The Sloan Telescope used to conduct BOSS
A long time ago in a galaxy far far away…Well, to be precise, 14 billion years ago and at the beginning of the universe was the Big Bang. Ever since that moment, our universe has been expanding, but over the last 7 billion years that expansion has been accelerating. Why? Scientists don’t really know, so they came up with an ominous term as a placeholder: Dark Energy (Another possible explanation is that that our theory of gravity is wrong, but we’ll skip that for now). Recent calculations project dark energy makes up nearly 70% of the mass-energy of the universe. 70% of the universe is a mystery? That’s the kind of puzzle that inspires scientists to craft unique experiments.

One of those is BOSS, the Baryon Oscillation Spectroscopic Survey, is a new project to create a 3-D map of over 2 million galaxies and quasars representing the best data ever obtained on the large-scale structure of the universe. Baryon oscillations began as pressure waves through the hot plasma of the early universe. Those waves left an imprint on the matter that makes up the universe, including the dark matter. The survey will essentially act as a ruler, in order to measure how the universe has been expanding.

Next Monday, you’ll be able to meet David Schlegel, the principal investigator of BOSS. He’ll be part of a panel of Lawrence Berkeley Laboratory scientists discussing their search for dark energy. As a primer, check out QUEST’s story on Dark Energy from last year. The piece features astrophysicist Saul Perlmutter, who will also be speaking at the event.

See QUEST's Video on Dark Energy below:

QUEST on KQED Public Media.


Dark Secrets: What Science Tells Us About the Hidden Universe

Where: Berkeley Repertory Theater, 2025 Addison Street, Berkeley

When: Monday, October 26th 7-830 PM

Cost: FREE

Details: No mystery is bigger than dark energy — the elusive force that makes up three-quarters of the Universe and is causing it to expand at an accelerating rate. KTVU Channel 2 health and science editor John Fowler will moderate a panel of Lawrence Berkeley National Laboratory scientists who use phenomena such as exploding stars and gravitational lenses to explore the dark cosmos.

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.

Today QUEST takes you behind the scenes to see the most powerful microscope in the world, which happens to be in our very own backyard in Berkeley. This transmission electron microscope lives at the National Center for Electron Microscopy, at the Lawrence Berkeley National Lab. The microscope can produce images of things that are the size of half an atom of hydrogen. And hydrogen has the smallest atoms of any element – so that's pretty small.

The microscope is so big that it was hauled into the Center on a crane. It's housed in its own room, which is insulated to maintain an ideal temperature, and it's mounted on springs to isolate it from vibrations that make images blurry.

The TEAM 0.5, as the microscope is called, excels at producing clear images of atoms sitting side by side. This makes it very useful for the scientists who investigate the properties of the materials that we use to build everyday objects like computers and airplanes. In fact, the images they produce with the microscope may one day help build stronger, lighter airplanes, and smaller, faster computers.

Watch the World's Most Powerful Microscope television story online.

Magnets in the LHC. Photo copyright CERNUnless you live in another dimension, you've heard about the Large Hadron Collider — a 17-mile underground raceway where, just this week, physicists flipped the ON switch and sent protons looping from France to Switzerland and back again. News coverage has been everywhere: newspapers, magazines, and even an amazingly accurate rap video on YouTube. Here's an overview of some good articles and web content about the Large Hadron Collider, to get you up to speed on particle physics.

When protons smash together at velocities approaching the speed of light, tiny short-lived particles are produced. If we can see these particles and learn how they behave, we can answer some pretty important physics questions — like what, exactly, is mass? The Exploratorium has a great website that explains physics' Standard Model — what matter is made of, and how the different components of matter interact. In his op-ed piece in the New York Times, Columbia University physicist Brian Greene describes the particles that physicists are looking for: the Higgs boson, the supersymmetric particles, and the transdimensional particles. Is there really a fourth dimension? Or a fifth or sixth? We may soon find out.

The latest nickname for the LHC is "the why machine." That moniker originated on the physics blog Cosmic Variance. Hopefully this feat of engineering will explain why E=mc2. Or, say some, just open up a microscopic black hole that will swallow the entire universe. This is exceedingly unlikely, but, says the Telegraph, some scientists have still received death threats from folks concerned about the impending end of the universe.

These mysterious particles may or may not be linked to the end of the universe, but they were certainly abundant at the beginning, with the Big Bang. To learn more about the Big Bang and the evidence for its occurrence, check out QUEST's interview with Berkeley physicist George Smoot — he won the Nobel Prize for detecting and analyzing the Big Bang's leftover radiation.

Parts of the Large Hadron Collider were designed and constructed by scientists here in the Bay Area. Scientists from the Lawrence Berkeley National Laboratory designed the LHC’s distribution feed boxes, which connect electrical power to the focusing magnets. And scientist from the Stanford Linear Accelerator Center designed the ATLAS pixel detector, which, like a giant digital camera, records what happens after particles collide.

If you're more interested in pictures than particles, then check out National Geographic's photos of the LHC –- it is a beautiful machine.

H-R diagram of 47 Tucanae

I started off my last post talking about the well-known properties of globular clusters, but I chose not to dive into the details of the stars inside the clusters. The stars really deserve an article all to themselves. Now is the time for that article.

Basically all of the stars in a globular cluster have the same age and formed under the same conditions. Observations of a globular cluster are a snapshot of one point along the evolutionary track of all these stars. Each star will have well defined properties depending on its mass and the age of the cluster. In the early 1900's, Ejnar Herstzprung and Henry Norris Russell made the first observations of this age and mass relation, thus earning the honor of having the model named after them. Not to be confused with more common corporate acronym, we now refer to the model describing the brightness and color of stars as the Hertzsprung-Russell diagram, or H-R diagram.

The H-R diagram shows the relationship between the brightness of a star and its color. In the figure at the top of this page, the y-axis shows the brightness of the stars in the cluster. The brightest stars are represented by the dots at the top of the figure. The faintest stars are near the bottom. The x-axis shows the color of these stars – red stars are on the right and blue stars are on the left.

All stars start on the main sequence, regardless of their mass. A star on the main sequence is burning hydrogen in its core. The more massive main sequence stars burn much more hydrogen, making them hotter, bluer, and brighter than the lower mass stars. The main sequence stars can be seen as the dots below the objects labeled “subgiant branch” in the H-R diagram at the top of the page. You should be able to see the bluer-brighter relationship that describes the main sequence stars.

The massive stars also consume all of the hydrogen in their cores very quickly, causing them to evolve off the main sequence much sooner than the lower mass stars. The stars that have just evolved off the main sequence are the “subgiant branch”. These stars still burn hydrogen but only in regions away from the core. They mark the turn-off from the main sequence and are used to determine the age of a globular cluster.

The more massive a star is, the further it has evolved from the main sequence in an old cluster. The more massive stars can be seen as the red giant branch, the horizontal branch (burning helium in the core), and the asymptotic giant branch. These stars are all still burning their material through fusion, but appear much different in color, size, and brightness than stars on the main sequence.

Finally, there are some stars that have made a huge jump from the top right hand corner of the H-R diagram to the bottom left. These are the white dwarf stars, seen as the faintest and bluest objects in globular clusters. These stars have burned the last of their available fuel and change from big, cool, and red to very small, hot, and blue very quickly when they purge their outer layers. They no longer burn any material in their cores and are simply radiating the last of their energy left from a lifetime of fusion into space.

I found many good examples of the H-R diagram on the web and you’ll need to run Java on your computer to see my favorite. This is a really cool program that allows you to simulate the evolution of stars. Just give it a mass and watch it go. You can see how it changes brightness, color, and size as it grows old. Check it out!

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: 37.8769, longitude: -122.247