# The Naked Scientists Forum

### Author Topic: Does the clock on the space ship slow down as the speed of the ship increases?  (Read 1957 times)

#### MythSurgeon

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##### Does the clock on the space ship slow down as the speed of the ship increases?
« on: 26/02/2014 03:55:57 »
Question 1:  Regardless of anyone's perception, does the clock on the space ship actually slow down as the speed of the space ship increases?
« Last Edit: 01/03/2014 10:40:57 by chris »

#### Ethos_

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##### Re: Perception v.s. Reality, Time Dialation
« Reply #1 on: 26/02/2014 04:21:46 »
Question 1:  Regardless of anyone's perception, does the clock on the space ship actually slow down as the speed of the space ship increases?
That question can't be answered if we disregard anyone's perception. Because the advance of time is always relative to the observers and their associated velocities. Maybe you sould rephrase the question?
« Last Edit: 26/02/2014 04:23:51 by Ethos_ »

#### lightarrow

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##### Re: Perception v.s. Reality, Time Dialation
« Reply #2 on: 26/02/2014 12:01:51 »
Question 1:  Regardless of anyone's perception, does the clock on the space ship actually slow down as the speed of the space ship increases?
No, it doesn't, it never does. You just have to make this simple consideration: "speed" is not an absolute concept, ma relative to the frame of reference you choose and you can choose any. With respect to a frame, you are stationary, with respect to another you are moving at 299,000 km/s in some direction, with respect to another you are moving at -299,000 km/s in the opposite direction. So to which speed your clock should refer?
The phenomena of relativistic light dilation, twin paradox, etc, are due to a different reason: the clocks/spaceships/astronauts make a different path on spacetime.

Metaphor: you and your friend take your cars, both odometers signing zero, start from A and arrive to B, both with the same average speed.
Then you compare your car odometers and you discover that yours signs more kilometers. Is it because your odometer has run faster?
Or because you simply have made a longer path?
(here the kilometers signed by the odometers stay, in the metaphor, as the times signed by the two clocks in the twin paradox)

--
lightarrow
« Last Edit: 26/02/2014 12:14:42 by lightarrow »

#### MythSurgeon

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##### Re: Perception v.s. Reality, Time Dialation
« Reply #3 on: 26/02/2014 15:02:02 »
Ethos, If the question cannot be answered because the answer relies on perception, then reality cannot exist, only perception if there is no actual clock operation.

lightarrow, If the clock on the space ship doesn't slow down, then are the reports of clocks slowing down that have traveled in space false or were they differences in perception?  Your remaining comments explain perception, I seek an explanation of reality.  If speed is not a constant in reality (not perception) then I seek the actual (not perceived) clock operation on the space ship and any actual (not perceived) difference in operation among other duplicate clocks.

#### jeffreyH

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##### Re: Perception v.s. Reality, Time Dialation
« Reply #4 on: 26/02/2014 15:13:31 »
Ethos, If the question cannot be answered because the answer relies on perception, then reality cannot exist, only perception if there is no actual clock operation.

lightarrow, If the clock on the space ship doesn't slow down, then are the reports of clocks slowing down that have traveled in space false or were they differences in perception?  Your remaining comments explain perception, I seek an explanation of reality.  If speed is not a constant in reality (not perception) then I seek the actual (not perceived) clock operation on the space ship and any actual (not perceived) difference in operation among other duplicate clocks.

Physical processes need no observer to make them real. If we didn't exist they would still happen. It's like if a tree falls in a forest and no one is there to hear it does it make a sound. Of course it does. All the little forest creatures hear it.

#### MythSurgeon

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##### Re: Perception v.s. Reality, Time Dialation
« Reply #5 on: 26/02/2014 15:30:20 »
JeffreyH, I agree.  I ask what is real, not what each person on/off the space ship (or plant/animal in the forest) perceived.

lightarrow/anyone, I understand that different perspectives will result in different perceptions of the same speed events.  I ask what is real with regard to time, given that you agree that the clock in the space ship should read the same time as the clock that never moved when the space ship returns and the clocks are next to each other again.  Note that I am asking what the clocks are actually displaying, not what any person's perception on earth is perceiving.  That is one of my future considerations in this discussion.  So, my question stands: if the clock on the space ship does not actually slow down (regardless of perception), are the claims that clocks that have traveled in space have slowed down false and that both the person in the space ship and the person who has remained on earth be the same age?  Are there any other claims of empirical evidence demonstrating time is not a constant in reality (not perception)?
« Last Edit: 27/02/2014 16:54:23 by MythSurgeon »

#### The Naked Scientists Forum

##### Re: Perception v.s. Reality, Time Dialation
« Reply #5 on: 26/02/2014 15:30:20 »