The wikipedia article Polydactyly in stem-tetrapods has some explanations on how we ended up with 5 fingers and toes.

The gist of it is that tetrapods (four-limbed vertebrate animals) evolved from a fish similar to a lobe-finned fish that had 5 sets of bones in each of its fins that evolved into fingers and toes. Some tetrapods have subsequently lost digits but the basal state was five.

There’s a book, Your Inner Fish by Neil Shubin that’s full of this kind of stuff. Highly recommend.

You Can’t Stump the Trump (Volume 4).

It was all fun and games and centipedes and 420 sniper headshot dubstep memes. And then shit got real.

Ska 'za? Nah brah.

Yeah probably true. I only thought to look it up because I knew active and passive sonar was a thing.

Passive radar?

machining

No idea about your algorithm problems but have you seen the Cutting Edge Engineering Australia channel? It’s so good.