Hitches blamed over CERN's 'faster-than-light' claim.

[freyar]

Was this actually proven to be the cause? My understanding is that this was a hypothesis put forth in a paper with no actual testing done. I know several labs are repeating the initial experiment, and we won't know for certain until then. However, it seems people are really quick to assume the "bad connection" hypothesis is correct without any basis in testing.

I have a feeling that the "bad connection" hypothesis took on a life of its own regardless of the facts either way. (And on ENWorld it most certainly did)

No, unlike some incorrect statements in initial news reports, it's unclear how much the two different equipment errors affected the measurement or if there's something else going on. At the moment, all that's known is that there are problems with two pieces of equipment that could have had effects on the measurement that are larger than the purported disagreement with relativity. I should also mention that the "faulty cable" error isn't that the cable was loose but that the perfectly tight cable leads to different readings depending on what angle it took at the connection. So it's something that could have changed if someone walked past and bumped something gently. Very subtle issue.

However, you are both getting something a little backward. The point is not that there is a measurement so we are obligated to hypothesize an explanation. The point is that any measurement has two types of errors: statistical, which just has to do with the fact that it's impossible to repeat any measurement process perfectly identically; and systematic, which has to do with how well the equipment works (roughly speaking). What OPERA is now saying is that they had (at best) dramatically underestimated their systematic error. If they had understood about these two pieces of equipment errors last fall, they would never have announced a discrepancy with Einstein's relativity because their measurement agrees with relativity to within experimental error. So we don't need to "prove" that the cable exactly accounts for the 60 nanosecond difference. What we know already is that it introduced an even larger error than the purported signal. In an attempt to find a discrepancy with relativity, OPERA (and other experiments) will have to redo the entire experiment after improving their equipment to reduce the systematic error.

Incidentally, we should also remember that OPERA was designed to measure something else, which it did quite well, so it was a successful experiment.

 

[Umbran]

What OPERA is now saying is that they had (at best) dramatically underestimated their systematic error. If they had understood about these two pieces of equipment errors last fall, they would never have announced a discrepancy with Einstein's relativity because their measurement agrees with relativity to within experimental error.

To give an analogy that may help understanding on this point.

Say the speed of light is 3.000 x10^8 meters per second.

Say the experiment originally reported that the particles moved at 3.05 x10^8 m/s, plus or minus 0.01 m/s.

That means that the particles were moving somewhere between 3.04 and 3.06 x10^8 m/s. Either way, faster than light.

They find this systematic error, and now would say that the particles were measured moving at 3.05 x10^m/s plus or minus 0.1 m/s. So, the real value of the speed is from 2.95 and 3.15 x10^8 m/s.

Thus, as far as their instruments could measure, the particles were moving from slightly below the speed of light, to slightly above it. Reporting this as a finding would be like a cop pulling you over for doing somewhere between 25 to 35 mph in a 30 mph zone - not something he'd do.

And speaking of bad connections - My TI35 had more processing power than the Apollo 11 too, but this doesn't mean rocket science isn't extensive. Remember all the technology for both products (TI calculators and iPhones) was born of miniaturization, a vital part of the "rocket science" industry.

And, the ship's processing power is used more to give/execute commands to other pieces of hardware than to make calculations. Orbital corrections are usually calculated on the ground, where there's a bazillion smart guys and more computing power than can fit on a ship or satellite.

 

[Thunderfoot]

To give an analogy that may help understanding on this point.

Say the speed of light is 3.000 x10^8 meters per second.

Say the experiment originally reported that the particles moved at 3.05 x10^8 m/s, plus or minus 0.01 m/s.

That means that the particles were moving somewhere between 3.04 and 3.06 x10^8 m/s. Either way, faster than light.

They find this systematic error, and now would say that the particles were measured moving at 3.05 x10^m/s plus or minus 0.1 m/s. So, the real value of the speed is from 2.95 and 3.15 x10^8 m/s.

Thus, as far as their instruments could measure, the particles were moving from slightly below the speed of light, to slightly above it. Reporting this as a finding would be like a cop pulling you over for doing somewhere between 25 to 35 mph in a 30 mph zone - not something he'd do.




And, the ship's processing power is used more to give/execute commands to other pieces of hardware than to make calculations. Orbital corrections are usually calculated on the ground, where there's a bazillion smart guys and more computing power than can fit on a ship or satellite.

True, they are called steerage and trajectory personnel. Although the Apollo & Gemini crafts had processors that could confirm the ground calculations. Often the pilot doubled as "science officer" for lack of a better term. Most trajectories are plotted, manipulated and maintained on the ground at various sites for various payloads. I can't say a whole lot more, but I'm very aware of that. *Shifting conversation away so the guys in black suits don't knock on my door.*

 

[Dannyalcatraz]

Often the pilot doubled as "science officer" for lack of a better term.

Soooo...he stared into a box of blue lights and whistled?

 

[Thunderfoot]

I just KNEW someone would go there. Why Danny, why? It's already hard enough for me to discuss some of this stuff as it is without revealing some pretty intricate (and classified) stuff. Why, bro, why?

 

[El Mahdi]

*Homer Simpson voice* mmmmmm Tang, alalalalalagggghhhh */Homer Simpson voice*

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[freyar]

An update: the ICARUS experiment, which is located in the same lab as OPERA, has announced the results of their version of the neutrino time-of-flight experiment. It's important to note that this experiment actually used the same neutrinos coming from CERN as the second OPERA experimental run used. In any case, ICARUS found no detectable difference between the speed of the neutrinos and the speed of light, which really makes it seem even less likely there's funny superluminal travel going on.

 

[Dannyalcatraz]

Bah, what does ICARUS know? He flew too close to the sun like a dummy.

 

[jonesy]

Bah, what does ICARUS know? He flew too close to the sun like a dummy.

Funnily enough, in some versions of the myth the wings were the sails of his ship and he didn't fly. He just tried sailing away, and fell overboard and drowned.

 

[Relique du Madde]

And in other myths he was turned into an eggplant*.



*

Spoiler

What do you mean the main character from Kid Icarus wasn't named Icarus? What kind of BS is that?!?!