SOUDAN, Minnesota — It's invisible, but people still look for it.
It's cosmic, but confusing.
We're talking about "dark matter." Find it, and it's worth millions.
For SMU physicists that — and curiosity — make it worth the search.
SMU professor Jodi Cooley tries to teach how the universe works. Still, it's a subject even she doesn't fully understand.
"I've always been attracted to things that are hard or difficult," she said. "If people say, 'It can't be done,' I've always said, 'Really? Are you sure? I'm going to go do it!'"
It's a drive that sends her to extremes.
Twice a year, Professor Cooley embarks on a journey that she hopes will take her to the farthest reaches of the universe.
That quest is by way of Soudan, Minnesota — a four-hour drive north of Minneapolis. It's a place where the skies open to land untouched by developers, and tiny towns forged a century ago by people working underground.
It's those old iron mines that now draw the country's top minds to this remote location.
"We're on the cutting edge," Cooley said. "We're trying things nobody has tried to do."
Her day starts before the sun rises, traveling deep underground using the same elevator the original miners took in the 1920s.
It's a bone-rattling three-minute drop in complete darkness, taking Cooley 2,000 feet under the earth's surface.
And it is a striking case of old meets new, where the most sophisticated technology known to man is found in a mine that was dug in the late 1800s.
Down here, Cooley is part of a team of scientists sharing their sophisticated laboratory with bats.
For years, she and other scientists have been searching for something most of us have never even heard of: Dark matter.
Dark matter is thrown around in sci-fi movies and TV. Truth is, it's a tiny particle. You can't see or touch it, but it's all around us.
Extremely complicated experiments (we won't bore you with the details) have convinced scientists that dark matter does exist. They just can't see it — yet.
And so they don't understand basic big questions, like why the galaxies are held together, or even how the universe was formed after the big bang.
The search for that answer is what drives Professor Cooley and her colleagues.
"It would be like flipping a switch on in a dark room. Ah! It would be great," Cooley said.
If they succeed in their quest half a mile below ground, not only are Nobel prizes at stake; it would revolutionize how we understand the universe.
There is serious competition in this quest.
Teams of scientists in mines all over the world hope to be the first to discover dark matter.
The quest at times consumes Cooley and the other scientists.
Her brain can handle extreme calculations, but she doesn't remember how many years she's been married.
"I'm going to go with eight years," she said. "He might... might be in trouble when I get home tonight."
To be fair, Cooley has been looking for dark matter almost as long as she's been married.
In theory, scientists could spot the dark matter particle anywhere, but they need the deep mine to shield their delicate equipment from outside interference that could taint the results.
Basically, here's how it works. Buried in this rat's nest of equipment is a crystal. The scientists simply wait for tiny, invisible particles of dark matter to hit it.
To prove the existence of dark matter, they need just five hits..
After two years of searching, the research team in the Minnesota mine has seen two — agonizingly close.
"I think it's quite feasible we're going to find dark matter in the next five years, and we're going to say it's here," Cooley said.
So for now, the race is on for Cooley and the others to find that light at the end of the tunnel.