The bounds of space and time are not what they once seemed, thanks to more than 150 AAAP-sponsored lectures over the past two decades. We’ve had the privilege to meet, marvel, and question some of the leading scientists in the field. The brief summaries below show the evolution of the science and the club’s interests over this period. The full synopses will be published in Sidereal Times issues later this year.    – Rex Parker

Sept 13, 1994. “The Big Bang and the Beginning of Time” – Dr. Edward Whitten, Inst for Advanced Study. (also addressed AAAP 10 yrs later, Sept 14, 2004.) Resolved the oldest paradox in astronomy, Olber’s Paradox, which describes how the sky is dark at night, but if our position in the universe is not “special” then the sky would be filled with stars and equally bright in all directions…

Sept 12, 1995. “An Ultraviolet Window to the Galaxy” – Dr. Edward Jenkins, Princeton Univ Astrophysics. If stars were the size of sand grains, each would be ~30 miles apart distributed randomly in a vacuum. Take half as much mass as the sand, vaporize it, and distribute it evenly: this is the interstellar gas…

Dec 12, 1995. “Earth Impacting Comets and Asteroids” – Freeman Dyson, Inst for Advanced Study. (Freeman also spoke at the Nov 11, 2002 and the Oct 11, 2001 AAAP meetings.) Strategies to detect and deflect asteroids and comets approaching earth with potential doom are not science fiction…

Sept 9, 1997. “A Planetarium for the Next Millennium” – Dr. Neil DeGrasse Tyson, Director, Hay-den Planetarium, AMNH, NYC. This was one of the last public talks by Dr. Tyson before the advent of the new Hayden/ Rose Center at AMNH, which itself is 130 years old and has housed some incredible Zeiss projectors…

Oct 14, 1997. “COBE and the Big Questions in Cosmology” – Dr. Max Tegmark, Inst for Advanced Study. His studies were predecessors to the Microwave Anisotropy Probe, MAP, championed by David Wilkinson and David Spergel (later called WMAP in honor of Dr Wilkinson) launched in Aug 2000. He convinced the audience that we are in the golden age of cosmology.

Jan 13, 1998. “Red-Shifted Galaxies (before SDSS)” – Dr. Michael Strauss, Princeton Astrophysics. There are ~34,000 galaxies of mag ≥15.5. But galaxies do not contain enough matter to account for their observed motion over billions of years, leading to the idea of dark matter. This was a driving question for SDSS…

Mar 3, 1998. “The Enigmatic Neutrino” – Dr. John Bahcall, Inst. for Advanced Study. He did more for neutrino research than perhaps anyone. In a breakthrough experiment, Davis and Bahcall used a 400,000 gal tank of tetrachloroethylene 1km underground in an old gold mine in the Dakota Badlands to capture solar neutrinos…

May 11, 1999. “The Hubble Deep Field” – Dr. David Hogg, Inst. for Advanced Study. The original Deep Field image covers ~1 arc-min X 1 arc-min and goes to 29th mag., with ~700 galaxies visible. This calculates to ~100B galaxies in the universe (at 100B stars/galaxy, this means ~1e22 stars in universe). May 2013 Sidereal Times Amateur Astronomers Association of Princeton

Oct. 12, 1999. “Refractor Design: the 4th Condition” – Dr. John Church, AAAP. Snell’s law defines index of refraction and leads to the lens-makers formula, the basis of centuries of attempts to perfect celestial images. John described the AAAP’s 1880 Hastings 6.25″ refractor; for more, see John’s articles in Sky & Telescope and…

Dec. 14, 1999. “Is the Solar System Stable” – Dr. Scott Tremaine, Princeton Univ. Astrophysics. (Dr. Tremaine spoke again to AAAP on Sep 11, 2007 om “Galactic Dynamics”.) Why are there 9 (8) planets in our system? Why are the gaps between them so clean? Dr. Tremaine described Lyapunov time – the time for small changes in a dynamical system to become chaotic – using the famous double pendu-lum demonstration…

Mar. 14, 2000. “Sloan Digital Sky Survey” – Dr. Michael Strauss, Princeton Univ. Astrophysics. The innovative SDSS studies rely on the innovative Sloan telescope located at Apache Point Observatory at 9000 ft elevation in southern New Mexico. The 2.5-meter telescope uses the drift scan technique and employs 30 (2048X2048) CCDs giving a wide 2.5 field with 5 band-pass filters…

May 11, 2000. “Pulsars: Testing Ground for Einstein’s Theory of Relativity” – Dr. David Nice, Princeton Univ. Physics Dept. (Dr. Nice was a former student of Nobel Laureate Joseph Taylor. He also spoke at the Oct 8, 2002 AAAP meeting.) Dr. Nice described his work on pulsars with radio tele-scopes using the Green Bank…

Oct. 10, 2000. “The Search for New Variable Stars” – Bodhan Paczynski, Inst. for Advanced Study. (Dr. Paczynski also spoke at the Oct 14, 2003 AAAP meeting.) The distribution of variable stars is being studied in the all-sky automated survey (ASAS) using arrays of 4″ lenses to observe optical counterparts to γ-ray bursts…

Jan. 9, 2001. “Optical SETI Project” – Dr. Ed Groth, Princeton Univ. Physics Dept. Working with Drs. David Wilkinson of Princeton and Paul Horowitz of Harvard, Dr. Groth has been developing the ideas and techniques for OSETI, the optical counterpart to radio SETI. The latter searches for narrow band emissions at the 21 cm neutral hydrogen line, which led Frank Drake in the 1960’s to develop…

Apr. 9, 2002. “Large Synoptic Survey Telescope” – Tony Tyson, Bell Labs. Leading the science and technical development of this unique telescope is Dr. Tyson, who discussed the early phase plans of the LSST. It will have the widest field of any large telescope (>7 sq deg) with very high speed data…

Jan. 13, 2004. “Brown Dwarves” – Dr. Gillian Knapp, Princeton Univ. Physics Dept. The sequence OBAFGKM describes star color (blue-white to red); L& T have now been added to represent brown dwarf classes, on the lower right corner of the H-T diagram. What to make of large objects cooler than M type stars…

Dec 12, 2004. “The CCD Astronomy Revolution” – Michael Carr, Princeton Univ. Astrophysics. The creator of “4-shooter”, Michael Carr has been James Gunn’s “right hand” through the years. The original “4-shooter, the first CCD camera on the Palomar Hale 200 inch telescope, now sits in the Smith-sonian…

Jan. 11, 2005. “The Search for Earth-Like Planets” – Robert Vanderbei, Princeton Univ. Over 120 extrasolar planets have been detected, most by spectral Doppler. Bob described the Terrestrial Planet Finder, whose ultimate goal is very challenging: to directly image exoplanets, preferably earth-like plan-ets, by their reflected light which is ~10-10 as bright as the star, 25 magnitudes difference! Moreover, the separation… May 2013 Sidereal Times Amateur Astronomers Association of Princeton

Jan 9, 2007. “Cosmology over the Past 50 Years” – Dr. James Gunn, Princeton Univ Astrophysics. A chief problem in this field of science is that the basic tenet of the scientific method – repeatability of observation – is not possible. 50 yrs ago we thought it was only matter (atoms), that it was expanding…

Apr 10, 2007. “The Atacama Cosmology Telescope” – Dr. David Spergel, Princeton Univ Astrophys-ics (chair). Dr Spergel talked about how telescopes drive advances in cosmology. The Atacama site is at 5200 m elevation in northern Chile. It uses an unusual, 6 meter off-axis Gregorian design segmented mirror and camera, built in the Princeton Physics Dept, using superconducting transition-edge sensors, a new approach…

Sep 11, 2007. “Galactic Dynamics and Massive Black Holes” – Dr. Scott Tremaine, Princeton Univ Astrophysics (former chair). About 1% of galaxies contain active nuclei, emitting non-stellar radiation. These include Seyfert galaxies, radio galaxies, Quasars and quasi-stellar objects (QSOs). QSOs and quasars are the most luminous with 100-100X typical galaxy luminosity, found at Z =2-3. Their power source is matter falling…

Jan 8, 2008. Voyage to the Int’l. Space Station” – Dr. Greg Olsen, GHO Ventures, Princeton. As 3rd ever civilian passenger aboard the Russian Soyuz craft to the ISS, launched from Kazakhstan with cosmonaut Sergei Krikolov, Dr Olsen’s description of this amazing adventure made each of us want to put up a cool $20M…

May 102, 2010. “Terrestrial Planet Finder” – Dr. Jeremy Kasdin, Princeton Univ Astrophysics. Direct imaging has been the “holy grail” of methods for extrasolar planets and only recently has been successful, where photons reflected directly from the planet are imaged. This has driven attempts to identify the “habitable zone”…