27 February 2007

Exoplanet data

The furthest discovered exoplanet is OGLE-2005-BLG-390Lb, at 21,500±3,300 ly distance. However, it is an anomaly, as it was discovered using gravitational lensing, which I believe allows us to detect things much further away than the other methods, so the fact that most exoplanets have been discovered by other methods leads me to think I should throw out lensing-detected exoplanets.

Wikipedia also has a list of all 212 exoplanets discovered to date, that I intend to comb though. It occurs to me that if I do a rigorous job of this, I could submit it as a literature review to a peer-reviewed astronomy journal. One problem is (in addition to getting primary sources for the Wikipedia info) it would require me to confirm that no one else has published the same thing. To that effect, a couple links for me (and anyone else curious):

  • ADS Abs - a searchable archive of all published peer-reviewed astronomy papers. I think it stands for Astrophysical Database Service Abstracts, but I could be wrong. Hosted by Harvard.

  • Astro-ph - another searchable archive of astronomy papers, not as good a search engine, but includes papers that are in the process of peer-review and aren't yet published. Hosted by Los Alamos National Labs.

26 February 2007

Today's Astronomy lesson

In local coordinates, besides 0º altitude being the (ideal) horizon, we have two other key points - the zenith at an altitute of +90º, and the nadir at -90º. These are both originally English words, though they're used less often lately. Zenith means "peak, height, best", for example "The pop star was at the zenith of her career." And nadir means "lowest, worst," as in "Britney Spears is at the nadir of her career."


Mad Movie Scientists

Linkie dink

And aw, shucks, Sclerotic Rings likes me. ^_^''

25 February 2007

Fuel cell car

Although this blog article on fuel cells isn't entirely correct (see my comments below the article), the author still makes some good points about fuel cells NOT being a solution to our fossil fuel problem.

23 February 2007

Question of the Month: Exoplanets

We now know of at least 212 extrasolar planets. All of these (except maybe a few) are what's known as "hot Jupiters" - they're as huge as Jupiter, but they're really close to their sun. The reason for this is always touted as being that our detection methods are biased to find high mass planets (big), and to find ones with short periods (close to the star).

My question now is what percent of stars in the studyable volume of space have so far been found to have these hot Jupiters? If it turns out there's only 400 stars close to us, and 200 of them have hot Jupiters, or 50% of nearby stars have hot Jupiters, then we've definitely more information than a detection bias, it'd would be a real tendancy. But how many is it really?

To answer this question (first order approximation), I'll need two bits of information: (1) how far is the furthest star around which we've detected a planet? and (2) what's the local stellar density? The latter I can find with a little searching, the former perhaps with a lot of searching. If anyone gets the info before me, let me know, otherwise I'll post my results when I have them.

20 February 2007

Flu experiment

CNN is all ranting and raving about a University of Michigan study in which some 2,000 students living in the dorms are wearing face masks and using hand sanitizer throughout flu season to empirically discover their effectiveness at reducing the spread of the flu.

Apparently even though there's lots of anecdotes about masks helping prevent illness, there haven't been any real solid data about it. On the one hand, I think it's great that they're getting hard empirical evidence about the spread of flu in preparation for a potential pandemic (as well as studying to sociological/psychological aspects of having people wear masks!), and on the other hand it strikes me as a "no duh!" moment.

And no good story goes un-anecdoted. In Spring 2006, a year ago, I was to start treatments with Remicade, which has immunosuppressant side effects. Because I didn't want to get sick while on it, before I even started the treatments, I started washing my hands or applying antibacterial gel after every class. Prior to doing so, I would typically get a mild cold during the first week of EVERY semester, and often catch a moderate cold during the middle of the semester. I did not get any notable illnesses in Spring 2006, so I repeated it in Fall 2006, also failling to catch ill. This Spring I was sick three days after the first day of meetings of Spring 2007 - I forgot to wash my hands all day.

I went a full year without illnesses, simply by washing my hands three times during my work day, every work day. Give it a try yourself; maybe you'll be pleasantly surprised. BUT do NOT try this with children. They need to build up their immune systems - as adults, ours are already fixed, but kids's immune systems have to learn it's ok to have some amount of germs around. Without continual mild exposures to germs, kids are at a higher risk for developing allergies and asthma, or so the latest research suggests (not that I have a source handy).

Australia bans incandescent bulbs

Awesome, Australia has decided to ban "normal" incandescent bulbs, in favor of CFLs (compact fluorescent lights). [BBC, CNN Video]

The motivation is that saving the electricity will save CO_2 production, and therefore slow global warming. That's great, but I have a couple questions still: (1) What about all the mercury going to landfills? and (2) can physical science teachers still obtain incandescents for demos? :-P

17 February 2007

Climate Change Report

I recently wrote an email to a colleague with whom I've been debating global warming. We both agree that it's happening, but he thinks we do not have sufficient evidence to conclude it's manmade (via CO_2) rather than solar variation.

My email:
FYI, here's a link to a summary of the IPCC report on global warming from Wikipedia.
And here's the full text.

The summary is in a nice bulleted format with section headers, so you can skip to the parts you're most interested in. The report includes data stating that

1) atmospheric CO_2 and methane levels are higher than at any other time in the past 650,000 years, and

2) since 1750, human activities have resulted in "radiative forcing" of 1.6 W/m^2, while solar variations have resulted in only 0.12 W/m^2.

Page 11 of the full text has a graph, Figure SPM-4, which compares the observed temperature increase since 1900 with computer models assuming only natural sources, and natural plus antropogenic sources - search through the full document on the word "solar" to find relevant sections.

I don't have permission to repost his reply, so I'll try and reword it at another time.

See also this paper on ice ages, this discussion of that paper, and this discussion of that discussion.

14 February 2007

Physics is Love

Earlier this week my students asked me if I'd cancel class on Valentine's Day. I replied of course not, because we all love physics! And to prove my point, check out this little treatise on romance as circuit diagrams. It's a little flawed as I mention elsewhere, but still entertaining and illustrates a point.

13 February 2007

PEAR Labs closes/relocates

Thanks to Sclerotic-Rings for the head's up. Princeton's Engineering Anomalies Research Lab is closing due to lack of funds, 28 years after its inception.

The group studied whether consciousness affected random events on a large statistical scale. They found minute but statistically significant influences from human thoughts, or (take your pick) statistical anomalies in their data. They published peer-reviewed articles about their work, and also published later work that failed to confirm their original work.

In the end, they say they have proven that consciousness does play a role in random events, denying the current state of physics that allows for no mechanism for such an interaction. I say that they may have valid arguments against current physics, however they fail to do the thing that real scientists do: propose an alternate hypothesis that can be further tested. To me they are no better than those who support Intelligent Design. I agree entirely with IDers' claim that Darwinian Evolution has flaws - (1) Punctuated Equilibrium has supplanted Darwinian evolution, so they're really barking up the wrong tree, but (2) Irreducible Complexity is something that is not well-explained by any of our evolution models. However, by failing to propose an alternative scientific hypothesis that does fill in the gaps of evolution, ID fails to be science. Similarly, it appears that consciousness could affect random events, but the PEAR Labs researchers fail to to propose any mechanism by which it might do so.

Until then, I will remain skeptical.

And to round off this discussion with a little humor...

11 February 2007

Science *union* Creationism

This NY Times article gives an interesting perspective of a scientist who is also a young Earth creationist - Dr. Marcus R. Ross (PhD from URI Geoscience dept) says the two are different paradigms, different ways to view the universe and one's place in it. The article also brings up an ethical quagmire, about whether it's legitimate for people to study something they don't believe, using their degrees to undermine science, and so on...

Go read.

Next time I'm bored

I'll check out Scientific American's Sci-Sudokus. They use letters instead of numbers, and there's a science clue along with them. I haven't yet done one so I don't know what the clue has to do with anything.

09 February 2007

NASA's shrinks

Did I call this one, or what?

Now, the Lisa Nowak affair has prompted NASA to announce it will conduct a review of its psychological testing procedures for astronauts.

The review might begin by dusting off a 1998 report. Facing the prospect of lengthy missions to the international space station and beyond, NASA commissioned the study to look at how to enhance compatibility among astronaut crews. One recommendation called on NASA management to "develop and implement a psychological evaluation process as an integral part of an astronaut's annual physical examination."

"That was one of the major recommendations made," Dr. Patricia Santy, a Michigan psychiatrist and former NASA flight surgeon on the Challenger mission, told TIME. "NASA was not interested and felt that the general flight surgeon would be able to identify problems on the annual physical exam." (Time.com)


If checking out the link above and also here, near the bottom, click on "Big Chill" and then the third photo, and read the accompanying text. If you're lazy...

Mark Goodsell wanted to document the bitter cold. He snapped this photo on his front porch in what he calls "mid-Michigan." Goodsell lives in Harrison, which is in the center of the state, and he adds that 20 degrees below zero was the actual temperature and not the wind chill.

What's wrong with this picture?

08 February 2007


One of my students told me they read that NASA doesn't have official policies regarding affairs among crew members. BUT, NASA has agreed they need to take a look at their psych screening proceedures.

Oh yeah, and the student suggested we call Nowak an "astronut." I've since seen the term used a few others places. Amusing.

06 February 2007

Soap Opera Science

Any little bit of credibility that NASA had leftover after the investigation into the Space Shuttle Columbia disaster revealed the same institution-wide hush-hush over flaws that doomed the Space Shuttle Challenger has now been thoroughly smashed by the astronaut love triangle that made international headlines when it turned murderous.

As I mentioned elsewhere, there's a *REASON* NASA does psychological screening of all potential astronauts. I really hope someone gets sacked for screwing this up so royally. I'm also starting to think that NASA should be entirely torn apart and rebuilt. This is a shame, because the process will likely also end up trashing a large number of other important projects, some cooperative.

05 February 2007


If any of you have been following the LJ Feed of this blog, my apologies for the recent redump of articles. I just switched to the "Beta" version and it decided to republish everything or something, so it might've just flooded your friendslist. Sorry!