The Universe is not expanding, or at least . . .

[Derek Smith]

http://www.dailymail.co.uk/sciencetech/article-216...

I think I can see their point. If the ruler stetches then all measurements are wrong.

I never did like dark matter and dark energy. Mind you, I can't say I'm too pleased about time stopping.

[R300will]

So if you had a watch at the end of the universe when time finished and it was ticking, time hasn't stopped?

[davepoth]

Bedazzled said:

I think their theory is suggesting the universe is still expanding, but it is not accelerating. Good riddance dark energy, but "time is slowing down"... what does that even mean? Out of the frying pan into the fire!

They're sort of the same thing, if memory serves. As we travel closer to the speed of light, our frame of time slows relative to everything else. At the speed of light time would stop. However it's impossible to travel at the speed of light because mass becomes infinite, therefore the energy needed to accelerate to the speed of light becomes infinite. It's likely that time would tend towards stopping but never quite get there. Anyone in our frame of reference would not really see it except for galaxies moving away more quickly than they should.

I believe Einstein wins again.

[TheTurbonator]

The Universe is expanding, which is different than moving. The speed of light is only a constraint for objects that exist within space-time, not for space-time itself.

[davepoth]

TheTurbonator said:

The Universe is expanding, which is different than moving. The speed of light is only a constraint for objects that exist within space-time, not for space-time itself.

Are you sure? I don't think anyone else is...

[Gene Vincent]

This sort of thing comes about by many people, even those who should know better taking 'spacetime' as actually 'something' rather than an account or metric of all the stuff out there and its subtle and not so subtle interactions.

Terms like 'fabric of spacetime' and similar should be treated with the contempt they deserve when just bandied about by the general public, even 'spacetime' is now a corrupted term.

[Gene Vincent]

Max Planck dealt with this issue decades ago.

[Gene Vincent]

My meaning was the issue of units of time and length.

Dissection and its lack of finality is seemingly endless.

[jjones]

42

[davepoth]

jjones said:

42

/thread

[mildmannered]

Hi all, only occurred to me the other day that there is a conflict (in my mind) about the expansion of the universe. We are told the universe is infinite, yet how can something be infinite, yet expanding?

[R300will]

It's not, it's now believed to be football shaped and when you go to one edge of it you end up coming in from the opposite edge like one of those old gameboy games.

[TheTurbonator]

mildmannered said:

Hi all, only occurred to me the other day that there is a conflict (in my mind) about the expansion of the universe. We are told the universe is infinite, yet how can something be infinite, yet expanding?

We know it isn't infinite because of Olbers' paradox. If it was endless and never-ending, every line of sight when you looked up at the night sky from the Earth, would end on the surface of a (very bright) star. Thus meaning the dark sky wouldn't be dark at all but completely bright.

[mrmr96]

TheTurbonator said:

mildmannered said:

Hi all, only occurred to me the other day that there is a conflict (in my mind) about the expansion of the universe. We are told the universe is infinite, yet how can something be infinite, yet expanding?

We know it isn't infinite because of Olbers' paradox. If it was endless and never-ending, every line of sight when you looked up at the night sky from the Earth, would end on the surface of a (very bright) star. Thus meaning the dark sky wouldn't be dark at all but completely bright.

But since light travels at a finite speed, and the universe is a finite age, we'll only be receiving light from a finite distance away from Earth.

[Gene Vincent]

This stems from a problem, the problem is nomenclature, the names we give to things and then misuse.

The Cosmos is finite, we don't know exactly its full extent, but we have a pretty good handle on it, sufficient to be certain it is indeed finite but growing. The Cosmos is everything that falls into having an appreciable existence.

The Universe is a another word which has a different meaning. The Universe is infinite, it has to be if you think about it.

We exist within the Cosmos, the Cosmos exists within the Universe.

Look into the night sky and you don't see the Universe, you see the twinkling lights of the Cosmos.

Hubble doesn't explore the limits of the Universe, it looks deep into the Cosmos.

That is why the discipline is called Cosmology not something else using the term universe.

Humans put names to things with good intentions, we do it to everything we encounter and we know that fire has a name and it's useful and understood, other things we name are not actually encountered in the real sense and it is those names that can take on a life of their own.

Physics is full of such nouns and even the most conscientious of speakers will use the shorthand words and not realise that although he knows what he means some of his audience won't and take with them their own meaning away with them.

Hope that helps.

[mrmr96]

Gene Vincent said:

The Universe is a another word which has a different meaning. The Universe is infinite, it has to be if you think about it.

Why does it?

[Gene Vincent]

mrmr96 said:

Gene Vincent said:

The Universe is a another word which has a different meaning. The Universe is infinite, it has to be if you think about it.

Why does it?

You really have to come to this through your own thought processes, some can and some can't. I am always reluctant to guide someone in this matter, it is fraught with problems.

For instance the Universe was available before the BB and our Cosmos although it may not have been present in terms we readily accommodate.

[R300will]

mrmr96 said:

Gene Vincent said:

The Universe is a another word which has a different meaning. The Universe is infinite, it has to be if you think about it.

Why does it?

Because you cannot leave it. So when you get to the edge you end up coming back in on the opposite side like an old gameboy game. Morgan Freeman did a programme on discovery about it i think. Presenting the latest answers to questions like that and what the current thinking is. It was pretty amazing tbh, there was proof of negative energy, 6th sense (i.e. when you get a feeling someone is watching you) there is actually something to it etc.

[mrmr96]

Gene Vincent said:

mrmr96 said:

Gene Vincent said:

The Universe is a another word which has a different meaning. The Universe is infinite, it has to be if you think about it.

Why does it?

You really have to come to this through your own thought processes, some can and some can't. I am always reluctant to guide someone in this matter, it is fraught with problems.

For instance the Universe was available before the BB and our Cosmos although it may not have been present in terms we readily accommodate.

Are you making me out to be a weak thinker, because you can't or won't attempt to explain?

[Gene Vincent]

mrmr96 said:

Gene Vincent said:

mrmr96 said:

Gene Vincent said:

The Universe is a another word which has a different meaning. The Universe is infinite, it has to be if you think about it.

Why does it?

You really have to come to this through your own thought processes, some can and some can't. I am always reluctant to guide someone in this matter, it is fraught with problems.

For instance the Universe was available before the BB and our Cosmos although it may not have been present in terms we readily accommodate.

Are you making me out to be a weak thinker, because you can't or won't attempt to explain?

Not at all!?!?

It is best achieved by your own path, language is a poor cousin to maths, and never more so than the conceptual jump to understanding that in the Cosmos that there has never been a time of there being nothing, there is no true '0' within the Cosmos but there is and was in the Universe and that nothing actually proved to be both nothing and quite possibly the driving force in the very existence of the Cosmos.

Do you see what I mean now about the inadequacy of any written language that uses words?

The written Maths work, the language to explain it outside of Maths is so clumsy and almost impossible to convey adequately.

It is not your failing, it is mine, I can't frame the words well enough to do it in less than a few thousand words.