UCSD’s division of physical sciences recently received a $400,000 gift to help fund the construction of a telescope that researchers hope will increase their understanding of the early universe..
UCSD’s new POLARBEAR telescope will attempt to examine the origin of the universe by detecting gravitational waves from the Big Bang era.
The telescope, called POLARBEAR for Polarization of Background Radiation, would allow scientists to study the origin of the universe within 10-36 seconds after the Big Bang by indirectly measuring tiny ripples in the curvatures of space-time known as gravitational waves. The researchers hope to use POLARBEAR to see further back in time than has ever been possible by observing the effects of these gravitational waves on the microwave radiation that is present throughout the universe.
The donation comes from the James B. Ax Family Foundation and will go toward the estimated $1 million cost of the project.
While the telescope will be built and funded in stages, researchers expect to begin installation and testing in 2008. POLARBEAR will be initially located at a research site near Owens Valley, east of the Sierra Nevada range.
According to the Big Bang theory, there should be a background of microwave radiation in the universe. This cosmic microwave background, or CMB, was discovered in 1964 by Bell Labs radio astronomers Arno Penzias and Robert Wilson, for which they received the 1978 Nobel Prize in physics.
Since that time, several large projects have studied this radiation, including NASA’s Cosmic Background Explorer. However, using CMB, astronomers can only study the universe back to a time around 400,000 years after the Big Bang (about 14 billion years ago).
Before this time, the state of the universe was opaque to electromagnetic radiation, and therefore CMB cannot be used to probe that era directly. But the CMB does carry an indirect signature left by its interaction with gravitational waves; and gravity, the weakest force, would have been able to propagate through the earliest state of the universe. The POLARBEAR project seeks to detect the imprint of these primordial gravitational waves on the CMB.
Brian Keating, an assistant professor of physics at UCSD and one of the leaders of POLARBEAR, compares the project to the use of ultrasound to observe the growth of a developing baby. With POLARBEAR, UCSD scientists will examine the polarization of the CMB to obtain an “”ultrasonic”” image of the “”embryonic universe.””
The actual telescope consists of an aluminum mirror 3.5 meters in diameter that will focus radiation onto an array of microwave-sensitive detectors.
It will be the first application of a new type of sensor that is integrated with the antenna, which makes POLARBEAR more efficient and more sensitive to the faint traces of primordial gravitational waves.
POLARBEAR is a collaboration between scientists at UCSD, UC Berkeley, Lawrence Berkeley National Laboratory and the University of Colorado.
