Information on Elementary Particles
Connecting Quarks with the Cosmos
Andrei Linde's Article on Inflation
Inflation, Cosmic Strings, and Quantum Gravity from the Cambridge Relativity & Gravitation Research Group
Berkeley/Carnegie Mellon press release, December 12, 2002
Using a powerful new instrument at the South Pole, a team of cosmologists has produced the most detailed images of the early Universe ever recorded. The research team, which was funded by the National Science Foundation (NSF), has made public their measurements of subtle temperature differences in the Cosmic Microwave Background (CMB) radiation. The CMB is the remnant radiation that escaped from the rapidly cooling Universe about 400,000 years after the Big Bang.
Images of the CMB provide researchers with a snapshot of the Universe in its infancy, and can be used to place strong constraints on its constituents and structure. The new results provide additional evidence to support the currently favored model of the Universe in which 30 percent of all energy is a strange form of dark matter that doesn't interact with light and 65 percent is in an even stranger form of dark energy that appears to be causing the expansion of the Universe to accelerate. Only the remaining five percent of the energy in the Universe takes the form of familiar matter like that which makes up planets and stars.
The researchers developed a sensitive new instrument, the Arcminute Cosmology Bolometer Array Receiver (ACBAR), to produce high-resolution images of the CMB. ACBAR's detailed images reveal the seeds that grew to form the largest structures seen in the Universe today. These results add to the description of the early Universe provided by several previous ground-, balloon- and space-based experiments. Previous to the ACBAR results, the most sensitive, fine angular scale CMB measurements were produced by the NSF-funded Cosmic Background Investigator (CBI) experiment observing from a mountaintop in Chile.
William Holzapfel, of the University of California at Berkeley and ACBAR co-principal investigator, said it is significant that the new ACBAR results agree with those published by the CBI team despite the very different instruments, observing strategies, analysis techniques, and sources of foreground emission for the two experiments. He added that the new data provide a more rigorous test of the consistency of the new ACBAR results with theoretical predictions."It is amazing how precisely our theories can explain the behavior of the Universe when we know so little about the dark matter and dark energy that comprise 95 percent of it," said Holzapfel.
The dark energy inferred from the ACBAR observations may be responsible for the accelerating expansion of the Universe. "It is compelling that we find, in the ancient history of the Universe, evidence for the same dark energy that supernova observations find more recently," said Jeffrey Peterson of Carnegie Mellon University.
The construction of the ACBAR instrument and observations at the South Pole were carried out by a team of researchers from the University of California, Berkeley, Case Western Reserve University, Carnegie Mellon University, the California Institute of Technology, Jet Propulsion Laboratory (JPL), and Cardiff University in the United Kingdom. Principle investigators Holzapfel and John Ruhl at Case Western led the effort, which built and deployed the instrument in only two years.
ACBAR is specifically designed to take advantage of the unique capabilities of the 2.1-meter Viper telescope, built primarily by Jeff Peterson and collaborators at Carnegie Mellon and installed by NSF and its South Pole Station in Antarctica. The receiver is an array of 16 detectors built by Cal Tech and the JPL that create images of the sky in 3-millimeter wavelength bands near the peak in the brightness of the CMB. In order to reach the maximum possible sensitivity, the ACBAR detectors are cooled to two-tenths of a degree above absolute zero, or about -273 degrees Celsius (-459 Fahrenheit). ACBAR has just completed its second season of observations at the South Pole. Researcher Mathew Newcomb kept the telescope observing continuously during the six-month-long austral winter, despite temperatures plunging below -73 degrees Celsius (-100 Fahrenheit).
The construction of ACBAR and Viper was funded as part of the NSF Center for Astrophysical Research in Antarctica. The U.S. Antarctic Program provides continuing support for telescope maintenance, observations, and data analysis. NSF's Amundsen-Scott South Pole Station is ideally suited for astronomy, especially observations of the CMB. The station is located at an altitude of approximately 3,000 meters (10,000 feet), atop the Antarctic ice sheet. Water vapor is the principal cause of atmospheric absorption in broad portions of the electromagnetic spectrum from near infrared to microwave wavelengths. The thin atmosphere above the station is extremely cold and contains almost no water vapor. "Our atmosphere may be essential to life on Earth," said Ruhl, "but we'd love to get rid of it. For our observations, the South Pole is as close as you can get to space while having your feet planted firmly on the ground."
For pictures or more information and drafts of the submitted papers,
STScI PRESS RELEASE NO.: STScI-PR02-08, March 21
Journey to the deepest regions of space and wrestle with the cosmic giants called galaxies.
In "Galaxy Hunter," students can go online and use actual data from NASA's Hubble Space Telescope to study galaxies in deep space. Produced by the formal education team at the Space Telescope Science Institute in Baltimore, Md., the interdisciplinary, Web-based lesson blends astronomy and math skills. A team of scientists, teachers, artists, and Web programmers developed the interactive lesson to bring the results of cutting-edge astronomical observations into the classroom. "Galaxy Hunter" is on the Amazing Space Website [amazing-space.stsci.edu]. Amazing Space is a group of Web-based, interactive activities primarily designed for classroom use, from kindergarten through twelfth grade.
The galaxies that students examine in "Galaxy Hunter" are part of the Hubble "Deep Fields," the Hubble telescope's clearest, most distant views of the universe ever obtained. Gazing billions of years back in time, the Earth-orbiting observatory uncovered a bewildering assortment of galaxies in various stages of evolution.
Scientists used mathematics to unlock many galactic secrets hidden in the two deep fields. Now students can analyze the same faraway galaxies that dazzled astronomers and sample the types of galaxies found in the deep views. Then they can compare their samples with those of astronomers to determine whether the galaxies in the two deep fields are similar. Along the way, they'll learn about bias in sampling techniques and the role of sample variability in determining the optimal sample size. Based on their sample analysis, students will try to answer the same question as the astronomers who observed the deep fields: Does the universe look the same in the two Hubble deep fields? Scientists believe that the universe generally looks the same in all directions.
The lesson also includes a teacher guide that helps prepare educators to present the lesson in the classroom. In the guide, teachers will find "science background" information, which explains the galaxy types, the galaxy classification system, and how astronomers selected the Hubble deep fields. The lesson also adheres to the National Education Standards for grades 9 to 12.
When students are finished hunting for galaxies, they can try unscrambling the schedule for a Hubble telescope servicing mission. Although the Hubble telescope's Servicing Mission 3B is over, students can still play the role of a NASA scientist who plans the Hubble servicing missions. In "Be the Mastermind Behind the Mission," another online, interactive activity, students attempt to fix a mixed up order of events for the Hubble servicing mission. Their job is to place the schedule of servicing mission events, which includes spacewalks and the launch of the space shuttle, in proper order. The interdisciplinary lesson focuses on reading and technology skills, and is aimed at sixth-through eighth-graders.
"Galaxy Hunter" and "Be the Mastermind Behind the Mission" are
available on the Amazing Space website at:
The Macho Project's homepage is
MACHO's Interactive Cepheid Period-Luminosity Web Display
for the ability to click on any star on the equivalent of Figure 20-16 of the text in order to see the star's light curve.
The Macho Project's homepage is www.macho.mcmaster.ca