Is Time Dilation Caused by Distance?

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Discussion Overview

The discussion revolves around the concept of time dilation, specifically whether the delay in observing a clock on the Sun from Earth, due to the distance light must travel, constitutes time dilation. Participants explore the implications of distance and mass on the perception of time between two different frames of reference.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant suggests that the time it takes for light from the Sun to reach Earth results in a perception of slower time on the Sun, proposing this as a form of time dilation.
  • Another participant counters that this is not time dilation, emphasizing that the Sun's greater mass affects time perception, and that clocks do not actually tick slower due to distance alone.
  • Some participants clarify that while the clock on the Sun appears to be running slow from Earth's perspective, it still ticks at a constant rate, and the observed delay is simply due to the time light takes to travel.
  • There is a repeated emphasis on the idea that the 8-minute delay does not change over time, indicating that the perception of time is consistent rather than dilated.
  • One participant uses an analogy of watching a delayed TV show to illustrate the concept of receiving information from the Sun after a fixed delay, reinforcing the idea that the clock's increments are not affected by time dilation.

Areas of Agreement / Disagreement

Participants express disagreement regarding whether the observed delay constitutes time dilation. Some argue it does, while others maintain that it does not, leading to an unresolved discussion on the nature of time perception in this context.

Contextual Notes

Participants do not fully explore the effects of gravitational time dilation or relative motion, focusing primarily on the implications of distance and light travel time.

R Power
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Time delation by distance!

Sun is so far that it take 8 minutes for its light to reach us. Let a big LED clock is placed at sun such that we can see it from earth. Now every second increment on sun's LED clock will be seen by us on Earth 8 minutes later. So for us time on sun is passing very slow. Is this time delation?
 
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That is not time dilation, but the sun is much more massive then Earth, so that difference less the relative motion time dilation would probably equate to time on the sun is slower compared to on Earth.

Note the Earth is not an inertial FoR :wink:
 


That is not time dilation, but the sun is much more massive then Earth, so that difference less the relative motion time dilation would probably equate to time on the sun is slower compared to on Earth.
But why that isn't time dilation. Clearly we will see the clock on sun runnning slow as compared to us!
 


No, it will still be incrementing once per second. Clocks that are time dilated actually tick slower. In other words, we will always see the time on the clock on the sun 8 minutes earlier than clocks on earth. If there were time dilation, that 8-minute gap would get bigger the longer we observe.

(I'm ignoring time dilation caused by gravity because I don't think you are asking about that.)
 


No, it will still be incrementing once per second. Clocks that are time dilated actually tick slower. In other words, we will see the time on the clock on the sun 8 minutes earlier than clocks on earth. If there were time dilation, that 8-minute gap would change the longer we observe.
I wonder why time will increment same as on Earth once after 8 mins? Let the clock at sun changes color from red to green alternatively to show second increments. So, a red light photon as a signal from clock move toward earth, it will take 8 minutes to reach. Now one second increment occurs at sun, so another green light photon is emitted and it will take another 8 mins to reach earth.
 


R Power said:
I wonder why time will increment same as on Earth once after 8 mins? Let the clock at sun changes color from red to green alternatively to show second increments. So, a red light photon as a signal from clock move toward earth, it will take 8 minutes to reach. Now one second increment occurs at sun, so another green light photon is emitted and it will take another 8 mins to reach earth.
Since the distance between the sun and the Earth is almost constant (at least I don't think that is your concern) and the speed of light is constant, the time it takes for the image of the clock or whatever coming from the sun will take the same amount of time, 8 minutes. It's like you are watching a live TV show on your TiVo but starting 8 minutes after it really started. Everything looks normal, just delayed by 8 minutes.
 
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R Power said:
I wonder why time will increment same as on Earth once after 8 mins? Let the clock at sun changes color from red to green alternatively to show second increments. So, a red light photon as a signal from clock move toward earth, it will take 8 minutes to reach. Now one second increment occurs at sun, so another green light photon is emitted and it will take another 8 mins to reach earth.
Sun emits red light at 1:00:00
Earth receives red light at 1:08:00
Sun emits green light at 1:00:01
Earth receives green light at 1:08:01
... and so on

The light flashes are one second apart for both sun and earth. (Ignoring any relative motion or gravitational effects, of course.) The Earth just gets them 8 minutes later.
 


ok... I got it! Thnx Doc Al
 

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