A fundamental physical constant in many areas of physics, the speed of light. The speed of light, which is constant and finite, is 186,000 miles per second. However, did you know that it is possible to alter the speed of light?
Lene Hau, a physicist from Denmark, achieved this first
slowing of light to 38 mph in 1999. Later, she was able to completely halt,
regulate, and move it.
Who is Lene Hau?
Lene Vestergaard Hau, a physicist born in Vejle, Denmark, on
November 13, 1959, is most known for her work slowing and stopping light. She
graduated from Aarhus University in Denmark with a bachelor’s degree in
mathematics, a master’s degree in physics, and a PhD.
Lene Hau’s Research on the Speed of Light
After years of effort, Hau mastered the art of riding a
bicycle at the speed of light in 1999.
Instead of cycling faster, she slowed light down to an
astonishing 60 kilometers per hour, accomplishing this impressive feat. She
accomplished something even more extraordinary, stopping light in its tracks.
Light travels at 186,000 miles per second. Hau has known
this but never anticipated breaking the light-speed slow-speed record. She
started a new research endeavor shortly after she got there: looking for the
Bose-Einstein Condensate, a brand-new state of matter.
Atoms are extremely sensitive to temperature; at a few
millionths of a degree above absolute zero, they lose their individuality and
merge.
This collection can behave like a single superatom at low
enough temperatures; it is referred to as the Bose-Einstein Condensate after
the two physicists whose research predicted its existence in 1924.
"I was so curious to see what this new state of matter
was like. We were incredibly happy. We had succeeded." Lene Vestergaard
Hau, Physicist
The Bose-Einstein Condensate was ultimately formed in June
1997 after Hau and her colleagues successfully cooled the atoms.
After creating it, Hau and her coworkers started looking for
uses for the condensate. They discovered they could make light pass through the
previously opaque condensate by precisely manipulating it with laser beams. And
they realized that no material had ever been identified that could delay light
as efficiently as the massaged condensate.
Using an electromagnet, a 0.2 millimeter-long cigar-shaped
condensate was suspended inside a vacuum chamber. They used a precisely
calibrated laser beam to illuminate the cigar from the side before firing a
pulse of laser light along its long axis.
As soon as the pulse touched the modified condensate, it
slowed and compressed. For a year, Hau labored through the night in the lab to
refine her test technique for slowing light. She started to notice the light
slowing in March 1998, at last.
"I thought, ‘gee, you are the first person to see light
go this slowly." Lene Vestergaard Hau, Physicist
She discovered she was moving quicker than her light beams
when she took a flight to Copenhagen that summer. She published her findings
that autumn when she successfully got light to move at a bicycle’s pace.
Her team advanced their research this year by successfully
stopping all light inside a Bose-Einstein Condensate. The scientists
immediately shut off the coupling laser once the light pulse had been fully
compressed and trapped within the condensate. The light became trapped inside
after this change. The initial light pulse emerged from the other end when they
turned the coupling laser back on.
Reference: Physics Central
If one can slow down the speed of light is it possible within that slowed light could time come to a stand still? I have always heard that time slows when you come closer to the speed of light.
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ReplyDeleteWell... sort of. The speed of light in a vacuum is constant. But in other mediums (e.g. glass, or water, or whatever) it's slower. In the center of the Sun, it's so slow that light takes 200,000 YEARS to get from the center to the surface.
DeleteYeah , I didn't want to get too technical. The space between particles is also a vacuum, meaning that the light travels from particle to particle at a constant speed. The density and energy state of particles affects the speed at which photons are absorbed and emitted, giving the illusion that the light itself is traveling at a different speed.
DeleteI take issue with how this article presents the distinction.
So if light can be slowed and there are records before this of the speed of light being slower, than the vast age and maybe distances within the universe would not be so great as thought.
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