Astronomy at home

If you’re looking for a constructive way to use your critical thinking skills in your spare time, then I have some good news for you: Galaxy Zoo wants your help!

In partnership with the Sloan Digital Sky Survey, Galaxy Zoo is looking for volunteers to help with image processing: identifying what types of galaxies SDSS has seen, and trying to understand how observed galaxy collisions may have happened. It might seem like these jobs would be a perfect application for computers. Actually, image identification is harder than you’d think – if it wasn’t, Captcha would be useless – and collision simulations are very cumbersome programs to run. The human eye (with brain attached) is a better tool for these sorts of problems, if you can get enough eyes (and brains) working together on all the data. And that’s exactly what Galaxy Zoo was set up for.

No scientific background is necessary. There are very helpful and easy-to-understand tutorials on how to answer the questions they’ll ask about each image. All you really need is your eyes, and you’ll be contributing to astrophysics research in no time. So go help out!

(Thanks to Elles for posting about this over at Teen Skepchick.)

December 2, 2009 · Written by
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Thoughts from March Meeting

I had a great time at the APS March Meeting. Since I’m attempting to blog anonymously, I’m not going to get into the specifics of which talks I found most interesting/relevant to my research, but there are a few more general things I want to talk about over the next couple days. I’ll discuss some more fun things in the future, but for now, a somewhat grumpy bit about mentoring graduate students.

One of the moments during the meeting which really stuck with me was when a professor got up to give a contributed talk and explained why he was standing there, rather than his doctoral student (whose name was listed in the program). He said something like, “My student was going to give this talk originally, but I decided it was too important not to present myself, so I pushed him away. [chuckle] I hope he isn’t too mad at me.” (The use of the verb “pushed” I remember clearly.) After a brief pause, there was some (I think nervous) laughter from the audience, then he plunged into the rest of his talk.

For what it’s worth, though the talk did cover a reasonably important development, they weren’t the only group talking about it or the first ones to have demonstrated it, and their results weren’t particularly breathtaking as far as I could tell. What I think happened was that a more well-known group was reporting similar results, and when this professor saw the abstracts scheduled, he wanted to seem just as cool as them. But I’m willing to grant for the sake of a thought experiment that the results are actually unique and important. Also, for clarity’s sake: plenty of people give talks for other people at March Meeting. Sometimes people are sick or unexpectedly busy and unable to make it, and someone else in their group covers for them. It’s no big thing. So that part’s not my issue.

I may just be lucky — no, I know I’m lucky — to have an exceptionally nice advisor… but doesn’t this professor’s behavior seem really out of line? I know he’s the one in charge, and (in some cases) the one working day and night in order to win the favor of his tenure committee, but I don’t see any reason for stepping in in this case other than sheer arrogance and credit-greediness. He could have given his own talk; it is okay for multiple talks to come from the same group. (Though he would have had to come up with something at least slightly different to talk about.) The first and, if you want, last slide in the talk can have the professor’s name on it. Really big, if you like. With a picture, so everyone can recognize and find him later if they want, for congratulations or questions. He can make sure to be in the audience. It’s not considered really out-of-line for PIs to jump in during the Q&A period after a talk with more thorough answers than their students give, or offers to discuss issues after the session, so he could have made himself visible to other conference attendees that way too.

I can imagine a professor trying to do important things and get credit for them in order to impress his or her superiors (to get tenure, to get a promotion, to get some other special responsibility assigned to them, etc.). What I can’t imagine is that the tenure committee, or department head, or whoever, cares who is standing in the front of this breakout room in the Pittsburgh conference center to give this 10-minute talk. It doesn’t change whose name is listed in the official record! And presumably all that matters to the tenure committee (or whomever) is that important work was done under the supervision and guidance of this professor. Training brilliant and successful graduate students probably also matters to them, a little bit, yeah? So, having your grad student give this important talk at March Meeting on behalf of your lab is presumably just as good as you giving it yourself, if not better, in terms of your own career advancement.

For the student, on the other hand, being recognized at the conference is potentially a lot more important. Networking is significantly harder when you’re one of the small fish, and a great way to meet people is for them to approach you and ask you questions after your talk. That student is probably going to want a postdoc position someday, probably in the not-so-distant future! It’s not crazy to imagine that he’d end up making contacts in other groups that could lead to eventual postdocs or even permanent jobs.

In talking about this with others, I heard the suggestion that the student might have been terrible at the talk during practices beforehand, and the professor could have been stepping in to save face for his group. In that case, though, I think there’s no reason to explain it this way in front of the audience. (Maybe it’s the explanation you give your student if it’s the last minute and you just can’t convince him he’s unprepared.) You say something like, “My student wasn’t able to present this talk today, so I’m taking his place.” Something that makes it sound like he could have been sick, though you might leave it ambiguous if you’re really averse to little white lies.

Why rant about this, Z? you are probably asking. This one guy was a jerk. Big deal. Well, I’ve read and heard other people’s accounts of working with nightmarish advisors, so I know he’s not the only jerk out there. Also, if I saw one guy like this in during the small slice of the conference I attended (12 out of 14 sessions, minus a few talks here and there that became part of my lunch breaks), there are probably a few more. Each session has about 40 rooms of simultaneous talks. If we assume I saw a reasonable sampling of personalities at the conference, that predicts more than a handful of other professors out there like this one (not to mention a few more who think his behavior is okay but didn’t happen to act like him this time).

I just wanted to put it out there on the tubes that I think this sort of behavior on the part of a professor is inappropriately selfish and not at all constructive. I’m very interested in hearing the opinions of others out there in academic-blogger-land, on how frequent this sort of thing is and whether it’s as bad as it seems to me. (Those links are to people I thought of off the top of my head who’d probably have something to say on this, but this question goes out to everyone.) Tell me: am I very sheltered, or right to be outraged?

March 22, 2009 · Written by
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Who’s afraid of the LHC?

Gail Collins’ latest column had me literally laughing out loud. It’s called “Digging Ourselves a Black Hole,” and it’s about the hyped-up fears that the Large Hadron Collider will create a singularity that will devour our planet. The LHC is a new particle accelerator built in Switzerland and intended to go into full operation later this year. Collins simultaneously debunks and embraces the black hole speculations, lending a bit of perspective to more common concerns:

I am bringing this up now because it is always important to remember that things could be worse. You may be worried about a new cold war or a major bank failure, or afraid of losing your job or your house or your credit rating. You may be depressed by your first look at the fall TV schedule. …

Perspective is all. If you’re going to fret, I say, fret about that black hole. For one thing, it makes it much easier to schedule unpleasant tasks for the second half of September. Heads, the planet survives. Tails, the root canal never happens.

I had a very similar realization right around when I took my first quantum mechanics course. One notable thing about quantum physics, as distinguished from classical physics, is that particles are described as having some small probability of being in places which are classically forbidden. Without getting too technical, let me make an analogy. Imagine you had a ball rolling back and forth in a valley, but on the other side of each hill is another valley. Classically, unless you let go of the ball at one hill’s peak, there’s no chance of it rolling all the way over into the next valley. It’s limited by the amount of total energy it has — potential plus kinetic. On the other hand, if the ball was a tiny particle governed by quantum mechanics rather than by macroscopic rules, there would be a small chance of it tunneling through one of the hills and popping out on the other side. (When I say small, I mean extremely minuscule. But nonzero.)

When I first learned about quantum tunneling, I had a horrifying thought: This means there is some chance of me spontaneously falling through my chair and the floor below me and landing on some poor unsuspecting student in the classroom below us! But then I had a more horrifying thought: Because the probability of tunneling decays exponentially with distance in the classically forbidden region, it’s many orders of magnitude more likely that I fall partway through the floor and then get stuck. Ew.

Of course, my body is made up of so many atoms, and even my flimsy chair was so thick from a quantum-mechanical perspective, that the probabilities we’re talking about here are so tiny as to be effectively zero. (I would be more likely to win the lottery while being struck by lightning for the second time and being bitten by a shark.) Nevertheless, “effectively zero” is not the same as zero. It is still technically possible… yet somehow, we manage to go on. (We laugh in the face of danger every day, we physicists. That’s why we’re heroes.)

In a way similar to this quantum tunneling issue, the black hole fears about the LHC are not entirely unfounded, but they do give a great example of making mountains out of molehills. We don’t know everything about particle physics — that’s why the LHC was built, after all — so we have a couple different theoretical questions that we’re trying to answer. The old “Standard Model” theory says that the LHC will not yield energies high enough to create black holes. It is hypothesized that the Standard Model needs to include large extra dimensions in order to account for various unresolved questions, and in very large-scale experiments like LHC the energies needed for black hole production might possibly be accessible. In fact, one of the many purposes of such large-scale experiments is to test for evidence that would support this hypothesis. Even if we did see black holes, though, they would be so tiny that they are likely to evaporate almost immediately by Hawking radiation. We don’t have any direct evidence supporting the idea of Hawking radiation yet, because its levels would be very small and difficult to detect, but it has held up to thorough theoretical checks and the safety of LHC has been accepted by the vast majority of physicists.

Recap: The mainstream theory says black holes cannot occur at LHC. One alternative hypothesis posits a possibility of micro black holes at LHC, but the mainstream understanding of these black holes is that they would evaporate almost immediately and pose no danger whatsoever.

Recap of the recap: You need to go to the alternative alternative theorists to get someone who believes there might be a danger from black holes at LHC.

Don’t get me wrong, though. The LHC makes me very afraid — just not about black holes. I’m afraid for the future of pure science research in the US. The LHC was built in Switzerland, already the home of CERN. ITER is going to be built in France. No large-scale experimental physics facilities are planned for sites in the US. Back in the early 1990s, the Superconducting Supercollider (SSC) was being built in Texas, but Congress decided to cut funding and the project had to be canceled.

It used to be the case that physics professors would come to American universities and research facilities to participate in international collaborations. If you were involved in a large-scale, groundbreaking project, chances were good you’d be spending part of the year in the US. Now that funding and facilities for new experiments are not available in the States, American professors and researchers are going to Europe and Asia for several months at a time to get their research done. I’m not saying this is objectively bad — science should be done everywhere, and people of every nationality are equally capable of doing it — but it’s definitely bad for the United States. When research is done here, researchers visit here and, for their careers, want to live here. A significant number of them start billion-dollar companies here, sometimes based on spinoff technology from their research and sometimes spontaneously spawned in the fertile intellectual environment of research-focused communities. Other already-existing companies also benefit from new discoveries. This creates jobs, contributes hugely to the economy in general, and raises the American standard of living. And Congress decided that this is not worth considering as a national priority? Now that’s terrifying.

August 24, 2008 · Written by
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