Witnesses of nuclear explosions have described their hands becoming transparent, and that they could see the bones. For example, see here. How does that happen?
In nuclear bomb explosions, witness describe their hands becoming transparent. How does that happen?
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1Supported on this video . I disagree with the premise of the question. – user190081 Sep 11 '18 at 16:31
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1you should give a link to the video that claims this – anna v Sep 11 '18 at 16:41
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8Everything has the potential to be "transparent" to certain radiation. Your hands are already transparent to neutrinos, X-rays (partially), gamma radiation... it turns out they're transparent to sufficiently bright light also. Test it out with a torch. – Lightness Races in Orbit Sep 12 '18 at 10:15
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4Experiment for you: In a dark room, cover a flash light with your fingers. Your mobile phone's flash light should be sufficient (if any). – phresnel Sep 12 '18 at 11:47
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I think I read about this in Richard Feynman's book "Surely you're joking, Mr Feynman?". I read it a long time ago, but I think I remember a passage where he talks about witnessing the first nuclear test, and not wearing the safety glasses he was given because he was observing from behind a pane of glass, which would block the most dangerous UV radiation. Here's where my recollection is more hazy: he either spoke about himself covering his eyes with his hands, OR he recounted stories from soldiers who had done so; and the experience was an afterimage of the hand's skeleton. – Aaron F Sep 13 '18 at 11:46
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Have you never seen the bones of your hand when covering a flash light at night? Imo it was just a very bright light over a large area and trying to shield the eyes the bones were seen.
anna v
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That was my best guess as well. Will see if the question produces an idea that is better then that. It would be interesting to reproduce (not just with a flashlight, but with a light source equivalent to what those people experienced. ) – radon Sep 11 '18 at 17:51
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it seems that intensities of explosions are kilojoules per meter squared https://books.google.gr/books?id=Hhb2CAAAQBAJ&pg=PA53&lpg=PA53&dq=measured+intensity+of+visible+light+in+hiroshima+nagasaki+explosions&source=bl&ots=Ju9TP7xmB7&sig=jMZjgVrVxlfrjpr60znjkuGLFIM&hl=en&sa=X&ved=2ahUKEwjrzriiw7PdAhUCdCwKHWE2BnM4ChDoATAGegQIBBAB#v=onepage&q=measured%20intensity%20of%20visible%20light%20in%20hiroshima%20nagasaki%20explosions&f=false , a bit hard to reproduce in the lab – anna v Sep 11 '18 at 18:00
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3@annav You might be surprised. It's hard to compare a deposited energy density to an energy flux, but if I'm reading the Synlight press material correctly, they can achieve intensities of the order of 10 MW/m$^2$ for extended periods of time, so they'd be able to deposit that energy density (though maybe only on a small target?) in a small fraction of a second. You certainly don't want to put human test subjects there, but it looks doable to me. – Emilio Pisanty Sep 11 '18 at 18:32
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32@radon why do you need "a better idea"? A bright enough light shines right through one's flesh and skin. Nuclear explosions are bright. Mystery solved. – IMil Sep 11 '18 at 22:58
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6Or just use brighter and brighter lights until you can extrapolate what would happen in extreme light. You don't really need to match nuclear explosion level of brightness on the initial testing. – Nelson Sep 12 '18 at 01:05
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The flashlight experiment shows that light makes it through the hand. It doesn't show that you can produce a clear image of the bones in the hand by shining visible light through it. I would think that the light that makes it through has been scattered multiple times in the hand and cannot produce a clear image of the bones. – jkej Sep 12 '18 at 19:12
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@jkej . One would have to do the experiment with very bright sources . Certainly bones will be very much less transparent than skin, and the depth of the skin in the hand with respect to the separation of the bones is comparable. That is why bones show up with a strong flash light. – anna v Sep 12 '18 at 19:44
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9@jkej "Clear image" may be an exaggeration or a false memory. High levels of stress tend to do this to you. Like, for instance, when nuclear bombs go off in your vicinity. – IMil Sep 12 '18 at 23:08
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Skin and flesh are of different ability to stop light. Extremely bright light can be detected through a thin layer of skin.
Also, a nuclear weapon releases electromagnetic energy all up and down the spectrum. Different wavelengths have different ability to penetrate. Here is a guy showing interesting effects with infrared.
https://www.youtube.com/watch?v=QaKxCMPLhTE
His example is a lot of fun because the wavelengths he is using penetrate but don't do any harm. The radiation released by a nuclear weapon includes wavelengths that are very harmful. But they can penetrate and scatter. When they scatter there is some tendency for them to scatter to lower wavelengths which are then visible.
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8In the video you cite, the person is using an IR camera, he mentions
"Quite bright but you have to use an IR camera; you will not see anything with bare eyes. "
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2@MartinBeckett You aren't going to see IR, even if a nuclear bomb is releasing it. – forest Sep 13 '18 at 00:50
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1Scattering doesn't change wavelength of incident light, only direction. A tiny fraction of the energy of a nuclear bomb is going into visible light, though it is likely still enough to appear as a very bright strobe and for this existing visible light to pass in a detectable amount through the flesh of a hand. – madscientist159 Sep 13 '18 at 06:44
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1@forest Depends on the kind of infrared. There isn't a hard cut-off, the eye just gets gradually less sensitive. If your (near) IR source is bright enough you definitely can see it, it just might not be eye safe (but nobody has claimed that nuclear bombs are eye safe ...). – etarion Sep 13 '18 at 08:31
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