This is a video of Pennsylvania physical science teacher Bruce Yeany demonstrating a bunch of the marble tracks he's built over the years to teach students various physics principals. I thought it was a great refresher course in basic physics. And by refresher course I obviously just mean fresher course because I did not know any of those things. Did I even learn physics in school? SPOILER: No I did not, because I was out the whole semester with mono from kissing girls on the playground. "He licked the monkey bars." IT WAS A SWING SET, MOM.
Keep going for the video (but feel free to skip around to see the various tracks) while I say a silent prayer everyone here is refined enough to not leave a playing with your balls joke in the comments.
Thanks to Nat, for inspiring me to want to be a teacher and spread my vast wealth of knowledge to today's youth.