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What is space?

by Philip7575
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chaszz
#37
Nov18-11, 08:52 PM
P: 47
Matter, when in motion, acts on time. The faster some object goes relative to me, the slower its time elapses compared to my time. Protons fired near the speed of light in accelerators become more massive, heavier and harder to accelerate faster as they get closer to the speed of light. They are also flattened perpendicular to the direction of flight, so they become vertical ellipses, because their space is shortened in that direction. Particles called muons which have a known rate of decay, when fired in accelerators, take longer (in our time) to decay because their time slows down as they approach the speed of light. A large gravitational mass like the Earth bends the space around it, and also slows down time near it. These are some of the interdependent relativistic relationships of space, mass and time. They are why "spacetime" is more than a convenient way of expressing something about two unrelated entities. These relationships have been proven to exist many times in experiments of many different types. Before making generalizations about what space is and its relationship to time, I suggest you guys might want to read the stickies and the FAQ in the Relativity forum. I am a layman myself and know that it can be cutting to be spoken to this way, and I am sorry about it. But these forums are supposed to be places dealing with verified physical conclusions, not opinions.
narrator
#38
Nov18-11, 09:35 PM
P: 219
Quote Quote by chaszz View Post
Before making generalizations about what space is
Mine is a "generalization" that has been repeated here many times in answer to questions. Space is nothing, has no effect on anything, and being nothing is not affected by anything, is basically the message. As one example, when talking about expansion, the oft repeated clarification is that expansion does not produce more space but more distance between objects, because space (being nothing) cannot be created.
Quote Quote by chaszz View Post
But these forums are supposed to be places dealing with verified physical conclusions, not opinions.
Verified physical conclusion expressed within the bounds of language, which at times can be imprecise.
Tanelorn
#39
Nov19-11, 09:56 AM
P: 711
Space and Time are simply dimensions and Spacetime is the apparent warping of these dimensions as a result of the interactions of Bosons and Fermiions.
Space and Time are therefore not like ponderable matter, Space and Time are simply the total range of all possible locations.
According to the standard model of particle Physics all large scale, macro, physical phenomena, ultimately must be derived from the behaviour, characteristics and interactions of Bosons and Fermions.
The standard model of particle Physics is the fundermental heart of all of Physics which is itself the root from which all of science is derived.


I feel like a preacher of religion, but I really do mean this in a rhetorical tone. Also these views are still relatively young and so are still being tested.
petm1
#40
Nov19-11, 10:54 AM
petm1's Avatar
P: 366
Space is the area that matter occupies, we measure it by the yard and the second. Relative space-time we measure using a photon, our yard stick, and a clock, us.
juanrga
#41
Nov19-11, 12:24 PM
P: 476
Quote Quote by Philip7575 View Post
I'm brand-new to this site, an English teacher, certainly not a physicist, but I'd sure appreciate some (gentle) help.

The short version of my question:

How can the universe expand into infinite space?

Are there two kinds of space? The first is the distances between galaxies in our universe, and the second, space, is something else?

Where did space come from? Was it there before the Big Bang?

If there is space and space, why isn't there time and time?
Universe is not expanding into infinite space.

There only a kind of space in the equations of the Big bang.

There are different speculations for what there was before the Big Bang, but none scientific hypothesis that can be tested.
chaszz
#42
Nov20-11, 10:40 AM
P: 47
Quote Quote by Tanelorn View Post
Space and Time are simply dimensions and Spacetime is the apparent warping of these dimensions as a result of the interactions of Bosons and Fermiions.
Space and Time are therefore not like ponderable matter, Space and Time are simply the total range of all possible locations.
According to the standard model of particle Physics all large scale, macro, physical phenomena, ultimately must be derived from the behaviour, characteristics and interactions of Bosons and Fermions.
The standard model of particle Physics is the fundermental heart of all of Physics which is itself the root from which all of science is derived.


I feel like a preacher of religion, but I really do mean this in a rhetorical tone. Also these views are still relatively young and so are still being tested.
Relativity does not take its cues from the Standard Model of Particles or from Quantum Mechanics, nor do they take their cues from Relativity. These all may be regarded as fundamental theories though they cannot yet be reconciled with each other. This probably shows that all these theories are not yet fundamental enough and something better is waiting in the wings, for how long nobody knows. The String Theories are candidates, but so far without a shred of proof.

In the meantime, the Standard Model needs the Higgs boson to be found, which may happen in the Large Hadron Collider at CERN. If it is not found, there may be a lot of trouble in the Standard Model. So it is not quite fundamental in any sense as yet. Also many have remarked over the years at the large number of constants in nature that must be "just exactly so" for the Standard Model to work. It may, or may not be, showing cracks in its foundation.

Relativity also may have serious challenges presented to it in (1) The possible exceeding of the speed of light by neutrinos, and (2) quantum entanglement where communication between two particles appears to take place at faster-than-light speeds. So perhaps quantum mechanics, which has no such challenges currently, and is the most successful physical theory of all time, is winning the fundamental wars at this point. But it has little to say on space and time.

Perhaps we may agree to disagree here on the nature of space and time, whether they are real ponderable entities or not, since there are no true authorities to fall back on in "fundamental" theories that disagree with one another and cannot at this time be reconciled. I at any rate am willing to leave it there.
McCartney
#43
Dec6-11, 01:05 PM
P: 28
Bosons and Fermions:

Are they floating in space?

If space is expanding. Is there a dilution of Bosons and Fermions?

Is there a vacuum in space?

I would say that if there was a vacuum then space is nothing.

Can space expand into nothing?
Imax
#44
Dec7-11, 08:24 PM
P: 186
Think of the Universe as having two possible shapes, infinite or finite. Imagine you’re on Earth and you’re going to travel the Universe in a space ship. You can start off in any direction but you have to travel in a straight line (i.e. a geodesic). If the Universe is infinite, then it doesn’t matter the direction you choose. You can never come back to where you started from. If the Universe is finite (i.e. compact), then you can choose a direction, following a space-like geodesic (i.e. straight line), and you will eventually come back to where you started from. Space doesn’t have to be expanding into nothing.
bill alsept
#45
Dec7-11, 10:06 PM
P: 124
Quote Quote by Imax View Post
Think of the Universe as having two possible shapes, infinite or finite. Imagine you’re on Earth and you’re going to travel the Universe in a space ship. You can start off in any direction but you have to travel in a straight line (i.e. a geodesic). If the Universe is infinite, then it doesn’t matter the direction you choose. You can never come back to where you started from. If the Universe is finite (i.e. compact), then you can choose a direction, following a space-like geodesic (i.e. straight line), and you will eventually come back to where you started from. Space doesn’t have to be expanding into nothing.
If the universe is finite then there is also the possibility that one would come to the edge of the universe. If this were possible then it could also be possible that the density out there would be low and time may be moving so fast out there that we or multiple generations could never live long enough to get there.
Imax
#46
Dec7-11, 10:49 PM
P: 186
If the Universe is finite and forms a closed manifold, then it’s compact without boundaries. There doesn’t need to be an edge. The density of Bosons and Fermions can change locally, but their density could be globally homogeneous. If the Universe is finite and compact, then it could take a very, very long time to circumnavigate a closed space-like geodesic. Just because it could be closed does’nt mean that the Universe is small or static. It's possible that we or multiple generations could never live long enough to circumnavigate the Universe.
PatrickPowers
#47
Dec8-11, 06:47 AM
P: 259
Quote Quote by Philip7575 View Post
I'm brand-new to this site, an English teacher, certainly not a physicist, but I'd sure appreciate some (gentle) help.

The short version of my question:

How can the universe expand into infinite space?

Are there two kinds of space? The first is the distances between galaxies in our universe, and the second, space, is something else?

Where did space come from? Was it there before the Big Bang?

If there is space and space, why isn't there time and time?
As far as anyone knows the Universe isn't expanding into anything. We don't know of anything outside of the Universe, more or less by definition.

When the Universe came into existence it was completely crammed with unthinkably dense stuff. Though for some reason it began to expand rapidly, there was no empty space whatsoever for quite some time.

According to Albert Einstein, time and space have no meaning unless there is matter and energy around. Matter and energy create time and space.

I believe that no one at this time has any idea what was there before the big bang.
McCartney
#48
Dec8-11, 08:24 AM
P: 28
Quote Quote by PatrickPowers View Post
As far as anyone knows the Universe isn't expanding into anything. We don't know of anything outside of the Universe, more or less by definition.

When the Universe came into existence it was completely crammed with unthinkably dense stuff. Though for some reason it began to expand rapidly, there was no empty space whatsoever for quite some time.

According to Albert Einstein, time and space have no meaning unless there is matter and energy around. Matter and energy create time and space.

I believe that no one at this time has any idea what was there before the big bang.
Einstein and Newton explained gravity; the former with more accuracy. However, I believe we really don't know what is gravity. We have read how mass bends the space, but we don't know how it happens. Sometimes it sounds like a fairy tale because it is hard to imagine such a thing.

Perhaps stars and planets in the universe are the equivalent of protons and electrons within an atom and they are somehow bound together by a force that we are trying to explain.
phinds
#49
Dec8-11, 08:35 AM
PF Gold
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P: 6,082
Quote Quote by McCartney View Post
Sometimes it sounds like a fairy tale because it is hard to imagine such a thing.
Depends on your level of imagination.


Perhaps stars and planets in the universe are the equivalent of protons and electrons within an atom and they are somehow bound together by a force that we are trying to explain.
You are right that we don't know WHY gravity does what it does, but the mechanisms of WHAT it does are well understood and your "protons and electrons" analogy sounds like something from a 1930's science fiction story, not something from a science book.
McCartney
#50
Dec8-11, 08:58 AM
P: 28
Quote Quote by phinds View Post
Depends on your level of imagination.




You are right that we don't know WHY gravity does what it does, but the mechanisms of WHAT it does are well understood and your "protons and electrons" analogy sounds like something from a 1930's science fiction story, not something from a science book.
Is more than imagination when one can see the bending of light, however, all we have done is come up with an explanation and the explanation works very well.

LOL, at least it was the 1930s and not 1905. Thanks for your sarcasm.

The issue is we do not yet understand gravity.
PatrickPowers
#51
Dec8-11, 09:16 PM
P: 259
Quote Quote by McCartney View Post
Einstein and Newton explained gravity; the former with more accuracy. However, I believe we really don't know what is gravity. We have read how mass bends the space, but we don't know how it happens. Sometimes it sounds like a fairy tale because it is hard to imagine such a thing.
I have read from reliable sources that General Relativity assumes inertia and derives gravity. At seems to be hard to say how this is derived, though.
Tanelorn
#52
Dec9-11, 07:56 AM
P: 711
My present understanding is that all macro forces and effects including gravity are as a result of the interactions of Bosons with Fermions and their residuals. The bending of space is simply an illusion because space itself has no objective existence. The same applies to spacetime and time.
McCartney
#53
Dec9-11, 08:51 AM
P: 28
Quote Quote by Tanelorn View Post
My present understanding is that all macro forces and effects including gravity are as a result of the interactions of Bosons with Fermions and their residuals. The bending of space is simply an illusion because space itself has no objective existence. The same applies to spacetime and time.
One needs more than one area in space with mass to have gravity.

Gravity weakens with increased distance among objects. Do bosons and fermions behave differently when they are in close proximity to mass.

Is the boson and fermion network (or concentration) in the universe a constant?
Tanelorn
#54
Dec9-11, 11:13 AM
P: 711
McCartney please take a look at this page. It details the Fermions (matter) and Bosons (force carriers). This should help answer your questions.

http://en.wikipedia.org/wiki/Standard_Model


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