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How Can a Star Be Older Than the Universe?

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Re: How Can a Star Be Older Than the Universe?

#71

Post by namirez »

marzell wrote: post #70
ajay-d wrote: post #59

GN-z11 is a galaxy that's 32 billion light years away. Here's the note from wikipedia: At first glance, the distance of 32 billion light-years (9.8 billion parsecs) might seem impossibly far away in a Universe that is only 13.8 billion (short scale) years old, where a light-year is the distance light travels in a year, and where nothing can travel faster than the speed of light. However, because of the expansion of t…

Seriously... what's the difference between 'universe expansion' and 'travel'? A particle can't travel faster than c but it can effectively if the universe expands in addition to its travel speed? Are there any established sci-fi concepts that replace the concepts of wormholes with 'universe compression'?

Yes, it's called Alcubierre Drive, where spacetime is compressed in front and expanded behind a ship to drive it through the spacetime like a gravitational wave.

https://en.wikipedia.org/wiki/Alcubierre_drive

Re: How Can a Star Be Older Than the Universe?

#72

Post by haecceity »

marzell wrote: post #70
ajay-d wrote: post #59

GN-z11 is a galaxy that's 32 billion light years away. Here's the note from wikipedia: At first glance, the distance of 32 billion light-years (9.8 billion parsecs) might seem impossibly far away in a Universe that is only 13.8 billion (short scale) years old, where a light-year is the distance light travels in a year, and where nothing can travel faster than the speed of light. However, because of the expansion of t…

Seriously... what's the difference between 'universe expansion' and 'travel'? A particle can't travel faster than c but it can effectively if the universe expands in addition to its travel speed? Are there any established sci-fi concepts that replace the concepts of wormholes with 'universe compression'?

The first one means the space time metric changes

Re: How Can a Star Be Older Than the Universe?

#73

Post by rpedela »

TallGuyShort wrote: post #37
sorenn111 wrote: post #32

Earlier quoted context omitted.

Quark Gluon Plasma (observed at the RHIC), at really early in the universe there was too much temperature and pressure to have stars or even atoms. At least that's my understanding.

Yes but Quark Gluon Plasma existed immediately following the Big Bang. We arrive at the Big Bang by reverse engineering lots of evidence we see in the universe. What evidence is there that nothing else currently inside the bubble of the observable universe could possibly have been there, very far away from the Big Bang, at the time of the Big Bang? I don't see why I'm being down-voted because as of yet no one has ans…

You are probably being downvoted because the big bang, our ability to estimate the age of the universe, etc is believed to be a fact by many including astronomers and astrophysicists. And yet there are so many unanswered questions that it is reasonable to question those things. In this case, it calls into question our age estimation for both planets and the universe.

Re: How Can a Star Be Older Than the Universe?

#74

Post by Simon_says »

groby_b wrote: post #52
TallGuyShort wrote: post #37

Earlier quoted context omitted.

Yes but Quark Gluon Plasma existed immediately following the Big Bang. We arrive at the Big Bang by reverse engineering lots of evidence we see in the universe. What evidence is there that nothing else currently inside the bubble of the observable universe could possibly have been there, very far away from the Big Bang, at the time of the Big Bang? I don't see why I'm being down-voted because as of yet no one has ans…

Mostly because space and time are most likely a result of the Big Bang. For all we can tell, "the beginning" was an infinitely dense singularity of space time - there is no "very far from the Big Bang", because, there's no space. Yes, you can somewhat debate that - we're not entirely clear what happened in the first 10^-33 seconds - but we don't know anything about that. So you might as well say "what evidence is the…

THat's one theory. Another is Eternal Inflation.

Re: How Can a Star Be Older Than the Universe?

#75

Post by turndown »

accnumnplus1 wrote: post #64

Does the microwave background come from the centre of the universe where the big bang was; and the light from stars on the far side, flying in the opposite direction to us, take longer to reach us than the microwave background does?

The Big Bang happened everywhere in the Universe, at once. Our CMBR is coming in from all directions, at all times, as more distant locations(eg further away from us at the start) finally reach us.

Re: How Can a Star Be Older Than the Universe?

#76

Post by ganonm »

TallGuyShort wrote: post #43
amelius wrote: post #38

Earlier quoted context omitted.

The universe is expanding. This started at some point, and I suppose the theory says that it started at the point where there was no space.

Correct me if any of the following is wrong, though: when we say the universe is expanding, we mean that matter is spreading out. The further apart the matter is, the faster it's spreading out. If we back-trace the position of stars, they all coincide at roughly the same point in time and space. This led us to believe that at some point in time all of this matter was together, incredibly dense, and in a very "hot", h…

Space itself is actually growing as well as celestial bodies having some relative motion that on average moves away from a common point. The growth in space itself is called inflation. Last time I studied cosmology (university) this was an accepted fact although the precise mechanism that explains this inflation was not agreed upon (scalar field, dark energy etc). I think there is some debate about whether inflation is speeding up or slowing down or how long it has occurred for but AFAIK the concensus is that it is a real thing.

To make an analogy, it is as if you had an elastic sheet with objects moving on its surface. The elastic sheet can be expanded which causes the distance between any two fixed points to grow.

(it's been many years since I studied physics so any corrections to my comments are appreciated)

Re: How Can a Star Be Older Than the Universe?

#77

Post by semiotagonal »

haecceity wrote: post #72
marzell wrote: post #70

Earlier quoted context omitted.

Seriously... what's the difference between 'universe expansion' and 'travel'? A particle can't travel faster than c but it can effectively if the universe expands in addition to its travel speed? Are there any established sci-fi concepts that replace the concepts of wormholes with 'universe compression'?

The first one means the space time metric changes

Is it possible that the universe stays the same size and everything within it shrinks?

Re: How Can a Star Be Older Than the Universe?

#78

Post by KingCobra »

It reminds me of the same question asked in this book, "The Birth of Time: How Astronomers Measured the Age of the Universe" by John Gribbin. The bottom line was that the calculations always have some approximations, which can throws off a number by a large factor.

Re: How Can a Star Be Older Than the Universe?

#79

Post by hirundo »

I think, by Occam's Razor, the most likely explanation is that there's a skybox surrounding the solar system that Voyager 1 may run into any day now, like Truman Burbank at the end of The Truman Show. It seems to be a more parsimonious explanation of the available facts that we're looking at the result of a super duper planatarium projector, as opposed to an actual vast and frequently inexplicable universe.
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