Observations takne at the speed of light

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SUMMARY

The discussion centers on the implications of traveling at or near the speed of light, specifically regarding visibility and light perception. Participants confirm that no object with mass can travel at the speed of light, as stated by DaleSpam. However, as one approaches relativistic speeds, light from the front becomes increasingly blueshifted, potentially shifting visible light into ultraviolet, X-ray, and gamma-ray frequencies. Conversely, light from behind becomes redshifted, moving into longer wavelengths, which may fall outside the visible spectrum.

PREREQUISITES
  • Understanding of Einstein's theory of relativity
  • Familiarity with the concepts of redshift and blueshift
  • Knowledge of electromagnetic spectrum and visible light
  • Basic principles of astrophysics and light behavior
NEXT STEPS
  • Research Einstein's theory of relativity and its implications for mass and speed
  • Study the effects of relativistic speeds on light perception
  • Explore the electromagnetic spectrum, focusing on redshift and blueshift phenomena
  • Investigate the technologies used in radio astronomy and infrared detection
USEFUL FOR

Astronomers, physicists, science educators, and anyone interested in the effects of relativistic travel on light perception and visibility.

BuddyPal
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I've heard the concept of an observer traveling at the speed of light, but when i placed myself in that observer's shoes i came to wonder; If someone was actually traveling at the speed of light, would/could they SEE anything at all? wouldn't the wavelength of the light be outside of the spectrum of visible light?
 
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It is not possible for any object with mass to travel at the speed of light.
 
Yeah, as DaleSpam said, an object with mass cannot travel at the speed of light. However, if one were able to travel at c, then the only light that would reach the observer's eyes would be the light directly in front of his or her eyes.
 
Last edited:
Lambda3 said:
Yeah, and the only light that will reach the observers eyes is the light directly in front of his or her eyes.
No. There is no 'and'. Dalespam's post has a full stop at the end.
 
BuddyPal said:
I've heard the concept of an observer traveling at the speed of light, but when i placed myself in that observer's shoes i came to wonder; If someone was actually traveling at the speed of light, would/could they SEE anything at all? wouldn't the wavelength of the light be outside of the spectrum of visible light?
While one cannot travel at the speed of light, can can get arbitrarily close to it.

As you approach relativistic velocities, the light coming at you from the front will get be more and more blueshifted. Indeed, visible light will be blueshifted way up the spectrum, into UV, X-ray and gamma ray frequencies. This is one of the big showstoppers for relativistic travel - it will bring with it lethal levels of very hard radiation.

Note BTW that, as far as what the observer can see: infra-visible light will be blue-shifted into the visible spectrum. So what was originally infra-red, microwaves and radio waves will now become visible.
 
DaveC426913 said:
No. There is no 'and'. Dalespam's post has a full stop at the end.

Excuse me. I've been texting too much with people who don't care much for things like that. As a result, I've gotten into some bad habits. :/ Thank you for pointing that out to me. I will be more careful in the future. I will fix it immediately.
 
the question I asked wasn't very specific, what i am really wondering about is when we travel very very quickly, not at the speed of light, but very fast away from a light source, wouldn't the wavelength of the light coming from the light source become so long that it is outside of the spectrum of visible light?
 
BuddyPal said:
the question I asked wasn't very specific, what i am really wondering about is when we travel very very quickly, not at the speed of light, but very fast away from a light source, wouldn't the wavelength of the light coming from the light source become so long that it is outside of the spectrum of visible light?

There's nothing special about "visible light". That's why we have radio astronomy, IR detection, etc. Just because it is outside of the visible light spectrum, it doesn't mean we can't detect it. We've been doing that already for a very long time.

Zz.
 
BuddyPal said:
the question I asked wasn't very specific, what i am really wondering about is when we travel very very quickly, not at the speed of light, but very fast away from a light source, wouldn't the wavelength of the light coming from the light source become so long that it is outside of the spectrum of visible light?
Yes. If you looked out the rear of your spacecraft , the light would appear more and more redshifted, down through microwave and radio frequencies.

Note though, that there is always UV light, X-rays and gamma rays impinging on you, which will be progressively redshifted down into the visible spectrum as you go faster.

So, you will still be able to "see", just things will look more and more weird.
 

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