View full lesson: http://ed.ted.com/lessons/human-sperm-vs-the-sperm-whale-aatish-bhatia

Traveling is extremely arduous for microscopic sperm — think of a human trying to swim in a pool made of…other humans. We can compare the journey of a sperm to that of a sperm whale by calculating the Reynolds number, a prediction of how fluid will behave, often fluctuating due to size of the swimmer. Aatish Bhatia explores the great (albeit tiny) sperm’s journey.

Lesson by Aatish Bhatia, animation by Brad Purnell.