Does time exist?

[Michael 345]

Those two particles are gravitationally attracted to each other.

sweetpea said

In this ''devoid empty space '', empty except for two points moving relative to each other, and later these points become stationary relative to each other, would there then be no time?

to which you replied as above.

HOWEVER sweetpea had given that question in response to a question from river which was

river

If I have a devoid empty space , how does one measure time ?

You should not answer any question with another question especially if your question changes (by adding two moving points) the parameters.

Even adding one point cancels the devoid empty space.

I would contend that the space beyond the outer limit of the light streaming away from our Universe may well be moving into a devoid empty space.

Choices for questions are

1. Answer as asked
2. Reply with a question
3. Make some sort of remark nothing to do with the question
4. Ignore

1. should be the preferred option.

Mr Humpty

 

[DaveC426913]

You should not answer any question with another question especially if your question changes (by adding two moving points) the parameters.

Correct. My initial answer was 'your thought experiment is invalid since it can only describe something nto of our universe'.

I would contend that the space beyond the outer limit of the light streaming away from our Universe may well be moving into a devoid empty space.

You would be wrong. You should read up on the Big Bang Theory, especially the part where it is described not as an expansion in space but and expansion of space. There is no "beyond" the universe.

 

[Michael 345]

You would be wrong. You should read up on the Big Bang Theory, especially the part where it is described not as an expansion in space but and expansion of space. There is no "beyond" the universe.

Will agree to the space within the Universe being the expansion of space.

May I ask what you think lies outside/beyond the longest tip of the light beam which left the furthest star at the edge of our Universe?

My answer would be devoid empty space until you reach one of the postulated other universes which may exist.

Spaced out (no not that) tired Humpty Zzzz

 

[DaveC426913]

May I ask what you think lies outside/beyond the longest tip of the light beam which left the furthest star at the edge of our Universe?

There is no such place.
The universe does not have an edge or boundary. It is finite yet unbounded.
There is no place light has not reached because all points in the universe were once the centre of the universe - and still are.

Some light reading:
http://math.ucr.edu/home/baez/physics/Relativity/GR/centre.html

 

[Michael 345]

There is no such place.
The universe does not have an edge or boundary. It is finite yet unbounded.
There is no place light has not reached because all points in the universe were once the centre of the universe - and still are.

Some light reading:
http://math.ucr.edu/home/baez/physics/Relativity/GR/centre.html

In 1929 Edwin Hubble announced that he had measured the speed of galaxies at different distances from us, and had discovered that the farther they were, the faster they were receding.

This part of your link I take to be indicating the furthest away galaxies are moving into an empty void as a result of the Big Bang which being a total void is offering no resistance.

space can be curved without there being any other dimensions "outside"

I would consider other dimensions "outside" as stupid. Remember my thought pattern tells me outside is a total void.

That all changes, of course, when our galaxy intrudes. The part of the total void which is intruded on becomes part of our galaxy and participates in our galaxy expansion.

There are other points in your link but need to do other things at the moment

Humpty Dumpty

 

[sweetpea]

Those two particles are gravitationally attracted to each other.

Trust you to bring physics into this, see below.

My view would be that a devoid empty space would have no movement (nothing to move) hence no change hence when the concept of time relies on change no time.

But that view supposes an existing ''devoid empty space'' whether there are particles present or not. Existence= duration.

My view may be... you need an existing space to have a particle/particles and movment. For particles to interact (say gravitationally), they and their fields must exist in the first place, i.e. they exist in an existing spacetime. But, to go the whole hog...To make sense of any of it, I may say...space,time, energy and mass started all together. So I may be agreeing with Paddo.

 

[Confused2]

'People' don't seem able to see the difference between 'change' and 'rate of change'. 'change' is (obviously) the change. 'rate of change' is how quickly the change takes place. If something moves (say) 10 feet in 10 years the 'rate of change' is 'change'/time.
10 feet/10 years = 1 foot per year.
If 0 change over 10 years
0 feet/10 years = 0 feet per year.
What seems to happen next is that 'people' are saying
IF 0/10=0 THEN 10=0 which is clearly a false conclusion.

 

[DaveC426913]

This part of your link I take to be indicating the furthest away galaxies are moving into an empty void as a result of the Big Bang

They are not.

The expanding balloon analogy will be helpful here. If the galaxies are glued to the 2-dimensional surface of the a balloon, they will all expand away from each other yet
- no galaxy can claim to be at the centre (they all were, early in the balloon's expansion)
- no galaxy can claim to be at the edge, and most significantly:
- there is no area of the balloon that is (or ever was) devoid of galaxies.

This 2D analogy can be extrapolated to our 3D universe.

And before you mention it, yes the balloon has a centre in 3 dimensions. That is where the analogy fails. It does not imply there is a 4th spatial dimension in our universe. The geometry of a finite unbounded 3D universe works without having to invoke a 4th dimension for it to wrap around.

 

[Michael 345]

But that view supposes an existing ''devoid empty space'' whether there are particles present or not. Existence= duration.

Got it.

Your saying you can't have a devoid empty space.

DaveC I think says much the same I think (emphasis) when in answer to my question

"May I ask what you think lies outside/beyond the longest tip of the light beam which left the furthest star at the edge of our Universe?"

he gives

"There is no such place.
The universe does not have an edge or boundary. It is finite yet unbounded.
There is no place light has not reached because all points in the universe were once the centre of the universe - and still are."

Ignoring the minor point the early Universe did not have light I contend YES the Universe is finite BUT unbounded puts it in the category of something expanding its boarders.

What is it expanding its boarders into I hear you ask.

Why the "... no such place" of DaveC which I have noted elsewhere in the thread is the aforementioned devoid empty space (I go more for Absolute Total Void). Devoid empty space gives redundancy.

Out there absolutely nothing until you arrive at another Universe which have been postulated.

When our galaxy intrudes into the Absolute Total Void that which is intruded into

1. Becomes part of our galaxy and
2. Participates in our galaxy expansion and
3. Becomes subject to our laws of physics

I also put Absolute Total Void in the basket of being Infinite (BIG VERY VERY BIG INFINITELY BIG )

Seems DaveC replied to another of my post just before I posted this post (we are unintentionally posting over each other )

Humpty Dumpty will drop off for a while, collect his thoughts which are all over the place, and get back later.

(Does a smart about face
exits into the void of
General Ignorance
throwing a snapy salute to the General
only getting a scowl back)

Upset Humpty Poe

 

[paddoboy]

From an early post on page 1 before this thread was revived.........

Ten Things Everyone Should Know About Time:
By Sean Carroll
1. Time exists.
2. The past and future are equally real.
3. Everyone experiences time differently.
4. You live in the past.
5. Your memory isn’t as good as you think.
6. Consciousness depends on manipulating time.
7. Disorder increases as time passes.
8. Complexity comes and goes.
9. Aging can be reversed.
10. A lifespan is a billion heartbeats.

Some important extracts from Carroll's extended explanations:
[1]The real question is whether or not time is fundamental, or perhaps emergent. We used to think that “temperature” was a basic category of nature, but now we know it emerges from the motion of atoms. When it comes to whether time is fundamental, the answer is: nobody knows. My bet is “yes,” but we’ll need to understand quantum gravity much better before we can say for sure.

[9] Reversing the arrow of time for living organisms is a technological challenge, not a physical impossibility. And we’re making progress on a few fronts: stem cells,yeast, and even (with caveats) mice and human muscle tissue. As one biologist told me: “You and I won’t live forever. But as for our grandkids, I’m not placing any bets.”

[10] about one and a half billion, if you simply must be precise. In that very real sense, all animal species experience “the same amount of time.” At least, until we master #9 and become immortal.
http://blogs.discovermagazine.com/c...everyone-should-know-about-time/#.VgiJmeyqqkp

 

[paddoboy]

DaveC I think says much the same I think (emphasis) when in answer to my question

"May I ask what you think lies outside/beyond the longest tip of the light beam which left the furthest star at the edge of our Universe?"

he gives

"There is no such place.
The universe does not have an edge or boundary. It is finite yet unbounded.
There is no place light has not reached because all points in the universe were once the centre of the universe - and still are."

Dave is correct: The BB was the evolution of space and time [henceforth known as spacetime] Matter came later:
In that respect, the BB can be seen to have happened everywhere at the same time, since everywhere was confined to the Singularity from which the BB/spacetime arose.
Also as analogous to a globe, say the Earth, the Universe can be seen not to have any edges or center, remembering that the surface of that globe/Earth, represents the 4 dimensional aspect of spacetime.
Also according to the BB, our space time is all there is, so as apparently counter-intuitive as it may seem, asking what the universe is expanding into is an invalid question.....the Universe isn't expanding into anything. By definition, the Universe is all that exists and contains everything.

Since of course all our knowledge and theories including GR break down at the BB singularity, and BH singularities, scientists sometimes speculate as to what may or may not be at these extremeties. But that is all it is...speculation as enthralling as it is to think about these things.

 

[paddoboy]

It is finite yet unbounded.

We do not yet know with any certainty whether the universe is finite or infinite.
Our observable universe is approximately 95 billion L/years in diameter, and that probably is just the tip of the iceberg.
This figure of course is a result of the finite speed of light, "c"
I like using the term that the universe is "near infinite" in extent, although that has upset some language purists in the past.

Some interesting answers here with regards to that.......
http://physics.stackexchange.com/questions/9419/how-can-something-finite-become-infinite

 

[Michael 345]

Time had its beginning at the BB 13.87 billion years ago, and it is and always will keep moving foward, even in the unlikely event of the universe collapsing back on itself, at least up to the stage that existed before the BB banged.

From book "The Invention of Space and Time" page 157, (c) The beginning of the Universe, paragraph 5.

But the physical non-existence of time abolishes the idea of the beginning of time, and the mist of time, and the end of time, all of which have become outdated metaphors. The hypothesis of time zero self-distructs, as the Big Bang would have been preceded by quantum fluctuations, which permit one to define a concept of time: a fluctuating time before the alleged time zero.

Now there's a thought Time before Time.

Humpty Dumpty out of time

 

[Xelasnave.1947]

We do not yet know with any certainty whether the universe is finite or infinite.

If we can say that what we started with was finite then it would seem that no matter how big the Universe may be it must remain finite.
It is my understanding that we can not multiply finite to infinite.

If we started with an infinite singularity it would still be expanding from its original point and will do so forever. Like one of those fizzy tablets in water if infinite it must fizz for ever.

Alex

 

[Michael 345]

If we can say that what we started with was finite then it would seem that no matter how big the Universe may be it must remain finite.
It is my understanding that we can not multiply finite to infinite.

If we started with an infinite singularity it would still be expanding from its original point and will do so forever. Like one of those fizzy tablets in water if infinite it must fizz for ever.

Alex

Have no problem with the Universe being finite and remaining finite no matter how much it expands.

It just becomes a bigger finite with no chance to become infinite.

However the Total Infinite Void the Universe is expanding into is INFINITY.

From Humpty Dumpty at The Egg of Infinity

 

[Xelasnave.1947]

However the Total Infinite Void the Universe is expanding into is INFINITY.

I don't think we expand into anything... The universe is everything so if there is something we expand into it is indeed part of the universe.
Irrespective of the universe being infinite or finite there apparently is no outside and if there is it is on the inside.
Alex

 

[Michael 345]

I don't think we expand into anything... The universe is everything so if there is something we expand into it is indeed part of the universe.
Irrespective of the universe being infinite or finite there apparently is no outside and if there is it is on the inside.
Alex

Agree we don't expand into anything.

We expand into nothing.

Unless you are going to claim what I call the Total Infinite Void as part of our Universe OK.

Personally I am only claiming the bit we actually move into.

Remember there may be other Universes out there doing their own expansion and claiming their own bit of the Total Infinite Void.

Glad to see there is no equivacation in the last paragraph.

Humpty Dumpty not void of ideas

 

[sweetpea]

Got it.

Your saying you can't have a devoid empty space.

Michael...Dave's point about you cannot have a devoid empty space is not the point I'm making, I agree with Dave.

What I'm trying to say is... To have any kind of space at all, be it devoid or full, means you are assuming that a space is existing in the first place, and that word existing means you have time/duration. Which makes no sense if your view/assertion is that you need movement for there to be time.
I think, in the metric expansion of space, you assume an existing space which expands.
It all started together space,time, energy, mass, rock and roll. (I think).
Clint said..A man's got to know his limitations. Well, a particle, moving or not, has got to be in a space.

 

[paddoboy]

From book "The Invention of Space and Time" page 157, (c) The beginning of the Universe, paragraph 5.

But the physical non-existence of time abolishes the idea of the beginning of time, and the mist of time, and the end of time, all of which have become outdated metaphors. The hypothesis of time zero self-distructs, as the Big Bang would have been preceded by quantum fluctuations, which permit one to define a concept of time: a fluctuating time before the alleged time zero.

Now there's a thought Time before Time.

Humpty Dumpty out of time

Yes, that's OK if one chooses to speculate [nothing wrong with that] but the problem is that our laws of physics and GR fail at t+10-43 seconds, so anything from that point backwards is speculative.
In effect I would say the correct thing to say is that the BB was the evolution of space and time, "as we know them"

If we can say that what we started with was finite then it would seem that no matter how big the Universe may be it must remain finite.
It is my understanding that we can not multiply finite to infinite.

If we started with an infinite singularity it would still be expanding from its original point and will do so forever. Like one of those fizzy tablets in water if infinite it must fizz for ever.

Alex

http://www.astro.ucla.edu/~wright/infpoint.html

It all started together space,time, energy, mass, rock and roll. (I think).
Clint said..A man's got to know his limitations. Well, a particle, moving or not, has got to be in a space.

Elvis, Chuck, Bill and Buddy plus rock n roll were definitely not around at the BB!
Matter/mass came into existence a short time after space and time came into existence. At the Instant of the BB, we think that the four known forces were actually one "Superforce": As pressures dropped with the expanding spacetime, the "Superforce" started to decouple.
This created false vacuums and phase transitions, and the excesses of energy went into becoming our first fundamentals.
We are talking within the first second post BB.
https://www.cfa.harvard.edu/~ejchaisson/cosmic_evolution/docs/fr_1/fr_1_part5.html

 

[sweetpea]

In effect I would say the correct thing to say is that the BB was the evolution of space and time, "as we know them"

Something like ... A definable spacetime geometry became possible at the end of the Planck era.
Paddo, just asking ,did you make sense of my last post? For me it was hard trying to think how to make the point about space existing.?? And that how using the word existing implies time/duration. That's time without moving particles??
Just checking I got that point across, you don't have to agree with it of course.