As you may know, my day job is as a Physics professor at Drexel. We just finished up our spring term, and once again I’m left exhausted by the process of assigning grades and enforcing the grading policy. To many students, grades seem like a reward or punishment. A high mark is something that a student “deserves” or, if not, something that could be granted if I were simply generous enough. At the end of every term, a few students will ask for the possibility of ad hoc extra credit in the hopes of showing that they are truly worthy of an A. Even passing a class is seen as a grace that can be bestowed by the professor. I know what you’re thinking. I must be drunk with power.

I don’t see it that way. Oh, sure, I recognize that grades are an incentive system. The basic reasoning is that I want my students to study and learn physics. Therefore, I want them to practice, attend lecture, learn the theory and how to apply it, and so on, and so ultimately they’ll be good scientists and engineers. Sometimes, though, the sun is shining or there is something good on TV, and the future reward of being a great engineer isn’t tempting enough, so I need to up the ante and give “points” for good behavior. They then attend class, study for their exams, and build bridges that don’t fall down.

Can I tell you how much I hate that system?

What should be a great opportunity to teach and learn becomes, in essence, nothing more than a market for grades. How much of my time, and my TAs’ time, is devoted to grading, telling students what’s going to be on the exam, or trading in points. While in my role of assigning grades I should be evaluating the students for their readiness for future courses, graduate school, or jobs, I find myself worrying far too much about the effect on a student’s GPA or whether I will be perceived as overly harsh. And, of course, it’s not just me. This conflict is the root cause of grade inflation.

There’s no real point to any of this. It’s just a frustration that has become particularly acute over the last term, and I thank you for indulging my little rant.

-Dave

I don’t know if any Drexel students are regular readers of this blog, but we had graduation last night, and I just wanted to take a moment to congratulate the class of 2009.

-Dave

I was listening to All Things Considered Science Friday the other day, and they were doing a story on the 400th anniversary of Galileo’s telescopes, when it occurred to me that I haven’t said anything about the International Year of Astronomy which, naturally, is meant to commemorate Galileo. In honor, here are some fun facts about the first telescopes:

1. Galileo didn’t invent the telescope. It was invented about a year earlier by a Flemish optician named Lipperhay. Galileo was, however, the first to use telescopes for astronomical observations. The chief selling point had previously been espionage and warfare.
2. I visited Galileo’s place of “house arrest.” It’s not clear what he had to complain about. It seemed pretty swanky.
3. Within the space of less than a year, Galileo observed:
   • That Venus had phases (suggesting that it was illuminated by the sun) and varied in size throughout the year, meaning that it was different distances from us and we couldn’t be at the center of its orbits.
   • That Jupiter had moons that went around it just like our own moon went around the earth. It’s hard to think that the earth is particularly special under those circumstances.
   • He also looked at the moon. You should, too. It looks really cool through a telescope.

So, I thought I’d give a few IYA/Philadelphia astronomy events:

1. Drexel hosts a monthly public observing night. They’re generally held the 1st Wednesday of the month (start times to be determined by the season). Check out what you can see in the Philadelphia night sky.
2. The Franklin (Institute) still has their Galileo exhibit going on (in addition to a Star Trek exhibit which just opened a few weeks ago). You can see one of only two extant Galileo telescopes. This one was made in 1610.
3. If you are an astronomer, or a science teacher, please consider getting involved in Project Astro. Basically, we’ll be having a workshop later this year which will be open to teachers and astronomy mentors. The astronomer will then give periodic visits to the teacher’s classroom to do projects with students. If you have any questions, or would like to get involved, send me an email.

Enjoy the remainder of the IYA!

-Dave

I’d be remiss if I didn’t point out that teh interwebs are abuzz with talk of time travel. My friend and former Mathlete Josh Kamensky sent me a couple of links, including one from John August’s Screenwriting blog about the relationship between pre-cognition (a la Minority Report) and time travel. It’s definitely worth reading, as is Sean Carroll’s list of 11 Rules for Time Travelers, although rules 0,6,7, and 10 are a little bit redundant with one another.

I wanted to write at least a quick post about all of the exciting things that have been flung into space lately. Really, there’s a bonanza of new telescope repairs and missions going on right now. To name a few:

• Kepler - On March 6, the Kepler observatory was launched. It will continuously observe about 100,000 stars. The idea is that if an earth-like planet passed in front of a star, the brightness would dim for a short while. We would, in fact, be able to detect earth using such an instrument. And, in case you’re confused, we’ve never detected anything smaller than 5 times the mass of the earth outside our solar system, and we’ve never detected anything that would be habitable for human life.
• Planck - On May 14, the Planck mission was launched by the European Space Agency. Planck is a microwave observatory (30-857 GHz) which will (like the WMAP satellite before it) measure the Cosmic Microwave Background (CMB). You may have seen press images of the “baby pictures of the universe”:

  

  Planck will measure unprecedented resolution in the CMB, allowing us to measure the primordial power spectrum to scales 3 times smaller than those probed by WMAP. The other big goal is to study clusters of galaxies using the multi-waveband capabilities of the instruments. Ideally, we’ll be able to measure the Integrated Sachs-Wolfe and Sunyaev-Z’eldovich effects which will, respectively, give us insights into the Dark Energy in the universe, and the formation of the first clusters of galaxies.

• Herschel Space Observatory - This is an infrared telescope that was launched on the same mission as Planck. Basically, it’s tuned to be sensitive to molecular chemistry, meaning that it will be able to measure star formation, planetary atmospheres (within our solar system), and the formation of early galaxies.
• Hubble Upgrade! - In May, the Hubble Space Telescope got its latest (and last) servicing mission. Of particular interest to me is the installation of the “Wide Field Camera 3″. As the name suggests, it’s set up for wide field surveying, with pixels that are diffraction limited (meaning that it would be pointless to make them any smaller). It’s particularly useful because it has filters which allow it to observe in the near IR as well as in the UV.

I know I’m supposed to be a theorist, but it’s hard not to get excited about all of the science that’s going to come out of these.

-Dave