If my ideas about physics were "conventional", then perhaps they wouldn't be my ideas. Clearly the fact that Galileos' ideas were unconventional didn't prove them to be scientifically wrong.

There can be a drift to fashion over fact, where the novelty is dismissed simply for being innovative in an unfashionable direction, not for being scientifically incorrect! (I'm well aware that political correctness is not my forte.) :-)

The 1950 U.K. Home Office Scientific Adviser's Branch report The Number of Atomic Bombs Equivalent to the Last War Air Attacks on Great Britain and Germany (National Archives document reference HO 225/16) concluded that the whole of WWII bombing on Britain is equivalent to 52 nuclear bombs of 20 kt (Hiroshima-Nagasaki) yield.

Since damage area and casualties scale as (yield)^{2/3} ("equivalent megatonnage" in Cold War jargon), 52 bombs of 20 kt has the same effect as 52*(20/1000)^{2/3} = 3.8 bombs of 1 megaton yield each.

However, HO 225/16 used a higher figure for WWII casualties than O'Brien's data. HO 225/16 states:

"This figure for the weight of high explosive equivalent to the atomic bomb for causing casualties increases as the amount of protection of the population increases. Thus for the night raiding conditions on London in the last war, where something like 60% of the population were in houses, 35% in shelter and 5% in the open, the number killed in inner London per ton of bombs was 4."

HO 225/16 was Top Secret for 8 years then Restricted until 1980. They didn't want to undermine nuclear deterrence by debunking exaggerations.

"Churchill was hardly apathetic about the atomic bomb ..."

Richard Rhodes quotes Churchill's reaction in The Making of the Atomic Bomb:

"Although personally I am quite content with existing explosives, I feel we must not stand in the path of improvement."

Churchill was just being realistic, and contrary to Rhodes, was proved right. It turned out to be too late to drop on Germany, and with most of the wooden medieval German city centres already burned out by firestorms, and better air-raid shelters in Germany basements than in Hiroshima, I doubt if the casualties would have been significant. Note that no historian, not even Dr Melissa Smith (Architects of Armageddon: the Home Office Scientific
Advisers' Branch and civil defence in Britain, 1945–68 has ever checked the Dirkwood Corporation's 1968 analysis of 35,000 Hiroshima and Nagasaki case histories with respect to survival rates outdoors or indoors, in shelter, etc. The bomb was only highly in Hiroshima against overcrowded wooden housing when most people were outdoors. There is too much prejudice to deal with this.

Rhodes gets all his "facts" wrong on this, presenting complete drivel. The Radiation Effects Research Foundation has a database, and survivors were able to document how many colleagues were working in the buildings in each case. There is no uncertainty that people survived in the firestorms because 100% of those with serious radiation sickness were within the firestorm radius (the initial radiation drops very sharply with distance, as shown in tests and thermoluminescence dosimetry in Hiroshima). They evacuated the firestorm area before the firestorm started, which wasn't instant but took about 2-3 hours to reach its peak.

In other words, the bomb would have been ineffective against modern (non-wood) cities in Germany or London. Terence H. O’Brien points out on pages 11-16 of the official British History of the Second World War, Civil Series, Civil Defence (1955) that in WWI, 103 air-raids (51 airship, 52 bomber) dropped 300 tons of bombs, causing 16 casualties/ton of bombs (29% of whom died), but only the worst two daylight air raids on London (June and July 1917) which caused 121 casualties/ton (26% fatal) and 16 night raids on London in 1917-18 gave 52 casualties/ton, used in civil defence planning calculations. Second, they assumed that the enemy would drop as many bombs as possible as quickly as possible. O’Brien states on page 12 that the British Committee on Imperial Defence in November 1921 predicted an air attack of 1,500 tons/month of bombs on Britain, adding on page 96 that on 28 October 1937 the Committee of Imperial Defence revised this for German rearmament to 600 tons/day or 18,000 tons/month, assuming a minimum of 50 casualties/ton, thus predicting 18,000 x 50 = 900,000 casualties/month. If that were true, Britain would have been exterminated in WWII. (A PDF of O'Brien is linked on my page.) Combining Appendices II and III on pages 677 and 680 of O'Brien gives us the WWII results for high explosive bombs (tons) and fatalities caused in Britain:

1940: 23,767 killed by 34,970 tons, 0.68 killed/ton
1941: 19,918 killed by 22,176 tons, 0.90 killed/ton
1942: 3,236 killed by 3,039 tons, 1.06 killed/ton
1943: 2,372 killed by 2,232 tons, 1.06 killed/ton
1944: 8,475 killed by 8,081 tons, 1.05 killed/ton
1945: 1,860 killed by 772 tons, 2.41 killed/ton

Before 1945, most of the bombs dropped were aircraft or slow V1 cruise missiles (doodlebugs), but in 1945, 86% of the bomb tonnage was V2s (O'Brien assumes each V2 equivalent to 1 ton of explosive). The average mortality rate was lowest in 1940 because of careful sheltering, it slightly increased to about 1 killed/ton from 1941-4 because people became used to air-raids (as the official Nov 1941 Shelter Survey showed), thus often stayed in doors at night in the cupboard under the stairs or under a table shelter, instead of going out to a cold, damp shelter. In 1945 in rose dramatically because the V2 is supersonic and thus gave no audible warning: the first sound was blast wave. So people had no warning to take cover.

O'Brien in Appendix IV (p681) states that London received 71 major raids (over 100 tons/raid) from 7 Sept 1940 to 16 May 1941, amounting to 18,291 tons of high explosive, 18.291 kilotons.

If the damage scaling was was linear, then for 50% blast yield (Glasstone and Dolan, 1977) we have a 36.6 kt nuclear bomb equivalent.

However, the diffraction (overpressure) damage areas (or number of buildings damaged) increases only as the 2/3rds power of yield. So bigger bombs produce a less-than-proportional increase in destruction. O'Brien states on p505 that the most common Blitz bombs dropped on London were 50 kg and 250 kg, and that Andersons survived undamaged at 6 ft and 20 ft, respectively. Let's take 100 kg as the mean bomb size for the high explosives in the London Blitz, hence 18,291 tons is equivalent to 183,000 bombs each of 0.0001 kt blast yield. Scaling up to 1 megaton blast yield bombs:

183,000*(0.0001 kt)^{2/3} = N*(1000 kt)^{2/3}

Thus: 394 = 100N

hence N ~ 4 bombs of 1 megaton blast yield (or 2 megatons total yield).

The Blitz blast overpressure effects on London were thus equivalent to 4 hydrogen bombs of 2 megatons yield each. Sure, there was no fallout, but if the Russians wanted to optimise blast and thermal effects they would have to air burst the bombs well above the fireball radius. Now, please tell me, why civil defence is supposedly not possible against nuclear weapons for all the orthodox historians? Can they calculate? :-)

Some of your other claims are a bit odd (leaving aside your unconventional ideas about physics). Churchill was hardly apathetic about the atomic bomb; he was the one to order the start of both British projects (the wartime atomic bomb project and the Cold War thermonuclear bomb project), and access to nuclear data and technology was a major theme of his diplomacy with the Americans. I'm not sure why you think Churchill's 1924 (not, as is sometimes reported, 1925) article 'Shall we all commit suicide?' to be significant either for Churchill's thinking on nuclear weapons or more generally. It's not even clear that he is referring to the atomic bomb: he doesn't use the term or mention radioactivity. Sandwiched in between a very brief discussion of death rays and robot bombers, he says:

Then there are Explosives. Have we reached the end? Has Science turned its last page on them? May there not be methods of using explosive energy incomparably more intense than anything heretofore discovered? Might not a bomb no bigger than an orange be found to possess a secret power to destroy a whole block of buildings -- nay, to concentrate the force of a thousand tons of cordite and blast a township at a stroke?

Of course, he could well be referring to atomic bombs; but I think he is hedging his bets and is talking about them as well as more powerful conventional explosives. He wasn't a scientist, after all, and he was not making a scientific prediction. (If he was, he was wrong anyway: you can't build a nuke the size of an orange.)

Laurence also gave away a detailed discussion of the neutron chain reaction uranium-235 fission principles for the atomic bomb in his 5 May 1940 front page New York Times article, "Vast Power Source In Atomic Energy Opened by Science," and then again in his 7 September 1940 Saturday Evening Post article, "The Atom Gives Up", which was widely discussed by the media world wide. Laurence emphasized that uranium fission had been discovered in 1938 in Germany by Hahn and others, and was a military explosive threat. he wanted America to get the bomb first.

In Men and Atoms (1959) he explains that after he was recruited to the Manhattan Project, General Groves's security officer sternly showed him a captured Werner Heisenberg scrap book containing his articles covered with cellophane, with German translations of the text on facing pages (from the "Alsos" project to document German atomic progress).

The bomb had also been widely discussed pre-war by H. G. Wells (The World Set Free) and even Winston Churchill in a 1925 newspaper article (reprinted in his pre-war book, Thoughts and Adventures). Laurence wrote a very detailed article on the atomic bomb based on interviews with Fermi and others. None gave away much, but he pieced the bits together from many interviews with different scientists to get an alarming picture of Germany racing for a bomb having discovered fission, while America procrastinated. Richard Rhodes in The Making of the Atomic Bomb ignores Churchill's 1925 article when discussing his apathy towards the bomb research during WWII. Churchill could see that the cost and time of making an atomic bombs exceeded that of dropping an equivalent amount of non-nuclear explosives and incendiaries. Given the equivalent megatonnage two-thirds power scaling law, there is no cost benefit to nuclear weapons over conventional weapons. Nuclear weapons just save money in requiring smaller delivery systems than an equivalent amount of conventional weapons.

If you are still interested in pre-Hiroshima references to atomic bombs, Alan, the novels I know of are listed in a previous post. In the Times digital archive I found just two references prior to the Lords debate. One was from a September 1939 letter to the editor and was in relation to Hitler's threat of an unspecified secret weapon; another was from the early 1930s and was the name of a racehorse which was scratched!

HRS Phillpott: Globe-Busting Bomb -- It Was Coming.

"'If what we are told about the atom is true', he said, 'every atom in the world might be disintegrated and the world would disappear."

(This would be Esme Ivo Bligh, ninth earl, and the son incidentally of Ivo Francis Walter Bligh, former president of the MCC and Kent County Cricket Club and the first English captain of an Ashes match with Australia.)

Based on the phrasing used in the above quotes, it seems to me more likely that they are drawing more on some knowledge of the German bomb project, than pre-war discussions: atomic bombs are referred to quite casually, as though the listener ought to be aware of them (and while there were a few -- not many -- atomic bombs in pre-war SF, how many peers of the realm would have read about them, or remembered what they were in 1945?); and the statement is also made that they were something which were very nearly developed in the war, which is not something you could just assume from pre-war discussions. Given the context of the discussions about how to control German science and prevent revenge missile attacks, it all very strongly implies that some stories about a German bomb were floating about. But still, without seeing those stories I can't be sure.