Is there a way to rapport an arcmin to a measurement that would be more easily understandable? Not necessarily as a multiple of grains of rice.
The moon is about half a degree or 30 arcminutes wide. This doesn't make sense but give it a try tonight if the moon is out.
FWIW many of the galaxies and nebula you see in astrophotography are actually bigger in the night sky than one might guess. Andromeda for example is about 6 times wider than the moon at ~3 degrees across - https://slate.com/technology/2014/01/moon-and-andromeda-rela...
The moon is between 29.4 and 33.5 arcminutes wide, depending on where it is in its orbit. So about a tenth of the width of the moon.
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?
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.
[1] https://astronomy.com/magazine/stephen-omeara/2010/01/stephe...