I believe if you gently step over the event horizon of a black hole, the light reflecting off the back of your head will wrap around accretion disk and back into your eyeballs. It requires a bit of setup and is kind of a one-time thing, but you’ll get a much better view than you could get with a mirror!
Small correction: You’ll want to be at the photon sphere, not the event horizon (1.5x the Schwarzschild radius). You can theoretically hover there for an unlimited time, and even escape, as long as you don’t mind the immense acceleration necessary. :)
This didn’t work for me at first, but I tried it a second time and it actually worked! You weren’t kidding about it being a one-time thing though, because I haven’t been able to do it since.
Next time you do it, remember what you did in your previous only attempts. It’ll help make the only shot you have be successful for once, since once is all you get. If you keep at it, you’ll get better with practice, and maybe eventually, you’ll be able to make it happen for the first time.
Easiest way is to stand with your back to a large bathroom mirror or vanity while holding up a hand mirror to your eyes to look back at the big mirror.
Source: cut my own hair.
Two mirrors.
A hand mirror and the bathroom mirror.
Just to add on: face away from the bathroom mirror and look into the hand mirror, angling it until you can see the reflection of the reflection of the back of your head.
(Figured if someone out there actually needed this advice, the actual method might not be totally obvious to them without explanation.)
- Two mirrors.
- Take a photo or video holding your smartphone behind your head pointed at you.
- I suppose if you needed to see it in roughly realtime, you could figure some way to live-stream your smartphone camera to a screen in front of you.
The only other ideas that are coming to me are joke answers like “bend over backwards and lay the back of your head on the bed of a photocopier” or “visit a hall of mirrors.”
What’s your purpose for doing so?
Two mirrors, a camera, moving faster than light so that you can catch the photons coming of the back of your head.
