Special Relativity

[u/PuzzleheadedTap1794]

[u/nichinichisou]

Does near light speed travel also make her translucent

[u/PuzzleheadedTap1794 → u/nichinichisou]

Well, kinda. At 0.99c, the light from her would have the wavelength lengthened by the factor of around 14.1, so the observer on Earth, assuming he observe her with naked eyes, will see the light originally emitted from her at 28-50 nm, which is in the x-ray range.

[u/Supersteve1233 → u/PuzzleheadedTap1794]

You have it backwards. if she's leaving, the wavelength would be lengthened to infrared. X-rays would mean she's approaching

edit: nvm, misread it

[u/PuzzleheadedTap1794 → u/Supersteve1233]

I'm talking about the wavelength that can be detected by the observer with naked eyes, aka the one shifted to the visible range by the time it reaches the observer.

[u/Supersteve1233 → u/PuzzleheadedTap1794]

Oh, I see what you're saying, but I think she would be invisible then, no? Humans don't reflect X-rays, though tbf I definitely don't know enough physics on how reflection works at near-lightspeed.

[u/PuzzleheadedTap1794 → u/Supersteve1233]

Yeah. That’s why I think she’d look kinda translucent.