John Cromwell Mather

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John C. Mather in
front of a model of the COBE satellite

John Cromwell Mather (born August 7, 1946 in Roanoke , Virginia ) is an American astrophysicist . Mather has worked at NASA his entire professional life . Most recently, he conducted research at NASA's Goddard Space Flight Center (since 1993 as Senior Astrophysicist) and from 2007 was Chief Scientist in the Science Mission Directorate at NASA headquarters.

For his contribution to the investigation of the cosmic background radiation , he was honored in 2006 together with George F. Smoot for their confirmation that the spectrum of the background radiation obeyed Planck's law of radiation of a black body , and the discovery of the anisotropy of the cosmic microwave background ( for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation ) was awarded the Nobel Prize in Physics . The measurements of the cosmic background radiation were carried out by Smoot and Mather using the satellite Cosmic Background Explorer (COBE).

life and work

Family and early years

John Cromwell Mather was born on August 7, 1946 in Roanoke , Virginia , United States . He was the son of Robert E. Mather and Martha Cromwell Mather. His father was a teacher at what is now the Virginia Polytechnic Institute and State University , Virginia Tech for short, and specialized in livestock husbandry , especially the effects of breeding research and feeding in dairy farming . His mother was a high school teacher teaching French . His parents moved to the Rutgers Agricultural Experiment Station in rural Sussex County near Rutgers University in New Jersey when Mather was about one and a half years old and stayed there for his entire childhood. Here his father was responsible for examining and regulating the amount of protein in milk, which he optimized through breeding experiments. John Cromwell Mather attended Wantage Consolidated Elementary School near Sussex . Unlike many of his classmates, he was not very interested in sports and instead read everything he got. Even in elementary school he developed an interest in the natural sciences and mathematics and, through the purchase of a small telescope , in astronomy . He was particularly interested in Mars , as the Mars channels can be recognized due to its proximity to the earth . At the age of nine he got a radio kit and built his own shortwave radio , later adding his own telescopes.

After elementary school, his parents sent him to Newton High School, which was reputed to be the best school in the area and where Mather concentrated on the various sciences. In the 10th grade he went to Assumption College and in the 11th grade to Cornell University as a summer school , where he attended introductory courses in quantum mechanics , relativity , nuclear physics , optics and cosmology and decided to want to work as a scientist. He studied physics at Swarthmore College and made his bachelor's degree in 1968 with, among others, David Todd Wilkinson , one of the later developers of the Cosmic Background Explorer (COBE).

Study and first work on background radiation

For his graduation he went on a grant from the National Science Foundation to the University of California, Berkeley , where he received his PhD in 1974 . He worked there at the Lawrence Berkeley Laboratory and first worked with Henry Frisch on the control electronics of a spark chamber . Mather hardly dealt with the Vietnam War and the protests, and since he is very short-sighted, he was not called up for military service. In 1970 he looked around for a topic for his doctorate and found out that Paul Linford Richards, together with Charles Townes and a young postdoc named Michael Werner, had started a project that dealt with the then newly discovered cosmic microwave background radiation and he decided to to join. They first developed an infrared spectroscope for the Barcroft Station on White Mountain in eastern California, where the university conducted studies of human physiology at high altitude. With the spectroscope, the team was able to measure the intensity of the background radiation, but the measurements were disturbed due to the interference with the earth's atmosphere . They later developed an infrared interferometer that could be used in a balloon experiment to measure the energy spectrum of the background radiation. Mather built the device together with David Woody , with Mather showing in his autobiography for the Nobel Prize that he had more skill in understanding than in realizing the technology. Due to failure of the measurement technology, the results were of little use and Mather, together with his doctoral supervisor Paul Richards, decided that he would write his doctoral thesis on the basic structure and construction of the measuring balloon and not on the results. This happened later in the work of Woody, who recognized the problems of measurement technology and was able to solve them. Mather received his PhD in 1974 .

Early NASA activities

After completing his doctoral thesis, Mather went to New York City as a postdoctoral fellow in January 1974 to the research group of Pat Thaddeus at the Goddard Institute for Space Studies (GISS) at Columbia University , which is a member of NASA . He began his work with the construction of a microwave amplifier ( maser ) based on silicon dioxide SiO 2 and, together with the institute's technicians, concentrated a microwave receiver that he used at the McDonald Observatory in Texas and at Navy's Maryland Point Observatory on the Potomac River . With the help of the device, he was able to observe the emissions of the silicon oxide at 43 GHz in the background radiation, which had never been noticed before. At the same time he made his first experiences with programming a System / 360 -IBM mainframe computer, which he wanted to program with a Fortran program based on punched cards without success .

Planning and implementation of the Cosmic Background Explorer (COBE)

Cosmic Background Explorer (COBE)
Background radiation captured by the Cosmic Background Explorer

By tendering NASA for the targeted projects Opportunity 6 and 7 as satellite missions based on Scout - and Delta - launchers joined Mather at Thaddeus approach and represented to him that his work could be realized for background radiation due to atmospheric interference better than satellite. Together with Rainer Weiss , David Todd Wilkinson , Michael Hauser , Dirk Muehlner and Bob Silverberg, they applied for the project. They wanted to install four instruments: an interferometer to measure the energy spectrum, two instruments to measure the anisotropy of the radiation and one to search for the diffuse infrared radiation of the oldest galaxies . Although the team had no experience with space missions, NASA was interested and wanted to realize the mission with the Infrared Astronomical Satellite (IRAS) already planned in cooperation with the Netherlands . Together with Ball Aerospace , which was to build the American parts of the satellite, it was considered whether instruments could be miniaturized to such an extent that they could be integrated into IRAS. Mather developed a concept for this, but it was rejected.

In the fall of 1976, NASA decided to review the research group's concept, but changed the research team. To chose Nancy Boggess , research director of NASA Headquarters, Hauser, White, Wilkinson and Mathers of the original team, adding that to be formed Mission Definition Science Team by George Smoot of the University of California, Berkeley, and Sam Gulkis from the Jet Propulsion Laboratory (JPL). Hauser then offered Mather a position at the Goddard Space Flight Center (GSFC) in Greenbelt , Maryland , which he accepted. The team hired Martin Donohoe, a project manager, as it was competing with 11 other projects, and chose Rainer Weiss as project manager. Hauser, Smoot and Mather were chosen as Principal Investigators and Mather was also hired by NASA as Study Scientist and was supposed to realize the project together with NASA engineers as Cosmic Background Explorer (COBE). The report was accepted by NASA and the team was given a larger team of engineers led by Jerry Longangecker , who had already built the International Ultraviolet Explorer (IUE). At this time, NASA was developing the space shuttle , which was to be used for all space transports from 1981. This meant that the COBE, which was designed for Delta rockets, had to be modified so that it could be transported by the Space Shuttle. NASA decided to have the COBE built at the Goddard Space Flight Center, whereby the engineering team was also regularly appointed as a top team for other projects such as the Hubble space telescope under construction .

In 1980 Mather married the ballet teacher Jane Hauser, whom he met in 1974 on a consultancy assessment course. From 1980 to 1995 Mather worked almost exclusively with the COBE project, for which he was largely responsible.

Nobel Prize and Later Work

Top of the James Webb Space Telescope (illustration)

Since 1995 Mather has also been involved in the realization of the James Webb Space Telescope (JWST) as a scientist . On the advice of his colleague Harvey Moseley , who worked on the Infrared Array Camera (IRAC) of the Space Infrared Telescope Facility (SIRTF), Mather was busy developing a small telescope to improve the optics for capturing distant galaxies. He submitted his concept of a Next Generation Space Telescope at the request of Ed Weiler from NASA headquarters, which was based on the infrared-optimized telescope requested by John Campbell, the project manager of the Hubble Space Telescope, to explore aspects of the early universe and education to examine the stars. It should also have an interferometer to find nearby planets that are similar to Earth. At the January meeting of the American Astronomical Society the following year, NASA's Dan Goldin presented plans to build a new and larger telescope. Mather and his team developed the plans for an 8-meter observatory and signed contracts with European and Canadian space agencies and signed contracts with TRW Inc. to build the probe, which was later handed over to Northrop Grumman . The probe was named after James Edwin Webb , NASA's second administrator. In 1997, Mather became a member of the National Academy of Sciences for his scientific achievements.

In 2000, the National Academy of Sciences added the James Webb Space Telescope to its top projects list, and it was originally scheduled to launch in 2013. Due to the enormous increase in costs, the Science Committee of the US House of Representatives issued a recommendation on July 13, 2011 to stop the construction of the telescope. The construction costs were estimated by NASA at the time at 8.7 billion dollars. By then, about $ 3 billion had been spent and about 75% of the necessary components had been purchased, including most of the scientific instruments. All elements of the primary mirror have also been completed. As of 2012, the financing including operating costs for the first 5 years is considered secure again and a start would be expected in 2018 at the earliest.

For his contribution to the study of cosmic background radiation as part of the COBE project, Mather was awarded the Nobel Prize in Physics in 2006 together with George F. Smoot . Officially, it was above all their confirmation that the spectrum of the background radiation obeyed Planck's law of radiation of a black body , and the discovery of the anisotropy of the cosmic microwave background ( for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation ) that gave them the Brought in the Nobel Prize. In the same year he also received the Gruber Prize for Cosmology together with the COBE team .

Honors (selection)

supporting documents

  1. a b c d e f g h i John C. Mather - Biographical on Accessed May 17, 2014.
  2. cris: $ 8.7 billion In: Süddeutsche Zeitung. Munich, August 24, 2011, p. 16.
  3. James Webb saved for the time being . Deutschlandfunk. April 27, 2012. Retrieved September 28, 2012.
  4. a b Cosmic Background Explorer (COBE) Team Wins Gruber Prize Research News, Berkeley Lab, August 15, 2006. Accessed May 17, 2014.

Web links

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