3 ms·
Wow, that scale! Thanks for posting that! If my calculations are right, Earth's diameter is about 12000km and its highest/lowest places are about 10km, so abou
by gregoriol 5y ago
Wow, that scale! Thanks for posting that!
If my calculations are right, Earth's diameter is about 12000km and its highest/lowest places are about 10km, so about 0.001
If a billiard ball is about 10cm, it's highest/lowest places equivalent to earth would be 0.1mm.
Not sure what are the standards for billiard smoothness, but that seems very smooth to me.
- zokier 5y ago0.1mm is not very smooth. According to wikipedia, 150 grit sandpaper has average particle size of 90-100µm edit: of course there is vigorous internet commentary about billiard ball smoothness compared to earth: https://possiblywrong.wordpress.com/2011/01/03/is-the-earth-like-a-billiard-ball-or-not/ https://possiblywrong.wordpress.com/2011/01/03/is-the-earth-... https://skeptics.stackexchange.com/questions/10763/is-earth-as-smooth-as-a-billiard-ball https://skeptics.stackexchange.com/questions/10763/is-earth-... https://billiards.colostate.edu/faq/ball/smooth/ https://billiards.colostate.edu/faq/ball/smooth/ Which mostly seem to agree that earth definitely is not as smooth as a (new) billiards ball, but there is lots of debate about the details.
- aardvark179 5y agoA billiard ball is about 50mm in diameter. I guess the question is to what tolerance they are made. I wouldn’t expect a small feature to stick up (you’d be able to feel or see those fairly easily) but the overall deviation from a perfect sphere could easily be that large.