CLOSE
Youtube user, 落合陽一
Youtube user, 落合陽一

Scientists Create 3D Laser Holograms That Are Safe To Touch

Youtube user, 落合陽一
Youtube user, 落合陽一

3D laser holograms sound cool, but they're generally hot. As in, hot enough to burn your skin. But now researchers at the Digital Nature Group, a Japanese lab, say they've figured out a way to create a 3D laser hologram that is not only safe to the touch but interactive.  

These "fairy lights" holograms are composed of light pixels called voxels fired at superfast speeds. (How fast? The laser bursts last 30 to 270 femtoseconds. A femtosecond is a quadrillionth of a second.) Voxels are emitted by plasma that's created when the laser's focused energy ionizes the air. 

Popular Science breaks down how DNG did it:

To create their hologram, researchers fired their femtosecond laser through a spatial light modulator, which continues the beam through a series of lenses, a mirror and a Galvano scanner, which positions a mirror to precisely direct the laser beams. A camera underneath the hologram captures user interaction, allowing the dots to respond to being “touched.”

Each tiny 3D image, many times smaller than the tip of a person's finger, is made up of about 200,000 voxels per second and is interactive based on touch. Some researchers reported that the holograms feel like sandpaper, and others like receiving a static shock. 

The interactive aspect is still simple—you can check a box or "break" a heart, for instance—but being able to touch the holograms at all represents progress.

This isn't the first time scientists have used femtosecond lasers to create images suspended in the air. But previous attempts to do so had less sharp resolution—and burned human skin. The trick to fixing that was making the lasers fire in especially short blasts. Lab studies found that anything longer than two seconds will burn human skin (or at least the leather researchers used to represent human skin). But firing the lasers at bursts from 50 milliseconds to 1 second left the "skin" un-singed.

For a more technical description and a chance to see the holograms in action, check out the video below. The technology is complicated, and likely prohibitively so. That is: don't expect holograms in your house anytime soon. 

[h/t Popular Science]

arrow
History
When Chuck Yeager Tweeted Details About His Historic, Sound Barrier-Breaking Flight

Seventy years ago today—on October 14, 1947—Charles Elwood Yeager became the first person to travel faster than the speed of sound. The Air Force pilot broke the sound barrier in an experimental X-1 rocket plane (nicknamed “Glamorous Glennis”) over a California dry lake at an altitude of 25,000 feet.

In 2015, the nonagenarian posted a few details on Twitter surrounding the anniversary of the achievement, giving amazing insight into the history-making flight.

For even more on the historic ride, check out the video below.

nextArticle.image_alt|e
Mrs. John Herschel, Wikimedia Commons
8 Stellar Facts About the Most Accomplished Female Astronomer You’ve Never Heard Of
Mrs. John Herschel, Wikimedia Commons
Mrs. John Herschel, Wikimedia Commons

Caroline Herschel (1750-1848) was a German woman who made great contributions to science and astronomy. 

1. SHE WAS THE FIRST WOMAN TO DISCOVER A COMET.

Herschel spotted the comet (called 35P/Herschel-Rigollet) in December of 1788. Because its orbital period is 155 years, 35P/Herschel-Rigollet will next be visible to humans in the year 2092.

2. SHE INITIALLY WORKED AS A HOUSEKEEPER.

In her early twenties, Herschel moved from Germany to England to be a singer. Her brother William (the astronomer who discovered the planet Uranus and infrared radiation) gave her singing lessons, and she was his housekeeper. She later became his assistant, grinding and polishing the mirrors for his telescopes.

3. BUT SHE LATER TURNED HER REAL PASSION INTO A PAYING GIG.

Herschel was the first female scientist to ever be paid for her work. Starting in 1787, King George III paid her £50 per year to reward her for her scientific discoveries.

4. SHE WAS TECHNICALLY A LITTLE PERSON.

Herschel was only 4 feet 3 inches tall—her growth was stunted due to typhus when she was 10 years old.

5. SHE BROKE BARRIERS, EARNING RESPECT FROM THE HERETOFORE MALE-ONLY SCIENTIFIC COMMUNITY.

Herschel was the first woman to receive a Gold Medal from London’s Royal Astronomical Society, in 1828. The second woman to receive one was well over 150 years later, in 1996.

6. SHE CHEATED AT MATH ... KIND OF.

Because Herschel was female and thus wasn’t allowed to learn math as a child, she used a cheat sheet with the multiplication tables on it when she was working.

7. EARTH'S MOON HONORS HER LEGACY.

By NASA / LRO_LROC_TEAM [Public domain], via Wikimedia Commons

A crater on the moon is named in honor of Herschel—it’s called C. Herschel. The small crater is located on the west side of Mare Imbrium, one of the moon's large rocky plains.

8. SHE GARNERED AWARDS WELL INTO HER NINETIES.

For her 96th birthday, Prussian King Frederick William IV authorized that Herschel receive an award: the Gold Medal for Science.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios