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In this issue:
Vanquishing Infinity: Old Methods Lead to a New Approach to Finding a Quantum Theory of Gravity
Energy Summer School Comes to SLAC
SLAC Blood Drive a Help to Local Hospitals
Panofsky Auditorium Closures This and Next Week

SLAC Today

Monday - August 24, 2009

(Image - Mondrian diagram)
Mondrian diagram. In the 1940s, Richard Feynman devised a graphical method for carrying out calculations. Bern et al. use different kinds of diagrams that permit large calculations. Owing to their resemblance to the work of artist Piet Mondrian, these graphical computational devices are sometimes referred to as Mondrian diagrams. (Image adapted from Bern et al., Phys. Rev. D 76, 125020, 2007.)

Vanquishing Infinity

Old methods lead to a new approach to finding a quantum theory of gravity

Quantum mechanics and Einstein's theory of general relativity are both extremely accurate theories of how the universe works, but all attempts to combine the two into a unified theory have ended in failure. When physicists try to calculate the properties of a quantum theory of gravity, they find quantities that become infinite -- infinities that are so bad they can't be removed by mathematical gambits that work in other areas of physics.

Now, Zvi Bern, John Carrasco, and Henrik Johanssen at UCLA, Lance Dixon at the SLAC National Accelerator Center, and Radu Roiban at Pennsylvania State University have found a way to carry out a new set of gravity calculations with the help of an older theory that has been known since the 1980s to be finite.

Their new results are reported in Physical Review Letters and highlighted in a commentary by Hermann Nicolai at the Max Planck Institute for Gravitational Physics in Potsdam, Germany, in Physics.

Read more in the APS news release...

SLAC Recovery Act Projects Web Site Online

From infrastructure upgrades to cutting-edge research facilities, SLAC is putting funds from the American Recovery and Reinvestment Act to work. ARRA project details are now available on The Recovery Act at SLAC Web site. Watch this site for updates as the work progresses.

Energy Summer School Comes to SLAC

(Image - Energy Summer School banner)

The Stanford Institute for Materials and Energy Science Energy Summer School arrives at SLAC today, kicking off the second and final week of the residential program. The event will bring more than 50 students and scientists to SLAC through August 28, with attendees who arrive from outside the Bay Area staying at the Stanford Guest House.

The week's program includes presentations in SLAC's Redwood Conference Rooms on topics from hydrogen storage, fuel cells, solar energy and superconductivity. Wednesday evening will feature a public lecture by LED inventor Shuji Nakamura at 7 p.m. at Panofsky Auditorium. The summer school will conclude with student project presentations on global energy systems to  reduce carbon emission, with the goal of an 80 percent reduction by the year 2050.

SLAC Blood Drive a Help to Local Hospitals

SLAC Site Office Manager Paul Golan and lab Director Persis Drell (back left) enjoy a snack with other donors at the SLAC blood drive. (Photo by Lauren Knoche.)

The SLAC blood drive on Wednesday, August 19, was very popular, including support from good friends Persis Drell and Paul Golan.

"It's more fun to go with a buddy," said Persis, who also pointed out the benefits of giving blood, such as checking your blood pressure and iron levels. In addition to these quick health checks, Golan mentioned the positive feeling he receives from being able to help others, adding that in these economic times some people may be unable to give monetary donations but "you can always give blood."

These benefits pale in comparison to the aid that hospitals receive from donated blood. Donations from the SLAC blood drive help support six hospitals, including the nearby Stanford Medical Center. Stanford's numerous transplant surgeries "go through a lot of blood," said Registered Nurse Wendy Pituley. With 47 blood donations by 2:30 p.m., organizers said they were pleased with last Wednesday's turnout.

"Supplies are low given the current usage [of blood]," Pituley said, "but this has been a good drive. We're right up where we've been in the past."

Panofsky Auditorium Closures This and Next Week

Panofsky Auditorium will close for roof work late this week and next weekend. The breezway, lobby, visitors center, bathrooms and auditorium will be inaccessible as follows:

  • Thurs–Fri, Aug 27–28 after 3 p.m.
  • Sat–Sun, Aug 29–30 all day
  • Sat–Sun, Sep 5–6, all day

Please respect any safety postings and watch out for work in the area.


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