How old is the Universe?

[idav]

The singularity was everywhere, and the remnants of the singularity are still everywhere; that is, the cosmic background radiation emanates from everywhere.


Contrariwise, I am still. This is the fun of motion, (and to a certain extent, rotation) being relative.

Also, the mechanisms of normal motion and the expansion of the universe are completely different. Notably, the first is well understood, the second is almost not at all.


It isn't, unfortunately. Time dilation is caused due to the mechanics of embedding motion in 3D space into 4D spacetime.

All spacetime was once that singularity. There is no center of the universe you can use as a reference.

Motion of objects through space, and the expansion of space between objects, are two very different types of "motion". So to say they occur for the same reasons, as far as current physics are concerned, is not accurate.

Motion due to objects moving with velocity through space, and "motion" due to expansion of space itself between objects, are fundamentally different concepts.

In this case, if the ants represent objects that can move through space and the rubber band is space itself, time dilation occurs for the ants motion along the rubber band, but not for the stretching of the rubber band itself.

If an object tries to move through space and accelerate, then as it approaches the speed of light, it will need more and more energy. It becomes exponential, and infinite energy is needed to reach the speed of light, and therefore the speed of light cannot be reached by objects with mass. As an object gets closer to the speed of light, time dilation occurs, but also length contraction. Objects will become infinitesimally short as they approach the speed of light.

When space itself is expanding between objects, however, this not the case. The objects are not moving through space, and therefore these various effects of relativity don't come into play. Objects can move away in distance from each other faster than the speed of light due to the expansion of space, but they're not moving through space at the speed of light and therefore the effects of relativity are not apparent. So they don't need infinite energy to do this and they don't become infinitesimally short or experience that sort of time dilation. And as previously stated, the rate of expansion is fairly slow. It only becomes a major thing over absolutely immense distances.

Motion of objects through space is fundamentally different than increases in distance of objects due to spatial expansion. Treating these as the same type of motion as though they follow the same type of physics for what they're doing would be incorrect as far as current physical models and evidence are concerned.

Interesting that there are "different ways of moving through space". It is counter intuitive but I can understand where the physics is coming from on it.

When I was stating we have a reference point for the singularity is because when we peer into the night sky we are seeing the leftovers of what once was. We look into the past so we see how the universe was forming so there is a reference point.

If time is another dimension does this mean it is limited because of universal constraints? I don't think time is really limited from my understanding.

So am I understanding correctly that there is a difference between moving through space and moving with space and how would we know the difference? Seems that if speed is really an issue then it wouldn't matter if you were moving with space because the same laws would be in play whether or not the fabric of space is actually affected by the laws.

 

[Sir Doom]

Think about two photons approaching one another. They are approaching one another at double the speed of light minus the expansion of space between them. Neither photon is exceeding the speed of light.

From one moment to the next, the expansion of space increases as the amount of space increases. Over very large distances this rate of increase is many times the speed of light.

To put it into numbers that don't fit our reality (for sake of example):

Lets say you have a 5 inch cube of space and the rate of expansion is 1/2 inch of cubic space per cubic inch of existing space per second. So at 0 seconds you have 5 cubic inches and at 1 second you have 7.5 cubic inches. At 2 seconds you need to expand the 'new' space just as much as the original space. So you have 11.25 cubic inches and so on.

If you extrapolate that to a cube of space that's 1 billion light years cubed and add 1 billionth of a light year per second, then anything on either end of that cube is going to 'move' apart from each other at a fantastic rate. Even though they don't have to move at all.

 

[PolyHedral]

When I was stating we have a reference point for the singularity is because when we peer into the night sky we are seeing the leftovers of what once was. We look into the past so we see how the universe was forming so there is a reference point.

In the words of Sagan, "the early cosmos was everywhere, white hot." The leftovers are the shell of the spherical Big Bang; however, we are looking at it from inside the sphere.

If time is another dimension does this mean it is limited because of universal constraints? I don't think time is really limited from my understanding.

All physically real (that is, time-like) paths through spacetime terminate at the Big Bang.

So am I understanding correctly that there is a difference between moving through space and moving with space and how would we know the difference?

The difference is the difference between swimming and being carried along by the current. (As to how we tell, it's to do with the distances, how fast we know the universe is expanding, and when the light we see now was emitted.)

 

[PolyHedral]

They are approaching one another at double the speed of light

No they're not! :cover:
This is the brain bender of Relativity: both photons approach each other at exactly the speed of light. (Caveat: An observer cannot travel at c, and therefore the photon's perspective is a really muddy one that doesn't really make sense.) Photons travel everywhere at the speed of light.

The expansion of space still drains energy from them; however, this does not cause them to slow down, but instead to red shift, and become lower frequency.

 

[Sir Doom]

Is suppose photons were the wrong thing to use when discussing closing speeds.

 

[savagewind]

First we have to understand what time is. Time isn't really linear therefore the age of the universe isn't linear either. Now what about something that is moving at the speed of light, does it really age? If the universe is expanding faster than the speed of light is it aging? With time being non-linear does that mean that the universe is eternal or some sort of time loop where everything exists all at once. Just trying to grasp time in relation to the age of the universe while separating the science from the fiction.

I believe time is existing "all at once". That is how I understand Matthew 22:32 "I am the God of Abraham, Issac and Jacob... He is not God of the dead, but of the living."

It also helps me understand the resurrection. The body need not be reconstructed. It comes from where it is.

 

[idav]

The difference is the difference between swimming and being carried along by the current. (As to how we tell, it's to do with the distances, how fast we know the universe is expanding, and when the light we see now was emitted.)

Your analogy here would imply that the physics of the universe would change when traveling through it depending on how you go through it. The way I understand it laws of relativity don't change because you happen to be caught in an expansion but I suppose it is possible.

 

[idav]

I believe time is existing "all at once". That is how I understand Matthew 22:32 "I am the God of Abraham, Issac and Jacob... He is not God of the dead, but of the living."

It also helps me understand the resurrection. The body need not be reconstructed. It comes from where it is.

We experience time in a linear fashion but it really isn't. Down at the quantum level it probably doesn't abide by the rules of time which makes me think that time existing all at once is possible.

 

[idav]

No they're not! :cover:
This is the brain bender of Relativity: both photons approach each other at exactly the speed of light. (Caveat: An observer cannot travel at c, and therefore the photon's perspective is a really muddy one that doesn't really make sense.) Photons travel everywhere at the speed of light.

The expansion of space still drains energy from them; however, this does not cause them to slow down, but instead to red shift, and become lower frequency.

Is suppose photons were the wrong thing to use when discussing closing speeds.

Since they are at the speed of light, photons are time traveling.

 

[paarsurrey]

It also helps me understand the resurrection.

Do you mean resurrection of Jesus from the near-dead when he was delivered from the Cross? Or. Do you mean resurrection of the all dead human beings in the hereafter?

 

[MissDiscerner]

How old is the Universe? At least 15 billion years old!

 

[savagewind]

Do you mean resurrection of Jesus from the near-dead when he was delivered from the Cross? Or. Do you mean resurrection of the all dead human beings in the hereafter?

If time is "all at once" how can there be a "hereafter"?
I believe the account that tells Jesus was dead for three days.

 

[greentwiga]

Since they are at the speed of light, photons are time traveling.

Since time slows down as one approaches the speed of light, then Photons, at the speed of light are not experiencing time? The same moment that they leave the farthest star is the same moment, from the photons frame of reference, that they arrive here?

 

[PolyHedral]

Since time slows down as one approaches the speed of light, then Photons, at the speed of light are not experiencing time? The same moment that they leave the farthest star is the same moment, from the photons frame of reference, that they arrive here?

Yes. This is what makes working with photon reference frames not really a good idea.

 

[apophenia]

If time is "all at once" how can there be a "hereafter"?
I believe the account that tells Jesus was dead for three days.

(Forgive my being so off-topic everyone, but I have to get this really important point off my chest :sorry1

In that case, savagewind, you would reject the idea of Easter Sunday celebrating the resurrection, right ? Because if he was dead for three days his resurrection was MONDAY. When I was a kid we gave each other easter eggs on Monday... What happened ? Can't people count anymore ?

It is stuff like this which drove me away from religion !

 

[greentwiga]

(Forgive my being so off-topic everyone, but I have to get this really important point off my chest :sorry1

In that case, savagewind, you would reject the idea of Easter Sunday celebrating the resurrection, right ? Because if he was dead for three days his resurrection was MONDAY. When I was a kid we gave each other easter eggs on Monday... What happened ? Can't people count anymore ?

It is stuff like this which drove me away from religion !

This is off topic, but you are applying modern cultural reckoning to a different culture. Back then, even just one month of an old year was counted as a year. Even one hour of an old day was counted as one day. Jesus died on Fri and was buried before sundown when the Sabbath started. He remained buried all Sat, and on Sun, sometime before dawn (so less than 12 hours of the third day) he was raised. By modern reckoning, it was at most a day and a half, but by ancient reckoning, three days.

Back to the thread. When a star collapses to make a neutron star, a whole region collapses. When a black hole is formed, we call it a singularity, but know that it could be a whole region within the event horizon. How do we know that the Big Bang was a point rather than some small but finite region?

Then, If the whole universe was visible to us, and we were not at the dead center of it, we should be able to see a difference from one side of the Universe to the other. We can't. This says that the universe is much bigger than what we see. If the expansion was limited to the speed of light, we should only see a maximum of 50% of the age of the universe. Since we see back to 5% of the age, we know that the expansion was much faster than the speed of light. If we are in a closed universe that light can't escape, what if it bent back and showed us those closer stars whose light was bent back.

With both Neutron stars and Black Holes, the outer edge has in-falling matter. What if the outer edge of our universe, that is 250 times farther away than we can see, has in-falling matter from some other state. How might this affect the rate of expansion of the universe? Could any of these affect our age of the universe calculations, even if only a little?

 

[BruceDLimber]

From the Baha'i scriptures:

LXXXII “... The learned men, that have fixed at several thousand years the life of this earth, have failed, throughout the long period of their observation, to consider either the number or the age of the other planets. Consider, moreover, the manifold divergencies that have resulted from the theories propounded by these men. Know thou that every fixed star hath its own planets, and every planet its own creatures, whose number no man can compute.”
--Gleanings, p. 182

Peace,

Bruce

 

[PolyHedral]

From the Baha'i scriptures:

LXXXII “... The learned men, that have fixed at several thousand years the life of this earth, have failed, throughout the long period of their observation, to consider either the number or the age of the other planets. Consider, moreover, the manifold divergencies that have resulted from the theories propounded by these men. Know thou that every fixed star hath its own planets, and every planet its own creatures, whose number no man can compute.”
--Gleanings, p. 182

Peace,

Bruce

There's going to be less than 10^80 of them. There.

 

[dust1n]

My question is also regarding the nature of space-time and the universes expansions. If the universe had been expanding at the speed of light ( which is what we used to get the measurement) then the universe really wasn't aging because time slows down when approaching the speed of light. Also time isn't even linear so is the universe really that old or maybe even older time itself.

What's important to note here is that the expansion of the universe is not objects moving away from each other near the speed of light, it is the creation of new space in between objects, and the rate at which that happens appears to be exponential and capable of making it appear as if things were moving away from us at or above the speed of life. If this is the case, I don't see why the apparent age of the universe would change. Time itself doesn't speed up or slow down, matter does.

 

[dust1n]

I think the second part of the question has to do with a misinterpretation of what it means for the universe to expand faster than the speed of light. The expansion of the universe through any finite amount of space is relatively slow. The expansion is not itself occurring at the speed of light. However, due to the vast distances in the universe, objects that are very far away from each other can move away from each other faster than the speed of light, due to the cumulative effect of expansion between them.

Aye, thanks for that. That is a much better way to talk about that and far more accurate than mine!