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by StrictDabbler 2669 days ago
We don't even know that he got lucky.

Lasers didn't exist yet to force us to study retinal exposure to bright non-UV light and the flash from the bomb didn't last that long, nor were the first few bombs that bright, so he may have been fine... but obviously if you stare at the sun through three inches of glass you're still going to burn your retinas.

He says "I figured the only thing that could really hurt your eyes (bright light can never hurt your eyes) is ultraviolet light. I got behind a truck windshield, because the ultraviolet can’t go through glass, so that would be safe, and so I could see the damn thing."

What we know from later laser research is that unless you have a comprehensive visual field test, it's often hard to identify that part of your retina has been scorched. Your brain just filters it out as a blind-spot and you don't realize what you're failing to see.

There's every chance that Feynman totally burned a section of his retina and never realized it, and there's every chance that he was fine because the exposure at his distance wasn't that bad, but at the end of the day he was more reckless than insightful in this situation.

5 comments

Maybe he should have closed one eye, but the first atomic bomb only explodes once. Your body won't last forever no matter how well you care for it (as Feynman well knew, having just watched his wife Arline die slowly of incurable tuberculosis); seeing the first atomic-bomb test with your own eyes seems eminently worth the risk of blindness, or even sacrificing an eye.
I really can't agree. I would not exchange my eyesight for the whole world, literally. Therefore the qudos of having looked at a novel explosion in no way compensates for any risk to my eyes.
>I would not exchange my eyesight for the whole world, literally.

FYI vacuum exposure can cause blindness, visual impairment, and death.

> bright light can never hurt your eyes

Before y'all criticize that statement, keep in mind it's coming from one of the best scientists of the 20th century.

He was talking before lasers. For a purely thermal source to hurt the eyes, it would have to be:

1. insanely hot

2. quite close to the observer

First condition is met by the nuke, but the second one, obviously, is not, unless you're a victim of the explosion.

Scientists, even the best ones, do dumb things all the time.

Source: Am experimental physicist; do dumb things. Sometimes my colleagues do too, even the best ones.

Los Alamos was replete with brilliant people doing dangerously stupid things.

https://en.wikipedia.org/wiki/Demon_core

I know. It was not meant as an absolute statement.
As much as a window blocks UV, I wouldn't trust a laser if a high-powered UV laser was aimed through it at my eye.
I have a scar on my retina near the fovea, and I can only see it if I deliberately focus on it.
Are we sure he wasn’t wearing sunglasses too?