Something to read

Not too long ago we discussed this paper on one of our informal seminars. The paper is called “The eighteen arbitrary parameters of the standard model in your everyday life” by R. N. Cahn, and the paper dates back to 1996. It is an RMP colloquia paper.

I think it still reads great and it explains what are the mysteries of particle physics and how making small changes in the Standard Model could lead to completely different physics.

Well, in those days there were only 18 parameters in the standard model. Now that we have neutrino masses there are a couple more. Because of this,  by many standards, this is considered prehistory. On the other hand, one can take this as a benchmark to calibrate  all the accomplishments of particle physics experiments since then.

What I like about the paper is that in some sense it gives a feeling for how non-generic the parameters of the standard model are.

 

 

What’s in a picture

Photograph

Today’s guessing game is:

What is this a picture of?

 

Happy new year!

Well, I guess it is 2012. 2011 just went by in a blink.

I expect 2012 should be the year for the discovery of the Hicks Bison. That was how it was pronounced by someone at a New Years eve party that I attended.

On another note, the weather is good where I’m at, the world hasn’t ended and quantum mechanics has not been disproved over the holidays.

I also made a resolution to write a few more posts here this year than last year. We’ll see how long I keep that resolution.

Blackboard humor

To celebrate the near end of the quarter I thought I would publish a photo of a blackboard near my office captured a few days ago.

 

The bottom equation proves that it comes from a bona fide physics department blackboard, although to me it seems that there might be a factor of missing . Well, maybe it can be counted as circumstantial evidence for coming from a blackboard in a physics department.

The areas of expertise I didn’t know I was an expert on.

I guess I’m easing my way back to writing blog posts. Of course, I could bore you to death with the list of things I was actually doing instead of writing here, but that will really have to wait for another day.

Today, I will just give you some information on some of the recent spam in my e-mail folder that comes from Open Journals (which I have discussed about in the past) and random conferences around the world. I just have the impression that my e-mail is in a “general list of scientists”, or “general list of scholars”, or “general list of people who have written something” that the companies buy and then bombard with queries asking me to select them for publishing in. The rest is a (sufficiently edited) list of such that I have gotten invited to contribute recently in:

1. Journals of Statistics.
2. Journals of Geometry.
3. Journals of quantum information.
4. Journals of applied mathematics.
5. Journals of law. (US law in particular).

I’m not really an expert on any one of these, although I could probably  do something with my research that might be considered for journals 1, 2, 3, 4 with a long stretch. But in item 5 I declare myself a complete amateur even though I do follow some court rulings and such because I find them interesting.

My inbox would also suggest that I am expert on informatics, engineering, cybernetics, communications, computing, molecular and cell biology, as I seem to keep getting invited to attend conferences on these subjects and maybe even chair one session or two on them. It makes me wonder how the hell I got into their e-mail databases.

In the meantime, I’ll go back to my cave where I will be back doing the things that I usually do that force me away from writing posts like this one on a regular basis.

 

 

 

 

 

 

 

 

 

Faster than light neutrino claim

Well, the press is all fired up about a claim of faster than light neutrinos. The claim from the OPERA experiment can be found in this paper. The paper was released on September 22nd and it has already gotten 20 blog links. Not bad for a new claim.

Considering that the news organizations are happily bashing special relativity, one can always rely on XKCD to spin it correctly.

Now more to the point: the early arrival time is claimed to be 60 nanoseconds. The distance between the emitter and the observer is claimed to be known to about 20 cm, certified by various National Standards bodies. A whole bunch of different systematic errors are estimated and added in quadrature, not to mention that they need satellite relays to match various timings.

60 nanoseconds is about the same as 20 meters uncertainty (just multiply by the speed of light) and they claim this to be both due to statistical errors and systematics. The statistical error is from a likelihood fit. The  systematic error is irreducible and in a certain sense it is the best guess for what the number actually is. They did a blind analysis: this means that the data is kept in the dark until all calibrations have been made, and then the number is discovered for the measurement.

My first reaction is that it could have been worse. It is a very complicated measurement.

Notice that if we assume all systematic errors in table 2 are aligned we get a systematic error that can be three times as big. It is dominated by what they call BCT calibration. The errors are added in quadrature assuming that they are completely uncorrelated, but it is unclear if that is so. But the fact that one error dominates so much means that if they got that wrong by a factor of 2 or 3 (also typical for systematic errors), the result loses a bit on the significance.

My best guess right now is that there is a systematic error that was not taken into account: this does not mean that the people that run the experiment are not smart, it’s just that there are too many places where a few extra nanoseconds could have sneaked in.  It should take a while for this to get sorted out.

You can also check Matt Strassler’s blog and Lubos Motl’s blog for more discussion.

Needless to say, astrophysical data from SN1987a point to neutrinos behaving just fine and they have a much longer baseline. I have heard claims that the effect must depend on the energy of the neutrinos. This can be checked directly: if I were running the experiment, I would repeat it with lower energy neutrinos (for which we have independent data)  and see if the effect goes away then.

 

 

 

 

 

A fun identity

So I’ve been working on one of my papers where we need to compute some numbers. They end up being determined by a cubic equation.

However, one often finds surprising identities when Mathematica spits out a bunch of numbers expressed in algebraic form. Here is one of them:

PS: I use italics in the word surprising above only because if one does not know the origin of these identities they might seem surprising.

Armchair economics

Seeing as the battle over raising the debt limit seems to have hit yet another impasse, it is time for me to speculate what could happen should the US default on its obligations, or follow the silly “cap, cut and balance” approach, with no tax increase on the horizon.

These speculations are just that. The markets are getting jittery and already gold is worth a lot more than it should.

Just let me digress.

Scenario 1: the Aug 2nd deadline is missed.

My gut feeling is that the market will punish the US very heavily for being so irresponsible. Money will flee the US, and the cost to further borrow for the government would go up. A lot.

If the US does not pay whoever it owns money to, either people will go hungry (from cuts of their retirement checks, etc) and the capacity of the populace to buy stuff would go down. The other option is not to pay some of the bondholders in which case the US debt would be considered junk and the crisis in confidence will not be something the US can recover from in any reasonable term.

Either way, the prospects for the US economy to grow would be shot for the short term and probably also the intermediate term. The interbank loan rate should go up and interest rates for mortgages etc will also go up, thereby slowing the economy further. The dollar should devalue, but its likely that a race to devalue currencies would ensue: after all, the US market keeps many of the other world economies going. This is a situation where inflation would be king.

 Scenario 2: Cap, Cut and balance.

In this case, the US does not default (slightly less bad), but given that I live in California where a similar set of laws exists, I can not tell you how lousy this option is. This is, the US would not be able to borrow to stimulate the economy, it would have to fire a huge number of individuals in government and the recession will continue: no one will be able to afford stuff. Moreover,  funding for innovation would be cut down. The prospects for the US economy to grow would go down and shrink: for the US to grow one needs a clear signal that the US government is willing to stimulate the economy. Shrinking the participation of the government in the economy is not going to do it. Again, I would expect that the stock market would also punish the US because the economy will shrink. I mean, who’s going to be buying stuff in the store when the number of layoff is increasing?

Currently in California we require a 2/3 majority to raise taxes: under a mandated balanced budget formula and given that there is a political party that treats the ‘no raise taxes’ as a religious mantra, the only way to keep things running is to cut, and keep cutting, even when there is nothing left to cut. This leaves the future generations paying for the mistakes of today by dismantling their chances of education, or even their availability of health care. We’re already seeing this. The only way for the University of California system to cope is to increase tuition. This is a tax on poor people: in some sense it forces them out of the ability to be educated and condemns them to be poor forever. I don’t wish this on the rest of the US.

Overall, I think it is in the best interest of the US to not tie itself into a straitjacket and to be able to respond to crisis by borrowing to stimulate the economy. Worse case scenario just print money and take a bit of a hit on inflation.

Last heard in 2005

Today as I was typing my long paper, my mood was to hear something slightly different, so I started looking for stuff that I had not heard in a  while in my itunes library. Turns out that there are some songs that have not seen airplay on my desktop since 2005 (I might have heard them since, but not from this platform). I was surprised by that. It seems to indicate that I’m listening more to the playlists I made than to the random song selection available in the program, especially since the genius feature was introduced. Just for statistics sake my current library seems to have about 3500 songs, but this was smaller then (probably by a factor of 1.5 to 2).

Copy and paste and oh what a waste

Right now I’m in the middle of writing a long paper. This is a rather intense and time consuming effort that I don’t find particularly gratifying. On a good day, I can write a lot. But when I get annoyed at how something is organized I usually copy/paste and end up reorganizing things and that is usually not bad (it’s easier than retyping). However…