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Physics, Astronomy & Cosmology / Re: Is all motion relative?

« on: 20/02/2019 14:36:37 »

That's a misconception of quantum waves. A wave is merely a probability description of where a particle is. E.g. when an electron is detected it has no spatial extent. Any spatial extent is merely the probability of where it would be found had its position been measured. All particles are point particles with the exception of particles made up of quarks.

Can that be rephrased as that the electron has a spatial extent (before measuring or interacting) that  may be any size but that it is most probably vanishingly small? (I am assuming that the probability graph of its position peaks  at the centre of that undefined spatial extent area)

I am not sure if I have not  written gobble-de-gook 

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Physics, Astronomy & Cosmology / Re: Is all motion relative?

« on: 18/02/2019 01:21:46 »

If an object is accelerating it must surely be a composite object.

Not at all. It could be a particle such as an electron which is not a composite object but a point object.

This is a confusing area for me. An electron would require an environment to "accelerate" though wouldn't it ?It could not accelerate under its own steam ,as it were.(unlike a composite object,perhaps)

I think Bill (in the OP) was proposing an object that was alone in the universe undergoing acceleration.

If there were only two electrons in the universe (shortly to become one ,if I understood correctly)  would those two electrons repel one another? That would seem like acceleration  to me...Would the acceleration be ongoing ?

Would the acceleration be inversely proportionate to separation and so taper off to zero eventually? (there would be no gravity presumably if there were no gravitons in the universe     )

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Physics, Astronomy & Cosmology / Re: Is all motion relative?

« on: 17/02/2019 23:10:40 »

If an object is accelerating it must surely be a composite object. So  there will always be relative motion  between the components of the accelerated object.

Even if the original companion (against which relative motion was measured) has magically disappeared  the acceleration will create new "companions" as elements of the now accelerating object.

Also the accelerating object (in the "empty" universe)  will, I suppose  be composed of elements whose relative momentums (correct term?) will add up to zero.

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Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 29/01/2019 11:42:16 »

One can always point out that we don't have a golden standard for what would be 'lowest energy state/time rate', unless? That's actually interesting

will have to think about that one.

That as we do define energy states in physics. Also 'lowest energy states', as defined by HUP. Then one just have to decide how one would like to define that in form of 'clocks', globally so or locally defined. Locally defined proper time is invariant, globally defined using this idea of energy states/'clocks' we have to redefine physics as 'clocks' now become 'discrete', as well as 'variant'. Which of course must include 'c' no longer being a constant as it can have different energy states.

Would you be happy with "  Objective "time" is descriptive of physical processes and is not a "thing" as such"?

If those physical processes are fundamentally discrete  then so will "time" be.

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Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 26/01/2019 03:22:51 »

understand that time passes in exactly the same way  everywhere. What you are probably referring to is the observed (and predicted) result that the rate of time as observed  from another moving frame of reference depends on the relative rate of motion between the two frames.

You got me a little confused. So for example, if you synchronize 2 atomic clocks, leave one on the ground and send the other in the space shuttle, when it comes back from space will the 2 clocks show the same time?

No,certainly not.

I was just attempting to address what may be a popular misconception that time will appear to go slow if one accelerates  to a relativistic speed.

(I am not sure whether it is possible to "slow time" if one uses acceleration or extreme gravitation but I do not think it is either.)

The (real) slowing of time only occurs from the perspective of another moving frame of reference and never from  one's own frame of reference.

Hope that was clear (I am not very skilled in the subject and well prepared to be contradicted by others if necessary)

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Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 25/01/2019 15:04:05 »

If this were not the case, wouldn’t we need some sort of “absolute measure” of time that was independent of all RFs?

Not sure .

(I have really had any problem with infinity as a mathematical process and never a number .Not that I am versed with all the "bigger/smaller  infinities" concepts whose validity I have no competence  to question. Nor can I comment on the meanings of infinities appearing in formulas  and what it is that that indicates; I understand there is also  a process called "renormalization" in quantum physics but I know nothing about that )

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Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 25/01/2019 10:58:28 »

Since Einstein said time is relative, we know it doesn’t flow evenly everywhere. When a minute passes here, 2 minutes, 30 seconds or any amount of time could have passed somewhere else, even 0. Although it may be difficult to imagine exactly how that happens it isn’t hard to understand the concept.

I understand that time passes in exactly the same way  everywhere. What you are probably referring to is the observed (and predicted) result that the rate of time as observed  from another moving frame of reference depends on the relative rate of motion between the two frames.

In each individual  frame the normal description (inadequate but perhaps helpful) is that time ticks at one second per second

Unless I have misunderstood and you were aware of (and accounting for) that.

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Physics, Astronomy & Cosmology / Re: Is there a zero sum energy theory of the universe?

« on: 21/01/2019 02:15:43 »

If the universe did not have an origin and was always there then at some point in the past entropy would have changed from a negative to a positive value. Meaning that entropy started with a value of negative infinity. This is an untenable position.

I wish I understood that (not meaning that  I dispute it;just that entropy is difficult for me to understand despite my various attempts).

If you are right  that would seem to be a very interesting finding (I have of late been predisposed to the "beginning" of the universe being infinitely long  and so would welcome this being shown to being erroneous)

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Physics, Astronomy & Cosmology / Re: Is there a zero sum energy theory of the universe?

« on: 20/01/2019 14:17:55 »

Is it possible that the sum total of energy at the/an "outset" could have been  actually zero?
I think the question is if a nonzero value makes any kind of sense.

I suppose so.

 Could  there be any possible relationship between the  extremely asymmetric matter/antimatter split which has been observed  and any possible non zero sum total of energy?

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Physics, Astronomy & Cosmology / Is there a zero sum energy theory of the universe?

« on: 20/01/2019 12:46:35 »

I have heard(and wondered)  as much. Can anyone put any flesh on the bone?

If the sum total (at the "outset" or at least some starting point presumably) is/was different from zero  could that be assessed in any way ?

What consequences might follow?

Could it have any bearing on any possible size to the entire (ie not just directly observable) universe?

Or on the rate of expansion?

Is it possible that the sum total of energy at the/an "outset" could have been  actually zero?

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Physics, Astronomy & Cosmology / Re: How fundamental is time?

« on: 12/01/2019 12:36:11 »

time separates events

Are there any scenarios where such separations do not exist? Even one example?

If not can we say that the separation is measured (not caused -which you are probably not saying) by time ?

Ad do some of us need to keep reminding  ourselves that time is not a "thing" ,more a description?

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Physics, Astronomy & Cosmology / Re: Does time stand still in the quantum world?

« on: 09/01/2019 15:36:14 »

If time is reversed would not cause and effect be reversed as well so that "locally there would be no difference?

I think there was recent speculation that there might have been 2 universes created at the outset  with time being reversed one vis a vis the other.

Would cause and effect not have operated just the same in either universe and would not time appear to be reversed simply from the perspective of the other universe?

Locally time ,cause and effect would operate the same (only possible) way.

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Physics, Astronomy & Cosmology / Re: Does time stand still in the quantum world?

« on: 06/01/2019 14:06:43 »

 I had to drop out of this thread as it became too advanced for me but does the preceding post put the matter of any posited reversibility of time to bed.?

If the existing universe cannot proceed along those lines is that all there is to say ? (except that there may be sub arenas where it remains possible.)

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Physics, Astronomy & Cosmology / Re: Does time stand still in the quantum world?

« on: 04/01/2019 03:14:33 »

If anyone has used a stopwatch they are aware of time as a measurement of change.

I can only speak for myself  but I  personally seem to feel a need to "anthroposize" time or more accurately to give it its own elemental existence (the Greeks certainly did this with their Chronos).

Naturally I assume that the "general population" shares my (outdated) instincts  and so might only  appreciate that a stopwatch only measured change if it was first suggested to them.

Perhaps ,even then they might only agree to that  in a lip-service kind of way and hold onto the notion that indeed "time is passing" as if it was a "thing" ...or maybe they would cop on more quickly than myself whom I admit to be a snail like learner at best.

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Physics, Astronomy & Cosmology / When does a Black Hole form?

« on: 03/01/2019 23:42:54 »

I understand  Black Holes come in different sizes.

Is there something they all have in common that  allows one to predict the tipping point when they form?

Are  they are all composed of the same kind of matter?

Do they all have it in common that light can never escape except by Hawking radiation?(if I have that right) 

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Physics, Astronomy & Cosmology / Re: Does time stand still in the quantum world?

« on: 03/01/2019 22:00:00 »

I like a good debate but the concept of time seems to be flogged to death for no reason. It is simply a mechanical means of measurement of change in one form or another. The fact that those mechanics don't always run at the same pace in different frames is not that difficult.

Yes,a fair point.

On the other hand "time" has always (I imagine) been a focal point of humanity's  thoughts....until ,amazingly we are introduced to time dilation and  the non existence of absolute time.

Small wonder we are ,on an individual basis trying to keep up with the new normal  some 100 years later.

And how many of the general public are even dimly aware what special and general relativity have meant for our understanding of what can be called the "timing as a measure of change" mechanism?

Would they care ? Would they "believe"?

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Physics, Astronomy & Cosmology / Re: Does acceleration (also) curve spacetime?

« on: 03/01/2019 18:01:01 »

Earth already has an event horizon in all directions due to the acceleration of spatial expansion.  That horizon would not exist were space to be expanding at a constant rate, or a slowing rate.  Were Earth to begin permanently accelerating at some rate in any one direction, it would change the location of the current event horizon.  1G of acceleration would put that horizon only a little more than a light-year away.

The horizon is about 15 billion light years away, not far outside the Hubble sphere.  That means that light from stars that are current receding at a little more than light speed will still get here eventually, but light from stars much more distant than that will never get here in any amount of time, assuming the expansion rate continues its current acceleration.

Thanks,I feel a bit more  comfortable with these ideas now.

The accelerated expansion everyone talks about is  different from everything accelerating away from everything else is it?

Maybe it is not yet understood why it happens-just that it does happen....?

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Physics, Astronomy & Cosmology / Re: Does acceleration (also) curve spacetime?

« on: 03/01/2019 15:52:13 »

Red shifted, yes.  If the observer was accelerating enough and the emitter was far enough in the rear, the rear part of the ship would not be able to keep up even given any amount of acceleration.  If the rear can keep up, the light emitted from there will reach the front.

Are you saying that if there was light coming from a distant enough star and this star was accelerating away by even only a small amount that that star would be forever invisible to an observer on the earth?

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Physics, Astronomy & Cosmology / Re: Does acceleration (also) curve spacetime?

« on: 03/01/2019 15:40:02 »

If there was a light emitter at the rear of the accelerating spacecraft and the observer was at the front (in the direction of acceleration) what effect would that have on the  way that the observer perceived the light coming from the emitter?

Just red shifted?

The observer can never accelerate to such an extent that the light never reaches him can he?

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Physics, Astronomy & Cosmology / Does acceleration (also) curve spacetime?

« on: 03/01/2019 14:11:24 »

So ,if we are in a spacecraft  that was accelerating at any particular moment and an observer on it attempted to make sense of what he or she was seeing ,would the curved spacetime model  give a correct interpretation of the data he or she was processing?

Is the difference between acceleration-caused spacetime curvature and that caused by gravity only really apparent for phenomena such as tidal effects?