The discovery process was particularly interesting, including Henri Becquerel's luck while observing phosphorescence, and Marie Curie's observation that the uranium ore were more radioactive than pure uranium, and must therefore contain other even more radioactive substances, which lead to the discovery of polonium (half-life 138 days) and radium (half-life 1600 years).
Most of the helium in the Earth's atmosphere comes from alpha decay, since helium is lighter than air and naturally escapes out out of the atmosphere.
As a result of that law, alpha particles have relatively little energy variation around 5 MeV or a speed of about 5% of the speed of light for any element, because the energy is inversely exponentially proportional to half-life. This is because:
- if the energy is much larger, decay is very fast and we don't have time to study the isotope
- if the energy is much smaller, decay is very rare and we don't have enough events to observe at all
Caused by weak interaction TODO why/how.
Most commonly known as a byproduct radioactive decay.
Gamma rays are pretty cool as they give us insight into the energy levels/different configurations of the nucleus.
Example: Figure "caesium-137 decay scheme"
The half-life of radioactive decay, which as discovered a few years before quantum mechanics was discovered and matured, was a major mystery. Why do some nuclei fission in apparently random fashion, while others don't? How is the state of different nuclei different from one another? This is mentioned in Inward Bound by Abraham Pais (1988) Chapter 6.e Why a half-life?
Some of the most notable ones:
- 1942: Chicago Pile-1: the first human-made nuclear chain reaction.
- 1943: X-10 Graphite Reactor: an intermediate step between the nuclear chain reaction prototype Chicago Pile-1 and the full blown mass production at Hanford site. Located in the Oak Ridge National Laboratory.
- B Reactor produced the plutonium used for Trinity and Fat Man.
TODO can you do Stern-Gerlach experiment with alpha particles?
Ciro Santilli once visited the chemistry department of an university, and the chemists were obsessed with NMR. They had small benchtop NMR machines. They had larger machines. They had a room full of huge machines. They had them in corridors and on desk tops. Chemists really love that stuff. More precisely, these are used for NMR spectroscopy.
Basically measures the concentration of certain isotopes in a region of space.
The equation is simple: frequency is proportional to field strength!
Used to identify organic compounds.
Seems to be based on the effects that electrons around the nuclei (shielding electrons) have on the outcome of NMR.
So it is a bit unklike MRI where you are interested in the position of certain nuclei in space (of course, these being atoms, you can't see their positions in space).
Using NMR to image inside peoples bodies!
More fun nuclear stuff to watch:
- Dr. Strangelove (1964)
- The World Of Enrico Fermi by Harvard Project Physics (1970)
- Fat Man and Little Boy (1987) shows a possibly reasonably realistic of the history of the development of the Trinity
Located in Washington, in a dry place the middle of the mountainous areas of the Western United states, where basically no one lives. The Columbia river is however nearby, that river is quite large, and provided the water needed by their activities, notably for cooling the nuclear reactors. It is worth it having look on Google Maps to get a feel for the region.
Unlike many other such laboratories, this one did not become a United States Department of Energy national laboratories. It was likely just too polluted.
The first human-made nuclear chain reaction.
Their website, and in particular the recruitment section, are so creepy.
There's not mention of bombs. No photos of atomic explosions. The words "atomic" and "weapon" do not even show up in the front page!!! The acronym AWE is instead used everywhere as an euphemism.
In the recruitment section we can see a bunch of people smiling: web.archive.org/web/20211007213222/https://www.awe.co.uk/careers/working-at-awe/, suggesting:
We make nukes, and we do it with a smile!There's even children outreach!!!
Ciro Santilli is not against storing a few nukes to be ready against dictatorships. But don't be such a pussy! Just say what the fuck you are doing more clearly! You are making weapons to kill people and destroy things in order to maintain the Balance of power. If the public can't handle such facts, then shut down the fucking program.
Ah, the choice of name, both grim and slightly funny, Dr. Strangelove comes to mind quite strongly.