berkeman's latest activity

It's a forum bug, reference now deleted.

Thanks @berkeman that hit my funny bone

You are just cheating yourself out of essential background understanding (which is the really fun part) if you've skipped chapters 1-3...

Cheaper fans use flat blades at an angle. Better fans use airfoils at an angle (like a propeller). Here is a good PF Insights article...

Thanks a lot. This certainly is a I am looking for.

which are composed of protein and chitin Your answer is in there somewhere. The laying down of the components has to have some...

https://en.wikipedia.org/wiki/Black_coral has a different answer to this question: However, the "skeletons" are not always black...

Thank you everyone who voted for me and others! Not sure I deserved it this year considering how inactive I have been over the last 12...

I didn't recognize his name, but when I clicked into the link I definitely recognize his face. I think I watched a number of his...

You "have reason to believe" that galaxies are at least seven times older than the universe they exist in? Out of morbid curiosity, what...

Thank you for the nomination.:smile: Congrats to all the winners.:partytime: To the mentors keeping the site running smoothly.:bow...

Okay, since we don't seem to have any good responses, what has your reading shown you so far?

Based on the sketch, it seems that ##\theta## is the angle of cylindrical polar coordinates, not spherical polar coordinates. I agree...