The 2,341st Meeting of the Society

January 23, 2015 at 8:00 PM

Powell Auditorium at the Cosmos Club

Presidents' Lecture

Grasping the Universe

Telescopes to See Almost Forever

John C. Mather

Senior Astrophysicist, NASA
Senior Project Scientist, James Webb Space Telescope
Co-recipient of the Nobel Prize in Physics 2006

Sponsored by Millen, White, Zelano & Branigan, PC

About the Lecture

Where did we come from, who are we, and where are we going? Astronomers worldwide are building and planning new telescopes to see farther and better than ever before. Already under construction are the Square Kilometer Array in South Africa and Australia, the ALMA in the Chilean high desert, the Large Synoptic Survey Telescope, the Thirty Meter Telescope, the Giant Segmented Magellan Telescope, the European Extremely Large Telescope, and the James Webb Space Telescope (JWST).

But even these instruments will not be able to observe many features of the cosmos, so astronomers and cosmologists already are thinking about the next generations of space telescope, such as the Advanced Technology Large Aperture Space Telescope, the even more powerful Life Finder Telescope, and future X-ray and gravitational wave observatories. All of these marvels are propelled by technological advances as well as by the thrill of possible discovery, and none of them are the end of the line either.

I will illustrate what these great telescopes do, talk about the new inventions at their hearts, and outline what it takes to conceive a new observatory like the JWST and take it to completion. I will talk about the open questions of astronomy, why they are still open, and what we are doing to answer them. I will speculate a little on how far astronomy can take us, about progress with robots and artificial intelligence, and about our ultimate future as the galaxies collide and stars burn out.

About the Speaker

JOHN MATHER is Senior Astrophysicist in the Observational Cosmology Laboratory at NASA’s Goddard Space Flight Center and Senior Project Scientist for the James Webb Space Telescope. His research centers on infrared astronomy, cosmology and the origins of the universe.

He earned a BS in Physics from Swarthmore College and a PhD in Physics from UC-Berkeley. He was an NRC Postdoctoral Fellow at the Goddard Institute for Space Studies, where he led development of the proposal for the Cosmic Background Explorer (COBE). He joined NASA’s Goddard Space Flight Center to serve as Study Scientist, then Project Scientist and finally Principal Investigator for COBE’s Far Infrared Absolute Spectrophotometer (FIRAS). Using data from FIRAS John showed with unprecedented resolution that the cosmic microwave background radiation has a blackbody spectrum within 50 parts per million, confirming the predictions of the Big Bang theory to extraordinary accuracy.

John received the 2006 Nobel Prize in Physics together with George Smoot for the COBE work on the cosmic background radiation. He is also the recipient of many other prizes and awards, including the Gruber Foundation Prize in Cosmology and the Franklin Prize in Physics of the Franklin Institute. He is a member of the National Academy of Sciences and of the American Academy of Arts and Sciences, as well as a fellow of many other learned societies. He is an author on numerous scientific publications and of “First Light” an account of the COBE project.

John works tirelessly for science education and for bringing science to life for the public, especially the young.

Minutes

President Larry Millstein called the 2341st meeting of the Society to order on January 23, 2015 at 8:04 pm. He announced the order of business, noted the deaths of long-time members John Wood and Robert Fristrom, announced new members, and reported the results of the General Committee election. The previous meeting's minutes were read and approved. The President presented a summary of the 16th meeting of the Society on December 2, 1871, noting that papers on the existence of the aether and Encke's Comet had been presented. President Millstein then introduced the speaker for the evening, John Mather, the co-recipient of the 2006 Noble Prize in Physics. His lecture was entitled, "Grasping the Universe: Telescopes to See Almost Forever."

Dr. Mather introduced his lecture by noting that his interest in telescopes began as a child, and he said he is still thinking about how to make bigger and better ones. The first part of his lecture was, accordingly, a summary of the history of telescope design and astronomy in general, beginning with Leonardo's and Galileo's work on telescope design and Galileo's lunar sketches. He discussed the work of Hale, Goddard, Lemaître, and Jansky, who built a radio antenna and detected signals from the center of the Milky Way in 1928. Dr. Mather remarked that we keep making equipment and discovering what we did not expect; equipment made the discoveries possible.

Other discoveries continued: Edwin Hubble showing that the universe is expanding; Alpher and Herman predicting the cosmic background radiation and its temperature; the Lovell Radio Telescope detecting quasars and verifying gravitational lensing. And then NASA was founded in 1958, with Dr. Mather specifically noting that the constituting legislation included public outreach in NASA's mission. The moon program was launched in 1962 with NASA's James Webb planning the missions and budget.

Additional discoveries followed: Penzias and Wilson discovering the cosmic background radiation in 1964; the Ryle Telescope cataloging quasars; the 300-foot Green Bank Telescope detecting pulsars with millisecond periods, and recently the 1000-foot Arecibo Telescope, mapping the Venusian surface and observing pulsar exoplanets, Mercury, and the lakes on Titan.

From 1984 to 1994, the Cosmic Background Explorer (COBE) measured the cosmic background radiation. It was a beautiful fit to the blackbody spectrum curve. The radiation, though, is not perfectly uniform, as it has hot and cold spots, that differ by 30 microKelvins. Hawking called this the greatest discovery in the history of science because it "proved" the expanding theory of the universe. (Dr. Mather was the co-recipient of the Nobel Prize in 2006 for this work on the cosmic background radiation.) Subsequently, the Wilkinson Microwave Anisotropy Probe produced an even higher-resolution map. Dr. Mather noted that all of this has been possible because of equipment and that the engineers deserve much of the credit.

In the next part of his lecture, Dr. Mather discussed the work of existing and to-be-built large telescopes and the future ahead. He discussed ALMA (the Atacama Large Millimeter Array) which recently took a picture of a solar system, 450 light-years away, in the early stages of its formation. The Square Kilometer Array is in construction in South Africa and Australia. There are also the Twin Keck telescopes in Hawaii and the four "Very Large Telescopes" in Chile, all in the eight to ten meter range. Larger telescopes of 25 meters and more are also under construction.

Dr. Mather then discussed the Hubble Space Telescope, which will celebrate its 25th anniversary this year, and showed images illustrating its important discoveries. Hubble's successor, the James Webb Space Telescope, is planned to be launched in 2018. Dr. Mather showed a video of the complicated engineering marvel that is the JWST.

Dr. Mather then talked about the future. Dark energy and other ideas like it will most probably be addressed by using computer simulations. Scientists cannot build equipment to observe such things, but instead will use tools to imagine it, benefiting from ever-expanding computing power.

Dr. Mather then overviewed techniques, technologies, and ideas still in the development and trial stages. For example, to detect exoplanets, he presented ideas such as focusing with diffraction gratings, the "Starshade" proposal, and the proposed New Worlds Telescope. Dr. Mather closed his lecture by noting that human space travel is a problem, as humans are fragile; but robots are getting smarter and tougher. Longer-range travel with humans will, in his opinion, not be easy.

After the question and answer period, President Millstein thanked the speaker, made the usual housekeeping announcements, and invited guests to join the Society. At 10:01 p.m., President Millstein adjourned the 2341st meeting of the Society to the social hour.

Attendance: 175
The weather: Rainy
The temperature: 2°C
Respectfully submitted,

Zeynep Dilli
External Communications Director & Recording Secretary