three oddball fun facts: Hypnic Jerks and Personal Bubbles

My brother had a bunch of science magazines in the 70's and I read them as a kid. I was thinking about what I remember from those magazines and three things came to mind:

Does this ever happen to you: You're in bed and you've almost fallen asleep. Then, the next thing you know, you daydream you're walking and you trip over something or fall down, which triggers you kicking your leg up in the air. There's a name for that: it's a Hypnic Jerk.

In the rain forests of Africa, scientists found one of the largest trees on the planet and determined one was completely hollow. A scientist rappelled into it and found multiple species that had never been seen anywhere else, such as snakes and frogs that were albinos with no eyes.

Everybody has an imaginary bubble around them that makes their personal space. Usually, when someone who is not a close friend encroaches your personal space, it makes you feel uncomfortable. This bubble is not circular, but oval shaped, and men's ovals are different that women's ovals. If you are standing in a room, a woman would be willing to stand closer to you standing face to face, whereas a man would be willing to stand closer to you side by side.