# QuestionAbout The Limits of Light

#### SuperDan

Considering that space in the universe has what's commonly thought of as fabric or a medium for things to happen in, plus massive gravity wells can affect it so that it can be thought of as having mass, why can't light particles be thought to have resistance of the farthest distanced object, being 13 1/2 billion light years away, only allowing it to propagate that far? I hope that makes sense. It's the idea that light can only reach us from 13 1/2 billion light years away because of space's medium only letting it get that far.

David-J-Franks

#### David-J-Franks

Considering that space in the universe has what's commonly thought of as fabric or a medium for things to happen in, plus massive gravity wells can affect it so that it can be thought of as having mass, why can't light particles be thought to have resistance of the farthest distanced object, being 13 1/2 billion light years away, only allowing it to propagate that far? I hope that makes sense. It's the idea that light can only reach us from 13 1/2 billion light years away because of space's medium only letting it get that far.
The universe is expanding faster than the speed of light, so there is a boundary beyond which light isn't fast enough to ever reach us. The inside of this boundary is called the 'observable universe' and beyond is the 'whole universe' which we can never receive light or information from. The observable universe is 46. 5 billion years radius, because for the 13.8 billion year age, it has been expanding faster than light speed.

When you say we can see back 13.5 billion light-years away, it probably should mean 13.5 billion years back in time. In that time the object may well be a lot more than 13.5 billion light-years in distance further away, because of the faster than light expansion.

It's not the fabric of space stopping the light, light is just not fast enough to reach us from beyond the observable universe.

An average of estimates in a space.com article for the size of the whole universe is 250 x the observable universe.

'Steady State of The Infinite' theory
Infinite space - Infinite Universe's - No beginning - No end​

#### Hawkstein

An average of estimates in a space.com article for the size of the whole universe is 250 x the observable universe.

Is there any evidence to base these estimates on?

David-J-Franks

#### Mental Avenger

The universe is expanding faster than the speed of light, so there is a boundary beyond which light isn't fast enough to ever reach us. The inside of this boundary is called the 'observable universe' and beyond is the 'whole universe' which we can never receive light or information from. The observable universe is 46. 5 billion years radius, because for the 13.8 billion year age, it has been expanding faster than light speed.
Since the age of the Universe is determined to be ~13.8 billion years, the radius of the Observable Universe appears to be 13.8 billion light years.
An average of estimates in a space.com article for the size of the whole universe is 250 x the observable universe.
I have seen no evidence to conclude that the edge of the Universe as we know it extends much beyond the edge of the Observable Universe. Beyond that, empty space should extend to infinity.

David-J-Franks

#### voidpotentialenergy

The FTL expansion at the start of the big bang makes this a very difficult prospect to define a size of our universe.
ftl=? speed.
The slower than L speed bubble probably 48+ billion light years.
I tend to think we can see almost all objects in our universe or at least the part of the big bang that wasn't expelled at ftl.
As relative speed increases to L speed things will start to vanish and that process probably already happening.

I personally don't believe our universe is everything so beyond our universe more of the same in different phases of expansion, contraction or universe size black hole waiting for a FTL collision .
quantum fluctuation, universe, quantum fluctuation, universe etc forever.

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David-J-Franks

#### David-J-Franks

Since the age of the Universe is determined to be ~13.8 billion years, the radius of the Observable Universe appears to be 13.8 billion light years.

I have seen no evidence to conclude that the edge of the Universe as we know it extends much beyond the edge of the Observable Universe. Beyond that, empty space should extend to infinity.
Maybe, but equally, there's also no evidence to say the whole universe can't be a lot bigger.

I think the uncertainty comes from the inflation theory which is a bolt on to the big bang theory, it's this which needed faster than light expansion. If that turns out to be correct then the whole universe will be bigger than 13.8 billion light-years. If not then your thinking is nearer the truth.

It looks like we both agree that space, empty, (or full of something in my theory) extends indefinitely - what I call 'The Infinite'.

So, now, how do you explain why there's just our universe, a one-off, and that all the rest of 'the infinite' is empty? I'm thinking that whatever laws allowed, or enabled or gave rise to our universe must also apply throughout 'the infinite'. Therefore I think 'the infinite' contains an infinite number of other universes, after all, physicists love to assume the laws are the same all over our universe so why not beyond? Why do you think the here and now is a special one-off.

If space was truly empty then I see only 2 choices our universe has always been here or it came from nothing. If its always been here then why would it have waited an infinite amount of time and then suddenly decided to go bang 13.8 billion years ago? The only way around that is to invoke the cyclic universe theory i.e. endless rebounds and re-collapsing.

To summarise, how I see your explanation as working, is a universe, sitting on its own in infinite empty space, endlessly re-collapsing and rebounding. It could also expand indefinitely, but that would be the end of everything if the rest of space is empty.

The only thing that works for me is to assume all 'the infinite' contains infinite universes and crucially that all space is filled or composed of something such as quantum field/foam/fluctuations, aether, vacuum energy, dark energy or whatever

If you accept space is infinite, then I find it too bizarre to think our universe is the only matter in this infinite space. It would mean stuff in our universe is a one-off special, an other-wise exception to an infinite void. There's no reason to believe any laws of physics could allow 'something' here and absolutely nothing any where-else. What enables or gives rise to something here, will enable or give rise for something to be everywhere- so no void! Stuff here, is not a special case - If there's something here, there's something everywhere!

Since there's no reason to believe our stuff and laws of physics are special to our universe, it's reasonable to assume stuff and laws are the same throughout 'the infinite'. This, in turn, means there's a connection or something in common throughout 'the infinite'. So I suggest the underlying commonality is just space and what it consists of, (quantum field/foam/fluctuations, aether, vacuum energy, dark energy or whatever).

If the laws of physics allow one universe, the same laws must allow an infinite number. So, if there's a universe here, why not over there and over there etc., until there's an infinite amount. So, I suggest that whatever mechanism gives rise to a universe, then there must be an infinite number of them!

Furthermore, if you accept that matter-energy can not be created or destroyed, then I think, an infinite number universes have always existed and always will (through recycling of a mixture of matter from other expanded and universes)

'Steady State of The Infinite' theory
Infinite space - Infinite Universe's - No beginning - No end​

voidpotentialenergy

#### David-J-Franks

Is there any evidence to base these estimates on?
I got my figures from:
and:

#### voidpotentialenergy

I got my figures from:
and:
28 diameter and around 48 bubble.

IMO i don't see the universe as a separate entity from fluctuation, just a product so for me a measure of the big bang is just an expansion into what already exists.
foggy Bubble until it encounters other foggy bubbles.

How far away that is ?
Maybe (dark flow) has some good hints and the increase of our universe speed probably showing how close we are to them as our internal gravity now overwhelmed from other bubbles.

#### David-J-Franks

The FTL expansion at the start of the big bang makes this a very difficult prospect to define a size of our universe.
ftl=? speed.
The slower than L speed bubble probably 48+ billion light years.
I tend to think we can see almost all objects in our universe or at least the part of the big bang that wasn't expelled at ftl.
As relative speed increases to L speed things will start to vanish and that process probably already happening.

I personally don't believe our universe is everything so beyond our universe more of the same in different phases of expansion, contraction or universe size black hole waiting for a FTL collision .
quantum fluctuation, universe, quantum fluctuation, universe etc forever.
I personally don't believe our universe is everything so beyond our universe more of the same in different phases of expansion, contraction or universe size black hole waiting for a FTL collision .
quantum fluctuation, universe, quantum fluctuation, universe etc forever.
I agree, but why does it need a faster than light collision? I'm thinking as elements become more unstable as they get bigger, eg uranium, then maybe, as black holes get bigger, they also become more unstable. So it might only take a small collision to trigger a big bang! In my theory, I wrote it might only take one small black hole to collide with a universe size black hole. After-all black holes cant just keep getting bigger and bigger or there would be nothing left now except black holes. So one way or another, the matter has got to come back out sometime, probably, as you and I suggest, i.e. with a big bang.

The only other, also likely way, is for the matter to conglomerate from a mixture of merged and collided universes, and then collapse under its own gravity, before all the matter has been sucked into black holes - and then rebound immediately into a new universe! The only problem for me now is will all the matter in the merged universes have been sucked into lots of small black holes by the time these universes have expanded enough to merge? Or will there still be lots of stars and galaxies floating about?

'Steady State of The Infinite' theory
Infinite space - Infinite Universe's - No beginning - No end​

#### voidpotentialenergy

I agree, but why does it need a faster than light collision? I'm thinking as elements become more unstable as they get bigger, eg uranium, then maybe, as black holes get bigger, they also become more unstable. So it might only take a small collision to trigger a big bang! In my theory, I wrote it might only take one small black hole to collide with a universe size black hole. After-all black holes cant just keep getting bigger and bigger or there would be nothing left now except black holes. So one way or another, the matter has got to come back out sometime, probably, as you and I suggest, i.e. with a big bang.

The only other, also likely way, is for the matter to conglomerate from a mixture of merged and collided universes, and then collapse under its own gravity, before all the matter has been sucked into black holes - and then rebound immediately into a new universe! The only problem for me now is will all the matter in the merged universes have been sucked into lots of small black holes by the time these universes have expanded enough to merge? Or will there still be lots of stars and galaxies floating about?

'Steady State of The Infinite' theory
Infinite space - Infinite Universe's - No beginning - No end​
I think at the very start it was cannibal country with partial universes forming universes over extreme lengths of time.

That process could still happen in the universe of today but i think at some point an (e) balance is only going to allow a universe to have so much mass and energy before it isn't balanced.
That also could be a good reason for a big bang.

Getting into a black hole is a pretty easy process but getting that compression out is a different story.
I think since a black hole is a compression of time/activity the only real way to escape from that is to disturb that compression.
Only real way i see that happening is the collision of something that is a distortion of the rules in it's nature.
That FTL fits the bill.
Or a big bang could be just to much (e) in one region of space as it cannibalized to much (e).

For sure the universe has some mechanism to escape one or us thinking about it would be problematic

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