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December 30th, 2012, 09:01 AM
The most common answer I find is that it occurred everywhere but I am wondering about this. If all the galaxys are moving away from each other cannot we reverse their courses and at the point they intersect is where the big bang took place? Any replies will be helpful. Thanks
As we look out into the universe, we see that all the distant galaxies are moving directly away from here. There is no difference in the apparent recession speed of distant galaxies, whatever direction we look in.
We assume that the Earth does not inhabit any special place in the universe. If the expansion is the same everywhere, then wherever you are you would trace the expansion back to yourself. This makes sense, as if everything was in the same place to begin with, then all places can equally claim that they are the origin for expansion, and that everything else expanded away from them.
There is a bit of a subtlety here. Because the universe has a finite lifetime and light has a finite speed, there hasn't been time for light to reach us from all parts of the universe. However, everything we see looks the same, and we see no sign that any part of the observable universe is especially near an edge of the entire universe. We also see that all of observable space is on average essentially flat. Under those circumstances, the simplest assumption is that space remains flat even where it is too far away for us to see it, and that the full universe is infinite. Now two things follow:
1. A uniform, infinite system has no point that can be logically called a center. Therefore the complete universe has no center.
2. An infinite object that contracts by a set percentage is still infinite. It does, however, become more dense since any finite part of its mass is now contained in a smaller volume. Hence what happens as we imagine watching the Big Bang backwards is that the density increases everywhere, any two points in the universe get closer together, but there is no center. The universe remains infinite.
Incidentally, we don't really know how to extrapolate the density backwards until it becomes infinite, because after a certain point we don't know experimentally how the matter in the universe would behave. From what knowledgeable people seem to imply, I believe, although I haven't done and couldn't do the calculation, that General Relativity extrapolates time back to a finite point. We might as well call this point t=0, even though we don't know how matter would behave at this time.
A part of the difficulty resides in visualising a whole universe contracting into a single point.Originally Posted by newscience
In a single point there are no LINES able to intersect anywhere.
An "easier" example: Imagine you begin diving into an angle. Entering the letter "V" from upwards. As you fall towards the point of intersection you will not reach it unless you shrink yourself so as to escape collision with the walls.
But THAT enlarges the picture and it seems as if you have not moved closer to the intersection...
How then can you ever imagine entering it?
nowhere,no place,no center of the universe,no center of gravity. there are many unknown stuff about the universe,and you know how we start with all this? just by knowing this whole thing has a begining.take it from there,expand the board,expand your mathematics,your equations, and just at a point everything will look siller,almost incomprehensible.but view it again from the begining and it becomes clearer.
This is a tricky one as the universe is expanding away from itself at every point in the universe. If we were at the Triangulum galaxy and then went forwards in time by 10 billion years then we were at the Milky Way we would find that both relative to themselves have seen the universe receding away from each other at the same rate. The thing is both are the centre of the universe and the expansion rate is relative to the position that you occupy.
This is a theory for why we cannot see earlier than 300,000 years at some points after the Big Bang, in isolated spots of the universe the light would take 300,000 years to reach those parts of the universe and now in fact it is no longer there, only residual radiation from the Big Bang which we see as Cosmic microwave background radiation.
Theoretically if the big bang was a 0 dimensional point and so was the universe, then every space in the whole universe is technically where the big bang took place.
Sounds good. But there is something "mystic# about points: Do they exist? Are they real?
Theres infinitely many of them in any smallest possible volume.
After all: No points have ever been observed. Why do we believe in them?
May we stop believing in them?
Should we assume there was just one big bang ? or many ?
"Assume" is definitely the word here. There is no observational evidence for multiple big bangs in different regions of the universe, and as far as I know no theory with a decent argument for anything like that. Since the super-hot phase of the big bang erases most if not all signs of anything that came before it, there is no way to detect previous bangs of the entire universe. When it was still observationally possible that the expansion of universe was decelerating, there was a lot of work on ideas for a collapse back into another hot period, followed by another big bang. However, now that it appears that the expansion is accelerating instead, the simplest assumption is that there will not be another big bang and that there hasn't been any other in the past. However, there is no compelling evidence one way or the other.
In the middle.
You are the middle. Everywhere is!
Im not sure in what sense you use "simpler"? Its simpler not trying to resolve an anomaly but... if a few complications removes the anomaly then the complicated theory in a sense IS simpler."Assume" is definitely the word here. There is no observational evidence for multiple big bangs in different regions of the universe, and as far as I know no theory with a decent argument for anything like that. Since the super-hot phase of the big bang erases most if not all signs of anything that came before it, there is no way to detect previous bangs of the entire universe. When it was still observationally possible that the expansion of universe was decelerating, there was a lot of work on ideas for a collapse back into another hot period, followed by another big bang. However, now that it appears that the expansion is accelerating instead, the simplest assumption is that there will not be another big bang and that there hasn't been any other in the past. However, there is no compelling evidence one way or the other.
Was it Lee Smolin who introduced The Darwinistic picture? Fractal universe maybe its called.
.[/QUOTE] Im not sure in what sense you use "simpler"? Its simpler not trying to resolve an anomaly but... if a few complications removes the anomaly then the complicated theory in a sense IS simpler.
Was it Lee Smolin who introduced The Darwinistic picture? Fractal universe maybe its called.[/QUOTE]
By "simpler", I mean roughly explaining the existing data with fewer and/or more straight-forward assumptions. If the universe were to show fractal geometry, and a multiple big-bangs explained why, I would have no problem with multiple big-bangs. Currently, I don't think it will turn out that way, but it should be remembered that I am not an active cosmology researcher.
A fractal universe means the universe is of a fraction dimension and not whole like 3d...fractal is a shape which each big opening is from a small opening...
Points are real as anyother geometry feature are...for a straight line to exist there must be two points that can be linked with a moving point...in the early universe,all the points fell in on themselves,just to stay contained in this universe..but this did'nt last,as the big event occurred.
From http://mathworld.wolfram.com/Fractal.html:
"A fractal is an object or quantity that displays self-similarity, in a somewhat technical sense, on all scales. The object need not exhibit exactly the same structure at all scales, but the same "type" of structures must appear on all scales. A plot of the quantity on a log-log graph versus scale then gives a straight line, whose slope is said to be the fractal dimension. The prototypical example for a fractal is the length of a coastline measured with different length rulers. The shorter the ruler, the longer the length measured, a paradox known as the coastline paradox. "
General Relativity is about the dimension of the space containing the object [topological dimension], rather than the fractal dimension. A "fractal universe" is one in which the clustering observed at intergalactic distances repeats itself many times as the scale gets larger. Since the scale would very soon exceed the distance that we can actually view, which is finite since the universe has a finite beginning time, a fractal universe can only be confirmed theoretically. At the moment, the data seems to suggest a smoothing out at the largest available scales.
I knew I was the center of the universe!You are the middle. Everywhere is!
Apparently mvb,i get you.
I would say that the big bang took place, close to the center, in the maps and diagrams of the universe.
(but only if the maps of the universe, show most of the universe, and not just a small part of it.)
If you Google search "maps of the universe", and other terms like that, universe map images come up.
While I was researching the following, I got off subject and searched for the Earths location, in a map of the universe.
Perhaps the following links map of the universe, gives one of the best answers to this question.
Penn State Live - Largest-ever 3-D map of distant universe revealed
(you must pause the 2 pictures, to read the information bellow them.)
The following was taken from this website, Where is Earth in the Universe? | eHow.com
"There has been an attempt by leading scientists at Princeton to make a 2-dimensional map of the universe, in which one end of the universe is where the Big Bang began and the other is the surface of the Earth. According to this map, the Milky Way galaxy is to the far right of the universe (see Resources). Also according to the map, the center of the universe is a galaxy known only as PSR-P1620-24."
The following links show maps.
File:Earth's Location in the Universe SMALLER (JPEG).jpg - Wikipedia, the free encyclopedia
http://io9.com/5893755/nasa-releases...ntire-universe
http://www.huffingtonpost.co.uk/2012...n_1399100.html
http://www.astro.princeton.edu/universe/ms.pdf
http://newscenter.lbl.gov/news-relea.../boss-quasars/
This is a great question,
Chad.
Last edited by chad; January 4th, 2013 at 12:03 PM.
If everything moves away from everything else, then there cannot be a common intersection point.If all the galaxys are moving away from each other
The problem with maps is that they can show only the part of the universe that we can see, the known universe. Much of the universe is so far from us that light has not had time to reach us, so we can't see it. Therefore we don't know where the edges of the universe are or even if there are any edges. Not knowing the edges, we can't determine of the entire universe. Therefore all the maps show only a part of the full universe.
Unfortunately, it is common to omit saying "observed" universe, assuming that the reader is consciously aware of that, which not all people are when they are looking at maps. Maps can then be subtly misleading about centers.
Everywhere is a point of intersection. This is true for all directions...looking for the center ain't going to help,there is no center,my house is a center,even my garage.
The problem with maps is that they can show only the part of the universe that we can see, the known universe. Much of the universe is so far from us that light has not had time to reach us, so we can't see it. Therefore we don't know where the edges of the universe are or even if there are any edges. Not knowing the edges, we can't determine of the entire universe. Therefore all the maps show only a part of the full universe.
Unfortunately, it is common to omit saying "observed" universe, assuming that the reader is consciously aware of that, which not all people are when they are looking at maps. Maps can then be subtly misleading about centers.
While I was researching this subject, I found many sources that said, what you said above. I just wonder if its old data?
The following sources say that NASA, has released pictures/maps of the "entire universe."
The Whole Universe In One Photo
NASA releases infrared map of the entire universe
And the following links, seem to show maps of the entire universe. The maps show 12 billion light years "out", from the center of the universe. (Perhaps?) these maps are missing 1 billion years, but it seems they show 12/13 of the universe at worst.
Measuring the Distant Universe in 3-D « Berkeley Lab News Center
Penn State Live - Largest-ever 3-D map of distant universe revealed
Perhaps you are 100% correct in what you say above. But at this moment I think its possible, that we have much better maps of the universe, than your above words seem to imply.
Those maps show almost all of the observable universe. There is presumably a lot more so far away that no light from it has reached us yet. Obviously we can't put on our maps what we haven't yet seen.
Since the edge of the observable universe is given by the distance that light can travel over the age of the universe, we are necessarily at the center of the observable universe. We can't tell if we are at the center of the entire universe because we can't see it all. It would seem exceedingly unlikely that we would be at the center of the entire universe unless it is infinite, in which case every point in the entire universe is at its center.
The terminology can get messed up, especially when talking about everything we can see. When the caption says "map of the entire universe," its intended meaning is "map of the entire observable universe." Anything else would be nonsense. How could we map the parts of the universe that are so far away that the light they emit hasn't yet reached us?
[Please note that I have switched terminology from "known" to "observable." I think that the switch may make what I am trying to say a bit clearer.]
I appreciate your comments and your help, to make me somewhat understand this subject.
But the following sources say that NASA, has released maps/pictures of the "entire universe" and the "whole universe."
NASA releases infrared map of the entire universe
The Whole Universe In One Photo
Image #1 in the following link, shows a map of the universe from Penn State, going out 12 billion years, from a center point.
Penn State Live - Largest-ever 3-D map of distant universe revealed
I just think that (perhaps) its strange, that NASA, Penn State, Berkeley, and other respected scientific groups.
Would just leave out the words "known" and "observable."
And then replace those words with "entire" and "whole".
All I know is that NASA has released "an infrared map of the (entire) universe"
And NASA has released a "picture of the (whole) universe."
Penn State has also released a map of the universe, that goes out 12 billion years from a center point.
Last edited by chad; January 8th, 2013 at 12:22 AM.
By entire and whole, they mean a full 3 dimensional map of the sphere of the universe (as seen from earth).I just think that (perhaps) its strange, that NASA, Penn State, Berkeley, and other respected scientific groups.
Would just leave out the words "known" and "observable."
And then replace those words with "entire" and "whole".
Yes, the center point is earth, because that's where we're observing from.Penn State has also released a map of the universe, that goes out 12 billion years from a center point.
Perhaps you are correct about the Penn State map?
But what did NASA mean, when they used the word "whole", to describe that 2D photo of the "whole" universe?
And the following link shows maps of the universe, where the Earth is far from the center of the map.
(These maps are towards the bottom of the page, maybe 70% down.)
Where Earth is in the Universe
And there has also been an attempt by scientists at Princeton, to make a 2-dimensional map of the universe, in which one end of the universe is where the Big Bang began and the other is the surface of the Earth.
According to this map, the Milky Way galaxy is to the far right of the universe.
Also according to the map, the center of the universe is a galaxy known only as PSR-P1620-24.
So their appears to be maps of the universe, where the Earth is (not) located in the center of the map.
None of your links are to NASA, just articles paraphrasing NASA. Here's what NASA said.
Perhaps you are correct about the Penn State map?
But what did NASA mean, when they used the word "whole", to describe that 2D photo of the "whole" universe?
And the following link shows maps of the universe, where the Earth is far from the center of the map.
(These maps are towards the bottom of the page, maybe 70% down.)
Where Earth is in the Universe
According to this map, the Milky Way galaxy is to the far right of the universe.
Also according to the map, the center of the universe is a galaxy known only as PSR-P1620-24.
So their appears to be maps of the universe, where the Earth is (not) located in the center of the map.
The whole visible sky.The sky can be thought of as a sphere that surrounds us in three dimensions. To make a map of the sky, astronomers project it into two dimensions. Many different methods can be used to project a spherical surface into a 2-D map. The projection used in this image of the sky, called Aitoff, takes the 3-D sky sphere and slices open one hemisphere, and then flattens the whole thing out into an oval shape.
As far as the 'maps' of the universe, I don't think cow-flipper.hubpages is really a source, especially when one of the drawings is from athe 'personal copy ' of a NatGeo from 2000. Besides, none of them appear to show what you think. You might also note that there's a large difference between photographic maps of the sky, where the earth is always at the center, and drawings, which can show anything the drawer wants.
Dear AlexG,
All to most of my links, showed data from places like NASA or Penn State.
Or could you list any data from my sources that is untrue?
Perhaps you are confused in this way. Many maps of the universe show the Milky Way, running (horizontally across) the center of the map.
Its not the Earth in the center of these maps, its the Milky Way galaxy.
Like this map,
New 3-D Map of Universe Is Best One Yet | Milky Way & Neighbor Galaxies | 2MRS Survey Map, 218th Meeting of the American Astronomical Society | Space.com
Do you think the Earth is in the (true) center of the map, or is the Earth in the center (but far to the right or left) ??
Last edited by chad; January 8th, 2013 at 03:04 AM.
You have answered your own question here. When we wind things back in time we get to "the point they intersect," which is where the big bang took place. Because all the galaxies have come together at that point, every galaxy is where the big bang took place; in other words, it happened everywhere.
You have answered your own question here. When we wind things back in time we get to "the point they intersect," which is where the big bang took place. Because all the galaxies have come together at that point, every galaxy is where the big bang took place; in other words, it happened everywhere.
The big bang did (not) happen everywhere.
The big bang happened around 13.7 billion years ago.
And the big bang happened in (1) very small area.
The big bang took place, in the yellow circle that says "big bang", in the left side of the chart, in the following link.
Google Image Result for http://www.particleadventure.org/images/history-universe-08.jpg
Or this link shows the big bang taking place, at the bottom of the chart, in the area that says "big bang."
Google Image Result for http://gallery.recycleb.in/galleries/info/History%20of%20Universe.gif
But that "very small area" (strictly speaking, volume) was the entire universe at the time; "everywhere" expanded from that initial small volume.
Remember that the big bang is an expansion of space not an expansion of "stuff" into existing space.
But that "very small area" (strictly speaking, volume) was the entire universe at the time; "everywhere" expanded from that initial small volume.
Remember that the big bang is an expansion of space not an expansion of "stuff" into existing space.
I personally would use the word "everything" above, instead of "everywhere."
I would say, "everything" expanded from that initial small volume.
Chad.
Well, as long as you include "space" in "everything" then that is OK. Therefore, as "everything" includes (all of) space, then all of space (aka everywhere) was part of the big bang. The big bang occurred in all of space (everywhere).
Well, as long as you include "space" in "everything" then that is OK. Therefore, as "everything" includes (all of) space, then all of space (aka everywhere) was part of the big bang. The big bang occurred in all of space (everywhere).
I apologize dragging you into my (personal/wrong) definition of the word universe.
When I hear the word universe, I consider the universe to be all matter and energy, that was created in the big bang.
But I believe the (proper) definition of universe is, all matter, energy, and space everywhere.
What word fits the following definition?
_________ - all matter and energy that was created in the big bang. (Big Bang being the explosion that created all the matter, that made our galaxy.)
Thank you,
Chad.
Hi!Well, as long as you include "space" in "everything" then that is OK. Therefore, as "everything" includes (all of) space, then all of space (aka everywhere) was part of the big bang. The big bang occurred in all of space (everywhere).
I apologize dragging you into my (personal/wrong) definition of the word universe.
When I hear the word universe, I consider the universe to be all matter and energy, that was created in the big bang.
But I believe the (proper) definition of universe is, all matter, energy, and space everywhere.
What word fits the following definition?
_________ - all matter and energy that was created in the big bang. (Big Bang being the explosion that created all the matter, that made our galaxy.)
Thank you,
Chad.
I think continuity has something to do with what a universe is.
The pieces the universe consists of fit together.
There can in principle be drawn a continious line throught all points within the universe.
So if there somehow exists a point not within the proposed line then that point belongs to another universe!
I think it is generally assumed that those two are the same thing. But I'm not sure we can answer that definitively. After all, we can only know for certain about the observable universe, which appears to have evolved from the early hot dense state in the process known as the big bang.
It seems reasonable to assume that the universe outside the observable universe is basically the same as the observable universe and therefore was also part of the same big bang. Whether that is true for the entirety of the universe is probably unknowable, though.
A couple of points:
1. We do not know if the universe was "created" by the big bang; we just know it was once much hotter and denser (aka smaller) than it is now.
2. The big bang is not well described as an "explosion"
The universe.
Our observable part of the universe is assumed to be only a small part of all the matter and energy that was created in the Big Bang.
If our observable universe (which means the part of the universe we can see) contained all the matter and energy created in the Big Bang, it would be a massive and totally unlikely coincidence.
Yesterday, we detected cosmic background radiation (CMBR) that has been travelling towards us since the just after the Big Bang. Today we detect CMBR too, which must have been originally released at a slightly greater distance than the CMBR we detected yesterday, as it has taken longer to reach us. We expect to continue to be able to detect the CMBR far into the future, and for as long as we do so the amount of the universe that we can see continues to grow, as we are continuing to detect CMBR original released at greater distances than before. It is the original distance that the CMBR we currently detect was released from (and how far that distance has receded due to the expansion of the universe since) that determines the size of the observable universe.
This is all completely understood by astronomers, but unfortunately they often leave the word "observable" out of their descriptions of the universe, even though that is what they are talking about. This can easily cause confusion.
It is interesting to think that we say it was 'created', it must have been a part of in which matter and energy came into existence from whatever was there, which begs the question could something else have arisen?
The universe.
Our observable part of the universe is assumed to be only a small part of all the matter and energy that was created in the Big Bang.
If our observable universe (which means the part of the universe we can see) contained all the matter and energy created in the Big Bang, it would be a massive and totally unlikely coincidence.
Yesterday, we detected cosmic background radiation (CMBR) that has been travelling towards us since the just after the Big Bang. Today we detect CMBR too, which must have been originally released at a slightly greater distance than the CMBR we detected yesterday, as it has taken longer to reach us. We expect to continue to be able to detect the CMBR far into the future, and for as long as we do so the amount of the universe that we can see continues to grow, as we are continuing to detect CMBR original released at greater distances than before. It is the original distance that the CMBR we currently detect was released from (and how far that distance has receded due to the expansion of the universe since) that determines the size of the observable universe.
This is all completely understood by astronomers, but unfortunately they often leave the word "observable" out of their descriptions of the universe, even though that is what they are talking about. This can easily cause confusion.
I have heard that some galaxy's in our observable universe, are moving in a unnatural direction.
Some scientists think that "a great mass" is pulling on them, they call this mass "the great attractor."
I have been assuming that this "great attractor", was located outside of the observable universe. But after researching I believe the "great attractor", is actually located within our observable universe.
The Great Attractor
Great Attractor - Wikipedia, the free encyclopedia
I have been believing that this "great mass" pulling on these galaxy's, was another (separate) huge group of galaxy's and supercluster complexes, created by a big bang (but not our big bang.)
But it still seems to me that perhaps the word universe, means everything that is everywhere. And even a huge group of superclusters , that was created by a (separate) big bang from ours, would still be considered part of the universe.
Perhaps there is no evidence that a big bang (separate) from ours, has ever happened.
But I still ask this question, what word would fit the following definition?
_________- all matter and energy that was created in the big bang (that created our galaxy.) _______ does not include separate big bangs (from ours.)
I know I am still pushing un-true and un-proven beliefs. But I believe that there must/should be a word to fit the above definition (at least in certain thinking circles.)
Last edited by chad; January 11th, 2013 at 12:49 AM.
From Wikipedia:
The fecund universes hypothesis of cosmology advanced by Lee Smolin, also called cosmological natural selection theory, suggests that a process analogous to biological natural selection applies at the grandest scales. Smolin summarized the idea in a book aimed at a lay audience called The Life of the Cosmos.
The theory surmises that a collapsing black hole causes the emergence of a new universe on the "other side", whose fundamental constant parameters (speed of light, Planck length and so forth) may differ slightly from those of the universe where the black hole collapsed. Each universe therefore gives rise to as many new universes as it has black holes. Thus the theory contains the evolutionary ideas of "reproduction" and "mutation" of universes, but has no direct analogue of natural selection. However, given any universe that can produce black holes that successfully spawn new universes, it is possible that some number of those universes will reach heat death with unsuccessful parameters. So, in a sense, fecundity cosmological natural selection is one where universes could die off before successfully reproducing, just as any biological being can die without having offspring.[4]
Fractals in theoretical cosmologyIn the realm of theory, the first appearance of fractals in cosmology was likely with Andrei Linde’s "Eternally Existing Self-Reproducing Chaotic Inflationary Universe"[5] theory (see Chaotic inflation theory), in 1986. In this theory, the evolution of a scalar field creates peaks that become nucleation points which cause inflating patches of space to develop into "bubble universes," making the universe fractal on the very largest scales. Alan Guth's 2007 paper on "Eternal Inflation and its implications"[6] shows that this variety of Inflationary universe theory is still being seriously considered today. And inflation, in some form or other, is widely considered to be our best available cosmological model.
Since 1986, however, quite a large number of different cosmological theories exhibiting fractal properties have been proposed. And while Linde’s theory shows fractality at scales likely larger than the observable universe, theories like Causal dynamical triangulation[7] and Quantum Einstein gravity[8] are fractal at the opposite extreme, in the realm of the ultra-small near the Planck scale. These recent theories of quantum gravity describe a fractal structure for spacetime itself, and suggest that the dimensionality of space evolves with time. Specifically; they suggest that reality is 2-d at the Planck scale, and that spacetime gradually becomes 4-d at larger scales. French astronomer Laurent Nottale first suggested the fractal nature of spacetime in a paper on Scale Relativity published in 1992,[9] and published a book on the subject of Fractal Space-Time in 1993.[10]
French mathematician Alain Connes has been working for a number of years to reconcile Relativity with Quantum Mechanics, and thereby to unify the laws of Physics, using Noncommutative geometry. Fractality also arises in this approach to Quantum Gravity. An article by Alexander Hellemans in the August 2006 issue of Scientific American[11] quotes Connes as saying that the next important step toward this goal is to "try to understand how space with fractional dimensions couples with gravitation." The work of Connes with physicist Carlo Rovelli[12] suggests that time is an emergent property or arises naturally, in this formulation, whereas in Causal dynamical triangulation,[13] choosing those configurations where adjacent building blocks share the same direction in time is an essential part of the 'recipe.' Both approaches suggest that the fabric of space itself is fractal, however.
The problem with that is at that time space was created also. The most popular way of understanding this is with a visual aid/analogy.
Suppose the universe is spatially closed (it’s a simple matter to generalize to open). Imagine the surface of a sphere. The entire surface of the sphere will be the analogy of the entire space in the universe. Now imagine dots placed on the sphere’s surface. As the sphere expands the dots become further and further apart. The further dots move away faster than the closer ones. Now imagine what happens when you decrease the size of the sphere? The dots become closer and closer and closer until they’re all at the same place. That’s the place where the big bang happened. But notice that there is no place like that anymore. Space changed since then. At that time all the universe as a sinlge point. You can extend this to a flat sheet instead of a sphere. The same visualiztion holds true for the analogy. That’s how the universe is imagined by cosmologists.
Here’s the limitation of that viewpoint. We don’t really truly know this. I.e. we don’t know what happens before a certain time in the past. We have no idea what happened at t = 0. Our knowledge begins only an incredibly small fraction of a second later. As Peebles explains in his text on physical cosmology on page 6
I think Peebles is being very wise here. He knows where to use caution when using this extrapolation.If there were an instant, at a “big bang,” when our universe started expanding, it is not in the cosmology as it is now accepted, because no one has thought of a way to adduce objective physical evidence tht such an event really happened.
As far as the definition of universe goes here is what I believe and what I see most physicists using - Our universe consists of all physical locations which one can draw a line to from our present location. That means that the most remote galaxy is in our universe. However there is a possibility for other universes to exist which are spatially disconnected from ours. Such universe are called "parallel universes" and are of current interest in cosmology. For more info search the internet using the term "Multiverse".
About a year ago I was riding on my bike thinking about stuff like this.
I was thinking about how some people think, if you left one side of the universe, you would instantly come out on the opposite side of the universe.
But then I looked up at the moon. I thought about gravity, the space between the moon and Earth, and the space all around us.
Even though I am uneducated, I just felt that many ideas about the universe, are more complex and bizarre, than they actually are.
Perhaps this has nothing to do with your above post, or anything that has been said here.
Sometimes it seems like some people, believe that space itself was created by the big bang, but I believe that the big bang took place, in an empty space that was already there.
I look forward to re-reading your post above.
I am not terribly well versed in the various multiverse ideas but I assume "the|our universe" would fit the above, with "other universes" for, er..., other universes (created by other big bangs).
You are, of course, free to believe that, or that the world is carried on the back of a giant tortoise. But you should be aware that your beliefs have nothing to do with well-established science.
As for those people who "believe that space itself was created by the big bang"; that is not a belief. That is a scientific conclusion; the current best explanation for the available data. (Well, actually, it is a popular distortion of the science; we don't know if space was created at that point, but it has certainly expanded since then.)
You are, of course, free to believe that, or that the world is carried on the back of a giant tortoise. But you should be aware that your beliefs have nothing to do with well-established science.
As for those people who "believe that space itself was created by the big bang"; that is not a belief. That is a scientific conclusion; the current best explanation for the available data. (Well, actually, it is a popular distortion of the science; we don't know if space was created at that point, but it has certainly expanded since then.)
Can you list sources or simply explain, this so called scientific data that states, "space itself was created by the big bang" ??
Or can you list sources or simply explain, "how space itself has expanded since the big bang" ??
Chad.
Last edited by chad; January 11th, 2013 at 04:01 AM.
Strange I did not intend to be sarcastic.
There are lots of resources on line. For example:
Evidence for the Big Bang (non-technical)
Ned Wright's Cosmology Tutorial - Part 1 (more detailed)
Just one quote from the first link:
That's OK. It didn't come across that way.
Thanks for the sources, they have good information.There are lots of resources on line. For example:
Evidence for the Big Bang (non-technical)
Ned Wright's Cosmology Tutorial - Part 1 (more detailed)
Just one quote from the first link:
That's OK. It didn't come across that way.
But neither source states, "space itself was created by the big bang" or "how space itself has expanded since the big bang."
Perhaps I am wrong, but I do not think you can provide a (good) source, that says the above things are true.
Imagine the universe collapsing into a very small area.
What would happen to the space the universe used to cover?
What would replace that space?
The section I quoted says exactly that. Here it is again.
It then provides more detail on this. For example:
There are many good sources. Many will be far too technical, I think. This paper has a reasonably non-technical introduction (and much of the rest can be understood even if you skip the math): [0707.0380] Expanding Space: the Root of all Evil?Perhaps I am wrong, but I do not think you can provide a (good) source, that says the above things are true.
VolumeImagine the universe collapsing into a very small area.
It is smaller/denser.What would happen to the space the universe used to cover?
You seem to have a view of the universe as ball of "stuff" in some larger volume. That misconception is addressed here: Frequently Asked Questions in Cosmology (the rest of that FAQ is worth reading as well).
This is a tricky one as the universe is expanding away from itself at every point in the universe. If we were at the Triangulum galaxy and then went forwards in time by 10 billion years then we were at the Milky Way we would find that both relative to themselves have seen the universe receding away from each other at the same rate. The thing is both are the centre of the universe and the expansion rate is relative to the position that you occupy.
This is a theory for why we cannot see earlier than 300,000 years at some points after the Big Bang, in isolated spots of the universe the light would take 300,000 years to reach those parts of the universe and now in fact it is no longer there, only residual radiation from the Big Bang which we see as Cosmic microwave background radiation.
Theoretically if the big bang was a 0 dimensional point and so was the universe, then every space in the whole universe is technically where the big bang took place.
I (believe/assume) that I heard, in the early days of the universe. The universe behaved in a predictable, rational, and explainable way.
But then something happened, and then objects in the universe started to move in non-predictable, irrational, and un- explainable ways.
I'm not sure where you would have heard that. The universe currently behaves in predictable, rational and explainable ways. If it didn't we probably wouldn't exist.
(Of course, at the quantum level, these predictable and rational behaviours are probabilistic but that doesn't mean totally random or unpredictable.)
Thank you very much for both sources.The section I quoted says exactly that. Here it is again.
It then provides more detail on this. For example:
There are many good sources. Many will be far too technical, I think. This paper has a reasonably non-technical introduction (and much of the rest can be understood even if you skip the math): [0707.0380] Expanding Space: the Root of all Evil?Perhaps I am wrong, but I do not think you can provide a (good) source, that says the above things are true.
VolumeImagine the universe collapsing into a very small area.
It is smaller/denser.What would happen to the space the universe used to cover?
You seem to have a view of the universe as ball of "stuff" in some larger volume. That misconception is addressed here: Frequently Asked Questions in Cosmology (the rest of that FAQ is worth reading as well).
I said it was unlikely that "all space was created by the big bang" or " space itself was expanding since the big bang."
But after browsing your first source, I must say theres a outstanding chance that space is expanding in the universe.
Its said that the basic premise of general relativity causes this expansion.
But I can still say that "all space itself was (not) created by the big bang."
I doubt (very) seriously you will be able to provide a source, to state that the above is incorrect.
Have a good one Strange.
Last edited by chad; January 11th, 2013 at 07:39 PM.
I'm not sure where you would have heard that. The universe currently behaves in predictable, rational and explainable ways. If it didn't we probably wouldn't exist.
(Of course, at the quantum level, these predictable and rational behaviours are probabilistic but that doesn't mean totally random or unpredictable.)
Maybe I was reading about the following, "the universe’s expansion was slowing down 11 billion years ago, before a mysterious entity called dark energy took over and began spurring the cosmos to expand faster and faster."
Glimpse at early universe finds expansion slowdown | Atom & Cosmos | Science News
I'm not sure where you would have heard that. The universe currently behaves in predictable, rational and explainable ways. If it didn't we probably wouldn't exist.
(Of course, at the quantum level, these predictable and rational behaviours are probabilistic but that doesn't mean totally random or unpredictable.)
I apologize if I have been rude, or acted in a stupid way in this thread.
You have taught me many things here. And I appreciate you taking the time to communicate these things to me.
Chad.
Ah, OK. So, we would expect expansion to slow down due to the effect of gravity. And it did. But we now find that, at some point it started accelerating again. The cause of this is given the label "dark energy" which is shorthand for "what the fuck happened there".
So, while it is true we couldn't predict that, based on the information we had at the time that is not the same as the universe becoming irrational and unexplainable.
I don't think you have (but I could be wrong - so watch outI apologize if I have been rude, or acted in a stupid way in this thread.
I wanted to post something in regard to the op. Sorry if this has already been covered. I'm having trouble staying focused to try to understand what I have read so far. but the longer I wait to post this the further the conversation will progress and I am likely to forget I even had a question.
Anyway. In regards to 'where' it happened, isn't location of a single point always described in relation to other known points in space? Such as 29 degrees south of point a, 70 degrees east of point b and 12 degrees north west of point c.
Yes indeed. We can only describe the evolution of the expansion of the universe through the relationship between "here" and other known points in space. This is what I meant when I said:
where? you have to think simpler. we can say where we are on earth, kind of. but if there is nothing in space we cant say where it was. can you say where the water comes from in a fountain? if you are an atom everythink is drifting away from you. but soon you will recognize everything is coming close to you because in the fountain time passes fast. in the univers there is not time which is comparable to ours because everything is so slow. besides we just know a few dimension. lets say four. if a sheet of paper is all dimension we know together (it is 2d). and the point is in the 3 dimension we cant find the point on the paper or in our dimensions if you know what i mean.
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