Sunday, October 30, 2011
Thursday, October 27, 2011
Wednesday, October 26, 2011
Bergeron on OPERA
Via Tommaso Dorigo, http://arxiv.org/abs/1110.5275
About Statistical Questions Involved in the Data Analysis of the OPERA Experiment
Authors: H. Bergeron
(Submitted on 24 Oct 2011)
Abstract: The authors of the OPERA experiment [arXiv:1109.4897] claim that "the measurement indicates an early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum". In this note we analyze the statistical aspects of the experimental results presented in [arXiv:1109.4897], assuming that no hidden experimental bias exists. Due to statistical constraints, we show (through two different methods) that the experimental data presented in [arXiv:1109.4897] do not permit to conclude unambiguously with the existence of a superluminal behavior of neutrinos. The problem lies essentially in the interpretation of the data and not in their veracity.
Tuesday, October 25, 2011
Neutrinos on the brain - redux
Readers of this blog may have noticed that ever since the OPERA collaboration announced finding neutrinos that travel faster than light, I have been scratching my head about something. Here, in the simplest possible terms is what I'm thinking about.
A how-to and a how to?
First - a how-to do something:
Second - a question about how to do something.
Second - a question about how to do something.
Friday, October 21, 2011
Auditors' contribution to the fiscal crisis
Floyd Norris has written in today's New York Times that the Public Company Accounting Oversight Board was harshly critical of 27 of 61 of the Deloitte & Touche's audits that it inspected, over three years ago.
Tuesday, October 18, 2011
Sneak Peek at Adobe's Image Deblurring
Rajan Parrikar sent this my way:
http://tv.adobe.com/watch/max-2011-sneak-peeks/max-2011-sneak-peek-image-deblurring/
http://tv.adobe.com/watch/max-2011-sneak-peeks/max-2011-sneak-peek-image-deblurring/
Posted by
Arun
at
10:41 PM
Sneak Peek at Adobe's Image Deblurring
2011-10-18T22:41:00-04:00
Arun
photography|
Comments
Labels:
photography
Neutrinos on the brain-12
(PDF) An attempt to understand the statistical error in the time-of-flight estimate in the OPERA experiment.
I'd rather stay up and finish this, but....
I'd rather stay up and finish this, but....
Neutrinos on the brain-11
Tommaso Dorigo tells us about the ICARUS collaboration's refutation of the OPERA superluminal neutrino result.
Sunday, October 16, 2011
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:
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.
Wednesday, October 12, 2011
Sunday, October 09, 2011
Saturday, October 08, 2011
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.
Friday, October 07, 2011
Thursday, October 06, 2011
Sunday, October 02, 2011
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.
On hyperaccomplishment
James Atlas has an amusing op-ed in today's NY Times. Excerpts beneath the fold.
Saturday, October 01, 2011
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.
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.
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