Skip to comments.
Speed of light broken with basic lab kit
New Scientist.com ^
 | 16 September 02
 | Charles Choi
Posted on 09/16/2002 7:26:53 AM PDT by aculeus
Electric signals can be transmitted at least four times faster than the speed of light using only basic equipment that would be found in virtually any college science department. 
Scientists have sent light signals at faster-than-light speeds over the distances of a few metres for the last two decades - but only with the aid of complicated, expensive equipment. Now physicists at Middle Tennessee State University have broken that speed limit over distances of nearly 120 metres, using off-the-shelf equipment costing just $500. 
Jeremy Munday and Bill Robertson made a 120-metre-long cable by alternating six- to eight-metre-long lengths of two different kinds of coaxial cable, each with a different electrical resistance. They hooked this hybrid cable up to two signal generators, one of which broadcast a fast wave, the other a slow one. The waves interfere with each other to produce electric pulses, which can be watched using an oscilloscope. 
Any pulse, whether electrical, light or sound, can be imagined as a group of tiny intermingled waves. The energy of this "group pulse" rises and falls over space, with a peak in the middle. The different electrical resistances in the hybrid cable cause the waves in the pulse's rear to reflect off each other, accelerating the pulse's peak forward. 
Four billion km/h 
By using the oscilloscope to trace the pulse's strength and speed, the researchers confirmed they sent the signal's peak tunnelling through the cable at more than four billion kilometres per hour. 
"It really is basement science," Robertson said. The apparatus is so simple that Robertson once assembled the setup from scratch in 40 minutes. 
While the peak moves faster than light speed, the total energy of the pulse does not. This means Einstein's relativity is preserved, so do not expect super-fast starships or time machines anytime soon. 
Signals also get weaker and more distorted the faster they go, so in theory no useful information can get transmitted at faster-than-light speeds, though Robertson hopes his students and others can now rigorously and cheaply test those ideas. 
Physicist Alain Hache at the University of Moncton in Canada adds that it may be possible to use this reflection technique to boost electrical signal speeds in computers and telecommunications grids by more than 50 per cent. 
Electrons usually travel at about two-thirds of light speed in wires, slowed down as they bump into atoms. Hache says it may be possible to send usable electrical signals to near light speed. 
 © Copyright Reed Business Information Ltd.
TOPICS: Front Page News; US: Tennessee
KEYWORDS: realscience; techindex
Navigation: use the links below to view more comments.
 first 1-20, 21-40, 41-60, 61-80 ... 101-107 next  last
    
1
posted on 
09/16/2002 7:26:53 AM PDT
by 
aculeus
 
To: maxwell; Robert A. Cook, PE
    max, is this the kind of stuff you play around with all day?
2
posted on 
09/16/2002 7:29:28 AM PDT
by 
xsmommy
 
To: aculeus
    This is weird BUMP.
3
posted on 
09/16/2002 7:31:10 AM PDT
by 
mercy
 
To: aculeus
    Amazing! Faster processing time means another step towards meaningful artificial intelligence. This means another step towards autonomous battlefield "robots". (Pretty scary in way) 
(If Bell Laboratories can hire these guys, maybe Lucent stock will become worth something again.)
 
4
posted on 
09/16/2002 7:31:58 AM PDT
by 
BenLurkin
 
To: aculeus
    Signals also get weaker and more distorted the faster they go, so in theory no useful information can get transmitted at faster-than-light speeds, though Robertson hopes his students and others can now rigorously and cheaply test those ideas.  Given that the peak can be observed, and its speed measured, this statement seems to be incorrect. A frequency modulation scheme would seem to offer a way of transmitting information.
 
5
posted on 
09/16/2002 7:33:55 AM PDT
by 
r9etb
 
To: aculeus
    Signals also get weaker and more distorted the faster they go, so in theory no useful information can get transmitted at faster-than-light speeds,That is not true, since by accurately timing the distortion you could take it into account. As well, sending a known test signal down the line before transmitting data would allow you to adjust for any slight differences due to temperature, etc.
 
6
posted on 
09/16/2002 7:34:35 AM PDT
by 
ikka
 
To: aculeus
    Alot of the slowdown in the future is not going to be the rate at which our computers receive data, but at how it processes it. You throw 200 GB in one second at your computer and see what happens.
7
posted on 
09/16/2002 7:35:43 AM PDT
by 
dogbyte12
 
To: aculeus
    bump .... so where's the warp drive already ? ;) 
To: aculeus
    Speed of light broken with basic lab kit... Wasn't me, I was taking a shower!
 I hope this isn't series.
 
To: mercy; All
    Now physicists at Middle Tennessee State University have broken that speed limit over distances of nearly ...  Another reason not to fixate on "prestige" universities.
 
10
posted on 
09/16/2002 7:40:31 AM PDT
by 
aculeus
 
To: aculeus
    Ha! And I've been snickering at my six-year-old son's plan to build his own rocket. When I explained that he'd have to study and then work for NASA, he said, "No, we can just go shopping at Home Depot." Maybe the kid is right.
To: FreedomFarmer
    I think it's very series. One day we will be able to send messages from the Moon to the Earth at faster than the speed of light. Then a father could explain to his kids that the Moon isn't made of cheese, while his son could tell the father all about how a moose bit his sister..., and all in record time.
To: aculeus
    "In a related announcement, the staff of Middle Tennessee State University have 'solved' the Unified Field Theory utilizing six soda straws, three empty beer cans, a ten-year-old Timex man's watch (leather band), twenty feet of plastic tubing (1/4" diameter), and duct tape."
To: aculeus; xsmommy
    Well, of course this isn't really news....
The National press corpse used to get their daily fax followup questions and spin briefing from the dnc even before the the media broadcast the first batch of lies from Hillary's White House.
To: Tired of Taxes
    Maybe the kid is right.  In a sense he is right. You really can build most of the necessary stuff from readily-available materials and get to some sort of orbit. 
 The cost comes when you start trying for high performance, precision, reliability, and (for manned flight) getting the crew home alive.
 
15
posted on 
09/16/2002 7:57:39 AM PDT
by 
r9etb
 
To: Notforprophet
    Some politician is gonna demand a speed limit be set and enforced, for 'da chilwrens', with his sister's cousin's second step-critter in charge of 'rite'n dem speeders up' for life.
To: aculeus
    I knew that appointing Jethro Bodine to the Middle Tennessee faculty would finally pay off!
17
posted on 
09/16/2002 8:00:00 AM PDT
by 
ArcLight
 
To: RightOnline
    LOL! Now if they could just solve the problem of chewing tobacco dribble, they'd be state heroes!
To: FreedomFarmer
    NYTimes: "Speed of Light Broken: Women and Minorities Hit Hardest."
To: aculeus
    QUESTION TO ALL:
  
 Doesn't Einstein's theory imply that if something travels faster than the speed of light, it would travel backward in time?
  
 That means if an electronic signal is traveling along a certain length of cable then the signal would arrive at it's destination at a point in space time prior to the point in space time that the switch was thrown to SEND THE SIGNAL in the first place. (Theme to jeopardy playing in background) 
  
 Any thoughts?.....And the SURVEY SAID?: 
 
20
posted on 
09/16/2002 8:02:25 AM PDT
by 
webboss
 
Navigation: use the links below to view more comments.
 first 1-20, 21-40, 41-60, 61-80 ... 101-107 next  last
    Disclaimer:
    Opinions posted on Free Republic are those of the individual
    posters and do not necessarily represent the opinion of Free Republic or its
    management. All materials posted herein are protected by copyright law and the
    exemption for fair use of copyrighted works.
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson