Einstein relativity- radiowaves when travelling at v>0.1c

  • Context: Undergrad 
  • Thread starter Thread starter grade12
  • Start date Start date
  • Tags Tags
    Einstein Relativity
Click For Summary

Discussion Overview

The discussion revolves around the effects of relativistic physics on the perception of radio waves while traveling at significant fractions of the speed of light (0.9c). Participants explore concepts related to time dilation and the relativistic Doppler effect in the context of a hypothetical scenario involving a spaceship and radio signals from Earth.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant poses a scenario where they are traveling at 0.9c and questions how 100 years of radio broadcasts would be perceived in only 50 years of their own time due to time dilation.
  • Another participant humorously suggests that the frequency of the radio waves would double, leading to a perception similar to that of "Alvin and the Chipmunks."
  • A different participant challenges the initial assumption about hearing radio waves the same as on Earth, referencing the "relativistic Doppler effect" as a factor that alters perception based on relative motion.
  • One post introduces a separate topic regarding the nature of time and space at the moment of the big bang, indicating confusion about the concepts of matter, energy, and their relationship to time and space.
  • Another participant notes that in the scenario described, the spaceship's velocity is perpendicular to the motion of the radio waves, suggesting that time dilation is the primary effect to consider.

Areas of Agreement / Disagreement

Participants express differing views on how radio waves would be perceived while traveling at relativistic speeds. There is no consensus on the implications of the relativistic Doppler effect versus time dilation in this context.

Contextual Notes

Some assumptions regarding the nature of radio wave propagation and the effects of relativistic motion are not fully explored, and the discussion includes varying interpretations of the relativistic Doppler effect.

Who May Find This Useful

This discussion may be of interest to students and enthusiasts of physics, particularly those exploring concepts related to relativity, time dilation, and wave phenomena in high-speed contexts.

grade12
Messages
1
Reaction score
0
So my grade 12 physics teacher asked our class this question which he didn't have an answer to.

Suppose I am in a spaceship traveling at 0.9c around the Earth. Because of time dilation, let's say 50 years (relative to me) have passed. Let's also say, for simplicity, that 100 years have passed relative to someone on Earth. Let's say i am listening to an Earth radio station. For all of those 50 years. Because radiowaves travel at c regardless of your relative speed, you should hear them the same as you would on Earth.

But my question is this: What would 100 years worth of radio sound like, when you're hearing it all in only 50 years?
 
Physics news on Phys.org
Double the frequency.

Everyone sounds like alvin and the chipmunks.
 
grade12 said:
Because radiowaves travel at c regardless of your relative speed, you should hear them the same as you would on Earth.

Nope. Do a Google search on "relativistic Doppler effect".
 
mehul ahir said:
it is told that matter and energy bending time and space but matter & energy can't be destroyed than how can time and space become zero at the time of big bang please reply me via email sir i m in very big trouble?//
We don't reply by email. The short answer is that there's no such thing as "the time of the big bang", at least not in the simplest big bang theory. The links in the last two quotes in this post might help you see some of these things a bit more clearly.
 
jtbell said:
"relativistic Doppler effect"
In this case, the spaceship's velocity is perpendicular to the motion of the radio waves, so the only effect that matters is time dilation (assuming that we treat Earth as a point instead of as a big ball).
 

Similar threads

  • · Replies 65 ·
3
Replies
65
Views
13K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 35 ·
2
Replies
35
Views
4K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 21 ·
Replies
21
Views
3K