By Patricia Daukantas

For most of the past week since my last blog post, I’ve been wondering: How can the field of optics and photonics help Haiti in its rebuilding effort? Telecommunications? Building sensors?

The full answer to that question is yet to be written, but I’ve found one organization, the Solar Electric Light Fund (SELF), that is accelerating its efforts to bring photovoltaic energy to health-care sites in the earthquake-stricken Caribbean nation.

Founded in 1990, SELF has long been providing photovoltaic home systems to residents of remote Third World villages. In some countries, the group has expanded its efforts into solar-powered computer labs, water-pumping stations and other electrification projects.

Fund officials now say on their Web site that SELF is intensifying its efforts to provide solar power to the Haitian clinics and field hospitals operated by Partners in Health (PIH), a Massachusetts-based medical care provider. The Web site states: “Diesel fuel, now used at the majority of PIH sites in Haiti, is already in short supply and will likely become even more difficult to obtain as time goes by. Solar can help fill a short-term need in terms of providing power for PIH's relief efforts, and over the long-term, solar energy can serve as a foundation for a robust and sustainable healthcare infrastructure in Haiti.”

Another solar-power charity, Light Up the World, says on its Web site that it is studying ways to provide photovoltaics to humanitarian operations in Haiti once the logistical challenges are worked out. That group has worked in Costa Rica, Papua New Guinea and other nations in the past, though not Haiti.

If you hear of any other organizations that aim to bring optical and photonic technologies to Haiti as the country rebuilds, please let us at OPN know – we would love to blog about them.

2010-01 January

By Patricia Daukantas

If you’ve seen the news reports about this week’s devastating earthquake in Haiti, you’ve probably seen the detailed satellite images of the Haitian capital, Port-au-Prince, showing just how many buildings have collapsed and how much debris has filled the streets.

The images came from the high-resolution satellite of GeoEye, whose systems engineering director, Michael Madden, gave a presentation on it at last year’s Photonic Applications, Systems and Technologies (PhAST) conference in Baltimore, Md. (U.S.A.). At the time, we blogged about it – see this entry and scroll down to the bottom.

The GeoEye satellite took 41-cm-resolution images of Haiti the morning after Tuesday’s earthquake. These photos stand in stark contrast to images captured only a few months earlier.

Many news organizations have reproduced these images online. Of particular note is the New York Times, which allows users to slide a bar from side to side to “flip” between before-and-after scenes. Wired Science also has a guide to the photos.

2010-01 January disasters, news, imaging

By Patricia Daukantas

Astronomers are tracking down a stellar mystery, but they still need your help!

As I wrote in the March 2009 issue of OPN, a binary star known as Epsilon Aurigae is undergoing a two-year eclipse cycle, and astronomers don’t fully understand the nature of the objects.

A binary star consists of two stars that orbit their common center of mass. If a binary system is close enough to us and its components are bright enough, we can see both of them. In other cases, we have to rely on indirect evidence, such as periodic dimming caused when one star eclipses the other.

Auriga, a Northern Hemisphere constellation, is that roughly pentagon-shaped group of stars that includes the bright star Capella. Epsilon Aurigae – some 2,000 light-years from us – is one of the three stars that make up a small triangle near Capella, and its roughly two-year-long eclipse began in the summer of 2009. (The eclipses happen every 27.1 years, and detector technology has improved a lot over that time period.)

At the recent Washington, D.C. (U.S.A.) meeting of the American Astronomical Society (AAS), scientists who have been looking at Epsilon Aurigae through NASA’s infrared Spitzer Space Telescope outlined a possible explanation for the behavior of the binary system. To Donald Hoard of the California Institute of Technology, the brighter half of the pair may be a dying star, with two or three times the mass of the Sun, that is sometimes eclipsed by a single star inside a disk. This contradicts a different hypothesis that says the brighter star is something called an “F supergiant,” 20 times as massive as our Sun. The infrared data also suggest that the disk, if it exists, is unusually deficient in small dust grains (the size of smoke particles) and higher in grains the size of sand.

How can you help figure out what’s going on over there? The Web site CitizenSky.org is a clearinghouse of information about Epsilon Aurigae itself and about what you need to collect meaningful observations, whether or not you have a telescope. The “Dr. Bob” on this Web site is University of Denver (Colorado, U.S.A.) astronomer Robert Stencel, whom I interviewed for last year’s OPN article along with the dedicated amateur astronomer Jeff Hopkins.

In fact, several high school and college students, along with their instructors, got to present their observational data at a poster session at the AAS meeting. Physics and astronomy professor Darryl Stanford of the two-year College of San Mateo (California, U.S.A.) and seven undergraduates have been using the college’s 8-inch Meade Schmidt-Cassegrain telescope outfitted with a self-guided spectrograph that gets 2.4-angstrom resolution. Sally Seebode, a science teacher at nearby San Mateo High School, and two of her students also participate in the measurement of prominent absorption lines in the spectrum of Epsilon Aurigae.

The Epsilon Aurigae project shows that so-called “classical” astronomy is alive and well, both for citizen scientists and for educational institutions with moderate-sized telescopes, said Arne Henden, president of the American Association of Variable Star Observers. Bright-star observing campaigns provide an opportunity to engage the public in science.

2010-01 January astronomy

By Patricia Daukantas

Like us at OSA headquarters, many of us have now returned to work after the holiday season. Less than two weeks ago, a passenger’s attempt to blow up a jetliner using explosives hidden in his clothing has added a note of worry to what would otherwise be a joyous time.

Because I’ve been following optical research and attending OSA meetings for some years now, every time I heard discussions about airline security and terrorism on the news reports, I started yelling at the TV set: “What about terahertz technology?” What about it, indeed? Known as “millimeter-wave scanning” in the popular press, terahertz-class body scanners and imagers have been a big area of engineering research over the last decade. As Martin Koch noted in a March 2007 OPN feature article about terahertz technology, millimeter waves cannot penetrate more than a few hundred microns into human skin, so they are good at looking through clothing but not at looking into our bodies.

As the editor’s note to an October 2004 OPN article by Kodo Kawase put it: “Until fairly recently, the terahertz range was considered little more than the dark gap that separated the two halves of the electromagnetic spectrum. Now scientists have come to view it as a bridge rife with possibilities for new applications and research.”

If you’re looking for quick explanations of body-scanning technology to give to your non-technical family members and friends, the New York Times and the Washington Post have both published “info graphics” comparing “millimeter-wave” or terahertz imagers to their low-dose X-ray counterparts. An article on the Discovery Channel’s Web site, which was posted just before the Christmas Day terrorism attempt, described recent research into these “T-rays.”

According to Reuters, the U.S. Transportation Security Administration currently operates 40 millimeter-wave scanners at 19 American airports – though that could change. I’m sure that more articles on terahertz body imaging – such as this Times blog entry about the possibility that airport scans might be “pornographic” in some cases – will appear in the media in the days and weeks to come.

Edited on January 6, 2010, to add: Canada is buying 44 full-body scanners to put into its airports, starting with Toronto (the country's busiest airport) and Vancouver (host of the Winter Olympics next month). The Calgary Herald describes them as millimeter-wave devices.

2010-01 January terahertz, millimeter-wave scanning, homeland security