[RAIN]
[MUSIC PLAYING]
This drop of water falling on soil is about to liberate the smell of rain,
which actually comes from the earth, not the water.
The scientist at MIT who made this video knew that much,
what they didn't know is now captured on video is how it happened.
You have to have the right size drop,
falling at the right speed,
on the right surface.
As it hits the ground, it traps tiny bubbles of air.
Those bubbles then burst from the drop like fizz from champagne,
and they carry with them the smell of the earth,
or rain-washed pavement,
or wherever they fall.
These bubbles are not just capturing the molecules in the earth that smell good,
they could also be transporting viruses or bacteria that cause diseases.
So it's bound to be useful to learn more about how it works.
[RAIN]