What will I see in this scenario? (involves rockets traveling near light speed)

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Discussion Overview

The discussion revolves around a thought experiment involving relativistic effects as experienced by an observer on Earth watching two rockets accelerate to near light speed. The focus is on the perception of time as measured by clocks on the rockets and the observer's clock, exploring concepts of time dilation and relative motion.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant describes a scenario where they observe a rocket (rocket #1) accelerating to 90% of the speed of light and notes that its clock appears to run slowly compared to their own clock.
  • The same participant introduces a second rocket (rocket #2) that also accelerates to 90% of the speed of light and questions whether they will see rocket #2's clock running even more slowly than rocket #1's clock.
  • Another participant asserts that rocket #2's clock will appear to tick normally, similar to the observer's own clock.
  • A later reply confirms the initial participant's understanding that they will see rocket #1's clock running slowly and that someone on rocket #1 will see rocket #2's clock running slowly.

Areas of Agreement / Disagreement

There is some agreement on the perception of rocket #1's clock running slowly from the observer's perspective, but the discussion includes differing views on the behavior of rocket #2's clock as perceived by the observer.

Contextual Notes

The discussion does not resolve the complexities of time dilation and relative motion as they apply to multiple observers in this scenario, leaving open questions about the implications of relativistic effects.

Who May Find This Useful

This discussion may be of interest to those exploring concepts in special relativity, time dilation, and the effects of high-speed travel on time perception.

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What will happen in the following scenario?

I am standing on the earth.

Right next to me, a small rocket containing a clock blasts off and accelerates to 90% of the speed of light almost instantly (within its 1st millimeter of travel).

As the rocket passes my head, I look at its clock and see that it is running very slowly.

Attached to this rocket is a second smaller rocket (which I will call "rocket #2). This rocket also contains a clock.

As I watch Rocket #1 pass my head, rocket #2 blasts from rocket #1 back towards Earth (rocket #2 is going in the opposite of direction of rocket #1). Rocket #2 also accelerates to 90% of the speed of light within 1 mm, so that relative to me, rocket #2 ends up resting motionless beside my head.

The time of rocket #1 is running slowly relative to me.
The time of rocket #2 is running slowly relative to rocket #1.

When I look at rocket #2 sitting motionless next to my head, what will I see? Will I see rocket #2's clock running even more slowly than rocket #1's clock?
 
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No, rocket 2's clock will be just like your own clock ticking perfectly normally.
 
ghwellsjr said:
No, rocket 2's clock will be just like your own clock ticking perfectly normally.

Thanks for the answer.

Was I correct in thinking that I will see rocket #1's clock running slowly, and that someone on rocket 1 will see rocket #2's clock running slowly?
 
Yes.
 

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