When you think of natural history museums,
you probably picture exhibits filled with ancient lifeless things,
like dinosaurs
meteroites,
and gemstones.
But behind that educational exterior,
which only includes about 1% of a museum's collections,
there are hidden laboratories where scientific breakthroughs are made.
Beyond the unmarked doors,
and on the floors the elevators won't take you to,
you'd find windows into amazing worlds.
This maze of halls and laboratories is a scientific sanctuary
that houses a seemingly endless variety of specimens.
Here, researchers work to unravel mysteries of evolution,
cosmic origins,
and the history of our planet.
One museum alone may have millions of specimens.
The American Museum of Natural History in New York City
has over 32,000,000 in its collection.
Let's take a look at just one of them.
Scientists have logged exactly where and when it was found,
and used various dating techniques to pinpoint when it originated.
Repeat that a million times over, and these plants,
animals,
minerals,
fossils,
and artifacts present windows into times and places around the world,
and across billions of years of history.
When a research problem emerges,
scientists peer through these windows and test hypotheses about the past.
For example, in the 1950s, populations of predatory birds,
like peregrine falcons,
owls,
and eagles started to mysteriously crash,
to the point where a number of species, including the bald eagle,
were declared endangered.
Fortunately, scientists in The Field Museum in Chicago
had been collecting the eggs of these predatory birds for decades.
They discovered that the egg shells used to be thicker,
and had started to thin around the time
when an insecticide called DDT started being sprayed on crops.
DDT worked very well to kill insects,
but when birds came and ate those heaps of dead bugs,
the DDT accumulated in their bodies.
It worked its way up the food chain
and was absorbed by apex predator birds