By Patricia Daukantas

Last month, OSA’s 93^rd annual meeting, Frontiers in Optics (FiO), featured more social networking than any of its predecessors. This week, however, a group of astronomers is holding a meeting devoted just to social networking and “Web 2.0” activities within that branch of science.

The second-ever .Astronomy (pronounced “dot-astronomy”) conference started today at Leiden University in the Netherlands. Building on last year’s gathering in Cardiff, Wales, the participants are talking about new ways of communicating astronomical science to the public, ranging from online robotic telescopes to the large image collections of Google Sky and Microsoft’s WorldWide Telescope to the communications media of blogging, podcasting and the Twitterverse. Morning conference sessions are even being streamed on live video (European time).

(Incidentally, one Twitter member, @ninajansen, posted that she had just bought a Galileoscope as her first-ever telescope, even though her Ph.D. is in astronomy.)

After I read over the .Astronomy 2009 press release this morning, I was wondering what form a “.Optics” conference would take. How excited are you and your colleagues over the new social media? Do you blog, tweet or post on Facebook? Do you follow any optics- or photonics-related blogs, and if so, which ones? I know that OSA Fellow Pablo Artal blogs in both English and Spanish. The Florida Photonics Cluster, mentioned in my November 2009 Optics Innovations column, also has a blog.

What kinds of social media assist you in your optical science or engineering career? Please comment on this blog or on OPN’s “fan” page on Facebook.

2009-11 November blogging, social media

By Patricia Daukantas

Two of the most amazing instruments of 20^th-century optics are going on display at the Smithsonian Institution in Washington, D.C. (U.S.A.).

WF/PC-2 and COSTAR, the instruments that gave the Hubble Space Telescope its clear vision after its spherical aberration was discovered in 1990, will be on view at the National Air and Space Museum from now on, except for a brief tour of other venues later this year and early next year.

Both of these instruments were installed on the orbiting telescope during the first NASA servicing mission in 1993. When astronauts revisited Hubble for the fifth and final time earlier this year, they replaced WF/PC-2 and COSTAR with newer cameras and brought the old instruments back to Earth.

WF/PC-2 – the Wide-Field/Planetary Camera 2 – took the most memorable space photographs of the last 15 years: colliding galaxies, puffy planetary nebulae, newborn stars emerging from gas clouds, and the famous Hubble Deep Field. Ed Weiler, associate administrator for NASA’s Science Mission Directorate, has called it “the camera that saved Hubble.”

COSTAR – the Corrective Optics Space Telescope Axial Replacement – served as the “eyeglasses” for the rest of Hubble’s instrumentation. It is no longer needed because every other camera and spectrograph that has been installed on Hubble servicing missions contains its own corrective optics.

We take Hubble and its awesome image and data libraries for granted now, but the discovery of its primary mirror’s spherical aberration in the summer of 1990 really threw astronomers and the space program for a loop. How was this flaw supposed to be fixed AFTER the telescope was already orbiting the Earth? Figuring out how to do just that was an enormous feat of optical science and engineering, and several OSA members played key roles in that accomplishment. At the 2008 Frontiers in Optics meeting in Rochester, N.Y. (U.S.A.), a session of the special “NASA at 50” symposium focused on the team effort to repair Hubble.

2009-11 November hubble

By Patricia Daukantas

Another example of the inroads that solid-state lighting is making: the New York Times reports that the star that tops the Rockefeller Center Christmas tree in midtown Manhattan is getting a makeover with LEDs.

The 5-year-old Swarovski crystal star has 12 glass rays and “a million glittery facets,” according to the Times, but the designer wanted to send more light through the rays. So workers retrofitted the star with 720 1-W white LEDs. The stainless-steel framework inside the rays had to be redesigned to accommodate the LEDs and their circuitry.

The Rockefeller Center tree, a decades-old tradition in New York City, will be illuminated this holiday season from Dec. 2 to Jan. 7. The rest of the tree was converted to LED lighting two years ago.

2009-11 November leds, solid-state lighting

By Patricia Daukantas

U.S. cities are beginning to use solid-state lighting (SSL) to save on electricity and maintenance costs, but they have much further to go, lighting experts told a congressional audience yesterday.

OSA and the U.S. House of Representatives’ Research & Development Caucus organized the Washington, D.C., briefing, at which several lighting experts showed off recent local-government success stories and discussed how to gain more acceptance for the technology.

The U.S. Department of Energy (DOE) has studied the history of compact fluorescent lamps (CFLs) to find out what went wrong in the marketplace with their initial introduction, said James Brodrick, manager of the DOE’s SSL program. He recounted the frequent complaints about the old-style CFLs from 20 years ago (they buzzed, they took a while to light up, they made people look like corpses).

More than 200 manufacturers have signed up for the Lighting Facts program, which is supposed to provide consumers with consistent energy-consumption information for bulbs and bulb replacements according to Brodrick. He also showed off the 90-lumens-per-watt entry for the L Prize technology competition:

LED performance is getting close to the “holy grail” of more than 120 lumens per watt, which would make outdoor and indoor lighting much more attractive, said Mathew Sommers of General Electric Co.’s Lumination division. He reviewed a number of the talking points used to pitch SSL technology to business and municipal customers: glare reduction in product display cases, more uniform coverage of outdoor sites, substantial reduction in maintenance costs (such as bulb replacement) and – oh, yeah – huge savings on energy costs over incandescent lights.

Although a representative from the government of Ann Arbor, Mich. (U.S.A.), couldn’t get to Capitol Hill to talk about that city’s LED lighting program, a representative of Cree Inc. (Durham, N.C., U.S.A.) reviewed several public-sector SSL projects: the parking garage at the Raleigh Convention Center, a street in Chapel Hill, N.C., and a dormitory at North Carolina State University. Deb Lovig, Cree’s LED programs evangelist, passed around the room an LED replacement for the recessed indoor “can light,” which usually takes an incandescent bulb.

Consumers are less interested than governments and other large organizations in return-on-investment arguments, noted OPN contributing editor Alexandre Fong, who moderated the discussion. Also, the U.S. lighting infrastructure, heavily based on screw-in lights that run on alternating rather than direct current, isn’t yet right for LEDs.

“There are four billion sockets out there,” Sommers said. “That’s a lot of sockets to put bulbs in.”

Indeed, bulb manufacturers will probably develop lots of interesting solid-state bulb replacements to fit into those sockets – and to meet the U.S. lighting-energy standards that go into effect in 2012 and become much more stringent in 2020.

A future issue of OPN will include much more coverage of the policy issues surrounding solid-state lighting development and usage. Stay tuned!

2009-11 November leds, solid-state lighting, energy policy

By Patricia Daukantas

Photons have momentum, according to Einstein, and a couple of things that recently crossed my desk reminded me of this small but potentially significant phenomenon.

In yesterday’s New York Times, Dennis Overbye wrote a lyrical article describing an experiment called LightSail-1, which a space advocacy group called the Planetary Society plans to launch into Earth orbit about a year from now (depending on the availability of a launch vehicle, which is still being worked out). The spacecraft will use 32 square meters of Mylar and will go into orbit 800 km above the Earth, where it could avoid the drag from the uppermost layers of our atmosphere.

LightSail-1 is basically a “proof of concept” experiment to see how well sunlight can propel a small craft, but some scientists envision a future era when solar space cruisers use the gentle but constant acceleration of radiation pressure to cruise around the solar system – or beyond it.

The article on the solar-sail project caught my eye because I remember reading a short story about light sailing in elementary school – it might well have been “Sunjammer” by the late Arthur C. Clarke, but it was a long time ago and further details have receded into the mists of time.

On a related note … recently I’ve been getting press releases from a contest called the Space Elevator Games. A “space elevator” – which doesn’t exist yet – would be a tether running vertically from the Earth’s surface up to the level of Earth orbit. According to space-elevator advocates, cargo, and eventually people, could travel up and down the tether to get to space with far less cost and energy expenditure than today’s chemical rockets.

The idea has been around for about five decades, but few took it seriously until the discovery of carbon nanotubes circa 1990. Nanotubes potentially could make a much stronger tether than other materials. Advocates also say that another technology developed roughly five decades ago – the laser – could provide the propulsion to lift cargo into space.

Anyhow, last week three teams of competitors met out in the Mojave Desert of California (U.S.A.) to try to win pots of money by sending a small vehicle up a 1-km-high tether using only “power beaming.” LaserMotive, a startup from Seattle (U.S.A.), won the level-1 prize of $900,000 by getting its 5.2-kg vehicle up the tether at an average speed above 2 m/s (and sometimes at 4 m/s). A second team called the “Kansas City Space Pirates” got its vehicle only about halfway up the tether, and a third group’s climber didn’t really get off the ground.

“Solar sails” don’t work in this type of application. The LaserMotive team turned light into propulsion by beaming an infrared laser array up from the ground and onto solar cells attached to the climber; the resulting energy powered the motor and other apparatus on the vehicle.

No team won the $1.1 million prize for getting their climber to ascend at 5 m/s, but undoubtedly these competitors and possibly more will be back next year for another crack at fame, adventure and cash.

2009-11 November

By Patricia Daukantas

In another example of the increasing collaboration between professional and amateur astronomers, three German high school students and a secondary school physics teacher have published their study of a cataclysmic variable star in a professional journal.

The students and teacher joined three professional astronomers in studying the light variations of EK Ursae Majoris, a close binary system in which one of the stars is pulling matter off its companion. From their home base of Göttingen, the teens participated in remote-control observations of the star with an optical telescope deep in the heart of Texas (U.S.A.). Then they had to learn how to reduce the CCD images and generate “light curves,” or graphs of the brightness of the binary star over the course of two months. Finally, they compared their data with observations taken by two X-ray satellites orbiting the earth.

This statement from the publisher of Astronomy & Astrophysics includes a link to a PDF copy of the four-page journal article, which was accepted for publication in August.

I’m always fascinated by students who pursue research before they get to college, and I wish them all the best in their future endeavors.

2009-11 November pro-am astronomy