Musings on optics, physics, astronomy, technology and life

Archive for November, 2013

A very scientific Thanksgiving

I hope all my U.S. readers had an excellent Thanksgiving yesterday, and I hope you all have an excellent weekend, whether you are getting an adrenaline rush out of the Black Friday sales or you are trying to dodge commercialism altogether.

This year we got a reminder that the eye surgery known as LASIK descended from some experiments on Thanksgiving turkey leftovers. I already knew about this, of course, but it’s great to hear that the tale will be going into the OSA Centennial History Book so that future generations will know the origins of this procedure, which has enormously benefited some of my highly nearsighted friends.

Yesterday afternoon, part of Greenbelt, Maryland, was hopping as Comet ISON passed close to the Sun. NASA hosted a Google+ hangout from Goddard Space Flight Center, just a couple of miles from my computer desk, and I was watching along and retweeting things on Twitter. At the time it really looked as if the comet had vaporized entirely when it grazed our local friendly star, but perhaps part of it survived the close passage. I guess that makes ISON a “zombie” comet! Hey, zombies are extremely popular these days.

This year, for my Thanksgiving dinner with friends, I made my from-scratch creamed corn with cornstarch instead of wheat flour, because a couple of the folks at the dinner table are gluten-intolerant. And I hurried home to do a Skype interview with a researcher in Australia. Yes, we used today’s optical communications technology to talk about tomorrow’s optical communications technology. We live in fascinating times indeed.


What I’ve been up to

November is almost half over, so if you have access to Optics & Photonics News, please hop on over to my feature article on the 150th anniversary of the U.S. National Academy of Sciences (NAS) and learn something new about this venerable institution.

The OPN editor assigned me this feature; I didn’t dream it up myself. At first, I worried that I would be able to connect NAS to OSA and the world of optics and photonics in only the most vague and general way, and I would leave my readers scratching their heads and wondering, “Why the heck is this in my magazine?”

Fortunately, just around the time I started my background research for this article, the NAS held a historical symposium at Woods Hole in Massachusetts. While listening to the live webcast, I learned that three of OSA’s most famous Honorary Members — George Ellery Hale, A.A. Michelson, and Robert A. Millikan — had played significant leadership roles within the Academy at various times in its existence. Hale, a solar physicist and observatory impresario, spurred the NAS to start publishing a Proceedings journal and served as the first chair of the National Research Council (NRC); Michelson, the first American Nobel physics laureate, served a term as NAS president in the 1920s, when the Academy opened its first headquarters building in Washington, D.C.; and Millikan, first to measure the electric charge of the electron, edited the Proceedings through the 1940s. Those connections helped me frame the story and make the history of the NAS relevant to today’s optical scientists. (After all, who hasn’t had to recreate either the Michelson-Morley speed-of-light experiment or the Millikan oil-drop experiment, or both, in undergraduate physics classes?)

In between my longer articles for OPN, I have been writing some short pieces as well: on a superfast quantum light switch, improved detection of high-frequency UV light, and a compound that can hide from infrared cameras at some temperatures.

Finally, back in April I mentioned that I had a “day job” working for some sort of educational center that hadn’t yet opened, but I didn’t get into details. However, now that the parent institution has started to advertise it, I can do The Big Reveal!

One month from today, the Smithsonian’s National Museum of Natural History will open Q?rius, a new hands-on learning center for ages 10 and up. I wrote a series of REALLY short (i.e., one-paragraph) essays about geological specimens that will reside in the Q?rius collection. Other museum staff members have been developing novel interactive experiments and demonstrations covering all aspects of the research going on at the museum. I can hardly wait for Q?rius to open, and I hope to see you all there!

The answer to a boy’s question

Way back when I was a graduate student in astronomy, a schoolboy asked me a question that I never forgot. It took scientists only another 20 years or so to come up with a reasonable answer to it.

For part of my teaching assistantship during my first year of grad school, I was assigned the public observatory program. I had to recruit faculty members and postdocs to give twice-monthly public talks, handle reservations for school and Scout groups who wanted their own private presentations, and corral fellow grad students into running the slide projector (before the days of PowerPoint) and helping with the telescopes. (I used to suggest that all grad students in astronomy should get an automatic master’s degree in slide projectorology.)

One evening a school group showed up for its talk an hour before the public lecture, and for some reason I gave them a presentation. I can’t remember why — perhaps someone had got sick or even forgot to show up. And I don’t even remember what I talked about — maybe the solar system or something really basic like the differences between stars and planets.

Anyway, when I was fielding questions after the talk, one boy — maybe about 10 years old — asked: “How many planets are there in the entire galaxy?”

“Ooh,” I said, trying to stall for my time while my mind raced. This happened to be after the discovery of a planet around a pulsar, but before the teams of Mayer & Queloz and Marcy & Butler had found any planets around “normal” (that is, main-sequence) stars. At the time I was really, really interested in the possibility of finding extrasolar planets.

“That’s a really good question,” I told the kid. “In fact, it’s such a good question that scientists are still trying to answer it!” I explained that astronomers were very busy trying to search for extrasolar planets but the search was really difficult, and maybe, just maybe, in future years they would be able to start answering that question.

Well, the exoplanet discoveries started to roll in a couple of years after that evening’s Q&A session. Currently, astronomers know of more than 1,000 actual extrasolar planets, with thousands more candidates awaiting confirmation.

Finally, just this week, astronomers came up with the first reasonable estimate of just how many Earth-like planets may occupy our galaxy: 40 billion. That’s 40,000,000,000. That’s how many potentially habitable worlds may be out there, in our own little spiral clump of stars, without even crossing intergalactic space to get to the billions and billions of other galaxies out there.

The thought takes my breath away.

And I keep thinking of that boy’s question. I have no idea what this kid’s name was, or where he went to school. Doubtless he is an adult by now, and wherever he is, I hope that he read that news story and realized that, after all these years, he finally got his answer.

You can read the full scientific paper here and New York Times writer Dennis Overbye’s coverage of it here.