I was just bitten by a radioactive stopwatch, gaining the voluntary ability to experience time at twice the usual rate. While doing so, for every second of real time, two seconds occur within my body.

Like previous question-askers, I'm effectively twice as strong, and outside forces affect me half as much. My voice is an octave higher and everything I hear is an octave lower. Breathing is more difficult and everything feels cold. That last part nearly killed me, but I rigged up a fancy respirator with heated high-pressure oxygen.

My current concern is vision. Light wavelengths double as they enter my eyes. Visible light becomes infrared, UVA becomes red, UVC becomes blue. Expanding on this answer, what does the world look like to me? What useful things can I see, and what commonplace visual features are indistinguishable?

  • 1
    $\begingroup$ To clarify, your eyes are still limited to perceiving the standard wavelengths? So the only thing you are seeing would be between UVA and UVC? $\endgroup$ May 7, 2020 at 13:55
  • 1
    $\begingroup$ I'm still of the opinion that it's a square multiplier rather than a linear one, but whatever. $\endgroup$
    – Halfthawed
    May 7, 2020 at 14:58

2 Answers 2


Light wavelengths double as they enter my eyes. Visible light becomes infrared, UVA becomes red, UVC becomes blue. What does the world look like to me?

You won't be seeing that much. The transmission spectrum of our atmosphere has several hills and valleys.

atmospheric transmission spectrum

Our window of 380-740 nm will become for your eyes 190-370 nm.

enter image description here

As you can see from the transmittance chart, you will be seeing some of our violet and near UV, and nothing more because the atmosphere is actually opaque. And considering that our eyes is mostly sensitive around the yellow (565-590 nm), your peak will fall (280-295) in the opaque part of the spectrum: you will be at least mildly visually impaired.

The useful feature I can think of is that you will be able to see ozone sources, since it blocks UV, so to you it should look like a fog/haze against a UV source.

  • 1
    $\begingroup$ As an addendum to L.Dutch's answer, there are some phenomena you would be experiencing. Your calorie intake would be greater and the same will be your water exchange by breathing. If you are confined in a vehicle, it may fog from your breathing. You will consume the Oxygen present in a medium faster, so scuba tanks last less for you. Bear in mind static buildup as well. On the other hand, since waves also affect sound, your poor light perception would be ameliorated with more sensibility for higher sound frequencies. Glass half full and all of that. $\endgroup$
    – Gustavo
    May 7, 2020 at 13:34
  • $\begingroup$ How opaque is air to UVB & UVC? If I obtained a UVB head lamp, would that work? $\endgroup$
    – Foo Bar
    May 7, 2020 at 16:26

An alternative consequence, if you prefer it, would be that -- contrary to the explanation you linked -- light dims for you, to half its previous intensity.

Yes, this is different from the way sound acts, but sound still is subject to Galilean transforms. Light, according to General Relativity, has the same speed in a vacuum to all observers. If you travel quickly enough that time dilation means you are moving at half the time as a stationary observer, you will still see light moving at the same speed as the observer.

Therefore you get only half the photons but they are still the same color.

(Yes, you can get Doppler shifting in light, but only when the light source, or observer, is moving swiftly enough that the distance between them changes by a significant amount during the wavelength of the light.)


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .