14 votes

Why did it take an army of physicists, working on a huge complex, so long to produce a working nuclear device, while it seems so easy in theory?

One of the big issues was isotope separation. Extracting uranium 235 from uranite was a huge problem that took quite an effort to overcome. In fact, just before the war started Niels Bohr believed ...
user avatar
11 votes

Why did it take an army of physicists, working on a huge complex, so long to produce a working nuclear device, while it seems so easy in theory?

(1) Weapon-grade uranium is hard to make - it took almost a year to separate 64 kg of weapon-grade uranium for the bomb in the Y-12 Oak Ridge facility, so "Little boy" bomb was not even tested (they ...
user avatar
8 votes

Why did it take an army of physicists, working on a huge complex, so long to produce a working nuclear device, while it seems so easy in theory?

You should do some preliminary research before asking such a question. It was not so easy, even in theory. They did not know anything about Plutonium when they started, it simply did not exist. They ...
user avatar
8 votes

To what extent were the scientists involved in the Manhattan project aware of the goals?

The sources are abundant and easy to find, for example Leslie Groves, Now it can be told. A history of Manhattan project (written by a project leader from the military side), Robert Jungk, Brighter ...
user avatar
7 votes

Why didn't Germany succeed in building a nuclear bomb in second world war?

On my opinion, there are two important reasons: a) German government did not press the matter. Nobody convinced it that the thing is plausible and important. (In the US there was a lobby who could ...
user avatar
7 votes

What new physics was discovered or needed as a result of the Manhattan Project?

A side note first - when dealing with non-physicists, they will generally regard quantum mechanics as the end-all-be-all of physics, the coolest weirdest stuff. So, it is not surprising that your ...
user avatar
7 votes
Accepted

Wasn't Feynman's parton model the same as the quark model?

Wasn't his parton model simply the same as the quark model? Didn't he [Feynman] "just" put some flesh on the skeletal concept of quarks present inside hadrons? Not at all! Before the ...
user avatar
5 votes
Accepted

Why is it said that Marie Curie died due to her work but the same isn't said for Fermi?

Is it simply that the causation between the work and the disease is more clear in the case of Curie but not Fermi? Marie Curie died of Aplastic anemia which was most likely due to exposure to ...
user avatar
  • 430
5 votes

Why did it take an army of physicists, working on a huge complex, so long to produce a working nuclear device, while it seems so easy in theory?

I can only recommend R. Rhodes, The Making of the Atomic Bomb once more and very strongly. It is also instructive to note that although Leo Szilard [sp] was inspired to understand and fight for the ...
user avatar
  • 51
5 votes

From a historical perspective why is beta decay associated with an anti neutrino instead of a neutrino?

Only after the neutrino's discovery did we come up with the concept of lepton number (based on the unexpected multiple lepton families), which warranted reclassifying "that other thing emitted in beta ...
user avatar
  • 1,620
5 votes
Accepted

Before the discovery of the neutron, how did scientists explain standard atomic weights?

Historically, the discovery of naturally-occurring isotopes of chemical elements by means of the mass-spectrograph provided a correct explanation for the fractional character of the experimentally-...
user avatar
  • 2,809
4 votes

To what extent were the scientists involved in the Manhattan project aware of the goals?

The website http://manhattanprojectvoices.org is full of interviews with participants in the Manhattan project. Some interviews address exactly the question asked here. For example, here are two ...
user avatar
  • 339
4 votes

To what extent were the scientists involved in the Manhattan project aware of the goals?

New scientific and engineering personal arriving at Los Alamos were given a series of lectures about the project, the relevant physics and the proposed designs of the weapons. These were later ...
user avatar
  • 534
4 votes
Accepted

When was it first noticed, or demonstrated, that radioactive material became warm?

I found the following at an AIP site on Marie Curie, apparently a copy of an article of hers in Century Magazine, pp 461-466 (January 1904). It appears to be a non-technical journal: Radium ...
user avatar
4 votes
Accepted

Did anything significant happened in 1960s that involve neutron?

Google Ngrams are based on searching mentions in book hits from the corresponding time period. By looking at the titles and contexts where the word is mentioned one can usually figure out what the ...
user avatar
  • 65.8k
3 votes
Accepted

What was known about the properties of the nucleus before the Liquid drop model was proposed?

Sizes and masses were roughly known since Rutherford's 1911 experiments. Gamow references some more precise measurements from 1920s in Mass Defect Curve and Nuclear Constitution. For example, size ...
user avatar
  • 65.8k
3 votes
Accepted

Who first noticed violation of aufbau principle of elements like Cr, Cu, Pd, Au, and how?

The Wikipedia article clearly states : [n+l rule] was suggested by Charles Janet in 1928...Janet "adjusted" some of the actual n + ℓ values of the elements, since they did not accord with ...
user avatar
  • 146
2 votes
Accepted

Lise Meitner's contribution to this experimental apparatus and research effort?

The above photo was reproduced in the biography: Lise Meitner, A life in Physics, by Ruth Lewin Sime; University Of California Press,1996, ISBN 0-520-20860-9. A brief description of the parts is given ...
user avatar
2 votes

Has anybody of famous physists thought nuclear weapons was impossible?

I've never heard of a physicist denying the possibility of building atomic weapons. The closest thing that I am aware of is Werner Heisenberg's statement “I don't believe a word of the whole thing,” ...
user avatar
2 votes

Why didn't Germany succeed in building a nuclear bomb in second world war?

By accident I stumbled upon a recent article about the topic in a german science journal: http://www.spektrum.de/magazin/warum-es-hitlers-atombombe-nie-gab/1427403 It is based on a the following ...
user avatar
  • 241
2 votes

What was the boat-carried nuclear bomb envisaged by the Einstein–Szilárd letter?

I think it's pretty obvious (at least in hindsight and having read Richard Rhode's excellent history ) that they simply didn't know the total mass (fissile plus compression explosives plus shell) of ...
user avatar
2 votes

What is the history of the use of the word daughter for a decay product in nuclear physics?

According to Wikipedia, a decay product is also referred to as a daughter product, a daughter isotope, radio-daughter or daughter nuclide. The term possibly arose from cell biology where its common to ...
user avatar
1 vote

What was known about the properties of the nucleus before the Liquid drop model was proposed?

What was known about the properties of the nucleus (its shape, its density etc) and the nuclear forces before the Liquid drop model was proposed? In 1897 Thomson discovered the negatively charged ...
user avatar
1 vote

Where did Fermi get the U235 for the first nuclear pile?

The uranium came from Belgian Congo, more precisely, from the Katanga Province. See this article explaining the central role of Edgar Sengier, ruler of the very powerful (Belgian) Union Minière du ...
user avatar
1 vote

Has anybody of famous physists thought nuclear weapons was impossible?

The question really hangs on when nuclear energy was thought possible; because once it is thought possible it's easy enough to speculate whether it could be weaponised. Now, in 1896 Wilhelm Rontgen ...
user avatar
1 vote

Why didn't Germany succeed in building a nuclear bomb in second world war?

As regards the Soviet's quick progress on the bomb please read Dark Sun which is Richard Rhodes second book on the making of the atomic bomb. Early on he describes the wholesale shipping of plane ...
user avatar
  • 11

Only top scored, non community-wiki answers of a minimum length are eligible