September 29, 2010
Click! The Universe
Margaret J. Geller
Senior Scientist Smithsonian Astrophysical Laboratory
Click! The Universe
Margaret J. Geller
Senior Scientist Smithsonian Astrophysical Laboratory
Minutes of the Third Meeting of the 69th Year
President Bob Varrin called the third meeting of the 69th year to order at 10:15. The invocation was led by Tom Fulmer; minutes of the last meeting were read by Lee Neuwirth. Our guests were Hella McVay, introduced by Scott McVay, and David and Pamela Henson, introduced by John Frederick. Approximately 110 members were in attendance.
Our speaker was Margaret Geller, Senior Scientist at the Smithsonian Astrophysical Laboratory in Cambridge, Massachusetts. Dr. Geller received her Ph.D. from Princeton in 1975. Over the past 35 years, she has accumulated a distinguished record of publications, presentations, demonstrations, and awards, including the MacArthur “genius” grant.
Dr. Geller’s topic was, “Click, the Universe” – how astronomers take photographs of the universe. When we take a photograph using our own camera, it creates an image that is virtually simultaneous with the object in our photo. When astronomers photograph the universe, they are recording particles of light that have travelled for millions of years before ending up in our telescope.
Dr. Geller works primarily in the MMT observatory jointly operated by the Smithsonian Laboratory and the University of Arizona. The site is south of Tucson, where the skies are relatively free of distracting ambient light. The Observatory’s buildings are designed to move to avoid distortion of the telescope observations. Several years ago, a car that parked too close to one of these mobile buildings was nudged into a ravine, leaving the driver to explain that damage to his car resulted from an attack by a restless building.
The principal camera used at the Observatory cost some three million dollars, and weighs 3.000 pounds. It is bolted on to the back of the telescope. The actual operation of the telescope is done by highly skilled technicians, who wouldn’t consider letting an astronomer touch it.
Dr. Geller showed beautiful photographs of some distant galaxies with billions of stars that are millions of light years away. To obtain the beautiful color images, numerous photographs are snapped, using various color filters. The colors enable us to interpret the images, by indicating the heat and age of the stars. So it is possible to determine the history of a galaxy, including super-heated stars that explode spectacularly.
Several galaxies have populations of “old stars” that date from the early years of the universe. Current theory describes a universe emerging from a “hot big bang.” This theory holds that the early universe was very hot and dense, but is now cooling and more dispersed. The Hubble telescope, which reaches to the limits of the universe, gives us observations of the universe as it was a billion years ago. Currently, we estimate the age of the universe at 13.7 billion years.
A number of questions followed Dr. Geller’s remarks:
Q. Do we know if heavy elements are present in these distant galaxies?
A. We don’t know; we must have a spectrum to ascertain heavy elements. We’re working on it.
Q. If the universe is 13.7 billion years old, what came before the universe? Are there perhaps multiple universes?
A. Science requires testable hypotheses. We cannot learn, scientifically, what preceded the universe. There are theories about the existence of other universes, but we haven’t the means to test those theories.
Dr. Geller concluded by saying,” Even in our lifetime, we have learned a great deal about our universe – and there’s so much more to learn.”
Respectfully submitted,
James Deneen
Our speaker was Margaret Geller, Senior Scientist at the Smithsonian Astrophysical Laboratory in Cambridge, Massachusetts. Dr. Geller received her Ph.D. from Princeton in 1975. Over the past 35 years, she has accumulated a distinguished record of publications, presentations, demonstrations, and awards, including the MacArthur “genius” grant.
Dr. Geller’s topic was, “Click, the Universe” – how astronomers take photographs of the universe. When we take a photograph using our own camera, it creates an image that is virtually simultaneous with the object in our photo. When astronomers photograph the universe, they are recording particles of light that have travelled for millions of years before ending up in our telescope.
Dr. Geller works primarily in the MMT observatory jointly operated by the Smithsonian Laboratory and the University of Arizona. The site is south of Tucson, where the skies are relatively free of distracting ambient light. The Observatory’s buildings are designed to move to avoid distortion of the telescope observations. Several years ago, a car that parked too close to one of these mobile buildings was nudged into a ravine, leaving the driver to explain that damage to his car resulted from an attack by a restless building.
The principal camera used at the Observatory cost some three million dollars, and weighs 3.000 pounds. It is bolted on to the back of the telescope. The actual operation of the telescope is done by highly skilled technicians, who wouldn’t consider letting an astronomer touch it.
Dr. Geller showed beautiful photographs of some distant galaxies with billions of stars that are millions of light years away. To obtain the beautiful color images, numerous photographs are snapped, using various color filters. The colors enable us to interpret the images, by indicating the heat and age of the stars. So it is possible to determine the history of a galaxy, including super-heated stars that explode spectacularly.
Several galaxies have populations of “old stars” that date from the early years of the universe. Current theory describes a universe emerging from a “hot big bang.” This theory holds that the early universe was very hot and dense, but is now cooling and more dispersed. The Hubble telescope, which reaches to the limits of the universe, gives us observations of the universe as it was a billion years ago. Currently, we estimate the age of the universe at 13.7 billion years.
A number of questions followed Dr. Geller’s remarks:
Q. Do we know if heavy elements are present in these distant galaxies?
A. We don’t know; we must have a spectrum to ascertain heavy elements. We’re working on it.
Q. If the universe is 13.7 billion years old, what came before the universe? Are there perhaps multiple universes?
A. Science requires testable hypotheses. We cannot learn, scientifically, what preceded the universe. There are theories about the existence of other universes, but we haven’t the means to test those theories.
Dr. Geller concluded by saying,” Even in our lifetime, we have learned a great deal about our universe – and there’s so much more to learn.”
Respectfully submitted,
James Deneen