Once I decided to build 2wd bicycle and faced the callenge. It wasn't that easy I expected but after few weeks 2wd bike works. All needed parts I found in old hand drill and some of them borrowed in a... continue reading

posted by newtboy 3 years 6 months 1 week ago • 129 views • 4:38

YouTube: I came across these four physics puzzles over the years in discussions with Neil deGrasse Tyson (riddle 4: which part(s) of a moving train are going backwards with respect to the ground?), Simon... continue reading

posted by PlayhousePals 7 years 11 months ago • 1,232 views • 4:24