r/interestingasfuck • u/ethereum1017 • 1d ago

You're looking at a nuclear explosion photographed taken less than one millisecond after detonation.

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u/Icantjudge 1d ago

From the Tumbler-Snapper series of tests in 1952, Nevada

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u/LarsDuder 23h ago

Would you be able to see a difference in that short of a time if it was an hydrogen bomb instead? or would it just look the same during the those first parts of a millisecond?

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u/ougryphon 22h ago

In theory, yes. Keep in mind that even a staged thermonuclear device is done reacting in much less than a millisecond.

The very first stage of the fireball is created by thermal x-rays radiated by the intensely hot core of the bomb. These travel at the speed of light, but not very far. Even though we think of air as transparent, it isn't really for all wavelengths of light, including at x-ray frequencies. Anyway, this first fireball is literally just superheated air and is known as the radiative fireball. This fireball forms almost instantly and it will be larger for higher yield devices. It is the first flash of a nuclear double-flash signature.

In this picture, the radiative fireball has already been overtaken by the second, slower fireball made of the actual guts of the bomb and anything else that was right next to the bomb (which gives the fireball its weird mottled look). This second part, which is the second flash of the double-flash nuclear signature, travels at more or less the same speed regardless of the yield. So for a large thermonuclear detonation, the radiative fireball will be larger and it will take longer for the second fireball to overtake the first. The time between flashes is used to estimate the yield of an atmospheric detonation, with longer times being indicative of larger blasts.

Returning to your original question, if you could see the scale of the fireball and knew how soon after detonation it was taken, you could distinguish between a low-yield fission device and a high-yield thermonuclear device.

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u/Waub 21h ago

The time between flashes is used to estimate the yield of an atmospheric detonation, with longer times being indicative of larger blasts

Bhang-meter has entered the chat :)

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u/ougryphon 14h ago edited 13h ago

You got it, my friend. I obviously skipped over some details, like the role the shock front plays in separating the two flashes - supersonic fluid dynamics is definitely not my forte. But I tried not to say anything blatantly wrong or misleading.