Thursday, September 29, 2011

Neutrinos on the brain-4

New Constraints on Neutrino Velocities

Authors: Andrew G. Cohen, Sheldon L. Glashow
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))

Wednesday, September 28, 2011

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
  6. 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 
  2. Slide 13/84 
  3. Slide 13/84 
  4. Slide 42/84  
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:(
    Plots from OPERA
    Notice the y-axis is binned as Events/150ns.

    PS: recent comments on OPERA's work
    1. Jon Butterworth
    2. John P. Costella -- 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.

    Friday, September 23, 2011

    Faster than Light Rumors

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

    Tuesday, September 20, 2011

    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

    Monday, September 19, 2011

    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.

    Sunday, September 18, 2011

    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.

    TED: Yasheng Huang: Does democracy stifle economic growth?

    Saturday, September 17, 2011

    Grasping at straws...

    It may be that "the major carbon repository in Earth is probably the mantle, rather than the atmosphere or biosphere, but it is the least well understood," Walter told OurAmazingPlanet. "The mantle reservoir might affect the global cycle over Earth's history."
    From here.   The grasping at straws part comes from the wild hope that the solution to our global warming problem somehow lies in harnessing the mantle.


    There apparently is significant variation in which genes express themselves and how and when.


    US Congressional candidates that I support - needless to say, all Democrats.

    1. Rush Holt (incumbent, NJ district 12, my representative)
    2. Bill Foster (seeking the Illinois 11th district seat)
    3. Manan Trivedi (seeking the Pennsylvania 6th district seat)

    Holt and Foster are ex-physicists; Manan Trivedi is a physician and also has the blessings of Arsha Vidya Gurukulam.

    I think this is the extent of my support for the 2012 elections, unless you find me some more ex-physicists. :)

    Trivandrum Rising

    Trump as a counterindicator on gold

    Amusing story.

    Oh, brother.

    When a self-promoter like The Donald jumps on a bandwagon, you know it's getting a little old. For all his big reputation, Trump's career over the past two decades is littered with the wreckage of high-profile deals he cut at the peak of each boom. Think: Trump Taj Mahal casino (bankruptcy, 1991). Trump Hotels & Casino Resorts (2004). Trump Entertainment Resorts (2009).

    Or the "Trump International Hotel & Tower," a luxury condo development in Fort Lauderdale planned and built in… happier times.

    News that Trump is backing gold comes after the metal has already skyrocketed in price. Gold has so far jumped nearly 30% so far this year, and more than 500% in a decade.

    What's next?

    Friday, September 16, 2011

    What goes up...

    What goes up, may come down. Here is the historical real price of gold, as per Paul Krugman:

    Of course, there are some secular trends now that were not there in the 1980s- namely the increasing buying power in the gold-hungry countries of India and China. So when the price of gold eases, it will probably stabilize at a higher real price than the 1985-2006 average. I suppose.

    Wednesday, September 14, 2011

    The Portents

    Republican Bob Turner won a Congressional by-election in a heavily Democratic district in New York, running on the theme that this was a referendum on President Obama.

    This points towards the Republicans gaining the Presidency, retaining the House and perhaps taking the Senate in 2012. There is already a Republican Supreme Court.

    Why this is a bad idea: the short version by CIP, or the long version by Mike Lofgren.

    I predict an overall end to the New Deal, beginning 2013, and another lost decade for the American middle class.

    PS: It is so unstoppable, all I can suggest, is put your head down and work hard to climb out of the middle class. Yes, that is unrealistic; but it is more realistic than trying to divert a hurricane.

    Graeber on the origins of money

    At Delong, or at CIP.

    Crudely: Gifts, credit, debt came first, money and barter followed.

    Friday, September 09, 2011

    In the shadow of Saturn

    NASA picture.

    Thursday, September 08, 2011

    Is our universe asymmetric?

    CIP highlighted a paper just out,< in which the researchers look at how fast the universe is expanding in different directions, and find an asymmetry. How they examine this is by looking at the data from 557 type1A supernovae. These supernovae are well-calibrated "standard candles" which means that we know their intrinsic brightness. Their observed brightness, and their redshifts tell us how far away they are and how fast they are receding from us. Well, they find an asymmetry. The link that CIP provided gives a better description than my two sentences above.

    If Obama purchased a car

    If President Obama were to purchase a car, especially if it were from a dealer who was Republican, Obama's starting bid would be Manufacturer's Suggested Retail Price.

    Wednesday, September 07, 2011

    The difference between two Presidents

    It is Thomas Friedman, but on the other hand there is Bush-bashing, who can resist.

    Why has this been a lost decade? An answer can be found in one simple comparison: How Dwight Eisenhower and his successors used the cold war and how George W. Bush used 9/11. America had to face down the Russians in the cold war. America had to respond to 9/11 and the threat of Al Qaeda. But the critical difference between the two was this: Beginning with Eisenhower and continuing to some degree with every cold war president, we used the cold war and the Russian threat as a reason and motivator to do big, hard things together at home — to do nation-building in America. We used it to build the interstate highway system, put a man on the moon, push out the boundaries of science, teach new languages, maintain fiscal discipline and, when needed, raise taxes. We won the cold war with collective action.

    George W. Bush did the opposite. He used 9/11 as an excuse to lower taxes, to start two wars that — for the first time in our history — were not paid for by tax increases, and to create a costly new entitlement in Medicare prescription drugs.

    Monday, September 05, 2011


    Shot at 1/5000 sec, so these look as though their engines have stalled.

    Friday, September 02, 2011

    A World of Hurt