Monthly Archives: March 2021

March 12, 2021

Friday Notes (Mar 12, 2021)

Over time I seem to be creating day of the week categories for posts. It started with TV Tuesday, back in August 2012. (Which I unfortunately made a Tag rather then a Category — something I’d like to change one of these days.) The very next month I created Wednesday Wow (as a Category), which languished for years but I’ve used more often lately.

I’m not exactly sure when I created Sci-Fi Saturday. The first post was in July 2011 (the month I began this blog), but the Category came later. I applied it retroactively (many SF posts were on Saturdays; go figure). Mystery Monday is a recent addition started in December 2019.

And now I’m starting Friday Notes.

22 Comments | tags: laser light, Lotus 1-2-3, Turing Completeness | posted in Friday Notes

March 8, 2021

QM 101: Quantum Spin

By Wyrd Smythe

Popular treatments of quantum mechanics often treat quantum spin lightly. It reminds me of the weak force, which science writers often mention only in passing as ‘related to radioactive decay’ (true enough). There’s an implication it’s too complicated to explain.

With quantum spin, the handwave is that it is ‘similar to classical angular momentum’ (similar to actual physical spinning objects), but different in mysterious quantum ways too complicated to explain.

Ironically, it’s one of the simpler quantum systems, mathematically.

40 Comments | tags: QM101, quantum mechanics, quantum spin | posted in Math, Physics

March 6, 2021

Chilling Sabrina

By Wyrd Smythe

I watched the first season of Chilling Adventures of Sabrina (Netflix) with mixed reactions. It had just enough to keep me watching, but I didn’t think much of the writing. It has the same problem as a lot of modern fantasy — random, irrational, downright dumb (and in this case very unoriginal) world building.

The latter season tipped the scales entirely to an Ugh! rating for me. Television shows are rarely known for their intelligence, but this one has given me a new standard of worst-ever.

To be clear here, ‘I come, not to praise Sabrina, but to bury it.’

16 Comments | tags: fantasy, Michelle Gomez, Netflix, witches | posted in Rant, Sci-Fi Saturday, TV

March 1, 2021

QM 101: Eigen Whats?

By Wyrd Smythe

Unless one has a strong mathematical background, one new and perhaps puzzling concept in quantum mechanics is all the talk of eigenvalues and eigenvectors.

Making it even more confusing is that physicists tend to call eigenvectors eigenstates or eigenfunctions, and sometimes even refer to an eigenbasis.

So the obvious first question is, “What (or who) is an eigen?” (It turns out to be a what. In this case there was no famous physicist named Eigen.)

14 Comments | tags: eigenstate, eigenvalue, eigenvector, matrix transform, QM101, quantum mechanics | posted in Math, Physics