• Email Us: [email protected]
  • Contact Us: +1 718 874 1545
  • Skip to main content
  • Skip to primary sidebar

Medical Market Report

  • Home
  • All Reports
  • About Us
  • Contact Us

Scientists Have Slowed Light Down To An Embarrassing 38 Miles Per Hour

September 10, 2024 by Deborah Bloomfield

The speed of light in a vacuum is the absolute speed limit of the universe. Nothing will go faster than 299,792 kilometers per second (186,000 miles per second), according to Einstein’s work, as it would require an infinite amount of energy to do so.

Advertisement

However, that doesn’t mean that light can’t be beaten in terms of speed under the right set of circumstances. In water, for example, light is slowed down to 225,000 kilometers per second (139,800 miles per second), which is still pretty zippy, but can be beaten by particles (e.g. in a nuclear reactor) and result in Cherenkov light.

But 225,000 kilometers per second is far from the slowest that light has ever traveled. In 1998, scientists were able to slow it to just 17 meters per second, or an embarrassing 61.2 kilometers (38 miles) per hour.

Slowing light was not the ultimate aim of the experiment. The team were keen to study Bose-Einstein Condensate (BEC), a state of matter first hypothesized by Albert Einstein based on the work of theoretical physicist Satyendra Nath Bose. When a gas of bosons – subatomic force-carrying particles that have integer spin – are cooled to temperatures approaching absolute zero, they form a single quantum object, often compared to it acting as a single atom. 

“The wave function of a BEC corresponds to the ground state of a macroscopic quantum object,” one paper explains. “In other words, a collection of atoms in a BEC behaves as a single quantum entity.”

In this strange new state of matter, first created in the real world in 1995, you get a macroscopic look at quantum behavior.

Advertisement



It has plenty of weird properties, including zero viscosity. You get some of this stuff in a glass, it will crawl up the side of the glass. They can sustain vortices that can be used to create analog black holes, and explode in a way similar to a supernova, termed a bosenova. It’s pretty clear why you’d want to study this stuff.

In 1998, scientists from the Rowland Institute for Science created a BEC by supercooling sodium atoms in a vacuum chamber. First they fired laser beams (moving at the usual speed of light) at the sodium, slowing down the particles as they absorb photons. Now slowed, they were put in another array of lasers, where the atoms were knocked back in whatever direction they came from, further slowing (and cooling) the cloud of atoms, kept in place by a powerful magnetic field.

Once this was done and a cloud of condensate was formed, the team fired one laser across the width of it to set up quantum interference, while a second laser was fired across its length. Under these conditions, the light was slowed dramatically.

Advertisement

“We obtain a light speed of 17 [meters per second] for pulse propagation in an atom cloud initially prepared as an almost pure Bose Einstein condensate (condensate fraction is ⩾90 percent),” the team wrote of their experiment. “Whether the cloud remains a condensate during and after pulse propagation is an issue that is beyond the scope of this Letter.”

While satisfying, the team realized they could do better.

“Soon after, we succeeded in stopping a light pulse completely in an atomic cloud cooled to a temperature just above the transition temperature for BEC,” the team explains on the Hau Lab website. “At the time when the light pulse is slowed, compressed, and contained within the atomic sample, we turn off the control laser field abruptly and then turn it back on at a later time. When the control laser is turned back on, the light pulse is regenerated: we can stop and controllably regenerate the light pulse.”

The letter is published in Nature.

Deborah Bloomfield
Deborah Bloomfield

Related posts:

  1. Analysis-Epic’s narrow win in App Store case toughens fight against Google Play rules
  2. UK firms raise their inflation expectations – BoE survey
  3. Roman Military Camps In Arabia Spotted Using Google Earth, Suggesting Desert Conquest
  4. Apparently We Have To Say This But Do NOT Try And “Body Slam” An Orca

Source Link: Scientists Have Slowed Light Down To An Embarrassing 38 Miles Per Hour

Filed Under: News

Primary Sidebar

  • Martian Mudstone Has Features That Might Be Biosignatures, New Brain Implant Can Decode Your Internal Monologue, And Much More This Week
  • Crocodiles Weren’t All Blood-Thirsty Killers, Some Evolved To Be Plant-Eating Vegetarians
  • Stratospheric Warming Event May Be Unfolding In The Southern Polar Vortex, Shaking Up Global Weather Systems
  • 15 Years Ago, Bees In Brooklyn Appeared Red After Snacking Where They Shouldn’t
  • Carnian Pluvial Event: It Rained For 2 Million Years — And It Changed Planet Earth Forever
  • There’s Volcanic Unrest At The Campi Flegrei Caldera – Here’s What We Know
  • The “Rumpelstiltskin Effect”: When Just Getting A Diagnosis Is Enough To Start The Healing
  • In 1962, A Boy Found A Radioactive Capsule And Brought It Inside His House — With Tragic Results
  • This Cute Creature Has One Of The Largest Genomes Of Any Mammal, With 114 Chromosomes
  • Little Air And Dramatic Evolutionary Changes Await Future Humans On Mars
  • “Black Hole Stars” Might Solve Unexplained JWST Discovery
  • Pretty In Purple: Why Do Some Otters Have Purple Teeth And Bones? It’s All Down To Their Spiky Diets
  • The World’s Largest Carnivoran Is A 3,600-Kilogram Giant That Weighs More Than Your Car
  • Devastating “Rogue Waves” Finally Have An Explanation
  • Meet The “Masked Seducer”, A Unique Bat With A Never-Before-Seen Courtship Display
  • Alaska’s Salmon River Is Turning Orange – And It’s A Stark Warning
  • Meet The Heaviest Jelly In The Seas, Weighing Over Twice As Much As A Grand Piano
  • For The First Time, We’ve Found Evidence Climate Change Is Attracting Invasive Species To Canadian Arctic
  • What Are Microfiber Cloths, And How Do They Clean So Well?
  • Stowaway Rat That Hopped On A Flight From Miami Was A “Wake-Up Call” For Global Health
  • Business
  • Health
  • News
  • Science
  • Technology
  • +1 718 874 1545
  • +91 78878 22626
  • [email protected]
Office Address
Prudour Pvt. Ltd. 420 Lexington Avenue Suite 300 New York City, NY 10170.

Powered by Prudour Network

Copyrights © 2025 · Medical Market Report. All Rights Reserved.

Go to mobile version