Oops

That isn't too plausible unless they have really, really slow edges on that light pulse. I sort of suspect that they loosened a connector, removed 40 feet of fibre, and then tightened it again.

Cheers

Phil Hobbs

One of my customers (you know who) tested one of my timing boxes and complained that the delay was 700 ns, about 600 ns more than we measure. It's fiber in and out, and they were using available 60 meter pigtails. Oh, they are in the laser business; you'd think they might have heard of the speed of light.

That's another one of those mistakes that only happens with a large and appreciative audience. Of course, the CERN guys shouted their mistake from the housetops of their own free will, no doubt with visions of Nobel Prizes and immortal fame. I rather suspect that there are a lot of damage control meetings going on there at the moment.

As the poster says,

The Six Stages of a Project:

Enthusiasm Disillusionment Panic Search for the Guilty Punishment of the Innocent Praise and honours for the non-participants

Cheers

Phil Hobbs

I saw this and my thought was "Why are these physicists trying to prove something that has been proven logically true"? I know they want so bad to prove multiple worlds, black holes, time travel, etc... but sometimes you just gotta accept the facts. Einstein proved beyond any reasonable doubt, given some very reasonable assumptions, that FLT travel is impossible(and IIRC information cannot travel FLT is a consequence). Surely there is better things to spend grant money on than chasing a pipe dream? There seems to be very little real physics going on today...

Like 1 watt blue laser diodes for $20 or less. Who'd a thunk it 10 years ago.

ter

be

Einstein didn't prove anything. He produced a remarkably coherent explanation of a very wide range of observations, and his explanations have yet to be falsified, which is as close to "proved" as any scientific theory gets.

You can prove a mathematical theorem, but mathematics is an art, rather than a science.

The CERN crew got an odd result, couldn't - at the time - find any plausible explanation of the oddness, and eventually (and rather reluctantly) published it. The how science works. Experimental observations are sacred (if they can be replicated) but theories last just as long as they fit the facts. Huxley talked about the scientific tragedy of the death of a beautiful theory slain by a single ugly fact.

-- Bill Sloman, Nijmegen

Light fibers are THAT slow? Then why not use less costly coax?

Well, since it is obvious to all that you are a non-participant, then...

About 2/3 c or something like that. About the same as coax.

We use fiber because of the horrible pulse transmission of coax over tens of meters... rise times go to hell, and ground loops make things worse. You can shoot a 10 ns pulse over a kilometer of multimode fiber and it hardly changes. You can get 10 ps RMS edge jitter with cheap parts. Ditto a hundred km of singlemode.

Multimode fiber is cheaper than good coax anyhow.

Grin... Yeah I hope we hear the details of how that 'connection' was tightend.. perhaps they meant time-wise.

George H.

t -

Well, that's what you get when you let physicists do electronics.

undoes-faster.html? rss=1&utm_source=twitterfeed&utm_medium=twitter#.T0VAu8O-G8w.twitter

But, according to Wikipedia, there's a bad crystal oscillator in there that affects the results the opposite way.

I have sympathy for the Opera folks -- they've found results that flies in the face of what they are trained to believe, and which makes them look profoundly silly to announce, yet are solid enough that they are compelled by honesty to do so. You can feel their discomfiture when you read their press releases.

Loss. Fibres have bandwidth-distance performance that coax can't get anywhere near. Coax has about the same propagation speed as fibre, v=c/n, where n=sqrt(epsilon_r*mu_r) is the refractive index.

Cheers

Phil Hobbs

As Elvis used to say, "Thankyuh. Thankyuh vemuch." ;)

Cheers

Phil Hobbs

;)

Cheers

Phil Hobbs

ttdesign.com

Hmm, mixed reports. The BBC article says the faulty connection worked to increase the apparent speed?

So a bad oscillator was the 'main' problem?

George H.

Yeah, really. They think "well, all electronics is really dependent on physical laws, so any physicist knows all there is to know about electronics...." You ought to see what it looks like when physicists do FPGA design! No synchronizers, no attention to clock boundary crossing, no timing constraints, and on and on. it gets pretty UGLY!

Jon

As bad as chemists...

About the same as programmers.