Friday, July 5, 2013

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Friday, July 5

3:30 p.m.


Monday, July 8


3:30 p.m.

4 p.m.
All Experimenters' Meeting - Curia II
Special Topics: LARP Report, MTA Report

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Friday, July 5

- Breakfast: regular breakfast menu
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Wilson Hall Cafe menu
Chez Leon

Friday, July 5

Wednesday, July 10
Guest chef: Teri Traum Welsh
- Grilled shrimp and tri-melon salad
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Physics in a Nutshell

E = mc2

Einstein's equation is the most famous one of modern physics; however, it never appeared in his first paper. Instead his paper included the unwieldy but equivalent, K0 - K1 = (L/c2) × (v2/2).

Einstein's equation is the most famous equation in history. Even people who have absolutely no interest in science recognize it. But what does it mean?

Well, like all equations, it has a left side and a right side, separated by an equal sign. On the left-hand side is "E," which means energy. On the right-hand side is "m," which means mass, and "c," which means the speed of light. The speed of light is simply a mathematical constant that converts units of energy to units of mass, similar to the conversion factor you'd use to translate feet to inches. In the middle is the equal sign, which just says that the right hand and left hand side are the same. Stated simply, this equation says that energy and mass are the same once you apply the c2 conversion factor to get the numbers right.

That last sentence is such an unassuming one, yet it has huge implications. If two things are the same, you can convert one into another. Scientists who use accelerators like those at Fermilab, CERN and other similar laboratories make this conversion all the time. We accelerate particles to high energies and slam them together. The particles' kinetic (motion) energy can convert into mass energy. This is how particles like the top quark and the Higgs boson are made.

It's important to note that the "m" stands for "mass," not matter. When we convert energy into mass, we do in fact convert the energy into matter, but we also simultaneously convert it into antimatter. Of course, the equal sign in the equation means the conversion can go both ways: You can combine matter and antimatter to make energy. This is the basis for the Dan Brown book Angels and Demons, in which a scientist isolated a quarter gram of antimatter. If that were technologically possible, Brown's story would be feasible. Combining a quarter gram of antimatter and matter would result in an energy release similar to those from the first atomic bombs. Luckily for mankind's safety, it is difficult to isolate antimatter. Fermilab's antiproton source was the world's most powerful facility for making antimatter, and yet 25 years of effort isolated only enough antimatter to warm five gallons of water from room temperature to the temperature of a decent cup of coffee.

One aspect of this equation is kind of mind-blowing. Consider ordinary matter of the kind that makes up you and me. We are made of atoms, which are made, in turn, of protons, neutrons and electrons. Electrons are far less massive than protons and neutrons. Protons and neutrons have similar masses, so we can conceptually combine them as a class of particles called nucleons, indicating their location in the nucleus of an atom. Thus most of your mass comes from the various nucleons in your body.

Things get really interesting when we ask where the nucleons' mass comes from. Each nucleon consists of three quarks, so the obvious answer is that each of the quarks carries about a third of the mass of a proton. However, that's not true. The mass of the quarks is only about 1 to 2 percent the mass of the proton. So where does the mass of the proton come from? Energy.

Inside a nucleon, the quarks are zooming around at speeds near that of light. This gives them a lot of kinetic energy. In addition, they are zooming around in a volume the size of a sphere a quadrillionth (10-15) of a meter in radius. To have something moving that fast in a volume that small requires very strong forces to hold them together. This requires a lot of potential (binding) energy. The combined kinetic and potential energy is the real source of a person's mass.

In essence, there is very little mass in the way we intuitively understand it. Everything is energy. Einstein's equation, first invented over a century ago, showed us a central truth of the universe. Matter is energy.

Don Lincoln

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In the News

Majorana copper taking shape

From Sanford Lab's Deep Thoughts, July 1, 2013

This summer there's copper, copper everywhere at the Majorana Demonstrator experiment (MJD), which is being assembled 4,850 feet underground in the Sanford Lab.

Read more

In the News

How the Higgs boson was found

From Smithsonian magazine, July-August 2013

A famous story in the annals of physics tells of a 5-year-old Albert Einstein, sick in bed, receiving a toy compass from his father. The boy was both puzzled and mesmerized by the invisible forces at work, redirecting the compass needle to point north whenever its resting position was disturbed. That experience, Einstein would later say, convinced him that there was a deep hidden order to nature, and impelled him to spend his life trying to reveal it.

Although the story is more than a century old, the conundrum young Einstein encountered resonates with a key theme in contemporary physics, one that's essential to the most important experimental achievement in the field of the last 50 years: the discovery, a year ago this July, of the Higgs boson.

Let me explain.

Read more

From symmetry

Big data and the X-ray laser

Ultrafast experiments at SLAC's Linac Coherent Light Source require powerful, unique data systems adapted from particle physics. Photo: Matt Beardsley, SLAC

The Linac Coherent Light Source X-ray laser, located at SLAC, produces a beam of ultrabright X-rays powerful enough to illuminate single molecules, to selectively knock out electrons from the core of atoms, to create superhot and superdense plasmas and to explore delicate nanocrystals of biological samples.

The LCLS's high-speed, high-resolution detectors, which collect information on these atomic- and molecular-scale processes and structures, require data storage at an extremely fast rate and enormous scale. An experiment at one LCLS instrument produces an average of about 10 million X-ray images in 48 hours. Larger LCLS experiments generate 150 to 200 terabytes (about 154,000 to 205,000 gigabytes) of data in the same timeframe.

Luckily for LCLS scientists, the particle physics community has been building expertise in extreme data collection for years.

From particle physics to photon science
The LCLS data acquisition system was built by the same group of experts who worked on the data acquisition system for BaBar, a particle physics experiment that took data at SLAC between 1999 and 2008.

The particle physics community is "where we come from," says Amedeo Perazzo, who leads the Photon Controls and Data Systems Department at SLAC, which manages LCLS data. As a member of the BaBar core data-flow group, Perazzo built a diagnostic tool for the experiment's parallel-processor computer architecture and was responsible for other enhancements to the BaBar trigger and data acquisition systems.

Igor Gaponenko, a research software developer for LCLS data systems who came to SLAC as a visiting scientist in 1997 to work on the BaBar collaboration, says, "Those of us who came with a heavy background in high-energy physics and its information culture—for us [the LCLS's unprecedented data rates are] not so surprising.

"That was the whole idea, to transfer the experience of high-energy physics to photon science, because it was anticipated that LCLS would be producing a lot of data."

LCLS adopted the same format to store its raw data as the BaBar experiment, a format called eXtended Tagged Container. This is because it's fast, easy to extend and allows read-back even as a data file is being written, Perazzo says.

Read more

Glenn Roberts Jr.

Photo of the Day

Coyote pups

Ed Dijak, PPD, snapped this photo of two coyote pups on the Fermilab grounds.

Today's New Announcements

Budker Seminar - July 8

NALWO event: How to create your own terrarium - July 12

July EAP webinar

Same-sex couples now eligible for immigration benefits

Batavia Road gate closed today and tomorrow

Registration for FEMA assistance due July 9

Behavioral interviewing course scheduled for July 18

Inside Money: Managing income and debt workshop being offered by TIAA-CREF - July 12

Fermilab Prairie Plant Survey (Quadrat Study) - July 19

NALWO potluck supper - July 19

Chris Lintott: How to Discover a Planet From Your Sofa - July 19

What's Your Financial IQ Challenge runs from July 1 - 31

Summer intern Friday tours

Puppet Fundamentals course offered in September

Martial arts

BuZheng Qigong & Tai Chi Easy

Join the Tango Club

English country dancing at Kuhn Barn

Scottish country dancing meets Tuesday evenings in Auditorium

International folk dancing in Auditorium for summer

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