I looked up the numbers for the present size of the known universe, the size of the smallest observable unit, and some miscellaneous other things, just for some perspective... The presently known universe scales from 1.708166198e-51 light years across (the size of the smallest observable unit, the Planck length) to about 92 billion light years across (the present largest extent of the observable universe)! Or, in other words, the known universe scales from 1 Planck length to about 5.4e+61 Planck lengths across! Our bodies are on the order of 1e-16 light years or 6e+34 Planck lengths in size. The smallest resolvable object we can perceive is about 1/10,000th that size. The distance from our eyes to the horizon when standing at ground level is only a few thousand times the body's height. Our remarkably light sensitive eyes can detect light from stars and galaxies much, much farther away than that, but that is mapped onto our normal perception space, without any sense of real distance or size. The words to the nursery song are "twinkle, twinkle LITTLE star." So we are trapped in a tiny sliver of space and time, around halfway between the boundaries of the smallest and largest known things, which themselves are "known" only to us as intangible abstractions, anyway. And we like to think we know what reality is!?!
— Gabriel Fenteany, November 8, 2015
