By Patricia Daukantas

Last night’s CLEO plenary session took the audience to places we’ve never been and things we’ve never imagined. How’s that for the power of lasers?

First, Gérard Mourou of the École Polytechnique in France, the pioneer of chirped pulse amplification, described the types of far-reaching fundamental physics that may be studied when the Extreme Light Infrastructure (ELI), an exawatt-class laser being designed by a consortium of 13 European nations.

“Lasers have revolutionized atomic physics, but we are still in the atomic regime,” Mourou said. The hugely energetic ELI pulses may push science into the realm of “photonuclear physics,” in which researchers could measure nuclear lifetimes, test electron dynamics at the attosecond scale, investigate ultrarelativistic laser-matter interactions and even break down the quantum vacuum and observe its components.

Mourou also paid tribute to Theodore “Ted” Maiman, who designed the first laser 50 years ago this week, and invited CLEO attendees to France’s own celebration of the laser’s historic anniversary next month (see the website in French and English).

Next, Douglas Simons, who grew from a butterfly-catching and backyard-stargazing kid to become director of the Gemini Observatory, reviewed the advances in laser-guide-star adaptive optics (AO) that have collapsed the point-spread function of astronomical objects from roughly an arcminute to a few milliarcseconds.

“Telescopes on the ground are becoming microscopes on the sky,” Simons said, noting that when he was a kid in the 1970s and 1980s, he never dreamed that he’d be head of an observatory that monitors the weather on Io and Titan, moons of Jupiter and Saturn respectively. Thanks to adaptive optics, astronomers have been able for the past decade to monitor the motions of stars swerving around the unseen black hole at the center of our galaxy.

Gemini’s next big project is developing a multi-conjugate adaptive optics (MCAO) system for its Gemini South telescope at Cerro Pachon, Chile. (In 2007 I visited its twin, Gemini North, on Mauna Kea in Hawaii.) The MCAO, dubbed Canopus, will use multiple laser guide stars simultaneously; these beams will be split off from a single 50-W solid-state sodium laser. Lockheed Martin and Coherent design the laser, which arrived in Chile just after the devastating 9.2-magnitude earthquake in February.

Simons compared Galileo’s first telescope-based hand drawing of our solar system family -- the rings of Saturn, the phases of Venus -- with the AO-facilitated photos of a planetary system around a star called HR 8799. He thanked the laser-science community for making the latter possible.

Incidentally, Konstantin Vodopyanov, one of the CLEO general co-chairs, gave us the stats for this year’s technical conference: out of 2,199 submitted papers, 1,085 oral presentations and 366 posters were accepted. We attendees are also being treated to something like 98 invited talks (some of which were submissions whose authors subsequently were asked to give longer presentations) and 33 tutorials.

Today (Tuesday) is going to be, in the words of CLEO blogger Jim van Howe, “a Mega-day or perhaps I should say Tera-day.” Our exhibit hall has opened, the Market Focus sessions are beginning, and tonight is the big “Lasers Rock” concert.

By Patricia Daukantas

Three physicists have figured out how to recreate a famous X-ray-diffraction experiment with a laser and other simple equipment. Their goal is to enable undergraduate students to follow in the footsteps of a chemical physicist who helped to decode the structure of DNA.

Rosalind Franklin (1920-1958), a young British scientist, took the famous X-ray diffraction image that was critical to identifying the structure of DNA as a double helix. Heidrun Schmitzer, Dennis Tierney and Gregory Braun of Xavier University (Cincinnati, Ohio, U.S.A.) include Franklin in their undergraduate course for non-majors on “Women Who Shaped Physics.” Featured scientists in the course include Marie Curie, Lise Meitner, Jocelyn Bell Burnell and Maria Goeppert-Mayer.

In their poster paper at this week’s American Physical Society March meeting in Portland, Ore. (U.S.A.), Schmitzer and her colleagues described the classroom experiment, which requires only simple tools: a red laser and the spring from a retractable ballpoint pen. Shining the laser beam through the spring projects a diffraction pattern strikingly similar to Franklin’s famous image. See the Xavier group’s photo of diffracted light and compare it to the X-ray image from 57 years ago (and an accompanying mathematical analysis).

By comparing the geometry of the pen spring to the diffraction pattern of the light, and then studying the Franklin X-ray image at its original size, the students “can determine the angle, pitch and radius of the DNA molecule, just like Rosalind Franklin,” Schmitzer wrote in the abstract.

Last night I did a quick trial of this with a spring from an old pen, my cats’ favorite laser pointer and a darkened room. Unlike Schmitzer, I did not block the bright center maximum with anything, so my result wasn’t as visually stunning. But I could see some evidence of the “X” pattern with faint characteristic stripes. I suspect that, with a bit more equipment and refined technique, this could make a stunning classroom demonstration.

By Patricia Daukantas

The clock is ticking down to the launch of the Large Hadron Collider (LHC), the massive international particle-physics experiment in Europe. The collider’s host, CERN, has its hands full with debunking rumors that the LHC is going to cause the end of the world.

Seems as if a small but vocal crowd believes that LHC will generate a tiny black hole that will keep sucking matter inward until it devours the entire planet Earth (mass: 6 × 10²⁴ kg). Court cases have been filed on both sides of the Atlantic Ocean to try to stop the LHC research; two Nobel laureates sided with the government to continue the experiments in one such lawsuit.

LHC defenders argue that there is no such physical theory that actually predicts the growth of microscopic black holes into macroscopic, planet-guzzling monsters. In a column called “Inside Science Research,” the American Institute of Physics (AIP) points out that if black holes really do evaporate as predicted by Cambridge University's Stephen Hawking, an attometer-sized black hole would survive for only a billionth of an attosecond – such a brief time period that there isn’t even a standard SI prefix to describe it.

In a more technical article written for scientists, Michael Peskin of the Stanford Linear Accelerator Center reviews a Physical Review D paper that found no evidence that black holes on the scale of 10¹² electron volts (TeV) could create damage over time scales shorter than the lifespan of Earth. Since our planet has already been around for 4.5 billion years and the Sun has enough nuclear fuel to last at least another 5 billion years, I’m not worried that the world as I know it will vanish while I’m sleeping tonight.

The “first beam” of the LHC – analogous to “first light” for a telescope – is set for early Wednesday at 3:30 a.m. EDT in the United States or 9:30 a.m. CET for most of Europe.

To celebrate the arrival of the LHC, the Boston Globe published a stunning Web photo essay showing off the various component instruments. And some young scientists at CERN assembled this “Large Hadron Rap” song that’s garnered more than 1.6 million YouTube downloads already.