Monday, June 28, 2010

What I'm doing with my Summer "Vacation"

I've realized that I've been taking a bit too much of a hiatus from the blogging world, so I figured I'd use this opportunity to fill everyone in on what I've been up to here in Illinois.

First of all, I also want to give a (belated) welcome to jmb275!

What I've been up to for Research: In one word: LASERS. This year is an exciting one for the laser. May 16th of this year marked the 50th anniversary of the first experimental demonstration of the laser. Ted Maiman's first ruby laser was only capable of brief spikes of laser light, observable, not as the bright red spot that most of us would be familiar with, but rather as a narrow spike on a spectrometer, completely washed out visually by leaked pump light. It wasn't until 2 years later that Willard Boyle was able to get semi-continuous wave light out of a ruby crystal. (It wasn't really a continuous wave laser, but rather a very rapid pulsed laser, but it worked for the time.) In the intervening 50 years, we have developed lasers that output peak powers of over 1015 watts (over 10,000 times the US peak generating power). We have included lasers in ever barcode scanner at every retail store, every CD, DVD, and Blue-Ray player ever built, and even sold them for $5.29 as a "Pet Toy" at the grocery check-out line (right below the beef jerky). We use lasers to make both some of the hottest and the coldest places on earth. My current research project revolves around designing a new type of laser using solid Hydrogen as the gain medium. (Technically, it's a Raman laser, so the gain is a little different than in traditional lasers, but still.) Suffice it to say, I love this stuff.

What I've been up to for Education: The last few weeks, I've been working with a project called EnLiST. EnLiST is a teacher-development project at the University of Illinois. We take area K-12 teachers, and give them a couple of weeks of very intense, very cool physics that they can take and use to improve the science programs at their schools. It is a combined project between the Physics department, the Chemistry department, the Business college, and the school of Education. Not only do teachers get some intensive content training, but the also get a number of networking tools, as well as options to write their own grants to the program for funding for their school's science program.

With all the things that the program does, I think perhaps the most important (and certainly the most fun) part is just re-igniting the excitement and reminding all of us why we fell in love with science in the first place. After dealing with hours of threshold calculations, scientific articles, laser alignment, trying to fix various pieces of broken equipment, etc, it can be really easy to wonder why in the world we're putting off getting a real job to do this. I think it's important to come back to basics every once in a while to realize what it all means, and why it's so cool.

It's amazing the type of physics that you can do with some simple equipment and a little imagination. In the last two weeks we, along with some Illinois high school teachers,

  • measured the radius of the earth with a GPS by walking around the university quad,

  • measured the speed of light 2 different ways with a $7 laser pointer, an oscilloscope, and some basic electronics that cost about $20 from Radio Shack,

  • measured the speed of light again with a little 2.4 GHz transmitter (a basic wireless connection setup) and a piece of aluminum,

  • built a laser radio that transmits information via the laser beam in a cheap laser pointer,

  • built a working speaker with some magnet wire, a neodymium magnet, and a paper cup,

  • derived the effects of special relativity using only the basic axiom that the speed of light is the same independent of reference frame,

  • built the core of an atomic clock (that would have been state of the art about 30 years ago),

  • demonstrated the effects of general relativity and how accounting for such is essential in a system like GPS.

Meanwhile, our elementary school teachers,

  • learned about the nature of science, scientific measurement, uncertainty, and model building,

  • empirically derived atomic properties by observing different states of matter,

  • discussed the history of atomic theory from the plum pudding model all the way through the full QFT model including effects from polarizing the vacuum (there's nothing like a little history to keep you scientifically humble),

  • experimented with heat, temperature, heat capacity and heat conduction (including why the seat belt in your car feels hot, but the seat doesn't, and why it is possible to gargle liquid nitrogen and why you shouldn't),

  • cleared up some misconceptions with basic mechanics, and derived Newton's second law with a spring, a stopwatch and a skateboard (and learned why the Greeks got it wrong and why it took several thousand years until someone like Newton came along and found the mistake),

  • learned about circuits, lit a fluorescent light bulb with just a balloon, made a simple motor, and learned how most textbooks get the shape of the earth's magnetic field completely wrong.

Wow! I just realized I sound like an infomercial. Anyways, it was a really great project to be involved on. I agree completely with what jmb275 said about the vital importance of creating a sense of wonder and awe about the world around us. Two of my favorite places out here are the St Louis Science Museum and the Magic House children's museum, also in St Louis. Whenever we go there, I always have at least as much fun as the kids. It's wonderful to re-ignite your sense of wonder with science.


  1. Hmmm, lasers. I worked on the NIF at LLNL at my last job. Not only is it the most powerful and energetic laser on earth but it is an engineering marvel ranging from building construction, to optics precision, to the unprecedented control system.

    Lasers are way cool!

  2. That sounds like some great outreach, Bill. I volunteer as a science fair judge in local middle and elementary schools and I can tell you that in many cases the number of elementary school teachers that actually understand the science they are teaching is woefully small. Most of them have memorized the facts but have no idea why any of it is true.

  3. By the way, I must say that lasers are pretty cool too. It's nice to have an experimentalist and an engineer in our blog to balance out all of our far-out theory mumbo-jumbo.

  4. Bill, great post. Anyone remember bouncing lasers of the "$10000" mirror at BYU to measure the speed of light? That was one of my favorite labs. Although, being me I could care less about getting the significant figures and other small details right. Doing it right to first order and getting a reasonable answer is all I cared about in the labs. Sorry to my former TAs about this. (Like Ryan. :))

  5. I am also very interested about lasers for my work.

  6. Hey Bill, nice post, and looks like really fun outreach stuff. And does this mean you've abandoned Astronomy for good? Or are these lasers going to be used for adaptive optics?

  7. Hmm, actually I had Bill pegged as one building a death star. What other conceivable conclusion could we draw from one who busies himself with astronomy AND lasers? We're watching you Bill!

  8. Hey Andrew, good to hear from you! Actually, my current research group is a cool mix of Astronomy, Physics and Chemistry. My adviser does high-resolution spectroscopy of astronomically important ions. Essentially, we take high-resolution spectra of ions that are ridiculously hard to isolate on earth, but are literally everywhere in space. We then take these spectra and compare them with astronomical observations. This way we can often constrain different parameters a lot better than the observations can by themselves. Admittedly, I am not the astronomer in the group. Nick is our resident Astronomy specialist. If you read his papers, you'll probably know more about exactly what he does than I do.

  9. jmb275 -- I'd love to hear more about the NIF. I know a little bit, but it would be really interesting to hear about some of the science that is done there / technical issues that have to be dealt with / etc. It would be great to hear more about your experiences.

  10. Re Bill
    "Actually, my current research group is a cool mix of Astronomy, Physics and Chemistry. My adviser does high-resolution spectroscopy of astronomically..."
    Yeah, all I hear is "blah blah blah...we're building a death star!"

    Just teasing.

    Yeah, perhaps I'll do some posts about the NIF. It's entirely unclassified so I can tell you quite a bit. I worked on the control system, so I probably can't relate some of the super cool physics that go on, but I'll do my best. And you'll appreciate the engineering challenges in any case.

  11. jmb275 -- Well, what can I say, you got me. We've got the star destroyer parked out back (the deal in our group is when you get a new paper published you get to take the ship out over the weekend). We're still working on the planet-destroying laser systems for the death star, but maybe you can help us. ("Join the dork side!") ;)

    Anyways, thanks for the comment, and I look forward to hearing more about what you did.


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