# The Naked Scientists Forum

### Author Topic: Does time dilatation explain quantum effects?  (Read 6989 times)

#### Ignorant Enthusiast

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##### Re: Does time dilatation explain quantum effects?
« Reply #25 on: 16/09/2013 10:40:20 »
Now how do we know how fast the car was travelling? Our experimenter on earth will have told us the length of the test track, and will transmit a signal every second. To make it simple, let's say the car travels 100m in 100s. So we receive 100 time pulses, after which we see that the car has travelled 100m. The effect of the blue shift has indeed been to increase the frequency with which we perceive the time signals c ompared with our clock, but whilst the car may appear to have been travelling faster than 100m/s by our clock, it hasn't done so by his clock - and that is the one we use to measure speed.
This is close to what I was asking, if it could appear to us that something could be travelling faster than light due to it being in a different frame of reference to us, without actually travelling faster than light in reality.  Which I am assuming is the case judging by your answer of "whilst the car may appear to have been travelling faster than 100m/s by our clock".

#### alancalverd

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##### Re: Does time dilatation explain quantum effects?
« Reply #26 on: 16/09/2013 11:22:01 »
The rate of the earthclock is as measured by the ship clock.

Ah, it's all semantics. Being a feet-of-clay experimental scientist, I would call that the apparent rate of the earthclock, knowing that the "true" rate is exactly the same as the ship clock because they are both ideal clocks from my workshop!

And I'm afraid that not every reader of this forum knows that we are only talking about ideal clocks unless we say so!

#### Pmb

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##### Re: Does time dilatation explain quantum effects?
« Reply #27 on: 16/09/2013 14:51:27 »
Quote from: alancalverd
Ah, it's all semantics. Being a feet-of-clay experimental scientist, I would call that the apparent rate of the earthclock, knowing that the "true" rate is exactly the same as the ship clock because they are both ideal clocks from my workshop!
When you make a statement like the that you're in effect saying that time dilation is only apparent since the clock isn't "really" slowing down, the slowing down is only "apparent." What is real or not is what you can measure and you can measure the earthclock to be running slower so this is not apparent at all.
Quote from: Pmb
And I'm afraid that not every reader of this forum knows that we are only talking about ideal clocks unless we say so!
So instead of saying "atomic clock" use the term "ideal clock" instead. I think it will make things much clearer. Otherwise readers will want to know why you have to use an atomic clock instead of an ordinary clock.

#### alancalverd

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##### Re: Does time dilatation explain quantum effects?
« Reply #28 on: 16/09/2013 15:18:21 »
Au contraire! If I'm on the ship I can see pulses from the earthclock arriving slightly further apart than the pulses from the shipclock, but knowing they are both atomic clocks and being wise to relativity, I know that the earthclock is not really running slower. Indeed by knowing that fact and no other, I can calculate my speed away from earth by measuring the apparent rate of the earthclock.

If we didn't distinguish between real and apparent rates, we would believe that the universe contains an infinite number of different elements! Fortunately we can identify the hydrogen spectrum from its pattern and deduce from the shift of its apparent center frequency that a galaxy is moving with respect to us, which makes astrophysics a lot simpler.

I'm perfectly happy to tell anyone why I'm using an atomic clock! From my present point of view it's very far from ideal because I can't wear it on my wrist, and less than 100 years ago an ideal clock would have been a ship's chronometer, but neither my wristwatch nor a chronometer could be relied on to behave like a standard cesium clock once the rocket engine starts.

#### Pmb

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##### Re: Does time dilatation explain quantum effects?
« Reply #29 on: 16/09/2013 15:37:29 »
Quote from: alancalverd
Au contraire! If I'm on the ship I can see pulses from the earthclock arriving slightly further apart than the pulses from the shipclock, but knowing they are both atomic clocks and being wise to relativity, I know that the earthclock is not really running slower. Indeed by knowing that fact and no other, I can calculate my speed away from earth by measuring the apparent rate of the earthclock.
You're confusing the effects due to Doppler shift and those due to time dilation. The arrival rate is caused by both of them acting together. However if you were to have an object moving so close to a wall that they are almost touching then you can exchange signals with that wall and track time by the rate at which spots were left on the wall by the moving clock. The rate at which spots are left will be soley due to the rate at which the clock is ticking and the speed it is moving. Doppler effects won't play a role. I'm surprised that you don't know this by now.

Quote from: alancalverd
I'm perfectly happy to tell anyone why I'm using an atomic clock!
And waste time in each post doing so for no good reason. If you were to do a survey of SR texts you'll notice that almost all of them will state what an ideal clock is, using an atomic clock as an example, then they never mention it again. And for very good reason.

#### jeffreyH

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##### Re: Does time dilatation explain quantum effects?
« Reply #30 on: 16/09/2013 22:04:35 »
If there was a theoretical point in the spacetime continuum where a global rest frame could be found then would an object residing there be older than the apparent age of the universe? A conundrum.

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##### Re: Does time dilatation explain quantum effects?
« Reply #30 on: 16/09/2013 22:04:35 »