Centuries ago the stars were believed to reside just beyond the planets of our solar system.It never fails to astound me how big the Universe is—how far away even the nearest stars are, let alone other galaxies scattered from here to near infinity….

How do we know how far away celestial objects are? This shouldn't be taken for granted, as it's not as straightforward as sounding the depth of the ocean floor with sonar, or determining the range to an object by bouncing radio waves off it and timing the reflection.

In fact, we have "pinged” the nearest celestial objects with radar to determine their distances very accurately. Examples are the Moon and Venus, where round-trip lightspeed travel is measured in seconds or minutes.

Before radar, the scale of the Solar System had to be determined geometrically, by observing events like Venus or Mercury transiting the face of the Sun from different locations on Earth and triangulating. Even this technique requires telescopes, which we've had only four hundred years. Before that, figuring out distances to just about everything except the Moon was mostly guesswork. In fact, it wasn't too many centuries ago that the entire Universe was believed to be not much larger than the Solar System—the Sun and it's nine…excuse me…eight planets—as we know it today.

Once the distance from Earth to the Sun was figured out, that length (the "Astronomical Unit”) in effect became a basic measuring rod for working out distances to everything else, by one means or another.

As Earth orbits the Sun, the direction from which we see stars shifts minutely, and we can observe a small change in a star's position compared to the more distant "background” stars. You can see the same effect by holding a finger in front of your face and looking at it alternately with one eye, then the other.

The geometry of this observation is a simple triangle, whose base is the distance between your eyeballs and whose legs are the lines from each eyeball to your finger. By knowing the length of the base, and observing the change in viewing angle against the background, the length of the legs (distance from your eyeballs) can be calculated.

In the case of Earth and a nearby star, the "eyeballs” are the Earth at two ends of its orbit around the Sun (six months apart) and the "finger” is the star.

But this measuring of distance by "trigonometric parallax," as it's called, only works for the nearest stars, as the minute shift in the star's apparent position diminishes with distance.

As astronomers learned more about the distance to nearby stars, they determined how to relate their temperature and mass to their actual brightness, and it became possible to estimate the distance of many stars by measuring their apparent brightness, with an understanding of how the brightness of light weakens with distance.

To measure the depths of space between us and galaxies far, far away, in which individual stars are indistinguishable from the overall galactic glow, we can turn to certain types of supernovae: individual stars that temporarily shine brightly enough to be observed and measured. Like the flare of a match struck in the dark night, the brilliance of the flash reveals how far away the striker stands.

We have built up our knowledge of the Universe's vastness over the past couple centuries, working out the problem from the near to the far. Even as science and technology have made the world on which we live smaller, it has done exactly the opposite to the Universe….

(left) A cell imaged with an optical microscope. (right) The same cell imaged by allowing the cell to absorb UCNPs and then irradiating it with infrared light. Each nanocrystal is one thousand times smaller than the width of a human hair. Image courtesy of PNAS."Like a silent black mist, nanoparticles began to come into the room underneath the west door…Inside the room, the particles appeared to spin and swirl aimlessly, but I knew they would self-organize in a few moments."

Thus proceeds Michael Crichton's 2002 thriller, Prey, as the protagonists face off against a malicious swarm of flesh-hungry nano-robots that are the offspring of a most unholy marriage of biological, computer science, and engineering research efforts.

Real science capabilities lag somewhat behind, but researchers succeeded recently in demonstrating an exciting new class of nanoparticle with potential applications in biological imaging. The new crystals, more formally known as lanthanide-doped upconverting nanoparticles (UCNPs), were fabricated and studied under the direction of principle investigators Bruce Cohen and James Schuck at Lawrence Berkeley National Laboratory's Molecular Foundry, and results were published on June 18^th in a paper by Shiwei Wu and others in the Proceedings of the National Academy of Sciences (PNAS).

Happily, while Crichton's nanoparticles coordinated an attack on a your vital organs, these particles behave more like benign light bulbs. After allowing a living cell to absorb the UCNPs, researchers shine infrared laser light on the cell, and the nanocrystals within light up like a Christmas tree in red or green arrays of dots. These, in turn, can easily be spotted using an optical microscope and used to map out particle distributions within a cell, yielding information impossible to obtain by other methods.

The method, known as single-molecule imaging, has been demonstrated using other nanoparticle types, but UCNPs are unique because of their uncommon brightness and stability, and because they are powered by infrared light. This is both good for the studied cells, because infrared light is less damaging than visible or X-ray frequencies, and good for the people measuring them, because it can probe more deeply into tissue than other types of light. In fact, one prospect for future research is the imaging of entire animals.

Reflecting on the research effort's long-term goals, Cohen commented that cross-disciplinary sharing of ideas is crucial. "In general, we'd like to bring nanoscience to the larger scientific community, especially biology, where few researchers have had much exposure to it," he said. "Our goal is to make interesting and useful new materials that will let them do all sorts of experiments that would otherwise be impossible."

A phonautograph, which made the first sound recordings (playback made possible thanks to Lawrence Berkeley National Lab

Last summer, QUEST told you about how scientists at Lawrence Berkeley National Lab have developed a technology to playback old audio recordings using visual scans. Along with bringing to life the wax cylinders we featured in our TV story, the Berkeley technology helped the world hear, for the first time ever, the oldest known sound recordings ever made. Now the historians who unearthed those recordings have discovered that they've been playing them all wrong.

The recordings were made by a phonautograph, invented by a Frenchman named Léon Scott more than 20 years before Edison came up with the phonograph. The technology worked by scratching sound waves onto sheets of paper covered with lampblack. Last year, historians used the Berkeley Lab's "visual stylus" to replay an 1860 recording of what they thought was a young girl singing the French song "Au Claire De La Lune". Since then, they've realized that they were actually playing the recording at double speed. Instead, it's likely the inventor himself doing the singing. You can hear both version at FirstSounds.org, or listen to an interview with the historians from NPR. It turns out learning to play old sounds isn't the only challenge — we have to know how to play them right!

Watch "How Edison Got His Groove Back" to learn more about how LBL's innovations are helping restore old sound:

QUEST on KQED Public Media.

This past Friday, a few thousand folks attended Lawrence Livermore National Laboratory to see dignitaries including California Governor Arnold Schwarzenegger and U.S. Senator Dianne Feinstein dedicated the world's newest and most powerful laser, the National Ignition Facility (NIF).

Governor Schwarzenegger, clad in a pink tie– an odd sartorial choice for dedicating this giant hulk of a building housing 500 trillion watt laser housed within– nevertheless succeeded in channeling at least some of his Hollywood days. When they originally visited the facility last November, "we were so excited that we said, 'We'll be back.'"

The project's goal is to focus 192 laser beams onto a BB-sized capsule of hydrogen fuel in order to heat it to the point of ignition, that is, to achieve a nuclear fusion reaction where more energy comes out of the capsule than is put in. Fusion is the common process for creating energy in the Sun, and has been demonstrated on Earth both in the apocalyptic specter of thermonuclear weapons and in the more hope-inspiring form of plasma reactors such as those at the Joint European Torus (JET) in Britain. However, ignition has yet to be demonstrated, as JET requires a constant influx of energy greater than anything it is capable of producing. If all goes well within the next several months, ignition could be achieved at NIF as early as 2010.

For all of these exciting aspirations and promise of new technology, the press' reaction to NIF throughout the twelve years of its construction has been often lukewarm, and at worst scornful. Some of this has been deserved, and it is certainly true that the facility's $3.5 billion dollar construction cost is a hard price tag to swallow.

However, NIF is a worthy scientific cause and might well turn out to be an excellent investment. To put things a little bit into perspective, other large science projects are similarly expensive. The Large Hadron Collider (LHC) at CERN and the Hubble Space Telescope have both been estimated at about $6 billion. Dianne Feinstein argued in the past (and reminded the audience at Friday's dedication) that Enron needlessly cost $9 billion during the California Energy Crisis. Put another way, with $9 billion you could (a) experience rolling blackouts while Enron power traders cheer for wildfires ravaging your countryside, or (b) assemble the world's most powerful laser and use it to bring the nation to the brink of being able to replicate, in a controlled manner, the sorts of reactions that power the Sun. Twice.

The physics promise of the NIF, meanwhile, is truly fascinating on all three fronts of NIF's stated goals: energy production, basic research, and national security.

Fission reactors, which extract atomic energy from the splitting of large atoms such as uranium, have been a viable source of energy since 1954. However, the waste they produce remains radioactive for thousands of years. Potential fusion plants, on the other hand, would operate by an altogether different mechanism: the merging of much smaller hydrogen atoms. Radioactive byproducts are still generated, but the timescale for their radioactivity is shorter, on the order of 10 to 20 years.

A significant line of inquiry has already been pursued toward commercially viable nuclear fusion at JET and its planned successor, ITER. Such experiments employ powerful magnetic fields to maintain hydrogen plasma in a confined space and heat it to the point of fusion as it soars around inside a doughnut-shaped ring.

NIF serves as a valuable compliment to these magnetic confinement experiments. Instead of forcing a fusion reaction to perpetuate using costly magnetic fields, the NIF laser will attempt to blast its fuel with so much energy in such a short time period that the fuel will have no time to expand before it undergoes fusion. "If it works, developments at NIF would entirely reshape the dialogue on nuclear fusion energy," said Brian MacGowan, a NIF Program Director.

Even the most optimistic estimates place the viability of these types of energy sources 20 years into the future. NIF itself will never be able to function as a power generator even if all experiments performed at the facility proceed exactly as planned. The raw potential for such power extraction is nevertheless tantalizing.

Additionally, there is basic research potential for NIF beyond fusion power. Stars are typically easy to observe from a distance but inevitably too far away and too inhospitable to explore up close. A miniaturized version of the reaction as created in the NIF target bay could provide an interesting model system. There is no way to tell, but it could be that hand in hand with this ability comes a better understanding of some of the deepest outstanding questions in physics as well, such as the nature of dark energy and dark matter.

NIF also offers a unique way for the U.S. to test the effects of nuclear weapons without violating the Comprehensive Nuclear Test Ban Treaty. NNSA Administrator Tom D'Agostino noted at the dedication that, particularly as the United States' nuclear arsenal ages, this will provide the U.S. with invaluable data.

We may emerge from this economic crisis a poorer, humbler country. Still, I hope that we are not yet so humble that we have lost the ability to dream big, and not yet so poor that we can no longer actively pursue at least a few of those dreams.

The renowned physicist Enrico Fermi (1901-1954)
On July 16, 1945, the United States executed Trinity, the world's first nuclear bomb test, and for better or worse, the herald of the atomic age. The physicist Enrico Fermi recalled the following: "About 40 seconds after the explosion the air blast reached me. I tried to estimate its strength by dropping from about six feet small pieces of paper before, during and after the passage of the blast wave…The shift was about 2 1/2 meters, which, at the time, I estimated to correspond to the blast that would be produced by ten thousand tons of T.N.T."

If we can forgive Fermi for his sterility, it is hard not to marvel at his ingenuity. The official estimate of the bomb's power turned out to be only about twice as large, and it was this uncanny knack for being able to calculate unwieldy quantities that helped earn Fermi a reputation within the physics world.

The concept of the "Fermi Problem"–a hard question made readily accessible by back-of-the-envelope calculations and familiar knowledge–is still powerful in physics and beyond. Science teachers routinely use these types of questions as brain teasers. Economists at the World Bank have used the method to estimate the cost of a potential flu pandemic. The method has even been employed, in the form of the Drake Equation, to assess the likelihood of the existence of aliens. With a little effort, you can try it, too.

To illustrate, consider the classic problem, "How many piano tuners are there in Chicago?" The idea of the Fermi Problem is to break the questions down into a series of steps that you can estimate accurately. For example, I could start with the knowledge that Chicago has a population somewhere in the neighborhood of a million people. It seems reasonable that there is about 1 piano for every 100 people because I have about 200 Facebook friends, and of that group maybe 2 own a piano. This gives me 10 thousand pianos. Then I could assume that a piano needs tuning perhaps once a year, so there are 10 thousand jobs a year. If a piano tuner needs 100 jobs to stay in business, the city of Chicago has about 100 piano tuners. Amazingly, if you are careful you will almost always arrive at the correct answer to within a factor of 10.

The piano problem might be so obscure that no one cares about the answer even after you do find it. Here are a few perhaps more interesting questions, and my estimations:

Technology: At any given point in time, how many people are watching a Rick Astley sing, "Never Gonna Give You Up"? (YouTube shows about 20 million views for the video's current incarnation, posted 1 year ago. Given 30 million seconds in a year, and a typical patience level of perhaps 10 seconds, you can assume that 10 people are being Rickrolled right now.)

Energy: How many power plants does the City of San Francisco need? (It takes about a billion Watts, or 1 nuclear or coal power plant. As Richard Muller points out in his book Physics for Future Presidents, you can obtain roughly the same amount of power midday by covering a landmass the size of San Francisco with solar panels. Tempting.)

Food: How many people can the state of Iowa feed? (A bushel is roughly 35 liters, providing perhaps 10 people or more a day's worth of food. Iowa produced 2.4 billion bushels of corn in 2007, so given about 300 days in a year, that's 10 million bushels a day, or food for 100 million people, or 1/8^th of the world's starving.)

Artwork from Jules Verne’s 1865 novel, From the Earth to the MoonLaunching a spacecraft bound for the Moon with the deliberate intention of striking the Moon in a spectacular impact!

Sounds like something out of a Jules Verne novel… but that's exactly what NASA's up to this year with the upcoming LCROSS (Lunar Crater Observation and Sensing Satellite) mission, scheduled for launch on June 2nd and impact sometime in October– exact date TBA.

And it's not unprecedented, either: the Lunar Prospector spacecraft back in 1998/1999, whose instruments detected possible signs of water ice in craters around the Moon's poles, was crashed into the Moon's South Pole at the end of its mission. The aim was to blast up a cloud of material from the lunar surface and spectroscopically analyze the plume in search of water vapor. None was detected then, but that's where LCROSS comes in.

LCROSS will seek to verify the presence or absence of water ice and related hydrated materials buried at the bottom of a permanently shadowed crater floor on the Moon's South Pole. Water ice cannot persist on any part of the Moon's surface that is subjected to sunlight, but because of the Moon's low axial tilt with respect to the ecliptic (the Sun's apparent annual path in the sky)– only about 1.5 degrees– there are craters at the Moon's poles whose floors never see the light of day, all month long and year round. Water ice could persist near the surface in these places.

LCROSS consists of two pieces: a "Shepherding Spacecraft" that will guide the whole affair to the proper location on the Moon's South Pole, and the Centaur rocket stage that propelled the spacecraft to the Moon. The pair will separate, and the Centaur rocket will become the primary impactor, striking ground and producing a crater and plume of ejected material. Viewing the event from above, the Shepherding Spacecraft will use cameras and other instruments to analyze the plume from a distance, and will then follow the same course as the Centaur, descending four minutes after impact through the ejected plume and analyzing material samples as it falls.

Then, the Shepherding Spacecraft, too, will impact the Moon– and the plume it kicks up may well be visible through modest sized telescopes on Earth. We're planning to watch the explosion live through our telescopes at Chabot, weather permitting. Keep an eye on our website for details.

Now, back to Jules Verne for a moment. The launching of a projectile with the intent of striking the Moon was indeed the subject of one of his novels, From the Earth to the Moon, published in 1865. Fired from an enormous cannon, the goal of that post Civil War mission was to catch the attention of anyone living on the Moon, to open up a line of communication with their civilization.

My wife asked me if crashing a probe into the Moon would have any harmful effects, particularly if in fact there is any form of life (subsurface microbes or such) living there. Well, certainly, if you happen to be a lifeform living at ground zero of the impact… but the fact is the Moon is frequently struck by meteorites much larger than the LCROSS impactor anyway. To paraphrase Douglas Adams, "that kind of thing goes on all the time."

One last fun tidbit about the Jules Verne novel: the launch site for his cannon-fired projectile was a place in Florida, 50 miles south of Tampa Bay, and only about 135 miles from the Kennedy Space Center, from which LCROSS will be launched…

A magnet is suspended over a liquid nitrogen cooled
high-temperature superconductor (-200°C). Image source:
Wikimedia
Take a familiar metal, such as the aluminum foil from the bottom drawer of a kitchen, the mercury you might find in a household thermometer, or the titanium used to build an expensive road bike. Cool it enough, and you will find almost miraculously that electricity can be sent though the metal without losing any of its energy.

This effect, known as superconductivity, has tantalized physicists with theoretical weirdness and seduced futurists with potential applications since its discovery in 1911. Some of the applications, particularly in magnetism, have already been realized. A typical MRI machine works because, hidden within its outer casing, electricity is pumped through a superconducting wire maintained 10 times colder than the average temperature of Pluto. The soon-to-be-running Large Hadron Collider at CERN in Geneva would not have been possible without the aid of giant superconducting magnets. Scientists at the High Field Magnet Laboratory in the Netherlands have even used superconducting magnets to suspend a living frog.

Even more exotic and exciting ideas have been dreamed up, such as large-scale lossless power transmission networks or commercially-viable magnetically levitated trains. Many of these have remained elusively beyond the cusp of practicality. This is because most materials become superconductors only in the frigid neighborhood of absolute zero (0-10 Kelvin). A few do have higher transition temperatures. For example, the cuprates, a class of material based on copper and oxygen, become superconductors as high as 133 Kelvin. Unfortunately, these are also brittle, difficult to work with, and bear limited current loads. However, times may be changing.

In February of last year scientists discovered a new candidate in their quest for a better superconductor, a material based on iron and arsenic. That's right– it is possible that one of the most promising candidates for next-generation energy technology is at least partly the same stuff Aunt Abby used to poison Mr. Witherspoon. The new class of material, collectively known as the iron pnictides (pronounced "NICK-tides"), has taken the physics community by storm, inspired more than a thousand research publications and stolen the show last month at the world's largest annual gathering of materials scientists, the American Physical Society March Meeting.

Is all the hype really merited? Maybe.

Much of the excitement surrounding the iron pnictides is becuase they turn superconducting at anomalously high temperatures, to date at least as high as 56 Kelvin. To be fair, this is still not exactly a high temperature compared to normal everyday experience. Room temperature is about 300 Kelvin. At 273 Kelvin you can get frostbite. At 56 Kelvin the air you breathe liquefies and your lung cavities fill with dry ice.

In the world of superconductors, however, a material with a transition temperature of 56 Kelvin is a rock star. This is the second warmest class of superconductor we know about, overshadowed only by the cuprates.

A few scientists feel optimistic that the pnictide family's transition temperatures may yet surpass even those of the cuprates. This would be a tremendous scientific and technological discovery, not simply because it would set a new record, but because it would mean that we now have two families of materials that become superconducting above the boiling temperature of liquid nitrogen (77 Kelvin). This would be fantastic because cooling materials with liquid nitrogen is both technically easier and less expensive than using the current standard of liquid helium.

Additionally, there may be reason to believe that the new iron pnictides may not have some of the problems that plague other high temperature superconductors. The cuprates have an annoying habit of spawning tiny electrical whirlpools in the presence of a magnetic field. Unless these whirlpools, or vortices (as they are technically called), can be pinned in place, lossless power transmission is impossible. While vortices still occur in the pnictides, pinning may prove to be easier than it is in the cuprates.

Even if we never are able to capitalize on the pnictides, they may have intrinsic scientific value. Scientists are baffled at the underlying mechanism that allows a material to be a superconductor above 40 Kelvin. Figuring this out may not ultimately satiate a desire for new technologies, but the simple desire to know is exactly the sort of thing that would make Darwin or Einstein proud.

Inside the Bevatron. Credit: Lawrence Berkeley National Lab.

Much as I tried to get Stewart Loken to wax poetic about the demise of the Bevatron, the truth is that he – and, I'll bet, a lot of scientists – just don't think that way.

As Loken put it, "science never stands still." However many Nobel prizes the Bevatron produced, this old, defunct particle accelerator is really just taking up space; its demolition, and replacement with a new, up-to-the-minute research facility, is, Loken feels, the best way to honor the work done here. Plans aren't finalized, but it's likely the facility to replace the Bevatron will forward work done at Lawrence Berkeley National Lab's Advanced Light Source (which, by the way, produces light a billion times brighter than the sun).

The new facility – described here – would allow scientists to watch "electrons joining forces, atoms snapping together within millionths of a billionth of a second, the real time of chemical reactions."

But that's a long way off. First, demolition workers must contend with a major disposal challenge, including getting rid of radioactive waste produced during experiments at the Bevatron. Some neighbors are concerned about the prospect of hauling the stuff through Berkeley's residential areas. Others have called for the Bevatron to be preserved as a national landmark.

But demolition is already underway, and picking up speed, thanks in part to $1.2 billion recently bestowed on federal research labs across the country under the American Recovery and Reinvestment Act. The Lab describes the environmental impacts of the Bevatron demolition project here.

See the Bevatron today and in its heyday - watch the "Goodbye to the Bevatron" slideshow online.

Go Bears! is more than a cheer, but a mantra to live life by…as long as you're a Berkeley alum like myself. On Saturday April 18^th, the University opens up to the public…lectures, interactive events, tours, all of the campus museums (most of which aren't usually open to the public)… and it's all free.

Many programs are geared for incoming students and their families. However, there are a few gems designed for everyone. This year's highlights feature hands on physics, discussions on energy & environmental issues, with the search for extra terrestrial life sprinkled in. For a complete listing of events, check out the Cal Day website. Here are my picks:

Darwin, Dover, and Intelligent Design: What's Next for Anti-Evolutionists?

10-11 am, 2050 Valley Life Sciences Building

Hear a national expert on evolution discuss the conflicts between evolution and creationism, and where this debate is headed.

Mobile Millennium: The System That Keeps Traffic Moving

10-11 am, Sibley Auditorium

This traffic-monitoring system collects data and sends it to your cell phone to help you take the best routes. Be an early adopter of this developing technology; learn how following the lecture or from 1:30 to 3 pm outside McCone Hall.

Are We Wired for Good?

11 am-noon, 145 Dwinelle Hall

Is the capacity for compassion, gratitude, and other positive emotions built into our nervous systems? Are such emotions the path to happiness? The founder of Berkeley's Greater Good Science Center has some answers.

What Is the Large Hadron Collider?

11 am-noon, 4 LeConte Hall

It's the world's largest and most powerful particle accelerator. Hear how it works and discover the exciting things it might reveal about our amazing universe.

Will Water Be the Oil of the 21st Century? A Quest for Sustainable Water Management

11 am-noon, 502 Davis Hall

Water is a limited natural resource, and its importance can be compared to that of oil. Examine the parallels between these two resources, and the future of water sustainability.

How Global Climate Change Will Affect the Oceans

Noon-1 pm, 141 McCone Hall

Warmer surface waters, rising sea levels, more storms, and increased carbon dioxide - all will have an impact on marine ecosystems, coasts, islands, estuaries, and wetlands.

The Dark Side of the Universe

Noon-1 pm, 100 Genetics & Plant Biology Building

The universe is mostly made up of "dark matter" - what evidence do we have that it exists? Hear how we're searching for this mysterious component of the universe.

Genes in a Bottle

Noon-2 pm, Latimer Hall

Learn how DNA is chemically extracted from organisms for research applications. Then extract DNA from your own cheek cells, and take it home in a fashionable necklace!

How Do Cars Fit Into a Clean-Energy Future?

1-2 pm, 105 Stanley Hall

Can car lovers also be planet lovers? How will our favorite vehicle evolve as the need to manage global warming intensifies? Energy and Resources Group Professor Dan Kammen

Is Anybody Out There?

1-2 pm, 3 LeConte Hall

Hear about Berkeley's SETI (Search for Extraterrestrial Intelligence) program at the world's largest telescope, the Allen array. Volunteers have a small but captivating chance that their computer will detect the first signal from a civilization beyond Earth.

The Stanford Linear Accelerator. Credit: SLAC.

On the heels of the opening of the Large Hadron Collider last year, I was curious about these particle accelerators: how they work, what research is conducted there, and most importantly why.

Luckily, there is a particle accelerator right here in the Bay Area. Last year, I took an intrepid group down to the Stanford Linear Accelerator (SLAC) to learn more about the these giant expensive research labs.

SLAC maintains an extensive public outreach program. An extensive tour (mine was 2 hours with very in-depth exploration of the facility), public lectures, weekly colloquia, and even science competitions for high schoolers.

I was surprised to find a wealth of research beyond the typical particle colliding at the facility. Many researchers use the state of the art facilities to study basic elements of our life, including water.

On Tuesday, Anders Nilsson is discussing his research on water at SLAC, an in-depth look at some of the stranger properties of water: its high heat capacity, how it is more dense than ice, even insight on using water as a power source (by splitting it into hydrogen and oxygen). Water: The Strangest Liquid, Tuesday February 24th 730-830PM at the Stanford Linear Accelerator.

However, our continued economics woes are threatening physical science research. SLAC is getting the brunt of money cut, missing out on $23 million of requested funding. In response, SLAC laid off 125 of its 1600 employees and shut down its PEP-II collider last year.

SLAC Public Lecture Series
The SLAC Public Lecture Series opens the doors to the inner workings of SLAC for the local nonscientific community. Find out what SLAC is all about: the research, the facilities, and the people that make this a world-class research institute.

SLAC Colloquium
The intellectual watering hole for the entire laboratory, where you can hear talks intended for a general audience on a wide variety of subjects. The colloquium will be returning later this year.

SLAC Science Bowl for High School Students
SLAC hosts an annual Regional Science Bowl for teams of high school students. The Science Bowl is a question-and-answer competition with buzzers, judges, and time keepers for high school teams of 5 students and 1 faculty coach. This year's competition is on February 28th.

SLAC Tour Information
Tours of SLAC will be available again later this year. On the tour, you get an extensive look at the operation of the accelerator, including a peek into the Klystron Gallery.