By Patricia Daukantas
Optical technologies such as laser scanning confocal microscopy (LSCM) and multiphoton excited (MPE) fluorescence microscopy have given researchers wonderful new ways to image live cells and biological tissues. Today the Nobel Prize in Chemistry went to three scientists who found something for these state-of-the-art microscopes to see.
Back in 1962, Japanese cell biologist Osamu Shimomura of the Marine Biological Laboratory and Boston University Medical School (both in Massachusetts, U.S.A.) first isolated the substance known as green fluorescent protein (GFP) from the Aequorea victoria jellyfish and discovered that it produced a fluorescent glow under ultraviolet light. American biologist Martin Chalfie of Columbia University (New York, U.S.A.) showed that GFP could act as a luminescent “tag” that traces biological phenomena. American biochemist Roger Y. Tsien of the University of California at San Diego (U.S.A.) studied how the fluorescence mechanism of GFP works and extended the phenomenon to other colors and other proteins.
In the June 2003 issue of OPN, Paul Campagnola and William A. Mohler explained how GFP works: “[T]he gene that encodes for it can be linked to the gene of virtually any cellular protein of interest. The resulting fusion is then placed in cells or a whole organism and the desired protein is expressed with the GFP label.”
Scientific American has a nice article explaining the significance of GFP, and in a statement, the president of the American Chemical Society, Bruce Bursten, said, “Green fluorescent proteins allow scientists quite literally to see the growth of cancer and study Alzheimer’s disease and other conditions that affect millions of people.”
At OSA conferences, I’ve heard many researchers describe how they used fluorescent proteins as part of their experiments to improve biomedical imaging. One example of this work is a “Scattering” published back in February 2008, describing a retinal flow cytometer. A quick search of Optics InfoBase reveals numerous articles on work involving GFP in such OSA journals as Optics Express and JOSA A as well as OSA conference proceedings.
Quantum dots are starting to supplant fluorescent proteins in biomedical imaging because of their longer lifetimes and increased flexibility. Nevertheless, GFP and its glowing-protein cousins will remain an important component of the biomedical imaging toolbox for years to come.
By Patricia Daukantas
No sooner did we report on the progress toward the next Hubble Space Telescope repair mission than we have to note that the repair mission has been postponed for several months.
NASA officials, including Preston Burch, the Hubble program manager at NASA’s Goddard Space Flight Center, today announced the delay after a serious communications glitch developed within the orbiting telescope. The shuttle mission, known as STS-125, may launch next February.
The glitch – which has nothing to do with Hubble’s optical systems – developed over the past weekend in the orbiting observatory’s science instrument command and data handling unit. An undetermined error caused “side A” of the unit to put itself into safe mode, thus interrupting the flow of science data from the optical instruments to researchers on Earth.
The Hubble team will try to activate “side B” of the data handling unit, which, like “side A,” has been in orbit since the telescope’s launch in 1990. Over the next few days, the team will assess whether that activation will pose any large risk to the telescope, and test out their theories using the Vehicle Electrical System Test (VEST), a copy of the Hubble support system bay that resides in the huge NASA Goddard clean room in Greenbelt, Maryland, USA. If “side B” can turn itself on, astronomers can resume observations with the existing Hubble instruments.
According to Burch, NASA has a backup copy of the dual-sided data handling unit here on the ground, and Goddard researchers will start testing it for flight qualification. If the unit passes the severe vibration, thermal vacuum and acoustical tests, the fresh unit will be added to the STS-125 payload and the spacewalking astronauts will have to make time (up to two hours) to install it on the telescope. Of course, the backup unit is as old as the one in Earth orbit, but the space agency expects that tests will show that it still works.
Leaving only “side B” on the telescope would leave Hubble with several potential single points of failure, while the complete replacement of the data handling unit will bring Hubble’s communications systems back to full redundancy, said Ed Weiler, associate administrator of NASA’s science mission directorate.
The VEST unit inside NASA Goddard’s clean room. (Photo by Patricia Daukantas)
By Patricia Daukantas
If you haven’t already seen the OPN article on NASA's final servicing mission to the Hubble Space Telescope, which has been online for a few weeks now, you’ll see it in your October issue of the magazine. It continues a long OPN tradition of Hubble coverage going back to the telescope’s launch in 1990.
Many developments have taken place since I wrote my article. Most importantly, the space agency has pushed back the target launch date of the space shuttle Atlantis, which will ferry seven astronauts to the orbiting Hubble, from October 10 to October 14, mainly because Hurricane Ike interrupted flight preparations at the Johnson Space Center in Houston, Texas. The astronauts lost a full week of training to the destructive storm.
Press reports also indicate that shuttle technicians had a few problems loading the equipment into the payload bay at the launch pad and have also had trouble with the insulation on the Hubble’s replacement batteries. Those issues seem to have been fixed. In addition to the instruments themselves, the Atlantis payload bay holds several specially designed carriers to anchor the Hubble instruments and the spacewalking astronauts’ tools securely in place for the high-acceleration, high-vibration ride into Earth orbit.NASA officials will hold a press conference on October 3 to announce an official launch date, based on flight readiness reviews scheduled for next week.
The Hubble repair mission follows on the heels of the 50th anniversary of NASA’s founding on October 1, 1958. It’s a good time to ponder the triumphs and challenges facing the space agency. Although the Space Telescope Science Institute administers the science programs relating to the Hubble Space Telescope – allocation of telescope time to professional astronomers, grand administration and public outreach activities – NASA has done and continues to do the heavy lifting work of launching the telescope into orbit, pointing it at the heavens and fixing it when necessary. Don’t forget that if NASA hadn’t sent astronauts to correct Hubble’s original spherical aberration problem in 1993, a lot of exciting science would never have been accomplished.
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.
By Patricia Daukantas
For hundreds of years, stained-glass windows have decorated medieval cathedrals and awed onlookers with their intricate, translucent designs. Now a researcher in Australia has discovered that some windows that date back to the Middle Ages contain 21st-century-style light-activated nanotechnology.
Medieval windows painted with pigments containing gold particles actually purify the air when lit by sunlight, according to Huai Yong Zhu, associate professor of chemistry at Queensland University of Technology in Brisbane.
Zhu and colleagues found that the gold nanoparticles found in many pigmented glass windows in Europe become activated when struck by sunlight and remove volatile organic compounds (VOCs) from the air. VOCs are light hydrocarbons that vaporize easily, and many of them are considered pollutants in the gas phase.
In Zhu’s words, sunlight causes the small gold particles to act like a “photocatalytic air purifier.” The solar energy boosts the magnetic field on the surface of the nanoparticles and this in turn breaks apart airborne VOCs. Zhu is interested in the process because it is solar-powered and thus energy-efficient.
By Patricia Daukantas
Most OSA members, I’m sure, are aware that negative-refractive-index metamaterials have been a hot topic of research for the past few years. Although scientists have found success making materials “invisible” to microwaves, several teams have been racing to extend these materials into the optical range – a development that would have much more interesting applications.
This week, two new papers from a California-based team hit the news wires. The researchers, based at the University of California at Berkeley and Lawrence Berkeley National Laboratory, made a prism out of optically negative-index metamaterial that closely resembles layers of tiny fishnets, according to the letter that appeared in Nature.
Xiang Zhang’s group made their metamaterial out of a stack of alternating layers of silver and magnesium fluoride; the size of the “fishnet” cells was on the order of a few hundred nanometers. The scientists tested the prism’s refractive index at near-infrared wavelengths from 1,200 to 1,800 nm and found that the index went to zero at around 1,475 nm.
In the brief Science paper, Zhang and colleagues reported on a different experiment that refracted red light via an aluminum-oxide array of nanometer-sized holes filled with silver. Negative refraction, however, happened only for transverse magnetic polarized light, not for transverse electric polarized light.
Journalistic interest, of course, is driven by the age-old human dream of invisibility, never mind the cloak and cloaking devices in the Harry Potter and “Star Trek” tales. Fortunately, some of the news coverage took pains to explain that practical devices made from negative-index metamaterials are still many years in the future.
Posted by Christina Folz, OPN Managing Editor
With 92 years of history under our belt, the Optical Society has accumulated scores of photos. Although we’ve captured many moments, we haven’t always captured the who, what and where information that must have seemed so obvious at the time the photo was snapped. Help us breathe new life into our images by providing your own imaginative captions to one of the images below. It could be a cartoon-style quote or a creative description of what you see. We’ll share your best captions in a future issue of OPN.
Send your captions to opn@osa.org or post them on our blog at www.osa-opn.org. (Remember to specify which image you are captioning…or don’t; it might be more fun that way.)
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By Deborah Herrin, OSA’s Director of Information Technology
Here are several very readable and enjoyable books about physics and the people who have shaped the science.
Galileo's Daughter: A Historical Memoir of Science, Faith, and Love, Dava Sobel
A biography of Galileo, with lots of great insights into the politics of the time, the role of the papacy and the internal struggle Galileo faced between his own religious beliefs and his scientific discoveries. I was reading this book during CLEO one year when I was invited to celebrate OSA past president Tony Siegman’s retirement. One of the presenters noted that scientists’ ability to measure was improving to such an extent that certain constants might prove to be variables in the future. I was struck by this juxtaposition of past and present: long-held truths that are proven to be incorrect.
Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time, Dava Sobel
Since Sobel had impressed me with Galileo’s Daughter, I went back to this earlier book of hers–and was not disappointed. She describes how determining longitude required a precise determination of time; yet the most precise timekeepers relied on pendulums, which failed to work accurately when placed on a ship crossing the sea. After reading this book, I toured the U.S. Naval Observatory just up the street from OSA on the grounds of the vice president’s house. During the tour, you learn about time-keeping issues that the U.S. faced and how Western Union played a role; you see the atomic clock and the Internet clock, which shows how many computers are connecting to determine time every second; you visit a beautiful library where you’ll see OSA’s journals displayed; and, weather-permitting, you climb into the observatory to take a look through the telescope. After that, I was fortunate enough to take a trip to Greenwich, England, where I visited the observatory, saw many of Harrison’s timepieces and straddled the prime meridian.
Nobel Prize Women in Science: Their Lives, Struggles, and Momentous Discoveries, Sharon Bertsch McGrayne
OSA fellow Barry Masters turned me on to this book when he gave a brown bag lunch talk to OSA staff on one of the women in the book. This book presents the stories of 15 women who either won a Nobel Prize in science or played a significant role in Nobel-Prize winning research. The stories serve to highlight not only the science, but also women’s role in science and society as a whole. As an aside, when Maria Goeppert Mayer won the Nobel Prize in Physics in 1963, the local paper reported “La Jolla Mother Wins Nobel Prize.”
E=Mc2: A Biography of the World's Most Famous Equation, David Bodanis
This little book provides lots of information about physics and the people involved in the science leading up to nuclear physics. Did you know that Maxwell’s equations weren’t written by Maxwell? Or that several Nobel gold medals were dissolved in a solution in Denmark to avoid discovery by the invading Germans during WWII? The medals spent the war suspended in a solution and, after the war, the gold was recovered and made into new medals. One important tip as you read the book: read the notes at the back of the book as you go.
Brighter than a Thousand Suns: A Personal History of the Atomic Scientists, Robert Jungk
The previous two books, plus interest in learning more about Los Alamos, where many OSA members are, led me to this book. If you’re interested in this topic, you also should check out the play/movie “Copenhagen”, which deals with a meeting between two of the scientists–Bohr and Heisenberg. The controversy surrounding the play resulted in the Bohr Archive releasing early documentation related to that meeting.
Right now, I’m reading Measuring the World, by Daniel Kehlmann (translated from German). It’s a novel based on two Enlightenment-age scientists: Alexander von Humboldt and Carl Friedrich Gauss, the latter played a key role in optics.
Next up: The Canon: A Whirligig Tour of the Beautiful Basics of Science, by Natalie Angier. I heard the author and her husband (both science journalists and local residents) speak at the Marian Koshland Science Museum of the National Academies of Science in January. The premise of the book is what key concepts scientists wish the general public understood. I’m also reading Color, A Natural History of the Palette, by Victoria Finlay–this was a find at the Phillips Collection one lunchtime.
If you’ve read a good book related to science, please post a comment here to let us know about it!
By Patricia Daukantas
Several interesting news stories recently crossed my computer screen. One involves a useful optical illusion and another an LED landmark.
First comes an Associated Press story via CNN.com about a test of fake speed bumps that look real to oncoming motorists. The pseudo-bumps are really flat plastic with embedded glass beads to make them reflective at night, but they are colored to look like three-dimensional pyramids sitting in the middle of the road. The U.S. National Highway Traffic Safety Administration (NHTSA) is testing these and other “calming” devices to see if they really do slow down speeding cars. You can read about the “Heed the Speed” program on NHTSA's Web site (the details are in this section).
Second, a public television station in Boston, Mass., is having trouble with its giant outdoor LED screen. Last September, WGBH-TV installed a 30- by 50-foot (9.1- by 15.2-m) LED video screen on the outside of its headquarters, where it would be visible to passersby on a major highway. However, the Boston Globe reported that some of the LEDs go dark when the screen gets too warm. Repairs may take a couple of months.
Finally, several news services have reported that dozens of partygoers suffered partial vision loss from a laser light show gone awry near Moscow, Russia.
By Patricia Daukantas
This year’s OSA congressional caucus briefing covered an extremely timely topic: solar energy. Last Friday, several policy analysts and industry representatives touted the benefits of both photovoltaic (PV) and concentrating solar power (CSP) technologies to congressional staff members.
Doug Hall, director of PV technologies for Corning Inc., explained to the Capitol Hill audience how PV devices work and how they have evolved from wafered silicon to thin-film panels. Nanotechnology, organic materials and flexible substrates—all of which have been described in OPN over the past few years—could eventually bring greater efficiency and lower costs.
CSP, on the other hand, uses reflecting troughs, reflecting dishes, Fresnel lenses or similar devices to direct incoming solar energy to a single place such as a power plant. The technology makes it easier to store the energy for use during cloudy days or at night, according to Chuck Kutscher of the U.S. National Renewable Energy Laboratory.
Other speakers addressed federal and private-sector investments in the various types of solar systems. OSA, who co-hosted the event with the Environmental and Energy Study Institute, has posted the viewgraphs from the congressional briefing on its Web site.