[Heacechig]

I guess it's the difference between being roasted or boiled.

[Jon Woodgate]

But, would you glow in the dark?

[somamasoso]

Are we trying to determine how much water a normal person would need to survive? Or how much water Arnold Schwarzenegger would need (answer: none)?

[sasquatch999]

Is it a European or African nuke?

ACK!

[Abedgebeefs]

Is the water being held in a fridge?

Damn, beat me to it

[asSexate]

People are still talking about that?

Remember Temple of Doom, when they survived falling out of a plane by using a life raft?

Indy has always defied common sense.

That one is a hell of a lot more believable than the refrigerator. OF course, that's not saying much.

[FelicitaJ]

Depends what you mean by small. With small devices, the amount of damage and the direction and power of the firestorm and radiation would depend on the actual size, the point of detonation in terms of above, on, or under ground, and the nature of the intervening buildings and such. "Small" as in 10 tons, a few inches of water would be sufficient if there were intervening buildings. "Small" as in 2,000,000 pounds = 1 kiloton, and the ground, including the pool, .25 mile away would be part of the mushroom cloud, meaning anyone in that pool would be radioactive dust.

Most small devices are the equivalent of less than one megaton of TNT. That's a lot of explosion at the high end. Those weights are not related to what the BOMBS weigh, only to the damage they do.

[NarunapyCalry]

First example was 10, second example was meant to be ~ 1000 tons which is about 2,000,000 pounds.

(I have edited it, leaving Snoopy's unhooked. I got distracted apparently, as 125 tons has no contextual meaning in what I said OR what I meant to say. Numbers from the clear blue sky entering one's posting are probably not a good sign.)

[Adamdjeffe]

I didn't know what you were talking about, until now. I just watched the movie last night.

What is so unbelievable?

It was a lead lined fridge and everyone knows that lead is a soft metal, thereby cushioning the shock of bouncing long distances.

ACK!

Even IF I were to accept that the lead would A) fully shield from radiation, B) not get superheated, and C) not break apart from the shock wave, the sheer amount of kinetic energy involved would at least break multiple bones as he rattles around in there, if not liquefy him. That, and there isn't even a perfect seal, just the flimsy strip of rubber between the base and the door, which would instantly melt and let in the extreme heat. That, and there didn't appear to be any latch or other locking mechanism in place, so we have to assume he held the door shut with his fingers wrapped tenuously around the flimsy condiment shelves. Even Ahnold couldn't hold on that tight. And that's just getting started...


(Yes I know you're just being facetious, but it's fun to vent anyhow.)

[TeLMgNva]

Like if you had a swimming pool with a deep end and jumped to the bottom, would that be good enough? Assume .25 mile distance from the device and a small fission device.

There are 3 key factors to consider:

1) Blast/overpressure
2) Thermal radiation
3) Ionizing radiation

Even a few feet of water would protect against lighter flying debris. I'm not sure what the overpressure effects would be underwater. My feeling is that it wouldn't be lethal.

Assuming that Hiroshima was 20 kt (8*10^13 J) and that ~50% of this was released as thermal radiation over a period of ~5 seconds an unprotected individual 400m from blast epicenter and 600 meters vertically below the blast would be exposed to an intensity of thermal radiation of 1.22*10^6 W/m^2 during this period. This is approximately 1000 times stronger than sunlight. Most of this would be released in the optical and ultraviolet. On the scale of meters water is almost perfectly transparent to optical frequencies. It is more opaque to ultraviolet frequencies, but a significant fraction of this thermal radiation would pass straight through to the individual at the bottom of the pool. Thus the water provides almost no protection from thermal radiation, and it seems to be high enough to cause almost instantaneous fatal injuries. You would be better getting behind a brick wall as a means of protecting yourself...

As far as ionizing radiation goes, alphas will be stopped cold by the water. Electrons and gammas of energy ~1 MeV (a nice nuclear energy scale) have a half-value layer in water of something like 10cm. Thus the water would actually provide significant protection against ionizing radiation of these types. Fast neutrons, on the other hand are electrically neutral and therefore interact with light nuclei via the residual strong force. Their absorption coefficient should be very low (?) therefore the water will not provide significant protection from this source of ionizing radiation.

In sum, given a few seconds warning the most important thing to do if caught near the blast zone of a nuclear weapon would be to get behind something which will absorb most of the thermal radiation and which will not collapse on you. Water provides significant protection against certain forms of ionizing radiation at nuclear energies, but will not protect against simple thermal effects in any significant way.

[Smittoh]

Muddy water? What about is the light kinda bouncing around or do you need to be in los. In which case, you wouldn't be. I guess I was thinking mjore that there woujld be super heated air and such...but I guess there is not so much of that for small nuke at ground level?

[AlexBolduin]

They interact well with water (are well thermalized) since the most advantageous collisions are with equal mass H atoms.

[Dastyh]

Actually, they interact with all sorts of materials, it is just that with H atoms it is more of an elastic reaction while with heavier atoms the neutrons are more likely to be absorbed or something (have lower momentum resulting scattered components).

Dense materials like Lead are good neutron shielding.

JM

[SDorothy28]

As far as I remember the predator was in a pit, which was in a valley, and Ahnold was already past the summit of a hill when the nuke went off.

[Dkavtbek]

For comparison's sake:

[pipittujbk]

The really unbelievable parts of that Indy clip, with that mushroom cloud going up like that, shouldn't the air around Indy be blowing towards the cloud?

Are they really trying to tell me that, after a nuclear blast and a refrigerator coming within inches of crushing him, that ground hog would still be there staring at Indy?

They go into holes for a reason people!



ACK!

[mashabox]

Muddy water? What about is the light kinda bouncing around or do you need to be in los. In which case, you wouldn't be. I guess I was thinking mjore that there woujld be super heated air and such...but I guess there is not so much of that for small nuke at ground level?

If the air becomes heated enough to do you damage (from primary...not from following firestorm) then you are already wayyyyyyy too close. Thermal radiation will wreck your day. Muddy water might well do it. Would flash boil the first few cm. Optical depth of muddy water is, at a guess, on order of ~10 cm. A meter of that is quite sufficient protection.

[truportodfa]

Arnie! Deep muddy water will save you from the bomb! If I ever see a rocket coming down, I'm swimming to the bottom OF a deep river. Sort of like how Huck and Jim have to go down and hold Mississipi mud while a steamship wheel actually turns over them. I figure, I would need to stay down as long as possible for heat to dissapate.

Helps also that the bomb was a groundburst. Puts a lot of of NRG into the ground (H and N were air bursts).