## lördag 8 augusti 2009

### If You Are Looking for Trouble

If you are looking for trouble, opportunities seem to be offered in the big-physics experimental projects of the Large Hadron Collider LHC and the Laser Interferometer Gravitational-Wave Observatory LIGO. LHC is constructed to detect the Higgs boson and particles and forces that reigned earlier than the first trillionth of a second of time. LIGO is constructed to detect gravitational waves.

LHC does not work, while LIGO works but does not detect anything but noise. New York Times reports in Giant Particle Collider Struggles:
• The biggest, most expensive physics machine in the world is riddled with thousands of bad electrical connections.
• After 15 years and $9 billion, and ashowy “switch-on” ceremony last September, LHC has to yet collide any particles at all. • But scientists say it could be years, if ever, before the collider runs at full strength, stretching out the time it should take to achieve the collider’s main goals, like producing a particle known as the Higgs boson thought to be responsible for imbuing other elementary particles with mass, or identifying the dark matter that astronomers say makes up 25 percent of the cosmos. • The collider was built to accelerate protons to energies of seven trillion electron volts and smash them together in search of particles and forces that reigned earlier than the first trillionth of a second of time. • But some physicists admit to being impatient. “I’ve waited 15 years,” said Nima Arkani-Hamed, a leading particle theorist at the Institute for Advanced Study in Princeton. “I want it to get up running. We can’t tolerate another disaster. It has to run smoothly from now.” • Pauline Gagnon, an Indiana University physicist who works at CERN: “The public pays for this, and we need to start delivering.” Earlier than the first trillionth of a second after Big Bang! Can you come up something more mind-boggling? • This fall, the ground-breaking fifth science run of the LIGO interferometers came to a successful conclusion as an integrated full year's worth of science data was accumulated with all three LIGO interferometers in coincidence. The interferometers--antennae tuned to detect the delicate ripples of gravitational-waves coursing through the fabric of space-time--have achieved unprecedented sensitivity and astrophysical reach, as well as excellent duty cycle. • LIGO now moves into its next phase of progress, Enhanced LIGO, an ambitious project to improve LIGO’s sensitivity by a factor of 10 and increase its source reach (the number of extragalactic sources within its range) by a factor of 1000. Advanced LIGO is expected to observe gravitational-wave signals from such cosmic sources as merging pairs of black holes and neutron stars at the rate of several each month. Because the characteristics of the source of the gravitational waves is encoded in the waves themselves, Advanced LIGO will pioneer a new form of astronomy utilizing gravitational waves to observe and interpret some of the most violent events happening in the universe. Construction on this stage will begin early in 2008, with first observations using the Advanced LIGO configuration scheduled to commence in 2014. LIGO did not detect any waves. What are the prospects that Enhanced LIGO will do it? If gravitational waves do exist, why are they so terribly difficult to detect? The cost of the big-physics projects LHC and LIGO is big, more than$15 billion together, but so far the result is zero. How much money will have to be put in to get anything but zero out?

How much is $15 billion? The cost of the US health care reform is estimated to$1 trillion, which is also about the total cost of US wars since 2001. The cost of LHC and LIGO thus so far is less than 2% of the war cost. In either case the result seems close to zero...and nobody knows if spending $1 trillion on big-physics will suffice... #### 2 kommentarer: 1. Dear Claes Johnson, I would like to correct some inaccurate statements on the LIGO project. 1) The "fifth science run of the LIGO interferometers" ended in the fall 2007. 2) Enhanced LIGo and Advanced LIGo are two distinct phases of the LIGO project. As a matter of fact, the Enhanced LIGO phase started about one month ago. 3) Gravitational waves are difficult to detect because they are extremely weak. (A typical gravitational wave would change the Earth-Sun distance by a fraction of the size of an atom! 4) The cost of the entire LIGO project is not$15 billion. Actually, it is of the order of a few hundred thousand US dollars. The LIGO budget is public. A careful blogger should be able to find easily this information.

5) The prospects that Advanced LIGO will find gravitational waves are high. In any case, even a "zero" is an interesting result sometimes in physics.

2. An estimate of $4 billion for LIGO was taken from http://www.misunderstooduniverse.com/LIGO_LISA_Cosmic_Money_Pit.htm which combined with$10 billion for LHC gave about \$15 billion.

The prospects for Advanced LIGO are unclear, as far as I can understand. The importance of very weak gravitational waves is also unclear, as far as I can understand. What is it I am missing?