Friday, Jan. 4, 2013
spacer
Search
spacer
Calendar

Have a safe day!

Friday, Jan. 4

3:30 p.m.
DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over

4 p.m.
THERE WILL BE NO JOINT EXPERIMENTAL-THEORETICAL PHYSICS SEMINAR THIS WEEK

Monday, Jan. 7

THERE WILL BE NO PARTICLE ASTROPHYSICS SEMINAR THIS WEEK

3:30 p.m.
DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over

4 p.m.
All Experimenters' Meeting - Curia II
Special Topics: Shutdown Work Status and Plans; Proton Improvement Plan (PIP); Recent Activities of the DES Supernova Group

Click here for NALCAL,
a weekly calendar with links to additional information.

Ongoing and upcoming conferences at Fermilab

Campaigns

Take Five

Weather
Weather Breezy
36°/21°

Extended forecast
Weather at Fermilab

Current Security Status

Secon Level 3

Current Flag Status

Flags at full staff

Wilson Hall Cafe

Friday, Jan. 4

A la carte items

Wilson Hall Cafe Menu
Chez Leon

Friday, Jan. 4
Dinner
Closed

Wednesday, Jan. 9
Lunch
- Northern Italian lasagna
- Caesar salad
- Cannolis

Chez Leon Menu
Call x3524 to make your reservation.

Archives

Fermilab Today

Director's Corner

Frontier Science Result

Physics in a Nutshell

Tip of the Week

User University Profiles

Related content

Info

Fermilab Today
is online at:
www.fnal.gov/today/

Send comments and suggestions to:
today@fnal.gov

Visit the Fermilab
home page

Unsubscribe from Fermilab Today

Physics in a Nutshell

GUTs and TOEs

GUTs and TOEs may sound like funny looking body parts, but for scientists, they are acronyms for Grand Unified Theories and Theories of Everything. These theories aspire to unify all of physics into a single idea.

Let's talk about GUTs. No, I'm not talking about that extra weight you put on when you visited your mom over the holidays. I'm talking about nothing less than the ultimate goal of all Fermilab physicists. I'm talking about a Grand Unified Theory.

There is a long history of unification in science. If you think about it, it's not at all obvious that the phenomenon that pulls you to the ground and gives you weight is related in any way to the march of the planets and occasional comet across the night sky. It took the genius of Isaac Newton in the late 1600s to say that these two seemingly different phenomena can both by described by his universal theory of gravity. Scientists say that Newton "unified" the phenomena of celestial motion and how a dropped apple behaves on Earth.

In the mid-1800s, a large number of scientists studied the phenomena of electricity and magnetism. Electricity is represented by a fleeting stroke of lightning, static cling and the behavior of a battery connected to wires, while magnetism is seen in the dogged determination of a compass to point northwards. After reviewing decades of work by other scientists, James Clerk Maxwell realized how everything was interconnected and wrote a set of equations that showed that electricity and magnetism were really one and the same thing. His equations unified the two phenomena, resulting in our now-familiar electromagnetism. The beauty of this unification was made even more evident when it was shown that electromagnetism also explained the behavior of light and all of chemistry.

The pattern repeated itself in the 1960s, when physicists were able to show that electromagnetism and the weak force were intimately related. Scientists now talk about the "electroweak" force. Again, two seemingly unrelated phenomena were unified. The recent observations of what might be the Higgs boson give us even more reason to believe that this unification is real.

Given the history, it is natural to ask, "Is it possible that the remaining three known forces—gravity, the strong nuclear force and the electroweak force—might be but a single force, made to appear different because of how we are looking at it?" If this idea is true, the resultant, single, overarching theory that explains it is called the Theory of Everything. A TOE is the famous theory that is so simple and so overarching, the equation of the universe could be written on a t-shirt.

Read more

—Don Lincoln

Want a phrase defined? Have a question? E-mail today@fnal.gov.

Milestone

Grid Computing Center earns EPA ENERGY STAR

Fermilab's Grid Computing Center has earned the Environmental Protection Agency's ENERGY STAR for 2013. This is the third time GCC has received ENERGY STAR certification, having previously earned it in 2010 and 2012.

An ENERGY STAR-certified facility meets strict energy performance standards set by EPA and uses less energy, is less expensive to operate and causes fewer greenhouse gas emissions than its peers.

In the News

Fiscal cliff deal delays major budget cuts, but includes reductions that could affect science

From Science, Jan. 2, 2013

Although few people are talking about it, the legislation passed yesterday by Congress to avert the fiscal cliff by revising tax policies also contains $4 billion in cuts this year to discretionary spending, including research. But it delays for 2 months the automatic, across-the-board reductions that science lobbyists have said would be a disaster for U.S. researchers.

Read more
Frontier Science Result: CDMS

The search for light dark matter

The figure shows the rates for light WIMP interactions (technically, the spin-independent WIMP-nucleon cross section) versus WIMP mass from several different direct detection experiments. The closed contours show possible hints for light WIMP detections from a few experiments, while the open curves indicate the lack of WIMP signals from other experiments (upper limits). The two black curves denoted by crosses show results anticipated in the coming year from the data being taken by CDMS at Soudan. Other experiments, such as the DAMIC experiment led by Fermilab, also expect results on light WIMPs in 2013.

Astronomical observations have shown that there is roughly five times more dark matter than normal matter in our universe. Particle physics theories such as supersymmetry predict the existence of weakly interacting massive particles (WIMPs) that could explain the nature of this dark matter. WIMPS would have been formed in the big bang, and simulations indicate that their gravitational interactions would have provided the scaffolding for normal matter to form galaxies, including our own.

If these ideas are correct, our galaxy is immersed in a cloud of dark matter, and millions of WIMPS are streaming through you as you read this. Fortunately for you, they almost never interact with normal matter. On the rare occasion that they do, the result is a "billiard ball" scatter from an atomic nucleus, imparting a small recoil energy to the nucleus. Since normal-matter particles usually interact with the atomic electrons more than with the nucleus, it is possible to distinguish WIMP interactions from those created by normal matter. In practice, experiments such as the Cryogenic Dark Matter Search (CDMS) have to be extremely well shielded to avoid an overwhelming rate of normal-matter interactions.

Some theorists have begun to suggest that there may be a "dark sector" containing a whole spectrum of dark-matter particles and forces separate from those that make up normal matter. One consequence of such theories would be the existence of low-mass WIMPs, or "light dark matter". The interaction of a light WIMP with a nucleus would be like a ping pong ball hitting a billiard ball; the latter would barely move. Thus experiments to search for light WIMPS must be sensitive to extremely small energy deposits.

CDMS experimenters mined their data to see if there is an excess of events at the lowest energies, compared with the predicted rate of events from normal matter interactions. Recently, the scientists also looked to see whether the rate of events varied over the course of a year as the WIMP rate is predicted to do, given the earth's motion through our galaxy. No evidence for light WIMPS was seen, and the resulting limits appear to rule out hints from other experiments. Stay tuned, though: CDMS and other experiments are enhancing their techniques in order to shed new "light" on dark matter.

—Dan Bauer

Announcements

Today's New Announcements

International Folk Dancing Thursday evenings in Kuhn Barn

Users' Center closed - today

English country dancing - Jan. 6

Martial arts classes - begin Jan. 7

Yoga - begins Jan. 8

Butts & Guts offered Mondays and Wednesdays

Zumba offered Tuesdays and Fridays

Fermilab Lecture Series - Building Bionics - Jan. 18

Gallery Chamber Series - Metropolis Quartet - Jan. 20

Fermilab Arts Series - Tomas Kubinek - Jan. 26

January 2013 timecards and float holiday

Timecard instructions for nonexempt employees working on half-holidays

Cafeteria holiday hours

Indoor soccer

Employee discounts on AAA membership

Classifieds
Find new classified ads on Fermilab Today.