Feeds:
Posts

## Faster than light, smaller than an atom

I was grading a test for my students, and I was surprised -again- by some of the answers that they can give.

They are happy to measure velocities in units of action, and energies in apples and oranges.

I also get answers of the form

$v = 8.909563829\times 10^{23} m/s$

a couple of orders of magnitude faster than the speed of light, or of wavelengths of the form

$\lambda=6.9 \times 10^{-23} m$

for an optical transition in the UV. This is only a couple of orders of magnitude smaller than the size of an atom, at distances that we have not yet been able to measure in any lab.

I wonder if there is a cure for this out there: some way to get the students to understand on their own if an answer is nonsense or not so that they can double check their work, rather than believe blindly the result of a bad computation.

Read Full Post »

## Gary Horowitz elected to the National Academy of Sciences.

Yesterday was a cause for great celebration in the physics department at UCSB. Gary Horowitz was elected to the National Academy of Sciences.

Of course, this is a great honor for UCSB, and we all think Gary is very deserving of such recognition.  Gary has been one of the champions of pushing towards understanding gravity in higher dimensions. His most cited paper was the one that introduced Calabi-Yau manifolds to superstrings. At the time it was thought that there were very few such objects. Now we know better.

He has done a lot of other stuff, much too much to mention.  Lately, he has been applying supergravity in higher dimensions to the study of superconductivity via various gauge/gravity dualities. He is great to have around and he is one of the nicest persons I know.

Apart from various rounds of clapping we also heard from some of the other members of the NAS that reside in the physics department  as to what the nomination entails. First, the members receive a bill for their dues to the academy. Secondly, they get a lot of extra e-mail (some might call it spam). Third, they get to sit on even more committees that do important stuff. They also get an extra line in their resume.

Read Full Post »

## So what happened?

In the New York Times it was announced that a certain cosmic ray experiment is delayed. This is the AMS experiment. This delay might require the space shuttle to be used  beyond its official phase out date. The delay is caused because they are changing some powerful superconducting magnet for a much weaker  permanent magnet, thereby reducing (quite substantially it seems) the specs of the equipment.

Someone told me that they’d much rather have 3 years of very good data than a much longer run of poor data, so it seems that some big failure happened with the equipment.

Read Full Post »

## Tax day

Tax day is here. This is a yearly ritual in the U.S.

I think it is one of the few days where most people get intimate with what they earn, and the ensuing effort that it takes to produce a tax return.

Apart from the fact that doing the work is not rewarding and that it is easy to feel that one is paying too much, I think that the whole exercise is beneficial: people should know how much they are paying the government. I have been in other places where everything is so automated that one just forgets the whole thing and it is as if taxes never happened and when they change people don’t really find out. They also don’t feel the yearly sense of shock about the experience.

In the end, taxes are paying for services that a lot of people here take for granted. For example roads, a working post office, law enforcement and education for their children. They also pay for Social Security and Medicare: some of the most costly entitlement programs that no politician can risk to touch without a backlash from their constituency.

It is also one of the few days where a lot of people get intimate with arithmetic (for a change). It always surprises me how many people seem to have trouble doing this activity, just because they don’t understand addition and substraction (and percentages). Oh well! I’m not going to worry about it.

in the end, like a lot of other people, I filed my taxes at the last minute. I wonder what the statistic of us, last minute filers, really is; as well as the reasons why.

Read Full Post »

## Allegory

This is a great short that was found by my family a while ago.  If you want to be methaphysical, it describes the research careers (or projects) that don’t fly. The moral is that they should be enjoyed while they last, well, that’s one take on it. The movie scripting is phenomenal and it really makes you think about what’s important.

Read Full Post »

## What I’m reading today

Its been a while since I have posted an entry here. Unfortunately this can not be ascribed entirely to my laziness: I just didn’t have much to say. Ha! More seriously now, I have been busy with the beginning of the quarter. This involves a lot of troubleshooting for the ‘electronic component’ of the course. Seeing as I have nothing to say, I thought it would be good to divert your attention to other stuff that should be read today written by other people.

In the arxiv, there are two very interesting papers. One is by George Smooth on ideas for a holographic Universe, and the other by Samanta on the thermodynamic origin of gravity. Of course, I haven’t had enough time to digest these ideas fully, but they look rather interesting to me.

I also had time to look at a paper on varying dimensionaliy at different length scales. Even by requiring very low standards, I can not take that proposal seriously. My guess is that a careful analysis of the data already available would show that the model they are discussing is wrong.

Finally, on a cute note, there was a humor piece article in the daily Nexus (the local student newspaper at UCSB) that was very amusing and fits the theme for physics perfectly.

Update: This was posted as an April’s fool joke, to try to get you to read what I consider to be the most unreliable papers on the arxiv for the day of April 1st 2010. I do not endorse these papers in any way whatsoever.

Read Full Post »