Special relativity noob problem 2, Dopler shift.

In summary, the conversation discusses a spaceship shuttle service between Earth and Mars that is equipped with identical monochromatic head and tail lights. The cruising speed relative to Earth causes the headlight of a homeward-bound spaceship to appear green and the tail-light of a departing spaceship to appear red. The question asks for the velocity of the spaceship relative to the speed of light and the wavelength of the headlight when observed from an outward-bound spaceship.
  • #1
-Vitaly-
39
0

Homework Statement



By 2025 a spaceship shuttle service operates between the Earth and Mars. Each
spaceship is equipped with identical mono chromatic head and tail lights, and their cruising speed v relative to earth, is such that the headlight of a homeward-bound spaceship appears green ( lambda = 500 nm) and the tail-light of a departing spaceship appears red(lambda = 600 nm).(i) What is v/c ?(ii) What is the wavelength of the headlight of an earth-b ound spaceship is observed froman outward b ound one?

Homework Equations



http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/reldop2.html"

The Attempt at a Solution


I have no idea where to start.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
-Vitaly- said:
Each
spaceship is equipped with identical mono chromatic head and tail lights …

Hi -Vitaly-! :smile:

The two lights are the same colour, but they look different because of the Doppler shift.

Just plug in the equations, and see what happens! :smile:
 

1. What is the Doppler shift in special relativity?

The Doppler shift in special relativity refers to the change in frequency or wavelength of a wave, such as light or sound, as observed by an observer moving relative to the source of the wave. This effect is caused by the relative motion between the observer and the source.

2. How does the Doppler shift affect the perception of color?

The Doppler shift can cause a change in the perceived color of an object. If the observer is moving towards the source, the wavelength of the wave will appear shorter and the color will appear bluer. If the observer is moving away from the source, the wavelength will appear longer and the color will appear redder.

3. What is the equation for calculating the Doppler shift in special relativity?

The equation for calculating the Doppler shift in special relativity is:
Δλ/λ = v/c
Where Δλ is the change in wavelength, λ is the original wavelength, v is the relative velocity between the observer and the source, and c is the speed of light.

4. How does the Doppler shift change at high velocities in special relativity?

In special relativity, as the relative velocity between the observer and the source approaches the speed of light, the Doppler shift becomes more significant. This means that the observed wavelength will change by a larger amount and the perceived color will be more noticeably shifted.

5. Can the Doppler shift be observed in everyday life?

Yes, the Doppler shift can be observed in everyday life. Examples include the change in pitch of a siren as an ambulance passes by, the redshift seen in the light from distant galaxies, and the blueshift seen in the light from stars orbiting around a black hole.

Similar threads

Speed of a star in Special Relativity
    • Introductory Physics Homework Help
Replies
6
Views
617
(Introductory SR) Light sent from a spaceship received by Earth
    • Introductory Physics Homework Help
Replies
6
Views
808
I Some thoughts about Bell's string paradox alternatives
    • Special and General Relativity
3
Replies
75
Views
3K
Special Relativity: Astronaut & Earth Light Speed Paradox
    • Special and General Relativity
Replies
6
Views
1K
Special Relativity spaceship problem
    • Introductory Physics Homework Help
Replies
1
Views
1K
Traveling to Planet X in 23 Years: An SR Challenge
    • Introductory Physics Homework Help
Replies
13
Views
1K
Relativistic Addition of Velocities
    • Introductory Physics Homework Help
Replies
1
Views
1K
Special relativity noob problem
    • Advanced Physics Homework Help
Replies
18
Views
4K
Spaceship voyage at close to light speeds
    • Introductory Physics Homework Help
Replies
11
Views
1K
Special Relativity: Time Dilation Prob
    • Introductory Physics Homework Help
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top