字幕 (41)
0:01- Is dust just people?
0:04You may have heard, like me, that the dust
0:06that collects around your house
0:07is mostly made of dead human skin cells.
0:12Well, as usual, the
answer's more complicated
0:14and more interesting, but
that's also not totally wrong.
0:18Humans shed about a
gram of skin every day.
0:20We actually replace our
entire outer epidermal layer
0:23every two to four weeks.
0:24That means that your
dead body does make up
0:26a significant portion of
the dust on your windowsill,
0:29but dust is also much more than that.
0:32dust contains a whole
world of shapes and colors.
0:34It's almost beautiful
in a really gross way.
0:37Now, one famous study of
households in the Midwest
0:40found that a third of dust comes
from stuff inside the home.
0:43In addition to skin cells
from you and your pets,
0:46that includes food debris
and fibers from clothing
0:48and furniture, plus microscopic dust mites
0:50just feeding on all that debris
0:52from you and your belongings.
0:53But the other two thirds of household dust
0:55actually comes from outside the house,
0:57including dirt, pollen, feces, eh,
1:00environmental pollutants.
1:01There's even trace amounts of
space minerals from meteorites
1:04and distant exploding stars
that just shower down to Earth.
1:07Dust is basically just a microcosm
1:09of your local environment.
1:10In fact, it's even used
by forensic scientists
1:13to help solve crimes.
1:14The DNA entombed in dust
from a person of interest
1:17can help provide valuable information
1:19about where they may have traveled.
1:21So dust is people. It's
just more than that, too.
1:24Guess that puts a whole new meaning
1:25on cleaning up after yourself.
1:27Follow me for more cool science videos.
