Sunday, February 11, 2007

GLAST Symposium

Stanford University was site of the First International GLAST Symposium. The Gamma-ray Large Array Survey Telescope involves researchers from Europe to Japan. Gamma rays are the most powerful form of radiation in the sky. They come from Black Holes, active galactic nuclei and even our Sun. Thr source of high-energy cosmic rays is still a mystery. Starting later this year, GLAST will open a new window to studying the Universe.

Thursday's concluding talk was given by Roger Blandford, head of Kavli Institute for Particle Astrophysics and Cosmology. As a young man he introduced the Blandford-Ivanek process for Black Hole jets. He is also close to those currently controlling supernova research. Barely 2 years ago, he was corralled into giving a public talk about "dark energy." To a big audience including children, Blandford tentatively "put forward the idea" that the Universe is filled with a repulsive force.

During Thursday's conclusion Blandford didn't mention "dark energy" at all. (He didn't mention DE at his AAS HEAD talk in October either.) One of the first issues he mentioned was "Violations of Lorentz Invariance." That's scientist talk for a changing speed of light. He said that once Lorentz Invariance is discovered, other researchers will claim that they knew it all along. Thanks for seeing my presentation, Dr. Blandford!

More of his bullet points: Study of solar flares will aid in travel to the Moon and Mars. Violent flares could release harmful radiation with a warning time of minutes! Such radiation would pose a big hazard to spaceflight. (Cosmic rays turned a spaceship crew into the Fantastic Four, and gamma rays created the Hulk.)

Blandford continued that the discovery of Gamma Ray Bursts (GRB's) has led to "epicyclic theories." Current physics can not adequately explain these huge sources of energy. Blandford acknowledged that "even the emission mechanism is up for grabs." These objects can be explained with supermassive Primordial Black Holes. Such objects could only form with a higher speed of light.

Pulsars were discovered by Jocelyn Bell in 1967, though she was late in receiving credit. At first people suspected they were signals from ET's. Even today their source of energy is a mystery. Blandford noted how little we know about them. "How do pulsars shine?" he asked, "How does coherent radiation form?" The behaviour of pulsars and their spinning jets can be explained with internal singularities.

This blog has reported on both the Vision for Space Exploration and the Beyond Einstein programme. Concerning the Vision, in the February 1 issue of NATURE Blandford is quoted as saying, "Everybody has to band together; the only way that any of this makes sense economically is as a global enterprise." He is smart enough to know that some scientist's grumbling about the Vision is counter-productive. He even shows how GLAST can aid the Vision by helping understand solar flares.

This year a decision will be announced on Beyond Einstein which may disappoint supernova researchers. In the same issue of NATURE, programme manager Michael Salomon assures us that "NASA is committed to the entire Beyond Einstein programme. There is no 'winner takes all' scenario here." My experience with senior people in science (Blandford, Michael Turner, Alan Guth, John Huchra) is that they are very receptive to new ideas. Though they will not jump into a new idea, they know a good thing when they see it.


Anonymous Anonymous said...

Hoover tower looks a lot safer than the Campanile at U. Cal. Berkeley. Nothing like 300 foot masonry towers in an earthquake zone.

7:39 AM  
Blogger L. Riofrio said...

HI Carl: The Hayward Fault running through campus ought to be a subject for concern. An earthquake would cause major damage in the East Bay. The physics department located behind the Campanile has been crumbling even without Mother Nature. Leconte Hall is in such bad shape that some people can't inhabit their offices. Since Smoot's contibution to COBE in 1992, what have they given us? Dark energy?

8:06 AM  

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