this is so much more digestible than "grain of sand at arm's length", and those two metrics dont feel at all equivalent -- the moon is not ten grains of sand at arm's length wide, right?
The moon is pretty darn small. Half a degree wide. Imagine gluing ten grains of sand together, balancing it on a fingertip, then stretching your arm out. Around a degree wide? Depending on your grain of sand, of course.
hmmm, about the size of an asprin tablet or pea at arm's length, seems to agree with somewhat smaller than thumbnail [1]. maybe i should find and measure some sand now :).
in either case, 1/10 the width of the moon is so much easier to comprehend. when is the last time anyone tried holding a grain of sand at arms length? what a weird comparison to make when everyone on earth already has a stable/familiar reference in the sky.
this is so much more digestible than "grain of sand at arm's length", and those two metrics dont feel at all equivalent -- the moon is not ten grains of sand at arm's length wide, right?