just like the cat is alive and dead at the same time...

No it's not.

take it up with schrodinger

Schrödinger happened to be the one that pointed out that it's one or the other, not both.

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

just like the cat is alive and dead at the same time...

No it's not.

take it up with schrodinger

Schrödinger happened to be the one that pointed out that it's one or the other, not both.

I learned that until you opened the box it was both. and if you never opened the box the cat would always exist in both realms.

Originally Posted by grmpysmrf

event horizons are not connected with the rest of the universe so once a particle crosses it that particle it ceases to exists...

The event horizon itself is part of the universe ( it's a surface of null geodesics without future end points ), but the region beyond the horizon effectively isn't.

I ask how can the event horizon be in space and not a part of the universe?

See above.

Also, another scientist (a plumber as I think I recall) has challenged Hawking and has said information is not lost in a black hole (what the event horizon leads to. I state for my clarification not yours) it is just mixed about so it is unrecognizable but the information is still there.

That depends what you mean by "information". When something falls through the horizon, its surface area will increase, and total entropy changes. However, just by looking at the entropy you will not be able to tell what it was that fell through the horizon. Do you know what I mean ?

So I would present that it's not ceasing to exist it's still there it's just looks different. It's undying/infinite

Again, it depends what you mean by "it". A photon falling into a black hole will cease to exist in the classical sense, but the total energy it carried does not, since that information becomes encoded on the area of the event horizon surface.

is it really "starting?"

That's the million dollar question. Personally I think not, but such ideas are mere speculation; in the context of currently established cosmology, the BB was indeed a "start".

Originally Posted by grmpysmrf

I learned that until you opened the box it was both. and if you never opened the box the cat would always exist in both realms.

Then you learned wrong.
That's not what Schrödinger said.
Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, the paradox is a classic reductio ad absurdum.
In fact he used the word "absurd" to describe the idea that it was both at the same time.

Originally Posted by Markus Hanke

The event horizon itself is part of the universe ( it's a surface of null geodesics without future end points ), but the region beyond the horizon effectively isn't.

ok I don't know what this means at all... I don't even have an inkling... The event horizon is part of the universe but the region beyond it (the black hole) is not part of the universe? How come? I ask completely innocently. if it's all contained within the universe how come it's not part of it?

I don't know what the "surface of null geodesics is."

That depends what you mean by "information". When something falls through the horizon, its surface area will increase, and total entropy changes. However, just by looking at the entropy you will not be able to tell what it was that fell through the horizon. Do you know what I mean ?

I think I do, but just because something is unrecognizable doesn't mean that it ceases to be. what I mean by "information" is just existence/energy/something

So I would present that it's not ceasing to exist it's still there it's just looks different. It's undying/infinite

Again, it depends what you mean by "it". A photon falling into a black hole will cease to exist in the classical sense, but the total energy it carried does not, since that information becomes encoded on the area of the event horizon surface.

maybe it's just semantics but a photon falling through a black hole not existing in the classical sense doesn't mean it's gone. theoretically with the right tools can't the energy left from it be reconstructed to the original photon?

that information becomes encoded on the area of the event horizon surface.

What does this mean? the event horizon has a surface? i thought it was just an arbitrary line that once passed became the point of no return. the horizon takes pictures? (encodes)

thanks for your patience with me.

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

I learned that until you opened the box it was both. and if you never opened the box the cat would always exist in both realms.

Then you learned wrong.
...

Good thing Daffy is here to angrily explain it...
BTW, what does the word Paradox mean to you? New shoes, right?

Dywyddyr is our resident duck who makes sure the pond is kept clean and ship-shape. He feeds on trolls, crackpots and wise guys. A lot of us like the way he is but it takes a while to get used to the taste of duck. Once you like it, you can take duck every day.....just don't ruffle his feathers :-))

Originally Posted by grmpysmrf

Good thing Daffy is here to angrily explain it...

Please don't impute emotions to me that I'm not experiencing.

BTW, what does the word Paradox mean to you?

I dunno... attending class and not learning? Having something explained to you by teachers who don't know what they're talking about?
Pick one.

Originally Posted by grmpysmrf

How come?

Note that I said it is effectively not part of the universe, i.e. it no longer affects anything outside the horizon. The reason is that the region below the horizon is not causally connected to the rest of the universe.

what I mean by "information" is just existence/energy/something

You are right as for the energy part, that is of course conserved. I don't know how you define "existence" though, since there is no longer a causal connection to the rest of the universe.

theoretically with the right tools can't the energy left from it be reconstructed to the original photon?

You can make a new photon with energy from the black hole, but the original photon which fell in remains forever behind the horizon. Do you see the difference ?

What does this mean? the event horizon has a surface?

It means only that the event horizon is a surface in the mathematical sense; it has of course no physical "substance", as you rightly point out.

Originally Posted by Markus Hanke

Note that I said it is effectively not part of the universe, i.e. it no longer affects anything outside the horizon. The reason is that the region below the horizon is not causally connected to the rest of the universe.

So, it could potentially be it's own universe? a container within a container?

You are right as for the energy part, that is of course conserved. I don't know how you define "existence" though, since there is no longer a causal connection to the rest of the universe.

existence is just that, the state of being. just because it's not connected to the rest of the universe doesn't mean it is not here... it's there. it still exists. I'm thinking of it like someone who emigrates from their home country. they are no longer part of the country but they still exist somewhere else, no? In this instance the photon still exists even if it's not readily seen, right?

You can make a new photon with energy from the black hole, but the original photon which fell in remains forever behind the horizon. Do you see the difference ?

I think so, but isn't the photon just energy anyway? so if the energy still exists doesn't that mean the photon still exists and just needs to be put back to the original photon state?

What does this mean? the event horizon has a surface?

It means only that the event horizon is a surface in the mathematical sense; it has of course no physical "substance", as you rightly point out.[/QUOTE]
So how do things get trapped there?

Originally Posted by Implicate Order

Dywyddyr is our resident duck who makes sure the pond is kept clean and ship-shape. He feeds on trolls, crackpots and wise guys. A lot of us like the way he is but it takes a while to get used to the taste of duck. Once you like it, you can take duck every day.....just don't ruffle his feathers :-))

He's adorable. I'll be sure to keep my pockets filled with crackers and bread when I'm here.

Originally Posted by grmpysmrf

So how do things get trapped there?

Taking a liberty here due to my lack of patience and don't mean to steal your thunder Markus. Markus will be able to give you far more details as I can only offer a laypersons perspective. He is a master in GR.

Ok. There is an interplay between the contents of an elastic container and the geometric properties of that elastic container. You can think of soap bubbles, balloons and whatever to get the picture. I like plado because it is all encompassing and does not just refer to a boundary condition. The constraints are everywhere and everywhen.

This interplay is a symmetry at work. Einstein realised this in General Relativity when he developed his field equations. On one side of his field equation you have the Einstein tensor which reflects a geommetrical condition. On the other side you have the stress-energy-momentum tensor which reflects the spatio-distribution of stuff (in terms of energy distribution).

In GR you can therefore describe a container of stuff either by the distribution of stuff (energy) inside that container or alternatively that description can also be deduced by the geometry of the container (it's manifold). This equation can be applied locally to say black holes or globally to the geometry of our universe. If we imagine the contents of our universe and its boundary to representive of this condition, then given the mass-energy spatio-distribution in this container, you can infer the geometric nature of the manifold.

Note however that the container constraints need not be a physical boundary per se but rather a mathematical description of the properties that would be found at all points in spacetime that could be visualised as a virtual container. Remember however that all points in spacetime literally mean that so I am simplfying when talking in terms of the container's boundary....but hopefully you get the picture.....Quantum Mechanics would have more to say about whether an actual physicality can be inferred from the properties of spacetime such as the properties arising from the quantum vacuum.

Ok,.....now down to black holes. You may be familiar with the notion of the passage of 'stuff' inside the container to be affected by the constraints applied on that container Think in terms of a marble trying to make its way through a plado ball. Curve that plado and the ball will follow the curve as it tries to follow the simplest path (which we refer to as a geodesic when dealing with curved space or a line when dealing with Euclidian geometry). When dealing with spacetime, that is what GR proposes. The curvature of spacetime tells 'stuff' how to move....and that stuff tells spacetime how to curve. This is due to symmetries at play, namely some very difficult to understand gauge symmetries. Another thread has recently been talking about these.

In particular intense gravitational situations arising from simple initial conditions where there is so much compressed stuff inside the container, then a limit is reached called the Schwarzchild radius. At this point the spacetime is so curved that it closes in on itself to form an effective spherical boundary for what is contained within that envelope. It doesn't stop things going in but it does stop things going out. At this point of something going in, it becomes causally disconnected from the exterior region of the black hole in that we can obtain no further information about the state of that infalling stuff once it passes that boundary.

You then effectively have a black plado ball of closed geometry (as nothing, not even light can escape the black hole) inside a bigger plado geometry (of three possible types - open, closed, flat ) that is our universe. An observer outside that event horizon has no information available to him/her on the state of that stuff once it passes that point.......however.......you can infer the amount of stuff inside the container from the external geometry of that container. For different types of black holes with different initial conditions (eg. not resulting in spherical Schwarzchild solutions) other properties can be inferred from the geometrical expression of spacetime at the boundary such as electric charge or angular momentum. Quantum Mechanics can go further in suggesting that the state of the infalling matter whilst not available can be inferred by the information contained on the area of that event horizon. This is necessary to prevent a serious conservation law (information law) violation associated with Black Holes that Stephen Hawking tossed into the mix.

In a nutshell - The stuff inside gets trapped there due to the curvature of spacetime (the constraints imposed) that tells that stuff 'inside' how it can move. :-))

A limit to everything that is? No. There is nothing, and there is everything. In mathematics it's expressed as infinite. And then there is that which is beyond our grasp. That that we can not even begin to envision. But you are getting at variations.

Originally Posted by Dywyddyr

Please don't impute emotions to me that I'm not experiencing.

you experience emotions? What emotion would that have been if not anger? C'mon, give me your best synonym.

I dunno...

Already?? As part of the welcoming committee you come off as that guy that knows everything. damn, didn't take long to stump you, did it.

attending class and not learning? Having something explained to you by teachers who don't know what they're talking about?
Pick one.

How about I just tell you what you probably already know.
I have no science background. Shocking isn't it? I was average in Biology but should have failed chemistry, but luckily for me the teacher graded on the curve. So, I got my two years of high school sciences needed completed and got out. Perhaps it was teacher fault in that they couldn't/wouldn't explain things to me that made sense.

I have no math background. Even more startling isn't it? I was bad at algebra, even worse at geometry, and flat failed Algebra II. So, physics and complex math are lost on me. So, whatever knowledge base you are expecting me to have probably isn't there, because my feeble brain doesn't understand it.

BUT I absolutely adore the pretty pictures captured from the telescopes and the theories that accompany all of the pretty pictures as well as the physics and science that go along with those pretty pictures, when it's explained at a level I can understand. So, when all of the formulas are crunched and the possibilities of what they mean are explained it's exciting to me.

What little I do know I've gathered through the science channel when they run all of their astronomy programming... So, my understanding and level of knowledge in this field comes from the teevee and the internet. Yes, I have a TeeVee and internet education in this field, but I want to know more which is why I am here.

BTW instead of being all pissy about schrodinger and his cat perhaps you could start an internet campaign to educate those less fortunate than yourself because the cat being alive and dead is all over the internet and is generally understood to be the case for his thought experiment. If that is not something that you feel like doing then it is you that makes the worst kind of "poor teacher"... Lazy

from the huffington post

If the research proves true, that would bolster the validity of a thought experiment suggesting a cat can be both alive and dead at the same time. The idea, called Schrödinger's Cat after the physicist,Erwin Schrödinger, who proposed it in 1935, goes like this: Put a cat in a box with a vial of poison gas. The vial opens when a tiny piece of radioactive metal emits an alpha particle (the nucleus of a helium atom) as it decays. Emitting an alpha particle is a quantum-mechanical process, which means that whether it happens in any given stretch of time is basically random.

'Schrodinger's Cat' Thought Experiment Put To Test By Physicists In Canada, Switzerland


So, coming at me for having a basic understanding of the thought experiment makes you look like a fool. but I guess you've already acceptd that role and is embraced by others

Originally Posted by Implicate Order

Taking a liberty here due to my lack of patience and don't mean to steal your thunder Markus. Markus will be able to give you far more details as I can only offer a laypersons perspective. He is a master in GR.

Lack of patience? You've been fine. as far as stealing someone's thunder, who cares about who gets the trophy as long as the information is understood? your "layperson's explanations" are just fine. Markus has been great in trying to explain things, but I think his knowledge is far beyond where I'm at. So his details will more than likely be lost on me, but I'm willing to try to understand. It's not enough to be smart, the truly brilliant people are able to break down the information so others may understand. Smart is kind of useless if you're the only one that knows what you're talking about.

Ok. There is an interplay between the contents of an elastic container and the geometric properties of that elastic container. You can think of soap bubbles, balloons and whatever to get the picture. I like plado because it is all encompassing and does not just refer to a boundary condition. The constraints are everywhere and everywhen.

This interplay is a symmetry at work. Einstein realised this in General Relativity when he developed his field equations. On one side of his field equation you have the Einstein tensor which reflects a geommetrical condition. On the other side you have the stress-energy-momentum tensor which reflects the spatio-distribution of stuff (in terms of energy distribution).

In GR you can therefore describe a container of stuff either by the distribution of stuff (energy) inside that container or alternatively that description can also be deduced by the geometry of the container (it's manifold). This equation can be applied locally to say black holes or globally to the geometry of our universe. If we imagine the contents of our universe and its boundary to representive of this condition, then given the mass-energy spatio-distribution in this container, you can infer the geometric nature of the manifold.

Note however that the container constraints need not be a physical boundary per se but rather a mathematical description of the properties that would be found at all points in spacetime that could be visualised as a virtual container. Remember however that all points in spacetime literally mean that so I am simplfying when talking in terms of the container's boundary....but hopefully you get the picture.....Quantum Mechanics would have more to say about whether an actual physicality can be inferred from the properties of spacetime such as the properties arising from the quantum vacuum.

I'm sorry, I understand none of this

Ok,.....now down to black holes. You may be familiar with the notion of the passage of 'stuff' inside the container to be affected by the constraints applied on that container Think in terms of a marble trying to make its way through a plado ball. Curve that plado and the ball will follow the curve as it tries to follow the simplest path (which we refer to as a geodesic when dealing with curved space or a line when dealing with Euclidian geometry). When dealing with spacetime, that is what GR proposes. The curvature of spacetime tells 'stuff' how to move....and that stuff tells spacetime how to curve. This is due to symmetries at play, namely some very difficult to understand gauge symmetries. Another thread has recently been talking about these.

I think I understand this... geodesic is the path but the path is determined/only exists by what is trying to travel it?

In particular intense gravitational situations arising from simple initial conditions where there is so much compressed stuff inside the container, then a limit is reached called the Schwarzchild radius. At this point the spacetime is so curved that it closes in on itself to form an effective spherical boundary for what is contained within that envelope. It doesn't stop things going in but it does stop things going out. At this point of something going in, it becomes causally disconnected from the exterior region of the black hole in that we can obtain no further information about the state of that infalling stuff once it passes that boundary.

So, it's a container within a container? a container that has an infinite ability to fill up ...? If this is the case, whether the particle/energy/whatever is able to escape the container is irrelevant because that inescapable container is still contained within the bigger container that is the universe. Kinda like walking into a house and not being able to get out. that house is still on the earth and so even though you can't leave the house you are still part of the earth. No?

You then effectively have a black plado ball of closed geometry (as nothing, not even light can escape the black hole) inside a bigger plado geometry (of three possible types - open, closed, flat ) that is our universe. An observer outside that event horizon has no information available to him/her on the state of that stuff once it passes that point.......however.......you can infer the amount of stuff inside the container from the external geometry of that container. For different types of black holes with different initial conditions (eg. not resulting in spherical Schwarzchild solutions) other properties can be inferred from the geometrical expression of spacetime at the boundary such as electric charge or angular momentum. Quantum Mechanics can go further in suggesting that the state of the infalling matter whilst not available can be inferred by the information contained on the area of that event horizon. This is necessary to prevent a serious conservation law (information law) violation associated with Black Holes that Stephen Hawking tossed into the mix.

I think I get it. you can't see the stuff in the container but you can guess at what might be in it based on what is on the event horizon and how big the container is?

just because you have a large container doesn't mean it's filled... Don't know how that relates to this. just what popped into my head upon reading what I wrote...

In a nutshell - The stuff inside gets trapped there due to the curvature of spacetime (the constraints imposed) that tells that stuff 'inside' how it can move. :-))

This is the plain english I'm looking for

Originally Posted by grmpysmrf

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

just like the cat is alive and dead at the same time...

No it's not.

take it up with schrodinger

Schrödinger happened to be the one that pointed out that it's one or the other, not both.

I learned that until you opened the box it was both. and if you never opened the box the cat would always exist in both realms.

Our resident duck is correct. its one or the other. not both.

However, this was a thought experiment to better explain the copenhagen interpetation on quantum mechanics. It was not ment to be taken literally.

2 key differences between them are 1.) A cat is much much larger than subatomic particles & 2.) the cat is a conscious being thus, effects the outcome.

Take for example, a double slit experiment where particles will act as a wave or solid depending on observation(however not both at the same time). a cat could be used as an observer if you get it to sit still long enough (cats are fickle creatures)

thus is Schrodinger thought experiment our kitty would of effected the outcome.

the duck is correct. HOWEVER It should be noted that darkwing duck was a much, much better duck than daffy XD

Originally Posted by GoldenRatio

Originally Posted by grmpysmrf

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

Originally Posted by Dywyddyr

Originally Posted by grmpysmrf

just like the cat is alive and dead at the same time...

No it's not.

take it up with schrodinger

Schrödinger happened to be the one that pointed out that it's one or the other, not both.

I learned that until you opened the box it was both. and if you never opened the box the cat would always exist in both realms.

Our resident duck is correct. its one or the other. not both.

However, this was a thought experiment to better explain the copenhagen interpetation on quantum mechanics. It was not ment to be taken literally.

2 key differences between them are 1.) A cat is much much larger than subatomic particles & 2.) the cat is a conscious being thus, effects the outcome.

Take for example, a double slit experiment where particles will act as a wave or solid depending on observation(however not both at the same time). a cat could be used as an observer if you get it to sit still long enough (cats are fickle creatures)

thus is Schrodinger thought experiment our kitty would of effected the outcome.

the duck is correct. HOWEVER It should be noted that darkwing duck was a much, much better duck than daffy XD

Thanks.

Originally Posted by grmpysmrf

Lack of patience? You've been fine. as far as stealing someone's thunder, who cares about who gets the trophy as long as the information is understood? your "layperson's explanations" are just fine. Markus has been great in trying to explain things, but I think his knowledge is far beyond where I'm at. So his details will more than likely be lost on me, but I'm willing to try to understand. It's not enough to be smart, the truly brilliant people are able to break down the information so others may understand. Smart is kind of useless if you're the only one that knows what you're talking about.

Very good point Smurf of Grumpiness

Originally Posted by grmpysmrf

I'm sorry, I understand none of this

Patience Padawan. Close your eyes and think of containers. That way you will see the force is but a constraining geometry not a seperate force such as electromagnetism......where is Luke by he way?....*screams Luke, your pies ready, do you want sauce wih that?*

Originally Posted by grmpysmrf

I think I understand this... geodesic is the path but the path is determined/only exists by what is trying to travel it?

A something is moving in spacetime. That spacetime is endowed with properties at all locations. Those properties constrain the movement of the thing to travel in a particular way. Without a force being applied, the path that thing follows is the simplest route within those constraints. Remember I told you to get rid of that pesky notion of force.......excuse me a second, Luke, how many times do I have to tell you your pies ready for crying out loud....now where were we, pies.....no,no.....general relativity.

Originally Posted by grmpysmrf

So, it's a container within a container? a container that has an infinite ability to fill up ...? If this is the case, whether the particle/energy/whatever is able to escape the container is irrelevant because that inescapable container is still contained within the bigger container that is the universe. Kinda like walking into a house and not being able to get out. that house is still on the earth and so even though you can't leave the house you are still part of the earth. No?

Be careful with your new found power Padawan for there are dark forces at work which need to be dispatched. That is quite a nice way to view it. Often it is simpler to talk in terms of systems inside of systems. Then you can ask, does one system inside another actually affect the larger system or not and how does that larger system effect that embedded system.....but that is for after pies.....speaking of pies........Luke, if I've told you once, I've told you a thousand times....wait till your father gets home....hold on I am his father....Oh I am so confused.......

Originally Posted by grmpysmrf

I think I get it. you can't see the stuff in the container but you can guess at what might be in it based on what is on the event horizon and how big the container is?

Bing!!!!!! Now go back to the early stuff you couldn't understand. It might just make more sense now.

Originally Posted by grmpysmrf

just because you have a large container doesn't mean it's filled... Don't know how that relates to this. just what popped into my head upon reading what I wrote...

Well as a container is filled it gets larger. A blackhole gets larger with more stuff falling in. There is a direct 'elastic' correspondence between the contents of a container and its mass........That's it.....anyone for a pie, I'm fed up with Luke. Take your force and shove it.:-))

Originally Posted by grmpysmrf

So, it could potentially be it's own universe? a container within a container?

Yes, that is very real possibility. If you omit two dimensions and embed the result ( called Schwarzschild geometry ) into Euclidean space for visualisation purposes, then space-time in and around a black hole actually looks like this :



This is the most simplistic case, being a black hole which is perfectly spherically symmetric, as well as stationary. Note that this isn't just a hole, but actually a bridge, and for that reason also called an Einstein-Rosen-Bridge. While this local geometry is an exact analytical solution of the Einstein equations, that solution cannot tell us whether the bridge connects two regions of our universe, or two completely separate universes ( that's because Einstein's theory fixes only the geometry, but not the topology of space-time ). The latter is thus definitely a possibility.

existence is just that, the state of being. just because it's not connected to the rest of the universe doesn't mean it is not here... it's there. it still exists. I'm thinking of it like someone who emigrates from their home country. they are no longer part of the country but they still exist somewhere else, no? In this instance the photon still exists even if it's not readily seen, right?

This is not a trivial question, and I don't think I can give you a definite answer. It all hinges on what happens in the central part of the black hole - currently we don't know for sure, because we are missing a crucial model ( quantum gravity ) to tell us what exactly goes on there. We do know though that this is where the photon will end up.

I think so, but isn't the photon just energy anyway? so if the energy still exists doesn't that mean the photon still exists and just needs to be put back to the original photon state?

Yes, that's what I said. I meant to point out only that energy has no "labels" attached to it, so what you use to construct a new photon mightn't be the same energy that the in falling photon carried. It's like adding more water to an already half-filled bottle, and then taking a sip - are you drinking the same water you just added ? How would you know ?

So how do things get trapped there?

The actual details are rather complicated, but intuitively you can think of the process as "time" and "space" trading places once you cross the event horizon. What was once the "down" direction now has become your "future" - and that is the singularity at the centre of the black hole. So once you cross the horizon, you will have the singularity in your future, no matter how and where you try to move around - it is simply inevitable, and there is no escape, since time ticks only in one direction, towards the future.

Originally Posted by GoldenRatio

the duck is correct. HOWEVER It should be noted that darkwing duck was a much, much better duck than daffy XD

On this forum I've seen evolution deniers, Young Earth Creationists, people who think Einstein was massively wrong and posters who think that psi powers are real.
Up until now I thought I'd seen the limits of how deluded humans could be...
But this takes the prize.

The men in white coats will be calling for you shortly.

Originally Posted by GoldenRatio

Our resident duck is correct. its one or the other. not both.

Just to clarify this a bit. The argument of Schrodinger related to a rebuttal of the Copenhagen Interpretation of QM. There are many different interpretations of QM which appear to be valid in various ways.

In the Copenhagen Interpretation the act of measurement itself causes collapse of a superposition of states described mathematically as the collapse of a wavefunction to a realised classical result. Sufffice to say, those that hold to this interpretation do not believe this wavefunction to be 'real' but rather a mathematical way to simply describe non-classical physics. So in this context the cat is either alive or dead but not both.

Other interpretations which were not the subject of Schrodingers argument view things differently including whether the wavefunction in reality collapses at all. Many view the wavefunction as the reality and the classical result as merely a single representation in our classical reality. In these interpretations (eg. Many Worlds interpretation) other realities 'exist' that represent the possible alternative histories described by the wavefunction. ....and there are other interpretations that have their strengths and weaknesses but are consistent with experimental observation. The quantum cat in some of those interpretations can be seen in their context to be both dead or alive even after measurement.

However fortunately a cat is a classical cat (a macroscopic object) in our classical world and not a quantum cat in our classical world. :-))

More here.

Originally Posted by Dywyddyr

Originally Posted by GoldenRatio

the duck is correct. HOWEVER It should be noted that darkwing duck was a much, much better duck than daffy XD

On this forum I've seen evolution deniers, Young Earth Creationists, people who think Einstein was massively wrong and posters who think that psi powers are real.
... ...
...

Were you expecting this from me?

Originally Posted by Markus Hanke

Originally Posted by grmpysmrf

So, it could potentially be it's own universe? a container within a container?

Yes, that is very real possibility. If you omit two dimensions and embed the result ( called Schwarzschild geometry ) into Euclidean space for visualisation purposes, then space-time in and around a black hole actually looks like this :



This is the most simplistic case, being a black hole which is perfectly spherically symmetric, as well as stationary. Note that this isn't just a hole, but actually a bridge, and for that reason also called an Einstein-Rosen-Bridge. While this local geometry is an exact analytical solution of the Einstein equations, that solution cannot tell us whether the bridge connects two regions of our universe, or two completely separate universes ( that's because Einstein's theory fixes only the geometry, but not the topology of space-time ). The latter is thus definitely a possibility.

existence is just that, the state of being. just because it's not connected to the rest of the universe doesn't mean it is not here... it's there. it still exists. I'm thinking of it like someone who emigrates from their home country. they are no longer part of the country but they still exist somewhere else, no? In this instance the photon still exists even if it's not readily seen, right?

This is not a trivial question, and I don't think I can give you a definite answer. It all hinges on what happens in the central part of the black hole - currently we don't know for sure, because we are missing a crucial model ( quantum gravity ) to tell us what exactly goes on there. We do know though that this is where the photon will end up.

I think so, but isn't the photon just energy anyway? so if the energy still exists doesn't that mean the photon still exists and just needs to be put back to the original photon state?

Yes, that's what I said. I meant to point out only that energy has no "labels" attached to it, so what you use to construct a new photon mightn't be the same energy that the in falling photon carried. It's like adding more water to an already half-filled bottle, and then taking a sip - are you drinking the same water you just added ? How would you know ?

So how do things get trapped there?

The actual details are rather complicated, but intuitively you can think of the process as "time" and "space" trading places once you cross the event horizon. What was once the "down" direction now has become your "future" - and that is the singularity at the centre of the black hole. So once you cross the horizon, you will have the singularity in your future, no matter how and where you try to move around - it is simply inevitable, and there is no escape, since time ticks only in one direction, towards the future.

I've seen that picture/graph before, but I've wondered how come it doesn't fill from both ends? both ends seem to be curved the exact same way. I've got more to add but I'm running late for work. I'll try to get more into depth (My shallow version of depth) later tonight. Again thank you for taking the time.

We've been hit by a large number of trolls lately. Sometimes it's best to first put down suppressing fire and ask questions later. You clearly survived which means at the moment you can share this pond, but if your eyes go cross-eyed for one moment it's curtains I tell's ya. The Dwyddyr duck will come at you so fast and furious and may be supported by a Demon that will make you feel like you are surrounded. :-))

Originally Posted by grmpysmrf

[




I've seen that picture/graph before, but I've wondered how come it doesn't fill from both ends? both ends seem to be curved the exact same way. I've got more to add but I'm running late for work. I'll try to get more into depth (My shallow version of depth) later tonight. Again thank you for taking the time.

The picture above describes the possible interior of a black hole that connects two seperate universes via a wormhole or alternatively provides a shortcut to a distant part of the universe via curved spacetime. Other diagrams that terminate in a singularity are also possible. There are a varierty of different geometries possible via GR in intense gravitational fields. Look here for example. Black holes can be of two types (Schwarschild non rotating black holes and Kerr rotating black holes). More info here. . General relativity can describe these situations mathematically but as we cannot interrogate the interior of a black hole past the event horizon by an observer exterior to the blackhole, we don't really know. :-))


.....and remember, no science is certain. We theorise through GR to delve into the interior of a blackhole and have many strong clues to think that black holes exist (and rightly so) but all we can do is progressively build on this assurity until we are proven wrong. For example, maybe all blackholes are Kerr blackholes. Also for example I think some of the forum experts here can put enough doubts in your mind that it may be possible to remove the interior of a Schwarzchild blackhole by certain mathematical processes we call transformations which validly questions whether the interior of a blackhole is what we think it is. Anyway, that is for the experts to describe if you are interested.

PS We are very small fish in this very big pond. There are real scientists and mathematicians who reside here. A lot to be learnt if you are interested. They are looking at us now and deciding whether we are food or play things.

Originally Posted by Implicate Order

We've been hit by a large number of trolls lately. Sometimes it's best to first put down suppressing fire and ask questions later. You clearly survived which means at the moment you can share this pond, but if your eyes go cross-eyed for one moment it's curtains I tell's ya. The Dwyddyr duck will come at you so fast and furious and may be supported by a Demon that will make you feel like you are surrounded. :-))

Well, if by "cross eyed" you mean spouting spiritual nonsense and adherence to an all knowing Sky daddy that "loves us" and "has a plan for us" and yet still let's terrible things happen to his flock, you will not get that from me. Nor will you get belief in ghosts (not that they belong in an astronomy thread anyway.) And while I like "Ancient Aliens" on history channel I am fully aware that it's junk "science" (science used loosely) and is pretty much akin to "God" statements. So, while I'm more than happy to discuss aliens, I've gathered, easily, that it belongs in the science fiction thread.

any other types of "cross eyed" will be because several of you has tossed things in my direction that I barely understand, if understand at all. I'm digging the patience the couple of you have handed me so for. so again a very heartfelt thank you.

Originally Posted by Markus Hanke

Originally Posted by grmpysmrf

So, it could potentially be it's own universe? a container within a container?

Yes, that is very real possibility. If you omit two dimensions and embed the result ( called Schwarzschild geometry ) into Euclidean space for visualisation purposes, then space-time in and around a black hole actually looks like this :



This is the most simplistic case, being a black hole which is perfectly spherically symmetric, as well as stationary. Note that this isn't just a hole, but actually a bridge, and for that reason also called an Einstein-Rosen-Bridge. While this local geometry is an exact analytical solution of the Einstein equations, that solution cannot tell us whether the bridge connects two regions of our universe, or two completely separate universes ( that's because Einstein's theory fixes only the geometry, but not the topology of space-time ). The latter is thus definitely a possibility.

I noticed you said that "This is the most simplistic case." Is that for the "Hole" or the possibility of the hole being another universe? I can understand it being a simple universe because based on the Geometry (as it's represented in the picture) that it doesn't leave room for that particular universe to have black holes other wise we would be seeing branches come off of the Bridge portions of the shape. Unless those holes are so ridiculously small that they would not show up on the picture... but they would show up mathematically wouldn't they?

I think so, but isn't the photon just energy anyway? so if the energy still exists doesn't that mean the photon still exists and just needs to be put back to the original photon state?

Yes, that's what I said. I meant to point out only that energy has no "labels" attached to it, so what you use to construct a new photon mightn't be the same energy that the in falling photon carried. It's like adding more water to an already half-filled bottle, and then taking a sip - are you drinking the same water you just added ? How would you know ?

I've been giggling at this all day. That happy moron giggle when you think something is neat and cool at the same time. So, my question is, is it possible to label that energy? In theory shouldn't we be able to create a set of tools that could tag those water molecules individually and find out if we had drank the recently added water? So to speak.

So how do things get trapped there?

The actual details are rather complicated, but intuitively you can think of the process as "time" and "space" trading places once you cross the event horizon. What was once the "down" direction now has become your "future" - and that is the singularity at the centre of the black hole. So once you cross the horizon, you will have the singularity in your future, no matter how and where you try to move around - it is simply inevitable, and there is no escape, since time ticks only in one direction, towards the future.

Maybe this isn't the place for this but I have a real problem with time. I think Time is a man made construct. Without Man time doesn't exist. All it is, is a way to map/categorize behavior. If there is another way to look at time I'm all ears.

Isn't any direction really the future? Like, for example, If time travel was possible, even though I'm traveling back in time (completely impossible since you can't walk back to behavior) that is still my future... walking backwards is still me going forward in my "time"

In the instance you provided wouldn't singularity represent "death" or perhaps a transformation of energy? Is singularity gravity? or the effect of gravity? (Kinda off topic but are there particles that aren't effected by gravity?)

Originally Posted by Implicate Order

There are real scientists and mathematicians who reside here. A lot to be learnt if you are interested.

Well, I'm sure I'm lower than the ape when it comes to their intelligence, so hopefully they don't lose patience in what I assume are preschool questions.
otherwise, looking forward to it.

Originally Posted by grmpysmrf

So, it's a container within a container? a container that has an infinite ability to fill up ...? If this is the case, whether the particle/energy/whatever is able to escape the container is irrelevant because that inescapable container is still contained within the bigger container that is the universe. Kinda like walking into a house and not being able to get out. that house is still on the earth and so even though you can't leave the house you are still part of the earth. No?

That is quite a nice way to view it. Often it is simpler to talk in terms of systems inside of systems. Then you can ask, does one system inside another actually affect the larger system or not and how does that larger system effect that embedded system.....

So my analogy doesn't quite work because the house is still on earth and that house still effects the earth whether it's the carbon footprint or wind blocker or whatever... Where as this container within the container has no bearing on the outside container...?

If that's the case though, doesn't the black hole affect the universe because is sucks in energy? So it would still affect the larger container because of what it eats.

Originally Posted by grmpysmrf

just because you have a large container doesn't mean it's filled... Don't know how that relates to this. just what popped into my head upon reading what I wrote...

Well as a container is filled it gets larger. A blackhole gets larger with more stuff falling in. There is a direct 'elastic' correspondence between the contents of a container and its mass...

Not necessarily. sometimes a container is filled and it spills out. in the case of an elastic container and it growing at some point it would burst... is that a big bang?

Originally Posted by grmpysmrf

Originally Posted by Implicate Order

There are real scientists and mathematicians who reside here. A lot to be learnt if you are interested.

Well, I'm sure I'm lower than the ape when it comes to their intelligence, so hopefully they don't lose patience in what I assume are preschool questions.
otherwise, looking forward to it.

Morning from here grmpysmrf. :-))

It's all good. As you may have noted, I am trying to make your stay here more fun and enjoyable. You seem to have the necessary fundamentals to pass the initiation tests on this forum so I am pulling your leg (but you already would have noticed that I think).

It's better if you are patient and learn from the experts on this forum in GR such as Markus and KJW and there are lot's of others who value the integrity of some well established mainstream scientific theories such as Strange, PhDemon, Dywyddyr and many many others and in other disciplines who I don't want to appear as though I have overlooked. Plus don't forget the moderators and Administrators who are fully fledged guru's. It's just that I have yet to understand all their ways or test their metal. They will all assist you in leading you down the straight and narrow path which is the correct path when trying to learn new things. I tend to bias my descriptions to more arcane views I have that can be de-constructive when you are trying to learn the correct methodology. It doesn't mean I won't pop up occassionally as I am like you just here to learn and like to test the boundaries of my learning.

Live long and prosper:-))

PS Word of caution. It is essential to very carefully read the words and sentences of Markus and KJW as they are exceptionally concise and laced with meaning. This is a knack that mathematicians have in being concise yet profound. If you don't take it slow and also confirm their words against other sources such as Google and quality literature you can get off the beaten track very quickly. You will note the subtle ways that even these guys deftly convert a viewpoint towards their preferred perspectives. It is subtle but incredibly powerful.

Originally Posted by grmpysmrf

I've seen that picture/graph before, but I've wondered how come it doesn't fill from both ends? both ends seem to be curved the exact same way.

Sorry, but I am not sure what you mean by this. Yes, the bridge is curved the same way at both ends.

Originally Posted by Implicate Order

Other diagrams that terminate in a singularity are also possible.

Actually, the situation is rather more complicated than the simple embedding diagram would have the beholder believe, because the geometry in the interior of the Einstein-Rosen bridge is not static, but oscillates rapidly. What at first glance appears simple is really highly non-trivial.

Also, it is important to point out that Schwarzschild coordinates ( the ones that "terminate" at a curvature singularity ) do not cover the entire space-time; you would need two such coordinate patches for a complete cover, or alternatively use a different set of coordinates such as a Kruskal-Szekeres chart.

Black holes can be of two types (Schwarschild non rotating black holes and Kerr rotating black holes).

There are actually four types of black hole solutions :

1. Schwarzschild ( no charge, no angular momentum )
2. Kerr ( no charge, has angular momentum )
3. Reissner-Nordstroem ( charged, no angular momentum )
4. Kerr-Newman ( charged, has angular momentum )

Version (4) is the most general, the other three are special cases. Having said that, it is unlikely that a physical black hole would possess a substantial net amount of electric charge, and it is also unlikely that there are black holes without any angular momentum. The most likely case is thus the Kerr black hole.

it may be possible to remove the interior of a Schwarzchild blackhole

Yes, that is possible through a simple coordinate transformation.

Originally Posted by grmpysmrf

I noticed you said that "This is the most simplistic case." Is that for the "Hole" or the possibility of the hole being another universe?

What I meant was that this particular geometry appears only if the black hole is perfectly spherically symmetric, has no angular momentum, no net electric charge, and is perfectly stationary. These are very restrictive conditions, which are unlikely to actually occur in the real world. It is possible to relax these conditions, but the resulting geometries are then much more complicated than the simple diagram I provided.

So, my question is, is it possible to label that energy?

No. It is also not possible to "label" an elementary particle such as a photon; all elementary particles of the same kind are physically indistinguishable.

If there is another way to look at time I'm all ears.

In the context of General Relativity, time is geometric aspect ( a geometric dimension ) of the underlying space-time manifold. It is therefore a "direction" on that manifold, but note that there are mathematical differences between time-like and space-like dimensions.

In the instance you provided wouldn't singularity represent "death" or perhaps a transformation of energy?

It is the boundary of geodesics, i.e. a boundary beyond which world lines cannot be extended.

Is singularity gravity?

Tidal forces would become infinitely large at a singularity, so in a sense it is a region of infinite curvature ( not quite correct, but close enough ).

(Kinda off topic but are there particles that aren't effected by gravity?)

No, all forms of energy are affected by gravity.

Originally Posted by Markus Hanke

Originally Posted by grmpysmrf

I've seen that picture/graph before, but I've wondered how come it doesn't fill from both ends? both ends seem to be curved the exact same way.

Sorry, but I am not sure what you mean by this. Yes, the bridge is curved the same way at both ends.

This is a graph of a black hole right?
well looking at the graph it looks like it's open ended on both sides, but only one side feeds on a black hole, right?... I would presume the top portion where we can start to see into the hole is the mouth side but if the graph is the same on both sides (as it looks) how come the hole on the other side doesn't feed... or does it?

Originally Posted by grmpysmrf

This is a graph of a black hole right?

Yes, this is the space-time geometry of a spherically symmetric, stationary black hole without any charge or angular momentum.

well looking at the graph it looks like it's open ended on both sides

Correct.

but only one side feeds on a black hole, right?

No, both "ends" have singularities and event horizons, and are perfectly symmetric. This wouldn't be a physically possible way to travel "one side in and the other side out".

@markus
With what you have purposed. How does the second blackhole form? Does another star go supernove at the exact same time as one in our universe? Or does the other universe simply have blackholes spontaneously jumping into existence?

but only one side feeds on a black hole, right?

No, both "ends" have singularities and event horizons, and are perfectly symmetric. This wouldn't be a physically possible way to travel "one side in and the other side out".

Ok, so if it fills from both ends how come the middle doesn't bulge?

Originally Posted by grmpysmrf

but only one side feeds on a black hole, right?

No, both "ends" have singularities and event horizons, and are perfectly symmetric. This wouldn't be a physically possible way to travel "one side in and the other side out".

Ok, so if it fills from both ends how come the middle doesn't bulge?

Stuff get's progressively more gravitationally compressed as it heads towards the singularity (from all exterior points of entry) It is impossible to convey this in diagrams and that is why Markus simplified his diagram through reducing the number of dimensions to visualise it (note however that Markus's diagram is a wormhole solution where the funnel from both ends does not end in a point but rather remains open as a bridging connection between both funnels). Think of mass/energy concentration (energy density) making spacetime curve towards it (the centre of mass). Remember in free fall, you are falling towards the centre of mass. Compare locations of high mass/energy density with areas of low mass/energy density in your container to see spacetime curvature.

EDIT: Note the following commentary needs review by an expert (eg. KJW or Markus). It is only an interpretation to test my understanding and I would appreciate your input in regards to this lay interpretation to assist in my own understanding by identifying errors and knowledge gaps.
Remember differences in energy-mass distributions in different regions of spacetime gives rise to different measurements of spacetime properties in each region. Where energy-mass density is concentrated in one region (eg. where a large mass is present), points in spacetime are closer together. Where energy-mass density is less in one region, points in spacetime are farther apart. Spacetime is elastic in a fashion (it is dynamic). When you connect the geometry between these different regions (effectively join the dots), spacetime must be curved to connect them together. The differential gradient in this curvature is the important part. We would expect that the gradient between the connection to not be linear as we knew from Newton's day that the force of gravitation was inversely proportional to the seperation of distance^2 between two gravitational sources. In this example above the curvature is actually attributed to the time component. For instance we would get straight lines connecting the points between these two regions (euclidean) by joining the dots without incorporating time, but the curvature of the line is attributed to the time seperation between points on this geometry. Now I might be wrong in this but I am assuming this relates to the fact that clocks located at each point in space time tick at different rates in this geometry. The further apart they are along this gravitational gradient, the greater the difference between ticks of the clocks. Namely those located towards greater mass-energy concentrations tick faster (EDIT: amend to slower) that those away from these concentrations. This curvature (namely the differential gradient in spacetime between different mass-energy distributions) is the manifestation of gravity. If there is no distinction between the spacetime properties in each region (the same energy-mass distribitions in each region) , then spacetime is flat and the geometrical connections between these regions follow straight lines. In this particular condition there is no gravity as there is no curvature. Once again, GRAVITY IS THE CURVATURE. Inertial objects travelling through such a system simply travel the simplest paths between points. Where there is no gravity, they travel in straight lines (follow euclidean geometry) but where gravity is present, the simplest path they can take is along the curvature. The spacetime properties guide this path.

While the paragraph above is a simplistic description of the interplay of varying mass-energy distributions between two regions of differing average mass-energy density, this description is used to reflect the dynamic nature of spacetime, the situation is compounded by the fact that this geometry evolves in time attributed to the inherent nature of concentrations of energy to dissipate throughout the system towards a state of equilibrium. At each point in time if you were an observer looking into this system you could describe the geometry dependent on the spatial density of energy. Over an extended time interval you could put all these together to get a spacetime history of the evolving geometry. The Einstein equation is used to describe this unfolding of geometry over time producing a variety of solutions dependent on the spatio-temporal density of the systems contents. Furthermore if additional sources of gravitation in different regions are included in this model, curvature is not uniform throughout but it curves and warps. The seperation between spacetime points in this more complex scenario depends on the graviational contribution of each system added to the mix and their spatio-temporal location. These effects of additional gravitational sources (tidal forces) are excluded from this simple description but need to be taken into account with more realistic examples. (EDIT Note that these tidal effects affect spatial curvature connections between points in this complex system as opposed to temporal curvature connections in spacetime.)

If you can get this notion in your head I think you might be on the way to getting a layman's appreciation of of what GR is about and then be able to account at first for inertial motion in this unfolding geometry before you head off to other forms of motion (eg accelerated motion) within this dynamic context. Also remember however that the many of the conditions of special relativity must be taken into account when looking at mechanics of moving bodies in this situation. The same universal speed limit applies and the principles of relativity apply (in respecting the relationships that apply between two different frames of reference) but here, inertial motion is travelling through curved space and not euclidean space. That is the only feature we have removed in considering the differences between GR and SR. Now just as in Special Relativity the geometry that is observed by an observer depends on the way they slice the eucliden geometry of their perspective of space time. In GR however, given the dynamic nature of the geometry, different observer's slices of this dynamic geometry representing their perspective produces different geometries. These different geometries are referred to as coordinate transforms associated with space and time translations.

So far we have dealt with inertial motion, but what about accelerations. Fortunately GR also gives us a basis to understand accelerations. We have already identified how in a local uniform gravitational field, inertial motion is in a state of free-fall by simply following the curvature. Through a thought bubble from Einstein, he also concluded that (EDIT: standing on the earth in a gravitational field where the earth pushes up is equivalent to constant acceleration in the absence of a gravitational field). The mechanics of both situations is identical but the only difference being whether or not the nobserver is or is not in the presence of a gravitational field. In spacetime without the presence of a gravitational field (flat spacetime) a constantly accelerating body is seen to curve as progressive measurements taken of a body in accelerated motion traverses incrementally longer distances at each tick of the clock or alternatively the same distance interval over longer tocks of the clock. In a spacetime diagram you see this as a curved line. It is exactly the same mechanics of inertial travel of a body in a local gravitational field with curvature. It is equivalent. That's why you can simulate gravity on a spacestation by the spinning of the space-station (constant acceleration) and feel as though you in the presence of a gravitational field. Now dependent on the frame of reference of an observer you can transform away this acceleration. For example, freefalling in a gravitational field mimics accelerated motion (as you appear to accelerate but you are actually travelling inertially without any forces being applied). (EDIT: Interestingly and accelerometer would record this freefall motion as acceleration) . So if in one frame of reference in a gravitational field you are actualy under inertial motion (without any forces) and in another frame of reference you can mimic the mechanics without a gravitational field by uniformly accelerating (a force is applied) you can see now why Einstein realised that you do not need a force applied in the presence of a gravitational field. Spacetime curvature is this 'fictitious force'. Hence gravitation is not a force at all.

Now that we have a context of curvature and inertial movement in a graviational field, we can now determine accelerations attribued to 'true' forces acting on an objects motion in this context by determining the variation of motion from the geodesic (deviation from the geodesic) which represents the inertial line of movement. Once we understand the context of mechanics in the presence of and absence of a gravitational field, then we can assess all types of motion. :-))

NOTE: I am free-forming in this description here as a learning exercise mainly for myself so others can comment on the validity of it or not. It is as much a learning exercise for you grmpysmrf as it is for me so we better wait for an expert to conform or invalidate this post. If this is a correct interpretation I will be chuffed at myself :-))

[QUOTE=Implicate Order;515646]

Originally Posted by grmpysmrf

but only one side feeds on a black hole, right?

No, both "ends" have singularities and event horizons, and are perfectly symmetric. This wouldn't be a physically possible way to travel "one side in and the other side out".

Ok, so if it fills from both ends how come the middle doesn't bulge?

Stuff get's progressively more gravitationally compressed as it heads towards the singularity (from all exterior points of entry)

well, If I'm understanding this right. This theory (is it a theory or proven?) lends itself to infinity. because if matter keeps getting smaller inside of it, it keeps having to get exponentially smaller to accommodate the constantly new material being introduced.

It is impossible to convey this in diagrams and that is why Markus simplified his diagram through reducing the number of dimensions to visualise it. Think of mass/energy concentration (energy density) making spacetime curve towards it (the centre of mass). Remember in free fall, you are falling towards the centre of mass. Compare locations of high mass/energy density with areas of low mass/energy density in your container to see spacetime curvature.:-))

Yeah, I understood none of this, again. Come on Einstein book, Get here... now!! <peeks out behind folded hands> damn!

Originally Posted by grmpysmrf

well, If I'm understanding this right. This theory (is it a theory or proven?) lends itself to infinity. because if matter keeps getting smaller inside of it, it keeps having to get exponentially smaller to accommodate the constantly new material being introduced.

That's about it. When stuff keeps being added to a system, or say a star of sufficient mass collapses as its nuclear fuel is spent, total gravitational collapse cannot be avoided at a particular mass-energy distribution threshold. That threshold is a defined point where any resistive forces (e.g nuclear forces) are exceeded and we therefore cannot avoid te collapse trending towards a point singularity where all the mass resides. What Markus however put up is a situation where a singularity could possibly be avoided through a wormhole solution. More here. :-))

Originally Posted by grmpysmrf

Yeah, I understood none of this, again. Come on Einstein book, Get here... now!! <peeks out behind folded hands> damn!

I was in the process of preparing a long winded verbal description to convey what was going on to you by visualising two embedded gravitational systems but I had to press cancel when my boss came in....*aaaaaagh*. It needed some thought to ensure it was faithful to the theory, so I could not risk sending it as is.

If you can't see your way clear in understanding GR with what Markus and others say, then I will try again at a later date to express things in a laymens way, as I have had to take that particular route myself. It is hard to get an appreciation of it if you don't understand the maths or the simplified reduced dimensional diagrams. :-))

total gravitational collapse cannot be avoided

This makes it sound like gravity no longer functions... not the case? it's the strongest gravity...?

Originally Posted by grmpysmrf

total gravitational collapse cannot be avoided

This makes it sound like gravity no longer functions... not the case? it's the strongest gravity...?

We can be fairly confident in gravitational collapse. It is simply the point that any possible resistive forces are exceeded. What we can't be confident about however is the singularity itself and more generally what actually happens beyond the event horizon. We don't really know what happens at this point but we can mathematically model it based on assumptions. Quantum Gravity hopefully will have something to say about this but the theory is not fully developed. Some physicists treat the singularity condition as demonstrating something is wrong with GR while others have no problem with it. Remember it is a mathematical description only and in the solution we are talking about here (Schwarzchild solution) it assumes very simple initial conditions and is idealised. I actually doubt nature works this way and the singularity is possibly avoided by more exotic structures. :-))

Originally Posted by grmpysmrf

total gravitational collapse cannot be avoided

This makes it sound like gravity no longer functions... not the case? it's the strongest gravity...?

It is collapse/compression due to gravity that cannot be avoided (there is nothing we know of (*) that will stop it), not the collapse of gravity. [just in case you were interpreting the phrase that way]


(*) The infinite density is likely an effect of our ignorance and incomplete theories, rather than a thing.

Originally Posted by GoldenRatio

With what you have purposed.

This isn't really my proposal, it is the full and correct solution to the Einstein field equations for a spherically symmetric, stationary, non-rotating and uncharged black hole. It is mathematically rigorous.

How does the second blackhole form?

What is depicted in the diagram is the solution for one black hole. As it turns out, such a solution has two singularities, and two distinct regions of space-time which are connected by the Einstein-Rosen-Bridge.

Or does the other universe simply have blackholes spontaneously jumping into existence?

It is not possible to determine whether the "other side" is a separate universe, or merely a different region of our own universe, since the Einstein equations don't constrain the global topology of space-time, only the local geometry.

Ok, so if it fills from both ends how come the middle doesn't bulge?

Ok, I think I see now what you mean. I must apologise, because I realise now that I have neglected to explicitly mention that the opposite end of the bridge, although completely symmetric, is time-reversed - it is what is called a white hole in pop-sci articles. In a black hole, once you cross the event horizon, you can never come back out; in a white hole, once you cross the event horizon from the inside, you can never go back in. This isn't immediately obvious from the highly simplified diagram I provided, but is made rigorous in the Kruskal-Szekeres coordinate chart which covers this particular solution of the field equations.

Originally Posted by Implicate Order

Now I might be wrong in this but I am assuming this relates to the fact that clocks located at each point in space time tick at different rates in this geometry.

Essentially correct. Curvature in the time direction manifests as gravitational time dilation, whereas curvature in the space directions manifests as tidal forces.

Namely those located towards greater mass-energy concentrations tick faster that those away from these concentrations.

Actually, they tick slower if they are closer to mass-energy concentrations

he also concluded that a state of free fall is exactly equivalent to constant acceleration in the absence of a gravitational field.

I am not sure what you are trying to say here. In a free-fall frame, an accelerometer will read exactly zero. In an accelerated frame, it will not. How are they equivalent ? Perhaps I am missing your point here.

What Markus however put up is a situation where a singularity could possibly be avoided through a wormhole solution.

The solution I am referring to actually contains not one, but two singularities; they are just not visible in the simplified diagram.

Originally Posted by Markus Hanke

Ok, I think I see now what you mean. I must apologise, because I realise now that I have neglected to explicitly mention that the opposite end of the bridge, although completely symmetric, is time-reversed - it is what is called a white hole in pop-sci articles. In a black hole, once you cross the event horizon, you can never come back out; in a white hole, once you cross the event horizon from the inside, you can never go back in. This isn't immediately obvious from the highly simplified diagram I provided, but is made rigorous in the Kruskal-Szekeres coordinate chart which covers this particular solution of the field equations.

Originally Posted by Markus Hanke

Ok, I think I see now what you mean. I must apologise, because I realise now that I have neglected to explicitly mention that the opposite end of the bridge, although completely symmetric, is time-reversed - it is what is called a white hole in pop-sci articles. In a black hole, once you cross the event horizon, you can never come back out; in a white hole, once you cross the event horizon from the inside, you can never go back in. This isn't immediately obvious from the highly simplified diagram I provided, but is made rigorous in the Kruskal-Szekeres coordinate chart which covers this particular solution of the field equations.

So black holes are kind of like a one way road? in this particular brand of black hole, that is. Once a particular piece of matter crosses the black hole it cannot turn around and go back out but once it shoots out the other side of a white hole it cannot turn around and go back in? However, (if the universe is a bubble) that matter, once shot out of the white hole, could potentially circumnavigate the universe and reenter that same black hole only to be shot out the other side of the white hole again...? So in a sense, a particular particle can cross an even horizon more than once...

Perhaps, the black holes with white holes attached go nowhere specific. they are just that, one way paths in space that just end up where ever the one way road ends, not necessarily another dimension or worm hole just a predetermined spot in the the universe. No different than taking the "carpool lanes" on the freeway.

Although, doesn't the white hole kinda of suggest an anti gravity situation, since things are being pushed out? or is that just a different affect of gravity? sometimes gravity pulls other times it pushes?(like satellites being flung out into space.)

Also, based on the black and white holes, can gravity be seen as magnets? you put the right ends together and they attract, put the wrong ends together and they repel...

Originally Posted by Markus Hanke

Actually, they tick slower if they are closer to mass-energy concentrations

Ok. I think I might understand this. I am thinking in terms of differentials in space and time between points in two seperate regions with different mass-energy concentrations. In one region of higher mass-concentration distance between spatial points is less than the other region. In trying to work out then what is the seperation in time between these two different regions I then apply the universal speed limit to both regions. As a consequence, in those regions (higher energy-mass concentrations) where spatial distance between points is less then seperation of points in time must be greater (dilated) to equal c in spacetime. The converse is true for the lower energy-mass concentration region. Is this an acceptable way to view it?

Originally Posted by Markus Hanke

I am not sure what you are trying to say here. In a free-fall frame, an accelerometer will read exactly zero. In an accelerated frame, it will not. How are they equivalent ? Perhaps I am missing your point here.

Ok I may have a problem here in my understanding of the equivalence principle and I think you might have nailed it for me. I greatly appreciate that. I experience a gravitational force using local accelerations (eg. standing on the earth and being pushed up) which is equivalent to travelling in an accelerating rocket in deep space in the absence of a gravitational field. I cannot mimic the state of free fall (no forces) in a gravitational field using local accelerations in the absence of a gravitational field. Therefore the accelerometer in free fall measures a 'false acceleration'. Is this a correct interpretation?

Originally Posted by Markus Hanke

The solution I am referring to actually contains not one, but two singularities; they are just not visible in the simplified diagram.

Thanks Markus. This is twice now you have had to correct me on this interpretation of mine. I think I am getting the picture now though.

PS Greatly appreciate your guidance here Markus. GR is truly a wonderful theory. It is so much more powerful than the Newtonian picture in the way it unifies spacetime with mechanics. :-))

So black holes are kind of like a one way road?

Yes, absolutely

Once a particular piece of matter crosses the black hole it cannot turn around and go back out but once it shoots out the other side of a white hole it cannot turn around and go back in?

You got it.

Although, doesn't the white hole kinda of suggest an anti gravity situation, since things are being pushed out? or is that just a different affect of gravity? sometimes gravity pulls other times it pushes?(like satellites being flung out into space.)

The repulsion effect comes about as a consequence of time being reversed, so it isn't really anti-gravity as such. The real story is much more involved than that, but I think it would be too confusing to go into the mathematical details, and I would lie if I said I understand all nuances of that myself.

Also, based on the black and white holes, can gravity be seen as magnets?

Not really - gravity and magnetism behave in quite different manners.

Originally Posted by Implicate Order

Is this an acceptable way to view it?

It might be easier to think in terms of gravitational potentials - differences in potentials lead to gravitational time dilation. Using the standard convention of placing the zero point at infinity and potentials being negative, clocks will go slower the lower the gravitational potential. This only really works in Schwarzschild space-times though, other cases will be more difficult.

I experience a gravitational force using local accelerations (eg. standing on the earth and being pushed up) which is equivalent to travelling in an accelerating rocket in deep space in the absence of a gravitational field.

Correct. It is very important to remember though that the only thing that is equivalent here is the reading of the accelerometer. In particular, there are no tidal forces in an accelerating frame ( size of order 1/g ), and space-time is completely flat in that frame. That is why the acceleration felt in an accelerated frame is sometimes called pseudo-gravity.

It is not possible to determine whether the "other side" is a separate universe, or merely a different region of our own universe, since the Einstein equations don't constrain the global topology of space-time, only the local geometry.


Do the GR equations describe space-time topology Markus? Or do you need other mathematics?

Good point RobinM. I understand how GR is used to describe local geometry by forcing simplying assumptions about the system under examination to make the solution mathematically tractable. In the same way a global geometry can be defined using the Einstein equation assuming simplying assumptions of isotropy and homogeneity of the universal contents. We therefore have to trust in these simplfying assumptions.

The reality is that the 'actual' global geometry needs to summate all the possible local geometries available and furthermore deal with their relative relationships to each other before we can apply a faithful description to our universe. And that's just for a finite universe. What 'if' the universe is infinite (......faints and falls over) If there is a 'tiny' failure with GR in it's description of a local geometry, or one of it's possible geometries, this effect could be magnified (like a butterfly effect) as the global volume gets larger to provide a totally different view of any possible global geometry. Unfortunately we can surmise but never actually take a birds eye view of the universe in GR as the priniples of relativity insist that it is the internal relational relationships that matter. The matter is further compounded if our single universe is infinite in extent. Heirein lies the problem of doing physics in a box when dealing with complex systems. :-))

In my opinion there is more than enough complexity in our single universe without having to conclude that their are other universes out there. We migt just have to try harder.

...anyway your question was for Markus. I thought I would just add to that question as well. We need to make him work hard for his NOT money :-))

Originally Posted by RobinM

Do the GR equations describe space-time topology Markus? Or do you need other mathematics?

No, the Einstein equations constrain only local geometry; global topology on the other hand is not uniquely determined by them. Having said that, constraining local geometry imposes some degree of constraint on topology as well; for example, you wouldn't expect the universe to have the topology of a pretzel, because no physically reasonable metric is compatible with such a shape.