LHC portal

Harbles wrote:And yet more criticism of technique. This time the effect of g being different at the two locations.
http://www.nature.com/news/2011/111005/ ... 1.575.html

That's pretty wild guess. They have caesium clocks on both posts continually being kept synchronized using GPS at sub-nanosecond precision, there is no way any significant (i.e. bigger than 1 nanosecond) deviation can occur. Who wrote that did not listen to their initial presentation closely enough.

On that 'starts with a bang' blog that 'Harbles' first linked to there were this comments that something might be wrong with the gps-system (link). And it made me wonder, don't they calibrate their gps system (and code) by comparing it to 'actual' shorter distances measured with 'real' mesurement tools, lets say over 1 to 10 km. Wouldn't it be possible do this in just a few days without any large costs. And it would give highly accurate results, but I can't imagine that they have done so already, no?

Chelle wrote:On that 'starts with a bang' blog that 'Harbles' first linked to there were this comments that something might be wrong with the gps-system (link). And it made me wonder, don't they calibrate their gps system (and code) by comparing it to 'actual' shorter distances measured with 'real' mesurement tools, lets say over 1 to 10 km. Wouldn't it be possible do this in just a few days without any large costs. And it would give highly accurate results, but I can't imagine that they have done so already, no?

GPS is being routinely used to synchronize clocks at distant places with picosecond precision, for radiotelescope interferometry for instance. And it works pretty well. I don't see any reason why should there be anything wrong with it being used with "only" nanosecond precisions in neutrino experiments.

And yet again it's about listening closely to their presentation. I also initially thought there might be something wrong with their GPS but I learned pretty soon throughout the presentation that they did not leave any room for error in that area.

Here is an other interesting idea:

http://johncostella.wordpress.com/2011/ ... ake-sense/

There’s only one simple explanation that comes to my mind: Leave the neutrinos with the m^2 values that we believe them to have (on the order of or less than eV^2), but have them not created directly (as with the Standard Model) but rather via some sort of intermediate tachyonic particle (that gets 60 ns or so ahead of the light-cone in the OPERA experiment) before decaying into neutrinos. That would explain the clean shape of the OPERA distribution, and would be consistent with SN1987A and all the other experimental evidence for small m^2.

Sounds a bit like a bow wave

A news item about "'Tension' emerges within OPERA collaboration" and those that did not sign the pre print.
http://physicsworld.com/cws/article/news/47427#comments

Harbles wrote:A news item about "'Tension' emerges within OPERA collaboration" and those that did not sign the pre print.
http://physicsworld.com/cws/article/news/47427#comments

Now, a larger fraction of the group leaders is concerned about the paper being submitted to a research journal. One member of OPERA, who does not wish to be named, says there is a "lot of tension" within the collaboration and that up to half of the members are opposed to an immediate submission.
...
 "It is not that people think there is a mistake that is being hidden," she says. "But since something going faster than light would kill modern physics as we know it, some researchers would feel more at ease with these independent checks."

I've posted this link already in the topic Comformity. Its interesting to see how an opinion of 10 out of 170 evolves to half the group and very well possible to whole the group:

http://www.youtube.com/watch?v=TrNIuFrso8I

And more relativistic arguments.
http://www.technologyreview.com/blog/ar ... 0/?ref=rss
I would think all these effects are cancelled out after averaging out the GPS signals over time but who knows.

*Edit This paper disputes the one above http://arxiv.org/PS_cache/arxiv/pdf/111 ... 2909v1.pdf


Ok. how about Quantum weak forces?

" Can apparent superluminal neutrino speeds be explained as a quantum weak measurement? " *
http://arxiv.org/abs/1110.2832

* Answer, probably not.

Experimentalists Aren't Idiots: The Neutrino Saga Continues;

http://scienceblogs.com/principles/2011 ... idiots.php

Tomaso Dorigo says that ICARUS says nah to Superluminal neutrinos.
http://www.science20.com/quantum_diarie ... inos-83684

Harbles wrote:Tomaso Dorigo says that ICARUS says nah to Superluminal neutrinos.
http://www.science20.com/quantum_diarie ... inos-83684

They're assuming that the neutrinos are traveling as normal neutrinos, which would quickly lose energy from emitting the weak force equivalent of Cherenkov radiation if they traveled faster than light. Sterile neutrinos don't interact with the weak force and would not lose energy. Most theories I've seen that attempt to explain the OPERA results have the neutrinos oscillating to superluminal sterile neutrinos. ICARUS is completely consistent with those theories.

This paper is getting a lot of interest... WHat does everybody think ???

http://arxiv.org/PS_cache/arxiv/pdf/111 ... 2685v3.pdf

There is an easy way to tell if the two clock are in sync. Yuo need to construct a dark fiper between the two ends. The path is not important. You inject a laser pulse at a know local time at one end and measure the recieve time at the other end. You then repeat in the other direction. The delay should be the same if the clock are the same. Note we have used this method to check sycn on our local networrk. The results are very good after you do some data reduction to remove outliers and satistical min in both directions.

Does anyone have the chart data to draw figure 3,,4 and 5 in the report. I have done an overlay fir for the leading and trailing edge. Would like to have all the data with errors bars. I emailed OPERA with a example of what I am tring to do with the data but have not heard from them.

Hi RocketMan !


I know the method you describe has been discussed. I even thought that maybe they had done that ?

Great discussion of the current topics..

http://www.theregister.co.uk/2011/10/18 ... ra_papers/

Xymox wrote:Hi RocketMan !


I know the method you describe has been discussed. I even thought that maybe they had done that ?

What they did was that they took a portable caesium clock, measured the Gran Sasso clock with it, then took it to CERN and measured the CERN clock with it. The absolute difference between the two clocks was 2.5 ns.