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Merged Puzzling results from CERN

Dancing David said:
Um error is what its is, no suspects.
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Perhaps, but 100 nanoseconds error for synced clocks? In a multi billion dollar scientific experiment? And the top notch scientists at CERN examining alternative explanations for 3 years couldn't find this error? :rolleyes:
 
Drachasor said:
You take a TON of measurements and average them together, essentially. You can get really good numbers doing that.
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Why doesn't the same averaging work as well for a derived clock synch, then?

Tim Thompson said:
It's the difference between an absolute measurement and a differential measurement. The 100 nano-second precision applies only to establishing the absolute time, as in "it is now 5 o'clock plus or minus 100 nano-seconds". However, if you ask what the difference is between multiple clocks, then yo can do much better. That's how differential GPS works, as I recall. That's how the GPS networks used to measure continental drift and earthquake offsets work.
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It's a differential measurement between signals received from different satellites, which obviously travelled through different paths in the atmosphere. So why aren't those measurements also affected by this 100ns uncertainty?

Something isn't quite adding up here.
 
Anders Lindman said:
Perhaps, but 100 nanoseconds error for synced clocks? In a multi billion dollar scientific experiment? And the top notch scientists at CERN examining alternative explanations for 3 years couldn't find this error? :rolleyes:
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If the synchronisation is the error, the fact that all these scientists couldn't find it just indicates the difficulty of the problem.
 
Acleron said:
If the synchronisation is the error, the fact that all these scientists couldn't find it just indicates the difficulty of the problem.
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But hasn't science by now come up with standard and reliable ways of synchronizing clocks? :confused:
 
Don't confuse the GPS specification with accuracy.

The 100 nanosecond is the specification for UTC(USNO) to GPS correction transmitted in the NAV message. The actual accuracy is currently good to about 10 nanoseconds.

The receivers used for time transfer are at a known location - they fix their position and only solve for time, not for time and position. I would guess the TON of measurements that Drachasor mentioned was used to survey the locations.

Dual frequency receivers completely remove the atmospheric delay problem, but it appears the OPERA team used a single frequency receiver.
 
If you wanted to redo the experiment eliminating this timing synch issue, how would you do it?
 
Myself, I don't know that there IS a timing synch issue. The difference (60 ns) is actually pretty large for time transfer with high accuracy receivers. I find it hard to believe the OPERA team was not aware and did not compensate.

ETA - this is JREF, so sue me for personal incredulity :)
 
Light as electromagnetic waves, or photons, are reactive with our senses. But neutrinos are not. Neutrinos are so irrelevent to our existence that evolution of their detection for survival purposes is moot. Even if neutrinos do travel faster than light in a vacuum their interaction with mass is, in effect, of zero significance for there not being any interaction or, more precisely, so little as to be tricky to distinguish from noise. Light travels at an appreciable speed thru lead even before being blocked and that is the significance that is placed on light, that light possesses momentum, carries energy, and is interchangeble with mass, but neutrinos? Very difficult to detect for their lack of charge, indeterminate mass, and irrelevence. So what if they are shown to exceed the speed of light in a vacuum and/or rock? So what?
 
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minorwork said:
Light as electromagnetic waves, or photons, are reactive with our senses. But neutrinos are not. Neutrinos are so irrelevent to our existence that evolution of their detection for survival purposes is moot. Even if neutrinos do travel faster than light in a vacuum their interaction with mass is, in effect, of zero significance for there not being any interaction or, more precisely, so little as to be tricky to distinguish from noise. Light travels at an appreciable speed thru lead even before being blocked and that is the significance that is placed on light, that light possesses momentum, carries energy, and is interchangeble with mass, but neutrinos? Very difficult to detect for their lack of charge, indeterminate mass, and irrelevence. So what if they are shown to exceed the speed of light in a vacuum and/or rock? So what?
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If they exceed the speed of light in a vacuum, it would show that there is a major problem with our current theoretical framework of the world. The best tested theories ever produced would need a major reworking.

You'd know that if you read the thread.

Similarly when the Michelson-Morley experiment showed that light travels at the same speed to all observers, it showed an effect that is tiny and "very difficult to detect", but it revolutionized physics.
 
Roboramma said:
If they exceed the speed of light in a vacuum, it would show that there is a major problem with our current theoretical framework of the world. The best tested theories ever produced would need a major reworking.

...snip...
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But wouldn't it be fantastic if it did need a major reworking?
 
I think the cynic in every physicist is going: "Oh great another case of mistaken measurement making us targets for every kook and nut bar out there."

At the exact same time, the giddy school kid in every physicist is going: "New physics! new physics! new physics! this is going to be soooooo awesome!"
 
I'm trying, for my own edification, to enumerate the possible outcomes of this ....

1) A mistake was made and the neutrinos didn't arrive faster than they would have traveling at the speed of light.

2) The "speed of light" speed limit was broken - and, therefore, isn't really a limit.

3) The value we've been using as the speed of light is wrong.

4) The neutrinos traveled at less than the speed of light, but took a short-cut through space.

5) ... any other options?

Whatever the result, it's obvious we're going to learn something important.

-- Roger
 
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