Convergent evolution
Convergent evolution is "the independent evolution of similar features in species of different periods or epochs in time".  A simple example is fish and dolphins.  Fish didn't just become dolphins.  First a non-fish became a fish, then they exited the water, then they grew legs, then they re-entered the water, then they lost their legs.  Both fish and dolphins became water-dwelling fin-propelled animals at completely different points in history and in different branches of the tree of life. 

Pretty much every section of that Wikipedia page made my jaw drop, but the part about light skin color evolving twice was pretty cool. #science

American statistics
Whenever I hear a statistic about America or Americans, it's pretty much never true.  America isn't really a country, it's actually a shell company containing 50 smaller countries, each with its own economy, geography, and culture.  You can't say "America is mostly [X]" or "Americans are largely [Y]" because it's probably not true for the vast majority of the country, but because of how statistics work, it's sort of true in theory. 

I guess this sort of applies to any large heterogeneous group, and it's especially noticeable for the people who fall outside the norms of whatever statistic you're looking at. #math

Multi-event sports
Here's a list of somewhat unrelated multi-event sports: 
  • biathlon - cross-country skiing, shooting
  • duathlon - running, cycling, running
  • triathlon - swimming, cycling, running
  • pentathlon - fencing, swimming, riding, shooting, running
  • heptathlon - short run, long run, hurdles, long jump, high jump, pole vault, shot put
  • decathlon - short run, medium run, long run, hurdles, long jump, high jump, pole vault, shot put, discus, javelin
  • tetradecathlon - shortest run, shorter run, short run, medium run, long run, longer run, short hurdles, medium hurdles, long hurdles, long jump, high jump, shot put, discus, javelin
  • icosathlon - shortest run, shorter run, short run, medium run, long run, longer run, even longer run, longest run, short hurdles, medium hurdles, long hurdles, steeplechase, long jump, high jump, pole vault, triple jump, shot put, discus, javelin, hammer

Maybe it's just me, but it seems like track and field people are just dying for more ways to compete against each other. #sports

Occupational identity
I was having a discussion with some friends the other day when the following sentence came up (paraphrased):  "I don't want to send my kids to that type of school because their curriculum is anti-[his profession]."  I thought that was an odd position to take, both because it's probably completely untrue, but also because I can't imagine identifying myself so strongly with my job.  I have a job, I'm somewhat proud of it, and I mostly like it.  But at the end of the day (literally), I stop doing my job and go home and don't think about it.  I think my job suits me well, but if I didn't have to do it anymore, I'd quit literally this second.  I'm defined by a lot of things, and one of those things is certainly my occupation.  But I would never say I'm primarily defined by my job.  If you or a school or anyone wants to criticize my profession or my industry, go for it.  It's certainly warranted.  The idea that a job is central to your identity and is above reproach is completely foreign to me. #business

Let me start by saying I'm not an expert and I didn't do any research for what I'm about to write, so I could be completely wrong. 

It's my understanding that humans spread germs to each other through their face holes.  People talk, whisper, laugh, sing, yell, cough, sneeze, and do a variety of other things to propel germs out of their bodies and into the bodies of the people around them.  It's disgusting. 

It seems to me that anything that can possibly prevent this from occurring is probably a decent way to reduce the spread of germs.  That could be
  • physical separation, i.e. distance
  • a solid barrier, like a wall or window
  • a flexible barrier around each person, like a bubble suit
  • a face shield like a welder's mask
  • a mask covering the mouth and nose
Somewhat obviously, a wall is a better germ barrier than a face mask.  But a mask still does something, albeit less than some of the other options.  Some mask materials are probably better than others, but I would imagine any mask is better at preventing the spread of germs than no mask at all.  Doctors and nurses and dentists have known and practiced this for decades (at least). 

There was talk early on in the pandemic about whether or not masks are helpful at all.  And there's been talk more recently about which mask material is best.  The LA Times actually has a good writeup of the CDC's history of discouraging and then encouraging mask use throughout the pandemic (whoops).  I would estimate, again not an expert, that masks are and were probably helpful at reducing the spread of Covid. #science

Matlab is two things
I use Matlab a lot for my job, and I've come to understand that Matlab is two distinct yet inter-related things: 
  1. It's a programming language
  2. It's an integrated development environment
I was taught a bunch of different things about it in college, ranging from "it can solve equations" to "it can plot things".  But at a more fundamental level, it's simply a programming language.  Or more accurately (I think?), it's an uncompiled scripting language and a script interpreter.  And the Matlab window itself is a development environment which debugs the code, runs it, and stores outputs in memory. 

There are countless other tools that check one or all of these boxes.  But I think two things that set Matlab apart are
  • it's good at array-based math (MATrix LABoratory), e.g; [1, 2, 3] + [4, 5, 6] is simple to do and built in
  • it's a very simple language where a bunch of things work in ways that they probably shouldn't, which makes it attractive for engineers who didn't study computer programming