Is blue shift a potential problem for near light speed travel?

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Discussion Overview

The discussion revolves around the potential challenges of blue shift and radiation exposure for spaceships traveling at near light speed. Participants explore the implications of the Doppler effect on light from stars and the resulting radiation risks associated with high-speed travel through interstellar space.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that spaceships traveling near the speed of light will face significant radiation from interstellar gas and blue-shifted starlight, raising concerns about safety.
  • Another participant presents a formula related to the Doppler effect to calculate the necessary speed for blue-shifting light from blue wavelengths to gamma rays.
  • A subsequent contribution indicates that achieving the required speed for such a blue shift would necessitate traveling extremely close to the speed of light.
  • One participant estimates that at a speed of 0.9992c, it would take 370,000 years to accumulate a lethal radiation dose from starlight, but highlights that approaching the sun would drastically reduce this time to 0.005 seconds.

Areas of Agreement / Disagreement

Participants express varying views on the severity of the radiation problem, particularly in relation to proximity to stars, indicating that while some agree on the risks, the specifics of the calculations and implications remain contested.

Contextual Notes

There are limitations in the assumptions made regarding radiation dosage and the effects of blue-shifting, as well as the dependence on specific definitions of lethal radiation levels.

Who May Find This Useful

This discussion may be of interest to those exploring the implications of relativistic travel, astrophysics, and the safety considerations of future space missions.

superpaul3000
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I've heard that future spaceships traveling at near the speed of light will have to deal with massive amounts of radiation due to interstellar gas. I think these spaceships might also have to deal with radiation from star light being blue shifted. How close to the speed of light would one have to get in order for the little bit of star light that exists to be blue shifted to gamma rays? What energy would the photons need to be blue shifted to so that they would become deadly to humans?
 
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Doppler effect .

lambda=sqrt((1-q)/(1+q))*(lambda2)
where q=v/c and lambda is the final shifted wavelength and lambda2 is the initial wavelength , so you could then calculate how fast you would need to go to shift the light from blue light to gamma rays .
 
Using the max precision my calculator goes to (not sure what that is) I get q = 1, so you'd have to be going extremely close to the speed of light.
 
yes you would
 
I guess this would not be that big of a problem until the spaceship got near a star. Given the amount of light incoming from the stars in the night sky it would take 370,000 years for a human to acquire the lethal radiation dosage (if they are traveling at 0.9992c which would blue shift star light to x rays). However traveling at that speed toward the sun, at 1 AU you would get the lethal dosage in 0.005 seconds.
 

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