Relativity?

How does science work? And what's all this about quantum mechanics?

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uwot
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Re: Relativity?

Post by uwot » Thu Oct 12, 2017 12:44 pm

surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Photons or any massless particles are timeless because nothing travelling at the speed of light is actually capable of experiencing time
It's actually a good deal simpler than that. The only thing that something travelling at the speed of light could experience, is a collision. Nothing is going to catch it up to affect it.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Saying a clock experiences time simply means it can measure time. It does not mean it is a conscious being capable of sensory experience
And it would stop when travelling at the speed of light because it could not experience or measure time as time itself would have stopped
'Time' doesn't stop; interactions, other than collisions with objects that cross your path, do.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
The closer a clock gets to the speed of light the faster time goes...
Slower...
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
...but at the speed of light itself time stops for any object of mass. Since clocks
are objects of mass then this would apply to them too.
OK. Assume that the speed of light really is as fast as anything can go. Suppose you have a grandfather clock travelling at c. If, in the simplest example, the pendulum is swinging in the plane of movement, it could swing backwards, but to swing in the direction of motion, it would have to exceed the speed of light; in which case, you have to abandon the premise that c really is the speed limit.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Though they would no longer be clocks at that point as the atoms that they were made
from and more specifically their electrons would become too unstable for them to retain their solidity and they would just disintegrate instead
Well, yes and no. If the clocks i.e. every atom they are made of, are travelling at the speed of light, there can be no interaction between them. The chances of them establishing exactly the same relations, when they drop to sub-c, are vanishingly small.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Anything that travels at the speed of light such as a photon does not experience time. But any observer could actually measure its speed in time
Only relative to their own inertial frame, but odds of that frame being at absolute rest are not significantly greater than zero.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
So a human being travelling at the speed of light between two planets would literally arrive in no time at all no matter what the actual distance was. Only an observer watching that human being would be able to measure the time taken since to them it would not have taken no time at all
but a finite amount of time measured from their particular frame of reference. And so long as they were not travelling at the speed of light also
In which case, the information would never reach them.

Walker
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Re: Relativity?

Post by Walker » Thu Oct 12, 2017 1:18 pm

Impenitent wrote:
Thu Oct 12, 2017 10:53 am
can sentience be shown to exist at the sub atomic level?

if not is the question moot?

-Imp
Infinite energy would be required to propel a thing to warp factor 1, the speed of light.

What happens at warp factor 9, since infinite mass and density has already been achieved?

surreptitious57
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Re: Relativity?

Post by surreptitious57 » Thu Oct 12, 2017 2:21 pm

ken wrote:
surreptitious57 wrote:
The clock would stop because any thing travelling at the speed of light cannot experience time which is why
photons or any massless particles are timeless otherwise they would not be able to travel as fast as they can
So how long does it take a photon or a clock or a human being or a ufo to travel the distance of 3 light years
A photon will take no time at all for it does not experience time while the others can only travel
below the speed of light but I cannot be more specific than that as their speeds will be arbitrary

davidm
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Re: Relativity?

Post by davidm » Thu Oct 12, 2017 4:59 pm

uwot wrote:
Thu Oct 12, 2017 10:48 am
ken wrote:
Thu Oct 12, 2017 10:22 am
Clocks do NOT experience time so that is NOT why a clock would stop at the speed of light.
A clock would NOT stop, travelling at the speed of light, just like a human being would NOT stop ageing travelling at the speed of light.
What you have to realise, is the role that photons play in making things happen. At the atomic level, the most important thing that happens is that a photon passes from one atom to another. In simple terms, imagine two atoms next to each other. If they are 'stationary', then a photon can take the shortest path between them and the 'event' happens in the quickest possible 'time'. If, however, the two atoms are moving together in a parallel course, then in order for a photon to pass from one atom to another, it has to take a longer path to where the atom will be when the photon arrives. So the event takes longer to happen. If, for the sake of argument, the two atoms could travel at the speed of light, then the event will never happen, because the photon is going flat out, just keeping up. While all that's going on, the Earth will still be spinning and going round the Sun, and in that sense, time will still be passing, but for the atoms, nothing happens. That is true whether it's two atoms, or two gazillion. So if you could travel at the speed of light, while days and years would still be passing on Earth, nothing at all would happen to you, and as far as you would be concerned, no time would pass.
The above is absolutely correct, of course, but it’s worth stressing why, exactly, this is so. One might be tempted to suppose that the photon adds the velocity of the atoms to its own speed, and if it did, this light clock would still be ticking in synchrony with a “stationary” light clock.

But it doesn’t! Light speed is invariant and will not adhere to the law of addition of velocities. So in the case of the moving atoms, it will take longer (as judged from the perspective of a “stationary” observer) for the moving photon to oscillate between the moving atoms, than it does for the stationary observer’s own light clock to tick off a given unit of time. This is time dilation — the literal slowing down of time.

See here.

One sees that for the rider in motion relative to the “stationary” observer, the photon makes one round trip (as judged from the ground frame) for every three round trips in the ground frame. If a round trip in this case is defined as one second, it follows that three seconds have passed in the ground frame for every one second in the moving frame.


uwot
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Re: Relativity?

Post by uwot » Thu Oct 12, 2017 5:38 pm

davidm wrote:
Thu Oct 12, 2017 4:59 pm
See here.
Or here: http://willijbouwman.blogspot.co.uk
I think I have it covered.

davidm
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Joined: Sat May 27, 2017 7:30 pm

Re: Relativity?

Post by davidm » Thu Oct 12, 2017 5:46 pm

uwot wrote:
Thu Oct 12, 2017 5:38 pm
davidm wrote:
Thu Oct 12, 2017 4:59 pm
See here.
Or here: http://willijbouwman.blogspot.co.uk
I think I have it covered.
I'm sure you do; I still have to make time to read your work. :)

davidm
Posts: 723
Joined: Sat May 27, 2017 7:30 pm

Re: Relativity?

Post by davidm » Thu Oct 12, 2017 6:16 pm

ken wrote:
Thu Oct 12, 2017 10:30 am
thedoc wrote:
Thu Oct 12, 2017 5:22 am
davidm wrote:
Thu Oct 12, 2017 12:34 am
Yes, if it turns into another train wreck like the evolution thread. :)
Too late.
Why does it appear to late, to you?
Maybe because of your post time stamped Thu Oct 12, 2017 5:22 am

thedoc
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Re: Relativity?

Post by thedoc » Fri Oct 13, 2017 3:42 am

Or it could already be on it's way to becoming a train wreck like the evolution thread, just waiting for some creationist to chime in with "It's only a theory".

Walker
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Joined: Thu Nov 05, 2015 12:00 am

Re: Relativity?

Post by Walker » Fri Oct 13, 2017 4:11 am

thedoc wrote:
Fri Oct 13, 2017 3:42 am
Or it could already be on it's way to becoming a train wreck like the evolution thread, just waiting for some creationist to chime in with "It's only a theory".
If that's all it took, it wasn't much.

ken
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Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

Post by ken » Fri Oct 13, 2017 4:17 am

uwot wrote:
Thu Oct 12, 2017 10:48 am
ken wrote:
Thu Oct 12, 2017 10:22 am
Clocks do NOT experience time so that is NOT why a clock would stop at the speed of light.
A clock would NOT stop, travelling at the speed of light, just like a human being would NOT stop ageing travelling at the speed of light.
What you have to realise, is the role that photons play in making things happen.
What role does photon play in making things happen.

At the atomic level, the most important thing that happens is that a photon passes from one atom to another.

Why is that the most important thing that happens?
uwot wrote:
Thu Oct 12, 2017 10:48 am
In simple terms, imagine two atoms next to each other. If they are 'stationary', then a photon can take the shortest path between them and the 'event' happens in the quickest possible 'time'. If, however, the two atoms are moving together in a parallel course, then in order for a photon to pass from one atom to another, it has to take a longer path to where the atom will be when the photon arrives. So the event takes longer to happen. If, for the sake of argument, the two atoms could travel at the speed of light, then the event will never happen, because the photon is going flat out, just keeping up.
That that photon would not catch up I agree with, but what event are you talking that would supposedly never happen?
uwot wrote:
Thu Oct 12, 2017 10:48 am
While all that's going on, the Earth will still be spinning and going round the Sun, and in that sense, time will still be passing, but for the atoms, nothing happens.
What do you mean for the atoms nothing happens?

The atoms are still travelling between objects at the speed of light, so that is what is happening, is this wrong?
uwot wrote:
Thu Oct 12, 2017 10:48 am
That is true whether it's two atoms, or two gazillion. So if you could travel at the speed of light, while days and years would still be passing on Earth, nothing at all would happen to you, and as far as you would be concerned, no time would pass.
What is the 'you' that supposedly nothing at all would happen to, if you could travel at the speed of light?

Why would supposedly nothing happen to that thing that is 'you', if you could travel at the speed of light'?

I agree wholeheartedly that WHILE a human body was travelling at the speed of light, if they could, then for that person there MIGHT a perception outside of the body that no time was passing. But, to Me, from when that human body was last at rest, before travelling at the speed of light, if it could, up to when it was at rest again, after travelling at the speed of light, if it did, then the days or years that that body took to travel the distance that it did, at the speed of light, then that is how much that body would have aged by. And, if for example that body was in front of a mirror when they were travelling, then for that person they would see a normal rate of change. If this is not correct, then why not?

Walker
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Re: Relativity?

Post by Walker » Fri Oct 13, 2017 4:56 am

ken wrote:
Fri Oct 13, 2017 4:17 am
I agree wholeheartedly that WHILE a human body was travelling at the speed of light, if they could, then for that person there MIGHT a perception outside of the body that no time was passing. But, to Me, from when that human body was last at rest, before travelling at the speed of light, if it could, up to when it was at rest again, after travelling at the speed of light, if it did, then the days or years that that body took to travel the distance that it did, at the speed of light, then that is how much that body would have aged by. And, if for example that body was in front of a mirror when they were travelling, then for that person they would see a normal rate of change. If this is not correct, then why not?
Ken, keep on the track:

If the twin in the fast spaceship could see his earthwalking brother, the brother would be moving very quickly. Super speed.

If the earth walker could see his flying brother, he would appear motionless.

For the flyer, everything on the spaceship appears normal.

For the walker, everything on earth appears normal.

When the flyer returns, he looks as he did when he left.
However, the earth walker is old and gray, on his last legs.

I forget the name of story, but here’s a great plot. A starship pilot lands on earth for some downtime. He goes to a public place and gives a child a rare space gem. It’s red, and he tells her where it’s from. He then leaves for his next flight to the stars. I think he’s flying goods. It’s the usual short flight. He picks up another gem and returns to earth for his time off. He goes to the park. He does the same thing with another kid. He gives the gem to a kid. Then, he does something else that he didn’t do the first time. He somehow finds the first kid. She is now a woman, and she has thought of him all of her life. For awhile he has a very good friend, until his next trip to the stars.

Many of the details escape me because I read it when I was a kid. But that’s the gist. It was a kid’s story, so don’t get weird.

So, what do you think, Ken?

Walker
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Re: Relativity?

Post by Walker » Fri Oct 13, 2017 4:57 am

thedoc wrote:
Fri Oct 13, 2017 3:42 am
Or it could already be on it's way to becoming a train wreck like the evolution thread, just waiting for some creationist to chime in with "It's only a theory".
Have you ever heard the Dzogchen anecdote about distraction?

ken
Posts: 1784
Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

Post by ken » Fri Oct 13, 2017 5:00 am

surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Photons or any massless particles are timeless because nothing travelling at the speed of light is actually capable of experiencing time
What is 'time'?

And, how could a senseless and sentientless thing like a photon be capable of experiencing any thing, let alone time?

A person travelling at the speed of light may not be capable of experiencing, what is generally perceived as being, 'time'. But this is only from an outward perspective, from an inward perspective 'time' could still be experienced. All of this is only while at the travelling speed of light too.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Saying a clock experiences time simply means it can measure time.
So then do you think it would be better to state that a clock measures time, instead of experiencing time?
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
It does not mean it is a conscious being capable of sensory experience
And it would stop when travelling at the speed of light because it could not experience or measure time as time itself would have stopped
BUT time has NOT stopped. While travelling at the speed of light it MIGHT APPEAR as though time has stopped, for some, but obviously "time", itself, can NOT stop. A clock also would NOT stop, travelling at the speed of light, because a clock does NOT measure "time". A clock is made to change at a SET rate, which was devised by and created by human beings. That set rate of change is what human beings call "time" but there is NO actual physical time itself that has nor could have an influence over clocks nor over any thing else. Obviously all physical things age or deteriorate the longer they have existed but that is because of events occurring not because of some thing that has been given the label of "time". Although the actual measurement that human beings set the rate of change or motion of a clock to is set to light, itself, which is obviously governed by the speed at which itself travels at, time, nor a clock, and nor will a human body just stop because they are travelling at the speed at which "time" is set by.
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
The closer a clock gets to the speed of light the faster time goes but at the speed of light itself time stops for any object of mass.
I have heard and read the exact same things, more than enough times. But just repeating it does NOT make it true. Where is the actual evidence for what you are saying?
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Since clocks
are objects of mass then this would apply to them too. Though they would no longer be clocks at that point as the atoms that they were made
from and more specifically their electrons would become too unstable for them to retain their solidity and they would just disintegrate instead
Yes I hear this same thing, over and over again, when discussing travelling at the speed of light. We have all heard this before. That is WHY I use that very important word 'if' when ONLY looking at some thing.

Saying, "But it is not possible to travel at the speed of light because atoms break down, ...." and similar is just like the priest saying some thing like, "There are some things we are not meant to know", when questioned about "If God supposedly created every thing, then who created God?"

What words could I use to stipulate once and for all let us concentrate on the issue here and that is if we, human beings, and a clock could travel at the speed of light, then would the human body keep ageing and would the clock keep moving at its set rate of change or would the human body not age at all and the clock just stop completely?
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Anything that travels at the speed of light such as a photon does not experience time.
Of course NOT, it is a photon after all.

But any observer could actually measure its speed in time [/quote]

How?
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
So a human being travelling at the speed of light between two planets would literally arrive in no time at all no matter what the actual distance was.
But if it takes 3 years to travel a distance of 3 light years away, then how could a human being travelling at the speed of light between two planets 3 light years in distance away from each other, for example, "literally arrive in no time at all"?

Would it not take that human being 3 years to travel that distance, if they were travelling at the speed of light?
surreptitious57 wrote:
Thu Oct 12, 2017 12:10 pm
Only an observer watching that human being would be able to measure the time taken since to them it would not have taken no time at all
but a finite amount of time measured from their particular frame of reference. And so long as they were not travelling at the speed of light also
This is a little bit convoluted to Me. For example who is the 'them' in reference to, and, what or where is the 'their' in relation to what/where "particular frame of reference?

Besides that, depending on where the actual frame of reference is what an observer actually observes may not in fact be the actual truth. Because to some observers what they observe is the travelling human being has traveled the distance instantly and therefore no "time" at all has been measured. But to another observer at another place a considerable amount of "time" has actually taken place and been observed.

An actual fact here also is the human being doing the travel might observe it took quite some time to travel a distance, when another human being observed that it took no "time" at all for that travelling human being to travel the same distance. Because every thing is relative to the observer it all also depends on where the observer is AND what frame of thinking they are in.

Obviously an open observer can see things a lot differently from a closed observer. Just some more to think about.

surreptitious57
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Re: Relativity?

Post by surreptitious57 » Fri Oct 13, 2017 5:56 am

ken wrote:
What is time
Time is defined as the passing of a thought or the passing of an event or
the distance between events where an event is a location in space time

surreptitious57
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Joined: Fri Oct 25, 2013 6:09 am

Re: Relativity?

Post by surreptitious57 » Fri Oct 13, 2017 6:03 am

surreptitious57 wrote:
The closer a clock gets to the speed of light the faster time goes
The closer a clock gets to the speed of light the slower time goes

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