Thread: Gravity

A thought just occured to me.

One of the fundamental laws of nature is that for every action, there is an equal and opposite reaction; agreed ?

And it is also widely agreed that the universe is probably expanding, yes?

So given those two demoninators, would it be fair to say that the equal and opposite reaction of the action of an expanding universe is, gravity ?

Originally Posted by leohopkins

And it is also widely agreed that the universe is probably expanding, yes?

And if the Universe is not expanding?

Well, if the Universe is expanding, it is of course due to the theoretical big-bang, BUT the thing about the theoretical big bang is that the pre-big-bang state would contradict what we know of space and time, and thus what we perceive as a PAST pre-big bang event is in fact in the future, meaning that the pre-big-bang state actually exists into out future, which would, in theory, represent the reaction to an expanding Universe, leading to a sterady-state universe.

Gravity is something we have yet to link with the E-M force system of our understanding of space-time. So, exclusively, it has something to do with mass, a type of need for mass to associate together, and thus as you would seem to propose, contract. Interesting how gravity causes a type of contraction, generally, and light the opposite. Maybe investigating space-time with a purely "dualistic" theme is in order, one day, for anyone doing a paper on the logistics of space-time?

I don't think that question can be answered in present times. I don't know to much on the big bang, does part of the theory explain what the initial force was and what it acted on? If not, then their is no way of answering the question.

I would say so yes, but who knows what happened when the big bang happened and shortly after it, the forces when they were unified could be that reason you are discussing.

You got me kind of thinking now. The way I see it is the universe would have to be pushing off of a central point, that is pushing back on the universe and since it is not a pull and it is a push that would mean it is anti-gravity?

Originally Posted by leohopkins

...would it be fair to say that the equal and opposite reaction of the action of an expanding universe is, gravity ?

No. Yer completely off the mark there.

Originally Posted by leohopkins

So given those two demoninators, would it be fair to say that the equal and opposite reaction of the action of an expanding universe is, gravity ?

No, not gravity. How about the reaction being all objects are moving away from each other proportionally?

but... couldn't it be both? maybe, the bending of spacetime is the force of the universe pulling out from every direction! How though would gravity fit into the

The way I see it is the universe would have to be pushing off of a central point

In fact, it's not. the universe, from what ive learned is pushing out from all points. the singularity started out as a singularity, and expanded. KICK ME IF I'M WRONG! I'm not a million dollar expert physicist. The planets moving is not a reaction. The motion is the expansion. This is such a complicated, crazy, subject, that Expert physicists argue on it. It is good to speculate and guess. Many discoveries have been made that way. most of the time though people just learn. Now... Prove to me scientificly that leohopkins is wrong. Lets get a good discussion going. I want proof, so that we can learn from eachother That's what this forum is all about! No proof? explain why you "think" he's wrong in a way that we can reply.

I probably should have said that when I said " the way I see it", I meant I was just taking a stab at it.

I hate to disappoint you but we can't argue over this because I just read an article and it turns out that your right.

"The inescapable conclusion was that some sort of antigravity force is pushing on all points of space, causing the universe to grow faster and faster with time. Cosmologists have called that force "dark energy.""
-chronicle.com/free/v48/i39/39a01901.htm

Well, Alot of physicists are making it seem like Dark Matter has been all but confirmed, however there are those that say by modifying the equations of what we understand about gravity, we not only get rid of the need for "Dark Matter", but solve other mysteries of gravity. They are working to confirm the hypothesis, but it may be that there never has been such a thing as dark matter!

http://newswire.ascribe.org/cgi-bin/...=2007&public=0

In physical cosmology, dark energy is a hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the universe. Assuming the existence of dark energy is the most popular way to explain recent observations that the universe appears to be expanding at an accelerating rate. In the standard model of cosmology, dark energy currently accounts for almost three-quarters of the total mass-energy of the universe. (wikipedia) if you don't like the source, I can show you more

In astrophysics and cosmology, dark matter is matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter. (same source, deal with it)

I just wanted to clairify that there is a differance between dark energy and dark matter. Yes, they are both unproven. They both have the same basic background: "We can't see it, hear it, taste it, or touch it, so... we'll call it dark matter/energy" they're not the same thing though.

Personaly, I belive that there is more than one kind of dark matter... because it represents up such a substantial portion of the matter in space)
We can't see it though, so... we don't know what it is. It might be some thing we can already define, (but can't see) the fact is that something is there, and so something exists. Until we define it, It's dark matter. The same goes for dark energy.

So we are just supposed to take all of this by what, blind FAITH!?

We are supposed to beleive in something we cannot measure, we cannot see, we cannot touch, we cannot hear, we cannot even prove except to say that the only way for the universe to fit OUR current understanding of the the universe is to make up an easy way out by getting everyone to believe this 'Dark Matter' and 'Dark Energy'. It is like mixing science with religion all over again, soon we will have religious nutjobs claiming that the 'Architect' of the universe IS dark matter!

I say we have to go by what we can study and base our Math and Science off of stuff we can prove!

Don't make something up just so the Universe once again fits the equations, change the equations to match the Universe!

Rmember how aeronautics physicists once said that it is aerodynamically impossible for Bumblebees to fly? Untill someone finally changed the math behind what we understood about aeronautics were we able to make what was observed fit the math.

Now we are able to apply what we learned from the bee into making smaller machines that can fly

Im just saying we shouldn't change the bee, we should change our understanding of it!

Originally Posted by SuperNatendo

I say we have to go by what we can study and base our Math and Science off of stuff we can prove!

Uh...that may be all well and fine, but are you proposing that we give up on all the things in science that we can't physically put our hands on?

There's a lot we can only study indirectly by the effects on other things.

Yer also assuming that we have the ability to prove things. Are you suggesting that we only tackle problems that we know we can resolve? You won't go far in science with that attitude, dude.

Oh, and since the math doesn't always work, you kinda have to theorize about how things work, in order to develop the math and understanding to figure it out. You think Newton was born with his equations already known in his head? Probably not. I'd say he took a good look at what was happening in observation, then tried to explain it conceptually, then tried to put it into a quantitative format.

It's like you're wanting us to only address problems that Newtonian physics can resolve, and that's cutting out quite a bit of stuff.

Originally Posted by Shaderwolf

The planets moving is not a reaction.

Please remember that the planets, galaxies, etc. did not exist. The expansion was the expansion of space carrying along a sea of radiation. Eventually, through cooling and pertrubations in a homogeneous universe, these objects formed.

It is good to speculate and guess. Many discoveries have been made that way.

Such as?

So we are just supposed to take all of this by what, blind FAITH!?

dark matter is proved to exist because of the effects it has on it's surroundings. We don't know what it is. That's why we call it dark matter. A black hole is a black hole because you can't see it. Like dark matter though, you can see the gravitational effects that a black hole has on it's surroundings.
Most of the "current understanding" of our universe that you challenge, comes from basic equations derived by Newton. The galaxy would not hold itself together if only the gravity of the planets were accounted. They do not have enough gravity altogether to hold the universe how it is. Challenging the equations that prove the existence of dark matter is challenging every aspect of modern physics. I have heard people in this forum challenge Eisenstein's equation and theories. They have been proven with particle accelerators, and improved upon.

Discoveries made by speculation?

Newton started with nothing. He speculated on the basic laws of nature. He would have to guess on the nature of nature, and then try to explain it mathematically. Let's go back to 5th grade science. First: formulate a hypothesis (educated guess) Second: test the hypothesis through gathering data and experiments.
I was saying that if we continued the discussion, someone would learn something...
continue to play the antagonist (Q), It drives conversations. Don't pull us to far off course though.
You want proof of dark matter?
http://www.nasa.gov/home/hqnews/2006...rk_Matter.html
not enough for you?

By the way wolf:
how did you get that "werd" smiley on?
and-I totally agree with your last post :wink:

Originally Posted by Shaderwolf

Discoveries made by speculation?

Newton started with nothing. He speculated on the basic laws of nature. He would have to guess on the nature of nature, and then try to explain it mathematically.

He observed gravity and made a prediction, then went about the math. That is not discovery by speculation.

prediction: "A prediction is a statement or claim that a particular event will occur in the future"
speculation:"To engage in a course of reasoning often based on inconclusive evidence"

this may mean that... let's check it out!

Please remember that the planets, galaxies, etc. did not exist.

energy and matter did.
no matter?
they're equivalent.

Originally Posted by Shaderwolf

Please remember that the planets, galaxies, etc. did not exist.

energy and matter did.
no matter?
they're equivalent.

True. For the purpose of the argument though, large concentrations of matter are required.

And for that purpose, speculation need not apply.

Theroey...

Since dark matter is proven, then wouldnt this be the body or plane on which we exist? It is not a static universe; every action has an equal and opposite raction.

If this is the case, then gravity is simply a temporal vortex caused by massive spacial distortion, the eye of which is the body's center of mass. The movement of massive bodies leaves a traceable history in the spacetime continum. This traceable history is rapidly filled with dark matter, the contium itself, carrying along with it bodies of lesser mass within the range of the gravitational field/distortion/vortex.

Hypothesise the graviton. This is a massless 'particle', thought to 'carry' bodies throught space; i.e. the graviton is mass starved. The truth of the matter is that since two bodies cannot occupy the same space at the same time, when a massive body moves through space, spacetime is pushed out of the way, and then immidiately rushes to fill the void left by the passing body, taking along with it whatever objects of lesser mass are along its surface. The graviton thus, is the center of any body where there is a void of space. Where motion is concerned, the eye of this void follows this vortex and thus results in a gravitational pull.


Thought experiment:

Think of spacial gravity as the undertow of a submarine. If you were submerged, and a submarine were to pass you at high speed, youd be sucked along the path of the movement by a vortex of water. Since spacetime is a mosaique of darkmatter, the same applies with respect to spacial distortions and temporal vortexes.


Does this make any sense?
Any feedback appreciated

Cheers

People seem to be missing my point, I did not say that just because we can't see dark matter that it doesn't exist, I'm just saying that I have yet to see proof of ANY effects of dark matter, visually or otherwise.

The only effect dark matter has had if it has existed according to some scientists is the perpetual expanding of space which should not have happened according to our CURRENT mathematical understanding of gravity. So to fill in the gaps or holes in our theory we say , "Well there must exist some sort of matter that is completely undetectable."?

When somebody says "Wait, I think I can explain it, we just had to update the MOG formulas to fit what we are observing now" we should really look into those discoveries before discounting them to try and prove an entirely theorized form of matter.

Oh and by the way, a black hole is very different from 'Dark Matter', we CAN constantly see the effects of black holes, we even understand how they are created, but I have yet to see solid proof of the existance of 'Dark Matter'---Apples and Oranges.

Oh and by the way, a black hole is very different from 'Dark Matter', we CAN constantly see the effects of black holes, we even understand how they are created, but I have yet to see solid proof of the existance of 'Dark Matter'-

Rotational speed of the outer rim of galaxies?

Originally Posted by KALSTER

Oh and by the way, a black hole is very different from 'Dark Matter', we CAN constantly see the effects of black holes, we even understand how they are created, but I have yet to see solid proof of the existance of 'Dark Matter'-

Rotational speed of the outer rim of galaxies?

That is evidence, not proof. There are alternate explanations.

That is evidence, not proof. There are alternate explanations.

True. Do we have proof of ANYTHING then?

Originally Posted by KALSTER

That is evidence, not proof. There are alternate explanations.

True. Do we have proof of ANYTHING then?

Nothing I can think of in an absolute sense, but we do have bodies of evidence that are of such depth and breadth and quality that they constitute proof for all practical purposes.

Right....um...so we haven't actually proven DM's or DE's existence yet, but we are seeing phenomena that we are trying to describe, and one of the ways we've come up with (so far) is DM and DE.

But I guess since we haven't proven DM or DE yet, we can't think about DM or DE....

Good one. :?

Dark matter is just a variable, and a description of what we see. Dark matter may be ordinary matter. The fact is that something's there that we can't see. In order to have an acurate mathematical description of our gallaxy, those effects must be included in the equations. Even if dark matter is merely some type of element that we already know about, the fact stands that because we can only see it through it's effects on other types of matter it is dark. The same with dark energy. Scientists are trying hard to define what dark matter is. Currently though, we need the variable that has been come to be known as dark matter to do any math on the composition of galaxies. That extra mass has to come from somewhere.
In the past, an experiment would show intresting results, and we would explain them as math. Those were the easy days of physics. Today, we've explained most of what we've found experimentaly. We say, if this is true, than this must be also. And continue until we have found a way to prove (or disprove) our theorys scientificly. That's what makes physics today so much harder than in the past.

Is it possible for the need for dark matter to be explained by vacuum polarization? I am thinking that a resultant gravitational field might result.

Originally Posted by KALSTER

Is it possible for the need for dark matter to be explained by vacuum polarization? I am thinking that a resultant gravitational field might result.

Careful, Kalster...If you can't calculate the answer to this problem, right now, with math, then you're not allowed to think about it.

Oh, but I don't give a shit. The first step in scientific investigation is to propose a possible answer to a problem. Then people discuss whether it even IS a possibility and then one could go further with the math, experiments and what not. The people you refer to, jump the gun by calling for immediate evidence without even discussing validity. If I, not being a scientist, propose something ridiculous, then at least I would expect a reason exactly why it is ridiculous. Thereby I can actually learn from this site, as I think is its function.

We're all in agreance? maybe?
so... what were we talking about again?
is dark matter antimatter?
no.
it would create massive amounts of energy whenever it connected with ordinary matter.
Who has a possible answer for us to discuss?
Also, I'm not an expert. does anyone see any fallacies in my explanations? I want to know if I'm wrong.

Originally Posted by I

Is it possible for the need for dark matter to be explained by vacuum polarization? I am thinking that a resultant gravitational field might result.

Vaccum polarization though would be caused by a backgrund electromagnetic field wouldn't it?
I thought that there was no radiation at all coming from where the dark matter should be. wouldn't even a virtual particle produce some kind of radiation?
You're streching to the very edge of my scientific knowledge.
A virtual particle has energy and momentum, so I suppose that there could be a resulting gravitational field. Could this be our "dark" matter?
I looked this stuff up on google. I might not know what I'm talking about. Anyone who knows more than me want to elaborate?

I don't really get why some people are opposed to the theory of DM and DE, simply because it can't be seen or poked yet. There's a lot of stuff we can't see or poke, yet we have come to regard it as real.

There's also the possibility that DM and DE are part of a whole new sect of physics that we don't know about yet. I mean, we didn't know about quantum mechanics or even Newtonian Physics at one point in history. Who's to say that DM and DE aren't the stepping stones into a whole new universe of stuff?

I don't want any rebuttals about this. I'm not saying that there aren't any other possible answers.

maybe, It's still good to theorise.
If we just say "it's a whole new branch of physics" and decide not to theorize until we've captured some for study... we might be waiting a long time. Until then I think it's safe to say that dm obeys some of the laws of nature...
What do we know about dark matter right now?