Condensed matter physics Updated +Created
Condensed matter physics is one of the best examples of emergence. We start with a bunch of small elements which we understand fully at the required level (atoms, electrons, quantum mechanics) but then there are complex properties that show up when we put a bunch of them together.
Includes fun things like:
As of 2020, this is the other "fundamental branch of physics" besides to particle physics/nuclear physics.
Condensed matter is basically chemistry but without reactions: you study a fixed state of matter, not a reaction in which compositions change with time.
Just like in chemistry, you end up getting some very well defined substance properties due to the incredibly large number of atoms.
Just like chemistry, the ultimate goal is to do de-novo computational chemistry to predict those properties.
And just like chemistry, what we can actually is actually very limited in part due to the exponential nature of quantum mechanics.
Also since chemistry involves reactions, chemistry puts a huge focus on liquids and solutions, which is the simplest state of matter to do reactions in.
Condensed matter however can put a lot more emphasis on solids than chemistry, notably because solids are what we generally want in end products, no one likes stuff leaking right?
But it also studies liquids, e.g. notably superfluidity.
One thing condensed matter is particularly obsessed with is the fascinating phenomena of phase transition.
Figure 1.
xkcd 2933: Elementary Physics Paths
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Video 1.
What Is Condensed matter physics? by Erica Calman
. Source. Cute. Overview of the main fields of physics research. Quick mention of his field, quantum wells, but not enough details.
Radioactive decay Updated +Created
Ciro Santilli finds it interesting that radioactive decay basically kickstarted the domain of nuclear physics by essentially providing a natural particle accelerator from a chunk of radioactive element.
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).
Marie Curie papers Updated +Created
Under Section "Publication by Marie Curie" I did a quick overview of the papers in which Marie Curie and collaborators publish the existence of new elements polonium and radium. Both are very understandable (except the chemistry), and have some cute terminology. I also cited those papers on her Wikipedia page: en.wikipedia.org/w/index.php?title=Marie_Curie&diff=1240252528&oldid=1238097626 Another good exercise in "old paper finding" + "Wikipedia markup/rules" as I looked at the Comptes rendus de l'Académie des Sciences a bit.
This was kickstarted by YouTube recommending me the following good video:
Video 1.
The RaLa Experiment by Our Own Devices
. Source.
which led me into yet a quick nuclear physics binge. I shouldn't do this to myself. I also ended up writing some tentative answers on Quora: