Ciro Santilli @cirosantilli 40

Ciro Santilli found out that he likes computer security researchers and vice versa.

It's a bit the same reason why he likes physicists: you can't bullshit with security.

You can't just talk nice and hope for people to belive you.

You can't not try to break things and just keep everyone happy in their false illusion of safety.

You can't do a half job.

If you do any of that, you will get your ass handed to you in a little gift bag.

All of this is closely linked to Ciro Santilli's self perceived creative personality and being naughty and creative are correlated.

It is said, that once upon a time, programmers used CSV and collaborated on SourceForge, and that everyone was happy.

These days, are however, long gone in the mists of time as of 2020, and beyond Ciro Santilli's programming birth.

Except for hardware developers of course. The are still happily using Perforce and Tcl, and shall never lose their innocence. Blessed be their souls. Amen.

Conda is like pip, except that it also manages shared library dependencies, including providing prebuilts.

This has made Conda very popular in the deep learning community around 2020, where using Python frontends like PyTorch to configure faster precompiled backends was extremely common.

It also means that it is a full package manager and extremely overbloated and blows up all the time. People should just use Docker instead for that kind of stuff: www.reddit.com/r/learnmachinelearning/comments/kd88p8/comment/keco07k/

You also have to buy a license to use their repos if you are part of a large-enough organization: stackoverflow.com/questions/74762863/are-conda-miniconda-and-anaconda-free-to-use-and-open-source

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.

The orthogonal group has 2 connected components:

It is instructive to visualize how the $\pm 1$ looks like in $SO(3)$:

As a result it is isomorphic to the direct product of the special orthogonal group by the cyclic group of order 2:

A low dimensional example:because you can only do two things: to flip or not to flip the line around zero.

Note that having the determinant plus or minus 1 is not a definition: there are non-orthogonal groups with determinant plus or minus 1. This is just a property. E.g.:has determinant 1, but:so $M$ is not orthogonal.

TODO is there any good intuitive argument or proof of conservation of energy, momentum, angular momentum?

A set of axioms is consistent if they don't lead to any contradictions.

When a set of axioms is not consistent, false can be proven, and then everything is true, making the set of axioms useless.

This is a general philosophy that Ciro Santilli, and likely others, observes over and over.

Basically, continuity, or higher order conditions like differentiability seem to impose greater constraints on problems, which make them more solvable.

Some good examples of that:

TODO synonym to analog quantum computer?

It is also possible to carry out quantum computing without qubits using processes with a continuous spectrum of measurement.

As of 2020, these approaches seem less developed/promising, but who knows.

These computers can be seen as analogous to classical non-quantum analog computers.