If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Scale of the small and large

2 videos
We humans have trouble comprehending something larger than, say, our planet (and even that isn't easy to conceptualize) and smaller than, say, a cell (once again, still not easy to think about). This tutorial explores the scales of the universe well beyond that of normal human comprehension, but does so in a way that makes them at least a little more understandable. How does a bacteria compare to an atom? What about a galaxy to a star? Turn on your inertial dampeners. You're in store for quite a ride!

Scale of the large

VIDEO 11:02 minutes
Attempting to comprehend the scale of the large

Scale of the small

VIDEO 13:14 minutes
From honey bees to cells, viruses, and atoms -- understanding the scale of the very small