Sciencemadness Discussion Board

What color is a nuclear explosion ?

fluorescence - 16-4-2017 at 06:21

Hey,

So I just watched a few scenes from Rogue One again, especially the part where they blow the planet up. And this massive amount of energy that is theoretically condensed into one spot and slowely expands over the whole planet is basically a yellow flame... then I remembered that every picture I ever saw of a nuclear explosion was yellow as well... but shouldn't the huge amount of energy released be more of a blue color? Now you might say that the sun is yellow, too but as far as I know is the sun more of a white color and it's earth's atmosphere that causes the color shift.


Sulaiman - 16-4-2017 at 06:44

http://www.abomb1.org/images/enw77b28.gif

ave369 - 16-4-2017 at 10:48

At the initial fireball stage, the nuclear explosion is the color of pure pain. It's so bright that you go blind and can't tell its color.

When the fireball cools enough to be safely observable, it cools down to the temperature of ordinary flame, which corresponds to the color yellow.

fluorescence - 16-4-2017 at 13:56

Oh okay...I always assumed the fireball itself was hot. But okay problem solved, thank you !

Fulmen - 16-4-2017 at 14:24

It's still hot, but by that time the energy is dissipated enough to produce a yellow color. The initial "true" blast will be mostly gamma-rays, which cools down to produce predominantly x-ray, UV and finally visible light.

PirateDocBrown - 16-4-2017 at 17:49

A nuclear fireball will incandesce, which is to say it will emit as a blackbody, as a first approximation. Therefore, emission wavelengths will conform to what is expected, at any given instant based on the temperature at that instant.

Melgar - 17-4-2017 at 01:03

To get a good idea of what color range is emitted by different temperatures, look at fluorescent bulb ratings. 3500K corresponds to black body radiation of a 3500K object, same for others bulb color ratings. Incidentally, 5000K is the temperature of the surface of the sun, which I believe is what we use to define "pure" white light.

Sachingare - 18-5-2017 at 12:44

The spectrum of the nuclear blast is dependant on the temperature and also on the elements produced by fission as they will radiate their specific spectrum as well.
The term Color wouldn'te quite accurate, as the absorption/emission lines will probably only be recordable by instruments and not the eye

zed - 21-6-2017 at 16:41

Well, to me, it looks sorta Gamma/X-ray-ish..... You know, that gremlisch-nobohoken purple hue. But, guys from your planet, live near a small, dim, second generation, yellow star, and you don't even have multifacted compound eyes. You can't see the really hot stuff. So It would figure, that we might perceive things differently.

Texium - 21-6-2017 at 18:47

Quote: Originally posted by ave369  
At the initial fireball stage, the nuclear explosion is the color of pure pain.
Reading this made my day.

Heavy Walter - 22-6-2017 at 07:32

Dr Richard Feynman watched the Trinity detonation through a car windshield and reported shapes and colors.

http://www.realclearscience.com/blog/2016/04/what_its_like_t...

Fulmen - 22-6-2017 at 12:56

Quote: Originally posted by zts16  
Reading this made my day.

Me too. It's one of the best descriptions I have ever heard. Physics at these energy levels defy human understanding. In fact it lies beyond pure pain.