[FirstClassSkeptic]

If you have a mushroom cloud 31,000 feet high and say 100 feet diameter at the stem, how much dust is that?

I was trying to find information on how much dust per cubic volume of air that it takes to make an opaque cloud. I can't find it on the net. Maybe it's too variable.

With the size clouds they describe for Hiroshima, Nagasaki, it seems to me that the dust would be considerable, as in, tons of it. Where did it come from, there being no crater. Where did it go to? There doesn't seem to be any eye witness account of dust falling back down on them. There was rain, which might have dust on it.

Any help you can offer me is appreciated.

[bamzam]

Maybe you could look at how much ash cloud is displaced in various magnitude volcanic eruptions. Unfortunately they are often explained to the public in terms of equivalent nuclear blasts to understand the scale.

[FirstClassSkeptic]

Looking at this article:
https://en.wikipedia.org/wiki/Volcanic_ash

It's not exactly what I'm looking for but there are a few interesting things.

The very fine particles may be carried for many miles, settling out as a dust-like layer across the landscape. This is known as an ashfall.[5] If liquid magma is ejected as a spray, the particles will solidify in the air as small fragments of volcanic glass. Unlike the ash that forms from burning wood or other combustible materials, volcanic ash is hard and abrasive. It does not dissolve in water, and it conducts electricity, especially when it is wet.

Did the mushroom cloud at Hiroshima travel for many miles?

Loud thunder, lightning, as well as the strong smell of sulfur accompany an ashfall.

Fluoride poisoning and death can occur in livestock that graze on ash-covered grass if fluoride is present in high concentrations

And they put that in your water, and tell you it's for your own good.

Electromagnetic wave insulation

Volcanic ash particles are charged and disturb communication by radio.

Were radio communications disrupted at Hiroshima or Nagasaki?

[FirstClassSkeptic]

ABOARD the Enola Gay, Nelson had already sent word that the mission was a success. Now Parsons handed him a second message that, when decoded, would tell General Farrell, waiting anxiously in the 509th's operations room on Tinian, the news he had been waiting hours to hear.

CLEAR CUT. SUCCESSFUL IN ALL RESPECTS. VISIBLE EFFECTS GREATER THAN ALAMOGORDO. CONDITIONS NORMAL IN AIRPLANE FOLLOWING DELIVERY. PROCEEDING TO BASE.

After a third and final circle around Hiroshima, Tibbets put the Enola Gay on course for Tinian. The Great Artiste and No. 91 formed up behind, and the three bombers headed down the "Hirohito Highway" for home.

https://www.ourcivilisation.com/smartboa ... /chap1.htm

Nelson was the radio operator. Naturally, the messages were sent by radio as there was no other way.

So the radio was working. No static, or not enough to hamper radio messages.

[rerevisionist]

Brilliant remarks FCS as regards radio, too. Well, there may have supposedly been a big EMP. But there was supposed to be a lot of radiation, too.

Bamzam's volcano comment is spot on. Many eruptions are supposed to have sent huge amounts of more or less fine solids into the atmosphere. Tons, in fact.


Moderator's notes added July 31 2012
In 1984, the BBC broadcast (in Britain only, I presume) Threads, a fictional treatment of the aftermath of a nuclear explosion on Sheffield. An earlier BBC film The War Game (1965) — not to be confused with a 1983 US film WarGames — was not shown at the time, to the director's annoyance. In both cases only one bomb was assumed to have dropped, for no obvious reason.

Anyway, as regards the 1984 Sheffield thing here's a comment by 'LordZontar' in Youtube mid-July 2012: During the making of this movie, there was a very real panic in Sheffield because the chemical charge used to produce the mushroom cloud for the distance shot looked like one formed by an atomic bomb blast and it was visible in the direction of the local TRAF airbase and people thought momentarily that an actual attack was underway.

In 2003, June I think, there was a huge explosion in North Korea, 2003; .. a mammoth explosion ... produced a mushroom cloud more than two miles across. A planned demolition for a hydro-electrical scheme. ... another non-nuclear mushroom cloud.

And I noticed a Youtube comment (which I couldn't relocate) querying why the claimed 'mushroom clouds' don't get blown by the wind. Fair point. Jet streams occur from 20,000 feet; but 'H-bomb' clouds are claimed to reach to 100,000 feet. Jet streams are exceptionally fast, but of course ordinary winds can have fairly high speeds: even a 'gentle breeze' is rated as 7-10 knots on the Beaufort scale, 8 to 11 miles an hour. More evidence that such static clouds never existed and had to be faked.

Bear in mind the 'jet stream' was not common knowledge in 1945 .

Volcanic cloud heights offer an interesting comparison. The claimed heights are greater than claimed for nuclear clouds, but estimating the heights is difficult - and it seems heights are estimated by watching the effect of winds!