Understanding Time Dilation: Confusions and Questions Answered

In summary, the conversation discusses the concept of time dilation and how it applies to a moving observer. The speaker expresses doubts about the symmetry of time dilation and asks if a clock moving at a high speed would appear to tick slower to an observer at rest. They also question how light follows a hypothetical path and how this is determined by instruments. The expert explains that the observed clock rate for a moving clock is dependent on the direction of motion and provides a graph to illustrate this concept.
  • #1
ritzmax72
15
0
In the proof of time dilation. Below http://www.phys.unsw.edu.au/einsteinlight/jw/module4_time_dilation.htm
I have a doubt in symetry of time dilation.
If there's a big lcd screen digital clock in jasper's verandah(at rest wrt ground). And zoe is moving at speed close to c. Do he see that lcd digital clock's ticks of 1 second is longer than his own clock?

Also another question. How could jasper(rest) see the path of light? Do she really see hypotheneus path? Or its just hypothetical that light follow that path? How do we actually got to know light followed hypothetical path? By which instrument?
 
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  • #2
ritzmax72 said:
In the proof of time dilation. Below http://www.phys.unsw.edu.au/einsteinlight/jw/module4_time_dilation.htm
I have a doubt in symetry of time dilation.
If there's a big lcd screen digital clock in jasper's verandah(at rest wrt ground). And zoe is moving at speed close to c. Do he see that lcd digital clock's ticks of 1 second is longer than his own clock?

Also another question. How could jasper(rest) see the path of light? Do she really see hypotheneus path? Or its just hypothetical that light follow that path? How do we actually got to know light followed hypothetical path? By which instrument?
For transverse motion, as in the case you reference, what Zoe actually sees is that Jasper's clocks goes at a rate of:

[tex]\sqrt{1 - v^2}[/tex]

So if for instance Zoe moves away with a relative speed of 0.6c she will see Jasper's clock tick 0.8 times the rate of his own clock.

For line of sight motion it is different, what Zoe actually sees or measures using his instruments is Jasper's clock divided by the line of sight Doppler shift which is:

[tex]\sqrt{ c+v \over c-v}[/tex]

So if for instance Zoe moves away with a relative speed of 0.6c she will see Jasper's clock tick half the rate of his own clock. However if he wants to consider what is simultaneous using Einstein's clock synchronization he would have to conclude that Jasper's clock ticks 0.8 times his own clock.

For motion in an arbitrary direction Zoe will see Jasper's clock rate as:

[tex]{ \sqrt{1 - v^2} \over 1+ v \cos \theta}[/tex]
 
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  • #3
ritzmax72 said:
In the proof of time dilation. Below http://www.phys.unsw.edu.au/einsteinlight/jw/module4_time_dilation.htm
I have a doubt in symetry of time dilation.
If there's a big lcd screen digital clock in jasper's verandah(at rest wrt ground). And zoe is moving at speed close to c. Do he see that lcd digital clock's ticks of 1 second is longer than his own clock?

Also another question. How could jasper(rest) see the path of light? Do she really see hypotheneus path? Or its just hypothetical that light follow that path? How do we actually got to know light followed hypothetical path? By which instrument?

You could use a bouncing ball rather than a photon and film the zig zag motion of the ball in Jaspers frame. The best way to do this would be to have a whole series of cameras mounted above the road and each camera takes a picture when the car is immediately below it and creating a film out of the sequence of pictures. The zig zag path is real in Jasper's frame. As for the LCD clock display, if this was mounted in Zoe's car then it would appear to be ticking slower than Jasper's clock, when observed by Jasper. If the LCD was on Jasper's verandah and was displaying Zoe's elapsed time, then this creates problems because of signal delays sending the time from Zoe's car to the LCD, so this is not a good idea.

P.S. Jasper is normally a "he" and Zoe is normally a "she". It is not clear whether you are talking about Jasper or Zoe when you say "Do he see that lcd digital clock's ticks of 1 second is longer than his own clock?".
 
  • #4
OH GENDER MISTAKE. NOT ACCQUAINTED with names.
I WAS TALKING ABT ZOE, "DOES(NOT DO) SHE SEE THE DIGI CLOCK TO TICK SLOW?" WAS THAT BECAUSE SHE PERCEIVE CHANGE IN DIGITS SLOWER THAN THEY ARE?? REASON; LIGHT WAVES TAKES ZIG ZAG PATH REACH HER EYES? IT THIS SO?
 
  • #5
@passionflower i didn't get ur reply's meaning. What zoe wud see is the clock in jasper's frame ticks at rate T=t/(1-v of zoe wrt jasper^2/c^2)^1/2
where t is zoe's own clock rate(duration of seconds, u can assume)
What is (1-v^2)^1/2 ?
 
  • #6
Here is a graph showing what an observer actually sees or measures about a moving clock traveling at 0.6c.

At the top of the red curve you see a rate of 0.5 indicating a clock moving away from the line of sight. At the bottom of the red curve you see a rate of 2 indicating a clock approaching from the line of sight. At the extreme left and right of the red curve, which represents transverse movement, you can see that the clock rates are identical to the calculated time dilation based on the Lorentz factor (gamma).
 

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FAQ: Understanding Time Dilation: Confusions and Questions Answered

1. What is time dilation?

Time dilation is a phenomenon in which time appears to pass at different rates for objects in motion relative to one another. According to Einstein's theory of relativity, time is not constant and can be affected by factors such as motion and gravity.

2. How does time dilation occur?

Time dilation occurs because of the relationship between space and time, known as spacetime. As an object's speed increases, its motion through space is converted into motion through time, causing time to appear to slow down for that object. This is known as time dilation.

3. Is time dilation a real phenomenon?

Yes, time dilation has been observed and confirmed through numerous experiments and observations. It is a fundamental aspect of Einstein's theory of relativity and has been demonstrated in various scientific experiments, such as the Hafele-Keating experiment.

4. Does time dilation only occur in extreme conditions?

No, time dilation occurs in all situations where there is relative motion or differences in gravity. However, the effects of time dilation are more noticeable in extreme conditions, such as near the speed of light or in the presence of strong gravitational fields.

5. How does time dilation impact our everyday lives?

The effects of time dilation are not noticeable in our everyday lives because the differences in time are incredibly small. However, technologies such as GPS systems must take into account the effects of time dilation in order to function accurately, as the satellites are in motion relative to the Earth's surface.

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