CLOSE
Original image

An Underwater River?

Original image

Mexico is home to some of the deepest, most complex cave systems in the world, but the Cenote Angelita is notable not only for its size but for its incredible underwater river systems.

If you aren't familiar with such a concept, you're probably wondering how a river can possibly appear under another body of water. The secret lies in the buoyancy of saltwater versus freshwater. In these caves, a thin level of hydrogen sulfate separates the freshwater up top from the saltwater below. The underwater trees that are only in the freshwater areas make the whole scene seem even more surreal, allowing for such mind-bending images as the one seen above by photographer Anatoly Beloshchin.

Original image
Justin Sullivan/Getty Images
arrow
travel
One Day, You May Not Have to Take Your Laptop Out at the Airport
Original image
Justin Sullivan/Getty Images

TSA security lines might be a little less annoying in the future. According to Condé Nast Traveler, the agency will soon test new airport scanners that allow you to keep your liquids and laptop in your carry-on bag during security screening, a benefit currently only available to those who have been accepted into the agency’s PreCheck program.

The ConneCT scanners have met the TSA's "advanced technology detection standards," according to the company that makes them, Analogic, meaning that they can be tested out at airports across the U.S.

Computed tomography scanning technology is regularly used in hospitals and research labs for everything from diagnosing cancer to studying mummies. The imaging technique uses x-rays that rotate around whatever object is being imaged to create 3D images that provide more detail than those created by the regular x-ray scanners currently used to inspect carry-on luggage.

The ConneCT scanners have been in the works for 10 years. The devices have x-ray cameras that spin around the conveyor belt that holds your bag, creating a 3D image of it. Then algorithms help flag whether there's something suspicious inside so that it can be pulled aside for further screening by hand. They've already been tested in airports in Phoenix and Boston, but haven't been used on a national level yet.

But don't expect to see the high-tech scanners at your local airport anytime soon. According to the TSA, they have to undergo yet more testing before any of the machines can be deployed, and there’s no timetable for that yet.

Until then, as you're packing your liquids, just remember—you can always just freeze them.

[h/t Conde Nast Traveler]

Original image
iStock
arrow
Big Questions
What Are the Northern Lights?
Original image
iStock

Over the centuries, many have gazed up at one of the Earth’s most fascinatingly beautiful natural wonders: the Northern Lights. In the past couple of weeks, some lucky American stargazers have gotten the chance to see them from their very own backyards—and could again this week, according to Thrillist. But what are they?

Before science was able to get a read on what exactly was happening in the night sky, ancient tribes had their own theories for what caused the jaw-dropping light show. Many early beliefs had roots in religion, such as that the light was a pathway souls traveled to reach heaven (Eskimo tribes) or that the light was an eternal battle of dead warriors (Middle-Age Europe). Early researchers were a bit more reasonable in their approximations, and most surrounded the idea of the reflection of sunlight off the ice caps. In 1619, Galileo Galilei named the lights the aurora borealis after Aurora, the Roman goddess of morning, after concluding they were a product of sunlight reflecting from the atmosphere.

Today, scientists have come to the general agreement that the lights are caused by the collision of electrically charged solar particles and atoms from our atmosphere. The energy from the collisions is released as light, and the reason it happens around the poles is because that's where the Earth’s magnetic field is the strongest. In 2008, a team at UCLA concluded that “when two magnetic field lines come close together due to the storage of energy from the sun, a critical limit is reached and the magnetic field lines reconnect, causing magnetic energy to be transformed into kinetic energy and heat. Energy is released, and the plasma is accelerated, producing accelerated electrons.”

"Our data show clearly and for the first time that magnetic reconnection is the trigger," said Vassilis Angelopoulos, a UCLA professor of Earth and Space Sciences. "Reconnection results in a slingshot acceleration of waves and plasma along magnetic field lines, lighting up the aurora underneath even before the near-Earth space has had a chance to respond. We are providing the evidence that this is happening."

The best time to see the Northern Lights is during the winter, due to the Earth’s position in relation to the sun (shorter days means darker night skies). And by the way, it’s not just the North Pole that puts on a show—there are Southern Lights, too. There are also aurora borealis on other planets—including Mars—so rest assured that future generations born “abroad” will not miss out on this spectacular feat of nature.

Haven’t seen them yet? Traditionally, the best places to catch a glimpse of the Northern Lights are in Iceland, Sweden, Norway, Finland, Greenland, northern Canada, and Alaska. Maybe you'll get lucky this week and sneak a peek from your very own window. Check out Aurorasaurus for regular updates on where they are showing.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios