Sitting in a small, non-descript room in the basement of the Lawrence Berkeley National Lab in Berkeley, physics graduate student Hannah Swift and physicist Saul Perlmutter are searching for supernovae, stars destroyed in huge explosions millions or billions of years ago. (They’re looking for ones that exploded billions of years ago). Through a computer hooked up to Hawaii’s Keck 2 telescope -– one of the largest in the world –- they are able to follow along as UC Berkeley post-doc Rahman Amanullah, a team member who had traveled to Hawaii a few days earlier, supervises the night’s observation.

Their goal is to use a device called a spectrograph to get a spectra of five to eight supernovae. This spectrum is a “photograph” of the light emitted by the supernova and it allows scientists to determine whether they are the type Ia supernovae that are useful for their research. By figuring out how far away these type Ia supernovae are (or “were,” since by the time their light reaches us, they have long since vanished) and observing how much the light traveling towards the Earth has shifted towards red wavelengths, they can determine how long ago the star exploded. With this information, they’re building a history of the expansion of the universe. The weather in Hawaii is good, and the researchers are forecasting a good “seeing.”

It’s encouraging and moving to see how young these researchers are. Swift is a twenty-something from Kansas. She’s so young that she has always understood the universe to be accelerating, that is, expanding faster and faster. She has never thought that the universe is decelerating, which is what the scientific community believed before 1998, when Perlmutter’s team at Lawrence Berkeley National Lab and another team simultaneously reported their findings that the universe is accelerating. When this announcement was made, Swift was in the 8th grade. Perlmutter himself is only in his 40s. When he started his post-doc, he and his colleagues had to beg for time on the big telescopes. That wasn’t that long ago: our understanding of the universe has shifted very fast.

A few days later, Swift invites us back to the lab to show us some of the data the researchers gathered during the observation. They obtained spectra for five supernovae – a good night’s work. Swift is now in the process of figuring out which of the supernovae are type Ia’s. To do this, she’s comparing their spectrograms to the spectra of a standard type Ia. Light is a very useful tool because different elements emit light of different wavelengths. Swift shows me the spectrogram for a standard type Ia. It has telltale peaks and valleys that reveal what exploding type Ia supernovae eject when they explode – silicon and cobalt, among other elements.

I wonder what big changes in the way we understand our universe will be commonplace when my one-year-old niece is in her 20s. What new discoveries will we use as points of reference in the coming decades? (Assuming we’re hip enough to use astronomical discoveries as points of reference!) Will scientists know by then the nature of dark energy, the now-mysterious “something” that is making the universe accelerate, pushing its fabric apart? Will I be able to preface a comment to my niece with, “When you were little, before we knew what dark energy is…”? And will she be able to reply, “Aunt Gabi, you’re so ooold!” I suspect she’ll do the latter no matter what.

Watch the “Dark Energy” TV Story online, as well as find additional links and resources. Also don’t miss our online photo set.

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.

Dave Barker of the Exploratorium
gets some batting tipsWhen I think of baseball and science, I always remember poor Sammy Sosa. In 2003, he was suspended from seven games with the Chicago Cubs for using a bat that had cork in it–an illegal move, according to Major League Baseball rules. I certainly don’t feel sorry for him for cheating (though he claims it was accidental), or for having to warm the bench for a while. But I do pity him for making a maneuver that probably never would have helped him anyway.

The idea behind “corking” a bat is that the bat will be lighter and the batter will be able to swing it faster, hopefully imparting more power to the ball. If you watch QUEST’s TV feature on the physics of baseball, you’ll see my Exploratorium colleague David Barker learning from the CalBears batting coach that getting the bat going fast is a key to whacking the ball as far as possible. In fact, today’s players use bats that are lighter and shorter than the ones swung decades ago, for just this reason.

Unfortunately for Sammy Sosa (and others before him who pulled the same stunt), corking the bat to make it lighter is a flawed approach. A wooden bat is a close-to-perfect swatting tool: it’s solid enough to resist absorbing much impact from the ball, but not so hard that it overly deforms the ball when hitting it. A bat with cork in the middle will be squishier, and won’t hit the ball as hard. Imagine the difference you’d expect if the bat were made of pillows. That’s a little extreme, but you get the idea. According to a recent Mythbusters show, corked bats don’t improve the power of a hit.

See for yourself what a difference swing speed can make. Check out our online “Scientific Slugger.” You can choose different swing speeds and pitches, and see which combinations go farthest (if hit perfectly).

Did Sammy know he was swinging a corked bat the day he was caught, or was it truly an accident? We’ll probably never know. But what’s clearer is that, in terms of a baseball career, it probably wasn’t worth the risk.

Robin Marks is a journalist and science writer who current serves as a Multimedia Projects Developer for the Exploratorium in San Francisco, CA.