QUEST Community Science Blog

Inside the National Ignition Facility. Lawrence Livermore National Lab is building the world’s largest laser. Actually, the National Ignition Facility won’t have only one laser beam. It will use 192 world-class lasers, all firing simultaneously. In a few billionths of a second about 500 trillion watts, which is nearly 1000 times the power generated in the entire US at any moment, will hit a target the size of a dime. The hope is that this will create enough heat and pressure to mimic the core of the sun and achieve a fusion ignition.

So in a nutshell, what is fusion? And how do lasers work? Why are you asking me? I was the kid who always struggled with math and would get hives on the eve of a high school science test.

Luckily, there are some darn good teachers out there and we were fortunate enough to feature one of them in our story. Richard Muller is a professor of physics at the University of California and has also become something of a web phenomenon. Thousands of “students” all over the world have viewed his lecture series titled “Physics for Future Presidents” on YouTube and Cal’s own website.

Muller designed this class to “stress conceptual understanding rather than math, with applications to current events.” As he told us, “imagine looking out on your classroom and picturing out there is the future president of the United States. What do you want that person to know?” What comes out is an explanation of the physics of energy, nuclear weapons, radioactivity, relativity and the universe– all explained in a way that the physics-challenged, like myself or maybe a future president, can understand.

Watch the “Super Laser at the National Ignition Facility” TV Story online, as well as find additional links and resources.

Chris Bauer is a Segment Producer for television on QUEST.

Illustration of a blast of solar wind impacting
Earth’s protective magnetic field. Credit: NASABreathe in, exhale. Feel the air in your mouth, windpipe, and lungs. That’s a sample of Earth’s atmosphere: the thin layer of gases enveloping our planet.

Did you know that the Sun also has an atmosphere, and that the Earth is inside it? In fact, the Sun’s envelope of gases extends well beyond the orbit of Pluto, out to the regions of the solar system where the 3-decade-old Voyager spacecraft are only now reaching.

“Space weather” refers to the conditions in space caused by the outflow of electrically charged gases (plasma) coming from the Sun—what we call the “solar wind.” The term “space weather” may conjure images of cosmic tornadoes, astral lightning bursts, and some Star Trek version of a galactic hurricane– but actual space weather is nothing so Earthly and familiar.

First of all, the “air” in space is nothing like the atmosphere we draw our breath from. Earth air, at the surface, is made of nitrogen, oxygen, argon, carbon dioxide, water vapor, and other trace elements, and is relatively dense. “Space air” is mostly hydrogen– ionized hydrogen at that (meaning stripped of its electrons and so electrically charged; the separated electrons are also blowing along in the solar wind).

Second, the gases of the solar wind are extremely rarified. Despite the talk of a solar atmosphere, solar wind, and space weather, space within the solar system is still almost a complete vacuum. At Earth’s distance from the Sun, the average density of the solar wind is somewhere between 6 and 9 atoms (mostly hydrogen) per cubic centimeter. If you spread out the gas contained in an ordinary party balloon to this same thinness, it would fill a volume of space over 10 miles across!

Third, the solar wind, for all its sparseness, blows fast! Depending on conditions of space weather, the flow of solar wind past the Earth can speed along anywhere from 200 to 900 kilometers per second! Earth’s fastest winds slug along at only a few hundred kilometers per HOUR.

So how does space weather—the changing conditions of the solar wind—affect us on Earth? How might you, personally, have experienced, directly or indirectly, the effects of the Sun’s gentle breeze?

The most familiar phenomenon caused by space weather is Earth’s beautiful auroras —the northern and southern lights. Interactions between the solar wind and Earth’s magnetic field and electrically charged particles trapped in it excite atoms in the upper atmosphere to emit light. And it’s not just a softly glowing night light: the most powerful auroras can generate up to a trillion Watts of power!

Solar wind “storms” can not only produce more active auroras, but can cause fluctuations in Earth’s magnetic field whose effects can be felt on the ground. These “geomagnetic storms” usually pass unnoticed, perhaps causing a tiny change in the direction that compass needles point– but have also been known to overload electrical power grids and cause blackouts.

In the space around Earth, solar storms have been known to damage or disable satellites, and can put unprotected astronauts at risk. Space walks on the International Space Station are scheduled for times when space weather is - so to speak -”sunny and calm.”

Thinking about space weather on Earth might seem like worrying over Atlantic hurricanes here in the Bay Area—but with more and more human activity taking place beyond the confines of our atmosphere, this is a very real and vital concern, and is taken very seriously.

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

It’s approaching that time of year again: Spring Equinox. The blaze in my home’s interior hallway has been signaling this for the last week.

The shadow of Chabot’s “solar clock” at noon
on the equinox produces a pattern of solid green
straddling the gnomonI noticed late in the afternoon a couple days ago that the windowless hallway where we hang all of our family photos was afire in a shaft of bright sunlight, entering a window in the adjacent bedroom. Only around Equinox (Spring or Fall), when the Sun sets about directly west, does this happen in my house. The rest of the year the Sun sets too far north or south for this window-and-hallway alignment to take place. It’s a striking event because for only a few days of the year my normally dark hallway explodes with radiance.

Ancient cultures all around the world made use of the changing rise and set position of the Sun to track the seasons, and either observed special alignments of sunlight and shadow with geographical features, or built structures that made the special alignments. Stonehenge is one famous example, but there are plenty of other seasonal observatories in just about every part of the world.

Unlike the more distant stars in the sky, which always rise and set at the same points on the horizon, the Sun (a star too, of course) wanders northward and southward in the sky throughout the year, and so its rise and set points migrate. On the Equinoxes the Sun rises directly at the east point on the horizon and sets directly at the west point-but at Summer Solstice in the Bay Area it rises a full 30 degrees to the north, and at Winter Solstice 30 degrees to the south.

The reason for the Sun’s annual wandering comes from the tilt of Earth’s rotational axis with its orbit around the Sun. At our (Northern Hemisphere) Summer Solstice, our hemisphere is tipped toward the Sun and the Sun appears at its most northerly point in the sky; we receive more hours of sunlight and more direct rays from the Sun-so it’s warmer. Winter Solstice is opposite, with our hemisphere tipped away and the Sun and the Sun farthest to the south, making for shorter hours of daylight and less direct solar rays–and so it’s colder.

Equinox is a middle point between solstices: the Sun is poised between the northern and southern extreme points of the solstices-positioned directly over Earth’s equator-and the hours of daylight and night are about equal.

Does your home or place of work function as a solar seasonal calendar, as mine does? Is there a special time of year when you notice a striking pattern of light and shadow, a special alignment of walls, windows, doors, or other features? From the location of Chabot Space & Science Center, at equinox the Sun sets directly on the Golden Gate Bridge… .

If you have noticed something like this, then you’ve experienced what many ancient peoples noticed about the seasonal changing of the Sun. Their observations led them to understanding, or at least making use of, the cycle of the Earth revolving about the Sun to establish the earliest calendar systems.

Take a look and see what you notice, especially around Equinox (March 19, Pacific Time-March 20 GMT).

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

Extreme close-up of the Sun’s visible surface,
showing ‘bubbling’ cells of convecting gas–each the size of
Northern California. credit: Hinode JAXA/NASA/PPARCBy all accounts, a new cycle-Cycle 24-in solar activity has begun… something you probably didn’t notice since the beginning of a solar cycle is quite subtle….

First things first: what is a solar cycle, and why is this one number 24? You’ve probably heard of sunspots and solar flares and disturbances in radio communications caused by solar activity, but had you noticed NOT hearing much about these things in the last two or three years?

The Sun exhibits a cyclic rise and fall in its level of magnetic activity. Being an enormous ball of roiling, circulating plasma (electrically charged gas), the Sun generates powerful magnetic fields in a way similar to how the circulating electricity in an electromagnet creates one.

Over the course of a solar cycle, the intensity and amount of magnetism generated by the Sun increases, like soup warming up on the stove, reaching a violent climax in which twisting, tangling magnetic fields break loose and release their energy in the form of solar flare explosions, coronal mass ejections, and tremendous heating of the solar atmosphere.

Sunspots are surface features formed by the presence of strong magnetic fields, and in general the number of sunspots that can be seen and counted indicate the level of magnetic activity on the Sun. For 400 years, since Galileo first started counting sunspots through his telescope, observers have kept track of sunspot counts, and over time a pattern in their number emerged. On average, the number of sunspot activity peaks every 11 years at a time called solar maximum.

I remember when I first started working at Chabot Space & Science Center, back in 1999/2000, during the last solar maximum. Using our Sunspotter telescopes on public observing days, in teacher workshops, and in my solar summer camp, we could easily count many sunspots-sometimes as many as 20 or more! Those were the days!

In the past two or three summers, however, it’s a lucky week to spot just a single sunspot! Most of the time, the Sun’s face has been a bland disk with few discernible surface features.

That status quo should start to change, now that we have allegedly reached solar minimum and are stepping onto the uphill slope toward the next maximum, which should happen sometime around 2011 or 2012. If you want to keep tabs on the rising solar activity, and you like lots of graphs and numbers and stuff like that, check out the Solar Cycle 24 website.

Oh, why is this Cycle 24? A 19^th Century astronomer who studied the then newly discovered sunspot cycle, Rudolf Wolf, established the cycle that spanned 1755 to 1766 as Cycle 1…and they’ve been counting up ever since.

But even in this “nap time” of the Sun, today’s modern solar observatories and spacecraft, with their arrays of high-tech cameras and sensors, see plenty on the Sun to keep them busy.

Japan’s Hinode spacecraft, launched in 2006, has returned libraries of amazing pictures and movies of solar flares, activity around sunspots, circulating hot gases, fine details of the life and times of magnetic fields…and all of this during solar minimum! I can’t wait until the Sun really gets going and Hinode becomes like a camera-happy tourist in Tahiti….

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

View our original YPOQ pilot
featuring photographer Russ MorrisDo you love photographing Science, Environment and Nature in Northern California? Would you like to collaborate on a 2-minute QUEST TV short about your photography for an audience of over 100,000 viewers?

We’re launching a call for submissions for our new series of TV shorts, “YPOQ: Your Photos on QUEST.” These are broadcast alongside our feature stories. Our pilot YPOQ broadcast in Season 1 featured local photographer Russ Morris.

We’re looking for more than stunning nature photography. We seek to collaborate with a local photographer who is inspired by science, environment and nature in Northern California, and uses innovative approaches to express their unique vision of our region.

Key Dates

Submissions due: February 27th, 2008
Selection announcenment: March 3rd, 2008.
TV Broadcast : May 20, 2008.

Although we can only broadcast one photographer’s work on the air on May 20, we also plan to feature selected submissions here on the KQED QUEST Community Science Blog.

We are running this call through Flickr, a website for sharing photos and much more. It’s free to join and participate. See our discussion topic on Flickr for details!

Craig Rosa is the Interactive Producer for QUEST.

Saturn’s moon Epimetheus from the Cassini spacecraft.
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
and APOD.

On the bus in Denali National Park a few years ago, I found myself sitting next a couple from the East Bay. If you’ve ever been on the Denali bus, you know that it’s a long ride and it was just a matter of time before we struck up a conversation. As often happens, we wound up talking about work and then about astronomy research. Both of them were very interested in the field but were unsure of where to find good information on the web. At the time, I hadn’t really thought about that and wasn’t much help.

Now that I’m writing for QUEST, I am much better suited to answer them. I spend a lot of time surfing the web for images and links to websites to provide the full details for readers who want to follow up on my posts. Over the course of a year or so, I’ve discovered quite a few resources and have settled on a few favorites. Of course, being a Berkeley and Cornell grad, I have a few biases…

First of all, it is common for a university astronomy department to organize a public outreach campaign. I won’t bother with the obvious disclaimers and instead will just say that two of my favorites are “Ask an Astronomer” at Cornell University and the Berkeley Center for Cosmological Physics.

These two sites are quite different. As the name implies, the Cornell site encourages questions and suggestions from readers. The content of the site is therefore governed by the public, covering a wide variety of topics in fairly brief, straightforward language. The Berkeley site is much more structured. They cover the history of cosmology and outline the history of our universe with all the appropriate links (scroll down to see the links). This provides a very detailed and organized explanation of a specific field of astronomy.

In addition to universities, there are quite a few NASA missions that maintain excellent public relations. Almost everyone knows the Hubble Space Telescope and Mars Rovers. Both sites are updated almost daily with galleries, discoveries, and recent news. NASA also has several other large missions at other wavelengths that are probably not as well known. Three examples are the Chandra X-ray observatory, the WMAP mission, and the Spitzer infrared observatory. Like the Hubble and Rover sites, these space-based observatories perform ground-breaking science and do an excellent job explaining their discoveries to the public.

Besides QUEST, there are also quite a few other excellent blogs out there. Each site has a different approach and finds its own balance between astronomy coverage, opinion, and discussion of general science. One of the most popular is the Bad Astro site–we even have a link on the right hand side of the QUEST blog web page. You can also check out About.com’s top ten space and astronomy blogs.

Of course, one obvious place to learn about astronomy is from journalists. Two websites that do a very good job of covering the field are Space.com and New Scientist (some content requires subscription).

Finally, if you enjoy beautiful images of the sky, a great place to look is the “Astronomy Picture of the Day.” This is where I got my image for today. If you look tomorrow you’re guaranteed to find something just as exciting!

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 37.8768, longitude: -122.251

More than meets the eye: The constellation Orion
in visible light (left) and infrared (right)
Visible light image: Akira Fujii;
Infrared image: Infrared Astronomical SatelliteSome months ago my blog, “SOFIA: Fly By Night,” talked about the up-and-coming astronomy ace of the night skies, SOFIA: the Stratospheric Observatory for Infrared Astronomy–a 2.5 meter infrared telescope built into a Boeing 747 airplane.

SOFIA’s been flying, and is gearing up to begin its first science flights in the not so distant future. SOFIA even put in an appearance in Bay Area skies a couple of weeks ago with a quick visit to NASA/Ames Research Center in Mountain View–then it was off again to its base of operations in the Mojave Desert.

Having worked on SOFIA’s predecessor, the Gerard P. Kuiper Airborne Observatory (KAO), in the last seven years of its operation, I thought I’d focus a bit on the science of airborne infrared astronomy, touching a bit on science done on the KAO over its 21-year career at NASA/Ames.

Why put a telescope on an airplane? Earth’s atmosphere, while transparent to the visible light the human eye can detect, is less so to many other wavelengths of light, including most infrared light. In fact, the water vapor in our atmosphere is pretty much opaque to a wide range of infrared wavelengths.

KAO flew at and altitude of 41,000 feet to get above as much as 99% of Earth’s atmospheric water vapor, giving astronomers a view of the infrared emissions from objects in space almost as if the telescope was out in space.

What’s so interesting about looking at infrared light? Aren’t visible light images taken from ground-based observatories enough?

Apparently not. Visible light is only a tiny fraction of the overall spectrum of electromagnetic radiation (the general term for “light” of all types–including gamma rays, X-rays, ultraviolet light, infrared light, microwaves and radio waves). There is a wealth of information contained in the entire electromagnetic spectrum that is only hinted at in the visible portion.

Visible light in our universe comes mostly from the photospheres of stars, either directly or by being reflected by objects such as dust, planets, comets, and the like; all of the light you see in the sky is starlight, either first hand or second hand.

Infrared light, however, is a lower energy form of electromagnetic radiation, and is emitted by any object or substance that is even slightly warm. So, interstellar clouds of molecules, rings of dust surrounding stars, atmospheres of planets–just about anything, in fact–emits its own infrared light, and observing the infrared emissions from these objects reveals a great deal about them: their chemical composition, their temperatures and densities, their velocities and structure–and a lot more.

One KAO astronomer observed the atmosphere of Venus to measure the relative abundance of hydrogen and deuterium (heavy hydrogen), looking for evidence of past oceans. Another observed Mars, looking for telltales of limestone (a mineral left behind by marine organisms) as evidence of past life on Mars. Others created detailed maps of clouds of complex molecules, probing the composition of the cooler material in our galaxy, as well as other galaxies.

The list goes on, as there’s plenty more cold matter in the universe than hot matter. Cooler matter can be more interesting, too, since complex molecules, like organic compounds and even life, don’t form in the sterile heat of stars.

So where KAO blazed an infrared contrail in the night skies, SOFIA may now follow and carry on the torch of astronomy, on the wing….
Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

latitude: 37.8768, longitude: -122.251

Star or Comet?Yesterday was a very long day at work. I was stuck in meetings with our collaborators for over 6 hours! To make it worse, we spent the entire time discussing a single topic. I even wrote my last paper on it. What could possibly be so captivating, you ask?

Remember the solar wind I wrote about a few weeks ago? This stream of protons does more than create comet tails and aurora, it also destroys all of those fancy electronics we work so hard to put into orbit.

The protons streaming from the sun carry a lot of energy, and they leave a lot of this energy behind as they pass through satellites and astronauts that don’t have the Earth’s atmosphere to protect them. The energy released wrecks havoc on the system, throwing electrons and atoms around like a game of ping-pong. This is one form of radiation damage.

Definitely a comet!
This radiation damage is harmless over short periods of time, much like an occasional X-ray at the dentist. However the solar wind becomes a problem for something like the Hubble Space Telescope or our proposed satellite SNAP which are exposed for many years.

To understand how a telescope degrades from exposure to radiation, let me give an extremely quick explanation of how we gather astronomical images. A telescope is very similar to a camera you buy in the store. The large mirror is equivalent to the lens on your camera. The part that suffers the most radiation damage is the Charge Coupled Device, also known as a CCD.

The CCD is essentially the same as the 8-megapixel chip in your digital camera. This serves as an electronic version of film, recording the image through the photoelectric effect rather than through a chemical reaction. If you can still remember how photography was in the days of film, I’m sure you can appreciate the relief of going digital. Astronomers realized this early on and were pioneers in the use of CCDs.

The photons from the subject of the photograph collide with electrons in the silicon of a CCD, knocking them free from their parent atom. The free electrons are then collected in a well near the site of the collision. Once the exposure is complete, charge is moved one well (or pixel) at a time toward a transistor which then reports the number of electrons found. This process is usually described through the analogy of a bucket brigade passing buckets of water from a reservoir to a fire.

When the CCD is brand new, the bucket brigade performs almost perfectly. If I want to observe a star, the image comes out crystal clear. However, after enough time in space and in the solar wind, the CCD begins to show its wear. The bucket brigade gets sloppy at work and has to contend with an increasingly difficult obstacle course, spilling a little bit of water (or electrons) during each transfer. That same star now leaves a trail of charge behind and begins to look more like a comet.

Now, if I am observing a star, I want my image to look like a star, not like a comet. Is that really too much to ask? Unfortunately, the CCD will inevitably deteriorate in space and astronomers have to find ways to predict and correct for this deterioration. This is what we spent yesterday discussing. We passed around some pretty good ideas but still have a bit of work to do before we can prove a new method for correcting the images. I just hope we it figured out before our satellite launches in 2015!

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 37.8768, longitude: -122.251

Cosmic microwave background and the infant universe.
From the WMAP science team.It was on the UC Berkeley astronomy website this morning that I was reminded of something I had wanted to post for QUEST. About a month ago, Cal publicly announced the Berkeley Center for Cosmological Physics. This was quite a big deal for the Physics and Astronomy departments at Berkeley.

The center was founded by George Smoot, who won the Nobel Prize in 2006 and was the focus of a QUEST TV segment. As described in our press release, George donated the bulk of his prize money to the founding of this new center. His donation seeded the center which now has an endowment exceeding $8 million in little more than a year of fund-raising. After watching my girlfriend raise funds for non-profits around SF, I can say that is quite impressive.

The center and endowment ensure that Berkeley remains competitive for years to come in the field of cosmology research. It helps Cal recruit excellent researchers by providing funds for postdoctoral researchers and students. The people supported by the Center can choose any project in the department, projects that I have covered in several of my QUEST articles. It also gives new post-docs the freedom to explore the department before starting on a specific project. This differs from the usual postdoctoral researcher who is recruited by a specific faculty member for a specific project.

The center will also sponsor researchers’ visits to Berkeley from other institutions, educational outreach to K-12 science teachers and several collaborative international workshops on cosmology each year.

Berkeley is actually both one of the first and one of the latest institutions to establish a center for cosmology research. In the ’90s, we had the Center for Particle Astrophysics, which was funded for 10 years by NSF. I think this was one of the first of its kind.

In the last few years, a philanthropist named Fred Kavli has funded quite a few cosmology centers all around the world. I just learned that the Kavli foundation also funds centers in other fields, like nanoscience research at my alma mater. The foundation funds 15 centers in all, including ones at Caltech, UC San Diego, Stanford, and UC Santa Barbara in California.

If you’re a big fan of MASH or Alan Alda, you’ll be a big fan of Kavli foundation. I just looked at their web page and see that they have made him the narrator for their astrophysics, neuroscience, and nanoscience initiatives. Maybe we can recruit Donald Sutherland to promote the movie version of the Berkeley Center for Cosmological Physics.

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 37.8768, longitude: -122.251

It’s one of the most expensive high-tech projects the United States has ever attempted, and some say it will never work. QUEST visits the National Ignition Facility in Livermore, where scientists will soon aim the world’s largest laser at a target the size of a pencil eraser. The goal? Nuclear fusion — and, they say, the answer to the world’s clean energy needs.

You may listen to the “Super Laser” radio report online, as well as find additional links and resources. Also don’t miss our behind-the-scenes photos for this report.

Amy Standen is a Reporter for QUEST and Radio News at KQED-FM.

latitude: 37.6871, longitude: -121.697