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In the age of the quantified self, products that promise to track your habits and fix your behavior are a dime a dozen. Find out how much you walk; <a href="https://www.washingtonpost.com/news/to-your-health/wp/2016/07/15/pokemon-go-leading-to-a-population-level-surge-in-fitness-tracker-step-counts/">do that more</a>. Find out how much junk you eat; <a href="https://www.washingtonpost.com/lifestyle/wellness/the-macros-diet-does-it-really-work/2016/06/07/d38a5434-2bf6-11e6-9b37-42985f6a265c_story.html">do that less</a>. Correct your posture in real time, and get feedback as you <a href="http://www.theverge.com/2015/1/26/7892551/kgoal-kegel-exercises-device-review">strengthen your pelvic floor muscles</a>. More and more companies are built on the notion that any problem can be solved if you get enough numbers to find a pattern.

In that sense, Sense — a sleep tracker made by the <a href="https://hello.is/">start-up Hello</a> — isn't all that unusual. But the company's new lead scientist is just getting his hands on two years of user sleep data, and he seems particularly passionate about using it for good.

<a class="markup--anchor markup--p-anchor" data-href="http://psychology.berkeley.edu/people/matthew-p-walker" href="http://psychology.berkeley.edu/people/matthew-p-walker" target="_blank">Matthew Walker</a>, a professor of neuroscience and psychology at the University of California in Berkeley, and director of the U.C. Berkeley Sleep and Neuroimaging Laboratory, does not mince words when it comes to snoozing.

[The science of smartphone batteries and how to keep them charged]

"It’s very clear right now that the sleep-loss epidemic is the greatest public health crisis in First World nations of the 21st century," Walker told The Washington Post. "Every disease that is killing us, in First World countries, can be linked to loss of sleep."

Indeed, the Centers for Disease Control and Prevention <a href="http://www.cdc.gov/features/dssleep/">states that lack of sleep</a> — in addition to causing fatal accidents and injuries — has been linked to an increase risk of hypertension, diabetes, depression, obesity and even cancer. Just about all scientists and medical professionals agree that good sleep helps keep the body healthy.

But <a href="http://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html">less than a third of American adults</a> get the seven-hour minimum recommended by the American Academy of Sleep Medicine. Walker has spent his career trying to change that, and he was intrigued by the idea that he might help the masses understand the "bespoke nature of their sleep."

"Reuniting humanity with sleep is my big ambition," he said.

Sense consists of a spheroid environmental sensor that tracks temperature, light and air quality along with a sleep-movement tracker that clips onto a pillow. For instance, it will tell you your sleep was restless, and it will indicate that your room was too hot or too bright on a night you didn’t sleep well.

The technology already addresses some of the big issues Walker sees in struggling sleepers. Most of us are familiar with warnings that bright, blue-tinted light from screens can keep our bodies from winding down before bed, but temperature is more important for healthy sleep than many realize.

[No, turkey doesn’t make you sleepy]

Anecdotally, it's easier to sleep in a cold room than a hot one. That, Walker explained, is because the body and brain need to drop about two degrees to fall into deep sleep. The advent of modern climate control has made that difficult, because most Americans keep their surroundings at the same, comfortable temperature all day. Without the natural cool of night vs. day, your body has difficulty adjusting.

"We dislocated ourselves from the natural ebb and flow of temperature," just as we dislocated ourselves from the natural cycle of daylight and darkness, Walker said.

Sleep inconsistency is another common culprit. Too many modern humans adjust their sleeping hours based on shifting daily schedules. The weekend is particularly tricky: Walker knows that many poor sleepers shift from going to sleep around 11 p.m. and waking up at 6 a.m. on a workday to going to sleep in the wee hours and waking up just in time for brunch on days off.

"Most people end up suffering from something called social jet lag," he said, with sleep and wake times shifted by three hours or more from one day to the next — a shift akin to flying from one coast to the other and back again every weekend. It doesn't help that alcohol is frequently involved in those late nights, either: Many think that a buzz helps put them to bed, but <a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/08/08/dear-science-why-do-hangovers-happen-and-how-can-i-make-them-go-away/">the sedative powers of alcohol interfere with real sleep</a>.

[A molecule called ‘Sandman’ could help solve the ‘mystery of sleep’]

Walker appreciates that Sense, which tracks poor choices and environmental factors, such as these, can help educate its users and empower them to control their own sleep conditions. But he also hopes that user data — which is collected by the company — will help him make new sleep discoveries.

"It's probably one of the largest data sets on human sleep on Homo sapiens; it’s remarkable," he said. Hello's CEO James Proud wouldn't confirm the number of active Sense users, but the company sold 21,000 units during its launch on Kickstarter two years ago. Since then the product has become available on Amazon, and it will be hitting mass retail shelves late this year. So far, Walker said, they have "millions of hours of recorded sleep."

"Here’s a wonderful paradox that we are now designing technology to fix the problems caused by technology," Walker said. "This is where I differ from many colleagues. They think the invasion of technology in the bedroom is the greatest enemy of sleep, and they’re right, but I also think it’s our potential salvation."

"I am desperately excited about what we can achieve," he added.

If Hello is truly able to turn its user data into solid sleep science, the company could help inform better bedtime practices around the world — even for those of us who won't choose to splurge on the Sense itself.

<a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/08/22/dear-science-how-do-i-stop-snoring/">Dear Science: How do I stop snoring?</a>

<a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/04/20/what-a-year-of-working-the-graveyard-shift-taught-me-about-sleep/">What a year of working the graveyard shift taught me about sleep</a>

<a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/09/14/these-strange-subterranean-cities-are-eerily-like-our-own-but-theyre-ruled-by-ants/">These strange, subterranean cities are eerily like our own. But they’re ruled by ants.</a>

<a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/09/14/gaia-space-telescope-reveals-the-most-complete-3-d-map-of-our-galaxy-ever/">Gaia space telescope reveals the most complete 3-D map of our galaxy ever</a>