[lit-ideas] Re: untestable proposition of the day
- From: JimKandJulieB@xxxxxxx
- To: lit-ideas@xxxxxxxxxxxxx
- Date: Sun, 21 Aug 2005 12:00:39 EDT
Funny, it popped up fine for me.... anyway, here's the article.
<< Scientists Mess with the Speed of Light
_Ker Than_
(http://us.rd.yahoo.com/dailynews/space/sc_space/byline/scientistsmesswiththespeedoflight/16155134/SIG=11md14tj9/*http://www.space.com/php/contac
tus/feedback.php?r=kt)
LiveScience Staff Writer
_LiveScience.com_
(http://us.rd.yahoo.com/dailynews/space/sc_space/byline/scientistsmesswiththespeedoflight/16155134/SIG=10sog4vj6/*http://www.livescience.c
om) Fri Aug 19, 4:00 PM ET
Researchers in Switzerland have succeeded in breaking the cosmic speed limit
by getting light to go faster than, well, light.
Or is it all an illusion?
Scientists have recently succeeded in doing all sorts of fancy things with
light, including slowing it down and even stopping it all together. Now a team
at the Ecole Polytechnique Fdrale de Lausanne (EPFL) in Switzerland is
controlling the speed of light using simple off-the-shelf optical fibers,
without
the aid of special media such as cold gases or crystalline solids like in
other experiments.
"This has the enormous advantage of being a simple, inexpensive procedure
that works at any wavelength," said Luc Thvenaz, lead author of the study
detailing the research.
Using a technique called Stimulated Brillouin Scattering, the researchers
were able to slow down or ratchet up the speed of light like the gas pedal on a
car. They succeeded in reducing the speed of light by almost a factor of 4
(although that's still plenty fast at 46,500 miles per second), but even more
dramatically, the team was also able to speed up the speed of light.
Light in a vacuum travels at approximately 186,000 miles per second, but a
popular misconception is that, according to Einstein's special theory of
relativity, nothing in the universe can travel faster than this speed.
This seeming paradox can be resolved because a pulse of light is actually
made up of many separate frequency components, each of which moves at their own
velocities. This is known as the pulse's phase velocity. If all the frequency
components have the same phase velocity, then the overall pulse will also
appear to move at that velocity.
However, if the components have different phase velocities, then the pulse's
overall velocity will depend on the relationships between the velocities of
the separate components. If the velocities differ, the pulse is said to be
moving at the group velocity.
By tweaking the relationship between phase velocities, it's possible to
adjust the group velocity and create the illusion that parts of the pulse are
traveling faster than the speed of light.
One area where such an advance could be enormously beneficial is in the
telecommunications industry.
Although information can be channeled through fiber optics at the speed of
light, it can't be processed at this speed because with current technologies,
light signals must be transformed into much slower electrical signals before
they are useful.
Thevenaz's technique would essentially allow light to be processed with light
without a costly electrical conversion.
The group's research will be published in an August 22nd issue of the journal
Applied Physics Letters.New Theory: How to Make Objects Invisible Light
Packets Slow to Jet Speed Blue Skies Only In the Eye of the Beholder Physicists
Bring Light to a Stop
Visit LiveScience.com for more daily news, views and scientific inquiry with
an original, provocative point of view. LiveScience reports amazing, real
world breakthroughs, made simple and stimulating for people on the go. Check
out
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Copyright © 2005 _SPACE.com_
(http://us.rd.yahoo.com/dailynews/space/SIG=grdpua;_ylt=AhfS6SYhWq9sSWnswRulD9D737YB;_ylu=X3oDMTA1MTZrdWFvBHNlYwNm/*http://www.
SPACE.com/) .>>
========Original Message======== Subj: [lit-ideas] Re: untestable
proposition of the day Date: 8/20/05 6:08:05 P.M. Central Daylight Time From:
_mr.eric.yost@xxxxxxxxxx (mailto:mr.eric.yost@xxxxxxxxx) To:
_lit-ideas@xxxxxxxxxxxxxx (mailto:lit-ideas@xxxxxxxxxxxxx) Sent on:
Well, then, whaddya make of this?
_http://news.yahoo.com/s/space/20050819/sc_space/scientistsmesswiththespeedofl
ight;_ylt=Aqg8b858IBrkrBmBzwrgwWgDW7oF;_ylu=X3oDMTBiMW04NW9mBHNlYwMlJVRPUCUl_
-----
Yahoo gave me:
Sorry, the page you requested was not found.
The story or page you were trying to access may have expired.
-----
I didn't get there in time.
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