From: nospam@de-ster.demon.nl
Paul.B.Andersen wrote:
> Den 03.01.2026 22:28, skrev Thomas 'PointedEars' Lahn:
> > Paul.B.Andersen wrote:
> >> Den 02.01.2026 16:35, skrev Thomas 'PointedEars' Lahn:
> >>> Paul.B.Andersen wrote:
> >>>
> >>>> According to Google's AI:
> >>>
> >>> LOL. "Google" is not a source; "Google's AI" is even less than that.
> >>>
> >>>> "Nuclear fission was discovered by German chemists Otto Hahn
> >>>> and Fritz Strassmann in late 1938, who observed uranium nuclei
> >>>> splitting into lighter elements like barium when bombarded with
> >>>> neutrons, with physicists Lise Meitner and Otto Frisch providing
> >>>> the theoretical explanation and coining the term "fission"
> >>>> shortly after, revealing the massive energy release. Hahn
> >>>> received the Nobel Prize in Chemistry in 1944 for the discovery,
> >>>> though Meitner's crucial role in understanding the process is
> >>>> now widely recognized.
> >>>>
> >>>> Fermi was the first who, in 1934, bombarded uranium atoms with
> >>>> neutrons and observed that strange things happened, but he didn't
> >>>> understand that the uranium atom was split.
> >>
> >> These are facts you cannot laugh away.
> >
> > These _claims_, if true, are irrelevant to your claim as by then the
> > equivalence of rest energy and mass was already known.
>
> These _historical facts_ are very relevant to our discussion.
>
> Why do you dispute something which so easily can be looked up?
>
> Strange attitude!
>
> >>>> The point is that the fission was not discovered because
> >>>> someone thought that since E = mc?, it must be possible
> >>>> to release energy by splitting atom.
> >>>
> >>> Non sequitur. We were not discussing just nuclear fission, but *the
> >>> creation of an atomic bomb*: an *uncontrolled* nuclear fission reaction,
> >>> possibly induced by nuclear fusion, *designed* to cause destruction.
> >>
> >> So the discovery of nuclear fission and the fact
> >> that ≈ 200 MeV kinetic energy is realised when
> >> a U-235 atom is hit by a neutron and split in two, is
> >> irrelevant to the creation of the fission atomic bomb? :-D
> >
> > You appear to be confused about your own argument. Now you are arguing,
> > *contrary* to what you argued before, that the known mass--energy
> > equivalence did play a role in the creation of the atomic bomb. Make up
> > your mind.
>
> You don't read what I write very carefully.
>
> My claim is:
> There would have been no atomic bomb in 1945 if
> the nuclear fission of uranium had not been discovered
> in 1938.
Or without the discovery of the U235 isotope,
in 1935, by Arthur Jeffrey Dempster.
> The fission was not discovered because someone thought
> that since E = mc?, it must be possible to release energy
> by splitting atoms.
Accurate values of nuclear masses had been known
from mass spectroscopy since sice the 1920s.
Through this it was already known that there were vast stores of energy
trapped in all atomic nuclei. (and not just radioactive ones)
People started speculating about liberating nuclear energy since then.
(without yet having a clue as to how this might be practically achieved)
The key discovery was that it was the rare U235 isotope
that was splitting under slow neutron bombardment,
not the more generally occurring U238 isotope.
(and that such a splitting of an Uranium nucleus would liberate
more free neutrons)
This insight was due to Lise Meitner and Otto Frisch,
who explained fission on basis of Bohr droplet model of the nucleus.
(Meitner, L.; Frisch, O. R. (1939). "Disintegration of Uranium by
Neutrons: a New Type of Nuclear Reaction". Nature. 143 (3615): 239.)
Meitner was of course passed over for the Nobel prize for it.
She was Jewish, a woman, and a mere theoretician,
so she didn't stand a chance,
Jan
--- SoupGate-DOS v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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