Lidar—a high-tech cousin of radar—uses light waves to peel back the layers of time.
WE USUALLY think of archaeology as involving intrepid explorers and lots of painstaking digging. But today, long-hidden cities are being revealed from the air, where modern archaeologists use laser beams to spot evidence of ancient life buried beneath thick vegetation.
Lidar, short for “light detection and ranging” (and a cousin of radio-based radar), involves directing a rapid succession of laser pulses— between 100,000 and 400,000 per second—at the ground from an airplane or a drone. Software captures the time and wavelength of the pulses reflected from the surface and combines it with GPS and other data to produce a precise three-dimensional map of the landscape below. These high-tech explorations have revealed long-buried Mayan cities, including Tikal, in the dense jungle of Guatemala, and Caracol, in Belize.
Denne historien er fra September 2018-utgaven av Reader's Digest US.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra September 2018-utgaven av Reader's Digest US.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
Election Day Memories - Stories about voting by the people, for the people
A Convincing Argument When my boyfriend and I were finally old enough to vote in our first presidential election, we spent months debating with one another about our chosen candidates. We were quite persuasive, as we discovered when we got home from the polls and learned that we'd both voted for the other's initial choice.―SHERRY FOX Appleton, WI
A New Way to Monitor Blood Sugar
Who can benefit from this wearable technology
A Flag for Dad
An old sailor made a last wish. His son was determined to see that it came true.
Sisterhood to Last a Lifetime
These college pals teach a master class in how to maintain a friendship for 50-plus years
...TO DIE ON A HOCKEY RINK
ONE MINUTE I WAS PLAYING IN MY BEER LEAGUE, THE NEXT I WAS IN THE HOSPITAL
Yes, There's a Museum for That!
These collections are wacky, wonderful and worth a visit
Town Meeting Is Called!
Once a year, the people of Elmore, Vermont, gather to practice a cherished right: democracy
Just Tight
Broken, battered and trapped in a ravine for days, a desperate driver wonders, \"Will anyone find me?\"
WHY OUR BODIES DON'T DIG DAYLIGHT SAVING TIME
Twice a year, when we spring ahead and fall back, we're more prone to sleepiness, depression and accidents
MONEYSAVING DO'S AND DON'TS
The run-up to the holidays doesn't have to bah-humbug your budget. A shopping expert shares strategies for saving big now and all year round.
