Calculating Frequency of Star's Radio Signals from Earth

  • Thread starter Thread starter crosbykins
  • Start date Start date
  • Tags Tags
    Relativity
AI Thread Summary
A star moving at 0.8c sends radio signals to Earth once every second according to its time scale. Due to time dilation, the signals are received every 2.24 seconds on Earth, resulting in a frequency of 0.45 signals per second. The calculation uses the formula Δts = Δtm/√(1 – (v^2/c^2)). A participant raises a concern about whether the increasing distance of the star affects the signal reception frequency. Overall, the discussion focuses on the implications of relativistic effects on signal timing.
crosbykins
Messages
50
Reaction score
0

Homework Statement



A distant star has been measured as moving at a speed of 0.8c away from Earth. If a planet of this star sends radio signals to Earth once every second (according to their time scale), how often would we receive them (according to out time scale)?

Homework Equations



Δts = Δtm/ √(1 – (v^2/c^2)

The Attempt at a Solution



Δts = Δtm/ √(1 – (0.8c)^2/c^2)
= 1/ √(1 – (0.8c)^2/c^2)
= 2.24 s

f = 1/2.24 s
= .45 signal/second

Therefore, we would receive .45 signal/second

*does this look ok?
 
Physics news on Phys.org
hi crosbykins! :smile:

have you taken account of the fact that the distance each signal has to travel is increasing?
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Relativistic Distance/Time Problem
Replies
7
Views
3K
(Introductory SR) Light sent from a spaceship received by Earth
Replies
6
Views
2K
Calculating Muon Decay in Relativity: A Scientific Analysis
Replies
2
Views
2K
Will Two Synchronized Atomic Clocks Remain in Sync After One Year?
Replies
1
Views
10K
Time for radio signal to get to a receiver
Replies
2
Views
2K
Rocket moving away from the Earth
Replies
38
Views
4K
B Feasibility of Sending a Radio Signal Detectable from a Neighboring Star
Replies
5
Views
156
SR - Time dilation, space-time diagram, and radio signals
Replies
1
Views
1K
Light Signal Travels Between Earth and a Spaceship
Replies
19
Views
3K
Optimizing Exposure Time for Different Magnitude Stars
Replies
7
Views
1K

Hot Threads

Recent Insights

Back
Top