Infinite Universe?

[Paradoxum]

I was watching a program recently that said that physicist have found that the universe is probably infinite in size. Does anyone know if this is true? Is it no possible that the universe could be like a sphere, so that if you go one direction, you will end up where you started?

I just find it hard to accept that anything is actually infinite.

 

[juvenissun]

I was watching a program recently that said that physicist have found that the universe is probably infinite in size. Does anyone know if this is true? Is it no possible that the universe could be like a sphere, so that if you go one direction, you will end up where you started?

I just find it hard to accept that anything is actually infinite.

Space is related to time. If the space is infinite in size, would the time also be infinite in length? Would you feel better when you think about the infinite time, rather than the infinite space?

 

[Paradoxum]

Space is related to time. If the space is infinite in size, would the time also be infinite in length?

I don't think that is how it works. What do you mean by infinite in time?

Would you feel better when you think about the infinite time, rather than the infinite space?

No. I find it hard to believe anything is actually infinite. For example when I was a Christian I didn't say God was eternal. I said he was timeless, which is different.

 

[Michael]

I was watching a program recently that said that physicist have found that the universe is probably infinite in size. Does anyone know if this is true? Is it no possible that the universe could be like a sphere, so that if you go one direction, you will end up where you started?

I just find it hard to accept that anything is actually infinite.

Infinity is hard for humans to wrap their heads around, but it's actually a distinct possibility.

 

[Michael]

FYI, it wouldn't necessarily need to be spherical, nor need it "wrap around''. I may just be infinite in all directions.

 

[Michael]

One of the laws of physics is based upon the notion that energy cannot be created nor destroyed, it can only change forms. Our laws of physics would suggest that the energy that exists in our universe today has existed eternally in some form or another. Infinity and eternity are not concepts that humans easily comprehend. We tend to think in the 'finite', births, deaths, beginnings and endings. It is actually much harder to think in terms of infinity and eternity, but in order to explain the current energy of the universe, you ultimately end up thinking in such terms.

 

[Paradoxum]

It is actually much harder to think in terms of infinity and eternity, but in order to explain the current energy of the universe, you ultimately end up thinking in such terms.

How so? What is infinite needed to explain?

 

[Bungle_Bear]

I may just be infinite in all directions.

Too many burgers?

 

[DrkSdBls]

I was watching a program recently that said that physicist have found that the universe is probably infinite in size. Does anyone know if this is true? Is it no possible that the universe could be like a sphere, so that if you go one direction, you will end up where you started?

I just find it hard to accept that anything is actually infinite.

Hypothetically, if the Universe is actually expanding then it wouldn't do much good to continue in a single Direction to arrive at your starting point for you'll never reach it. You would have to travel at a Speed greater then the universe is expanding.

If one is to reason that there is a finite velocity that one can attain and that Limit is the rate of the Universe expanding then this Brings to mind Zeno's Paradox of Motion (or a certain Variation of it). If the Universe is expanding then it would be logical to conclude that it is all of Space that is expanding at an equal rate (and not the Edge of the Universe "Growing" outwards), thus, regardless of your velocity, even the Space between to any given points would also be continuously expanding, including the space between Point at which you started at and the point in which you current are, between the Point in which you currently are and the point you are currently heading, and the space between where you are heading and the Point where you started.

Point A - Starting point
Point B - Current Location
Point C - Imminent Destination
{} - Where the Line loops back to the start


}----A--------B--------C----{

So, not only would the distance between point B and Point C be ever increasingly expanding at a Constant Rate but also the distance between point B and point A would also be increasing at the same rate meaning that traveling at the same velocity at which the Universe is expanding, you would actually be LOSING ground at a rate of 2 to 1 and thus never return to your starting point by way of a single direction.

Assuming the Universe was to cease expanding then Hypothetically you may be able to return to your starting your, assuming that the Universe was continuous as such....

But a Hypothesis based on an assumption is a Wild guess. And a Hypothesis based on an assumption based on another assumption is Madness.

 

[Michael]

How so? What is infinite needed to explain?

In terms of explaining the origin of energy, you need "eternity" in there somewhere, but not necessarily "infinity". If energy cannot be created or destroyed, then some form of energy has existed eternally and that energy will exist eternally in some form or another. If the universe is infinite, the energy simply gets recycled.

 

[Michael]

Too many burgers?

Nah, just too much plasma to see very far.

 

[Michael]

But a Hypothesis based on an assumption is a Wild guess. And a Hypothesis based on an assumption based on another assumption is Madness.

Welcome to cosmology theory 101 where madness is "typical" and it's even considered "scientific". If inflation, and dark energy, and dark matter.....full of wild guesses and one assumption compounded upon another.

 

[elopez]

I was watching a program recently that said that physicist have found that the universe is probably infinite in size. Does anyone know if this is true? Is it no possible that the universe could be like a sphere, so that if you go one direction, you will end up where you started?

I just find it hard to accept that anything is actually infinite.

Most scientists agree that the universe is finite in the past, while it could be infinite in expansion. The geometry of the universe is flat, so I would lean towards thinking it's not possible to go in one direction and end up where we first started, since the geometry is not a sphere.

 

[DrkSdBls]

Most scientists agree that the universe is finite in the past, while it could be infinite in expansion. The geometry of the universe is flat, so I would lean towards thinking it's not possible to go in one direction and end up where we first started, since the geometry is not a sphere.

Actually, there is no Evidence that the Universe is "flat" nor that "Geometry" has any actual meaning when describing it.

 

[Michael]

Most scientists agree that the universe is finite in the past, while it could be infinite in expansion. The geometry of the universe is flat, so I would lean towards thinking it's not possible to go in one direction and end up where we first started, since the geometry is not a sphere.

FYI, although you are correct that most scientists might agree on a finite past, that's not even universally true in all "bang" theories. Alfven's "big bang" theory was more of a cyclical, and relatively localized event, but it was not a "beginning" nor an "ending". The event itself is predated by preexisting matter and antimatter that simply come into close proximity due to gravity, interact and then expand again.

I agree with you over the issue of the universe being "flat". The evidence would suggest that the universe doesn't wrap around on itself.

 

[Michael]

Actually, there is no Evidence that the Universe is "flat" nor that "Geometry" has any actual meaning when describing it.

I suppose one's viewpoint depends on how one subjectively interprets the WMAP data.

 

[elopez]

Actually, there is no Evidence that the Universe is "flat" nor that "Geometry" has any actual meaning when describing it.

Actually, there is an ample amount of evidence. Depending on the total amount of matter in the universe it could exist in the three different types of geometry: open, closed, or flat. Scientists before the WMAP data, which confirms the universe is flat among other things, predicted the universe was flat by equations.

 

[elopez]

FYI, although you are correct that most scientists might agree on a finite past, that's not even universally true in all "bang" theories. Alfven's "big bang" theory was more of a cyclical, and relatively localized event, but it was not a "beginning" nor an "ending". The event itself is predated by preexisting matter and antimatter that simply come into close proximity due to gravity, interact and then expand again.

I agree with you over the issue of the universe being "flat". The evidence would suggest that the universe doesn't wrap around on itself.

I am aware a finite past is not universally accepted with those who advocate a Big Bang. Alfven's theory is mainly dismissed nowadays, hence our agreement on a a flat universe which correlates to Einstein's theory of general relativity. Back in 93' a theoretical cosmologist by the name of Jim Peebles said of one Alfven's books, "there is no way that the results can be consistent with the isotropy of the cosmic microwave background radiation."

 

[Paradoxum]

Hypothetically, if the Universe is actually expanding then it wouldn't do much good to continue in a single Direction to arrive at your starting point for you'll never reach it. You would have to travel at a Speed greater then the universe is expanding.

If one is to reason that there is a finite velocity that one can attain and that Limit is the rate of the Universe expanding then this Brings to mind Zeno's Paradox of Motion (or a certain Variation of it). If the Universe is expanding then it would be logical to conclude that it is all of Space that is expanding at an equal rate (and not the Edge of the Universe "Growing" outwards), thus, regardless of your velocity, even the Space between to any given points would also be continuously expanding, including the space between Point at which you started at and the point in which you current are, between the Point in which you currently are and the point you are currently heading, and the space between where you are heading and the Point where you started.

Point A - Starting point
Point B - Current Location
Point C - Imminent Destination
{} - Where the Line loops back to the start


}----A--------B--------C----{

So, not only would the distance between point B and Point C be ever increasingly expanding at a Constant Rate but also the distance between point B and point A would also be increasing at the same rate meaning that traveling at the same velocity at which the Universe is expanding, you would actually be LOSING ground at a rate of 2 to 1 and thus never return to your starting point by way of a single direction.

Assuming the Universe was to cease expanding then Hypothetically you may be able to return to your starting your, assuming that the Universe was continuous as such....

But a Hypothesis based on an assumption is a Wild guess. And a Hypothesis based on an assumption based on another assumption is Madness.

Oh, I agree. I just meant it as a hypothetical... if you could travel at any speed. Or, for example, if you were to draw a straight line on a map of the true universe, would it come back to where it started.

In terms of explaining the origin of energy, you need "eternity" in there somewhere, but not necessarily "infinity". If energy cannot be created or destroyed, then some form of energy has existed eternally and that energy will exist eternally in some form or another. If the universe is infinite, the energy simply gets recycled.

I don't see why conservation of energy would exist as a law before the big bang. Everything else seems to fall apart. Also, it doesn't mean it would have existed for eternity, it could be that before the big bang there was no time. So it would be timeless, not eternal.

Most scientists agree that the universe is finite in the past, while it could be infinite in expansion. The geometry of the universe is flat, so I would lean towards thinking it's not possible to go in one direction and end up where we first started, since the geometry is not a sphere.

I was reading about this yesterday and it seems as if the universe could be flat, but also finite (so you can come back to the same place). A universe in the shape of a torus (doughnut) but look flat.

Doughnut theory of the universe - Wikipedia, the free encyclopedia

Torus - Wikipedia, the free encyclopedia

 

[Radagast]

I was watching a program recently that said that physicist have found that the universe is probably infinite in size.

Well the universe is likely to be finite. It began as a speck with the Big Bang, and has expanded since for a finite time, therefore it's still finite.

Is it no possible that the universe could be like a sphere, so that if you go one direction, you will end up where you started?

Yes, it could be finite but unbounded, like the surface of a sphere. However, locally the geometry is almost perfectly Euclidean.