Neutrinos on the brain-10

C.I.P. points to this article from Technology Review. There is a discussion of a claim by Ronald van Elburg that the motion of GPS satellites is not factored into the time of flight calculations at OPERA.

My reply is that per this note the GPS satellite designers have thought of all of that. A key excerpt:

The concept of coordinate time in a local inertial frame is established for the GPS as follows. In the local Earth-Centered Inertial frame, imagine a network of atomic clocks at rest and synchronized using constancy of c. To each real, moving clock apply corrections to yield a paper clock which then agrees with one of these hypothetical clocks in the underlying inertial frame, with which the moving clock instantaneously coincides. The time resulting from such corrections is then a coordinate time, free from inconsistencies, whose rate is determined by clocks at rest on the earth's rotating geoid.

Neutrinos on the brain-9

Two pieces worth reading:
1. Tommaso Dorigo
2. Matt Strassler

Neutrinos on the brain-8

From -7.

Haha!

CIP reports hearing:

At the end of the last century America had Bob Hope, Johnny Cash, and Steve Jobs. Now we have no Jobs, No Cash, and No Hope.

Delusional!

RIP, Steve Jobs!

:(

Neutrinos on the brain-7

OPERA and CERN were kept in sync. by using GPS in the "common view time transfer mode".   The synchronization was verified by using a clock that was moved.  Much is being made of the problem of relativistic corrections to the moving clock.  But perhaps that is not so important.

Neutrinos on the brain-6

Some more curve-fitting.

On hyperaccomplishment

James Atlas has an amusing op-ed in today's NY Times.  Excerpts beneath the fold.

Neutrinos on the brain-5

There are three main lines of attack on the OPERA "faster-than-light" neutrino measurements:
1. Physics issues
2. Measurement issues
3. Data analysis issues

IMO, the data analysis is the least likely to have mistakes. Measurement issues, are for example, C.R. Contaldi's issues with the synchronization of clocks between CERN and Gran Sasso.  The real killer, however, is the Cohen-Glashow argument, that superluminal neutrinos, weakly interacting though they are, must shed energy rapidly; so much so as to make some OPERA observations impossible.

Peter Woit points out a slew of papers finding exotic ways to justify the OPERA results.

hep-ph is chock-a-block with papers purporting to explain the OPERA results, using theoretical models of varying degrees of absurdity.

Perhaps Sabine Hossenfelder has it right, in her tweet:

Explanation for OPERA result: A 5th force connecting the GPS with the collective physicists' subconsciousness begging for unexplained data.

Neutrinos on the brain-4

http://arxiv.org/abs/1109.6562

New Constraints on Neutrino Velocities

Authors: Andrew G. Cohen, Sheldon L. Glashow

(Submitted on 29 Sep 2011)

Abstract: The OPERA collaboration has claimed that muon neutrinos with mean energy of 17.5 GeV travel 730 km from CERN to the Gran Sasso at a speed exceeding that of light by about 7.5 km/s or 25 ppm. However, we show that such superluminal neutrinos would lose energy rapidly via the bremsstrahlung of electron-positron pairs ($\nu\rightarrow \nu+e^-+e^+$). For the claimed superluminal neutrino velocity and at the stated mean neutrino energy, we find that most of the neutrinos would have suffered several pair emissions en route, causing the beam to be depleted of higher energy neutrinos. Thus we refute the superluminal interpretation of the OPERA result. Furthermore, we appeal to Super-Kamiokande and IceCube data to establish strong new limits on the superluminal propagation of high-energy neutrinos.

Neutrinos on the brain-3

What I'm trying to do with curve-fitting is to convince myself that the following is plausible, or figure out that it is not.

Neutrinos on the brain-2

My previous post demonstrated that the proton curve was of the form:

y = c * exp( - exp( -a * x + b ))

Specifically, my eyeball fit was

y=exp(3.58)* exp( - exp( -0.0061*x - 2.9201))

Neutrinos on the brain

The OPERA faster-than-light-neutrinos has become a bit of an obsession. But I have made a little progress.

OPERA numbers

From the OPERA experiment that found faster-than-light neutrinos:

1. Width of the proton extraction: 10,500 ns
2. Protons per extraction: 2.4E13
3. Extractions per cycle: 2
   
4. Total neutrino events : 16,111
5. Total Protons delivered: 9.34E19

CNGS Beam Run 2010 (29 April - 22 Nov): Total 4.04E19 Protons on Target
CNGS Beam Run 2009 (27 May - 23 Nov): Total 3.52E19 Protons on Target
CNGS Beam Run 2008 (8 Jun- 3 Nov): Total 1.78E19 Protons on Target

1. Slide 15/84 http://cdsweb.cern.ch/record/1384486/ 
2. Slide 13/84 http://cdsweb.cern.ch/record/1384486/ 
3. Slide 13/84 http://cdsweb.cern.ch/record/1384486/ 
4. Slide 42/84 http://cdsweb.cern.ch/record/1384486/  
5. http://proj-cngs.web.cern.ch/proj-cngs/

Deduced numbers:


1. Number of extractions: 3.89E6
2. Probability of neutrino event per extraction: 4.14E-3
3. Probability of neutrino event per proton: 1.724E-16
4. Summed up over all extractions, average protons/ns = 8.9E15
5. Summed up over all extractions, the average neutrinos detected/ns = 16111/10500 = 1.5

Plot from OPERA:(http://arxiv.org/abs/1109.4897)

Notice the y-axis is binned as Events/150ns.

PS: recent comments on OPERA's work
1. Jon Butterworth http://www.guardian.co.uk/science/life-and-physics/2011/sep/24/1
2. John P. Costella http://johncostella.webs.com/neutrino-blunder.pdf -- confirms the intuition that the edges are what are important. By his eyeballs 919 neutrino events at the leading and trailing edge of the pulse give most of the statistical significance. (If the pulses were perfect square pulses, then only the leading and trailing edges can give timing information.)

PS: I don't buy Costella's arithmetic, however.

Faster than Light Rumors

If you want to know about superluminal neutrinos, read Tommaso Dorigo.

The danger of wildlife in my backyard

The danger of having wildlife around mainly comes from humans. I will explain this in a few easy steps.

1. The wildlife - there's deer of course, and now turkeys

 

Seeking reparation for 9/11

The Independent of U.K. reports:

A Lloyd's insurance syndicate has begun a landmark legal case against Saudi Arabia, accusing the kingdom of indirectly funding al-Qa'ida and demanding the repayment of £136m it paid out to victims of the 9/11 attacks.

The Brighton-based Lloyd's 3500 syndicate, which paid $215m compensation to companies and individuals involved, alleges that the oil-rich Middle Eastern superpower bears primary responsibility for the atrocity because al-Qa'ida was supported by banks and charities acting as "agents and alter egos" for the Saudi state. 

The detailed case, which names a number of prominent Saudi charities and banks as well as a leading member of the al-Saud royal family, will cause embarrassment to the Saudi government, which has long denied claims that Osama bin Laden's organisation received official financial and practical support from his native country.

Palestine 1896

Supposedly the first film shot in Palestine. Whether it is or not, still interesting.

Darwin and Economics

Just a week or so ago, I began thinking, in a shallow way, that perhaps the insights from evolution are required for economics. Just as random variation and natural selection can provide the illusion of intelligent design, perhaps it can also produce the illusion of the rational actor, upon which so much of economics depends.

Anyway, in today's NYT, Robert H. Frank provides yet another way that Darwin lends insight into economics. The insight is understanding the forces that leads individuals in a a group to behaviors that are detrimental to the group, and to themselves. Excerpts beneath the fold.