Traveling Talks

• Splendors of the Universe: Eighty slides of the universe, starting with the sun and the planets, then moving to star-forming regions within our Galaxy, to galaxies outside of the Milky Way (our Galaxy), and finally to clusters of galaxies. Sixty of the slides are the most beautiful, correct-color photographs of astronomical objects that have ever been taken. All of these pictures are presented with relevant explanations as to their meaning and significance, with questions solicited from the audience as the talk progresses.
• Creation of the Elements: an explanation of how nucleosynthesis in stars created the elements in the universe out of hydrogen and helium which were created during the big bang. The iron in your blood was created in a supernova explosion.
• The Whisper of Creation: how the initial explosion creating the universe can be listened to in microwave frequencies. This program is suitable for all school age groups and has been delivered in Vacation Bible School as well as other school groups. The level can be adjusted for the audience.
• Spectra of Stars, Analysis of Starlight: how the spectra and the color of stars reveal their properties. We shall look at the discrete emission spectra of hydrogen, helium, and neon gas discharge tubes by using hand-held diffraction gratings. We shall discuss the elemental composition of the universe, learn why hot stars are bluer and cool stars redder, and look at the absorption spectra of stars to determine their properties.
• Astrolabe Past, Present, and Future: An astrolabe was the most important astronomical instrument before the telescope was invented, and the most important astronomical calculator before the digital computer was invented. Geoffrey Chaucer of Canterbury Tales fame wrote the earliest work of science education in 1387, The Treatise of the Astrolabe, for his 10-year-old son Lewis. A Star Finder/plainsphere is a partially functioning astrolabe. A real astrolabe does what a plainsphere does and much more. Is it history or science?   Astrolabes.org a URL that I own and is rated by Britannica.com as the best source of information on Astrolabes on the web.
• Is Most of the Universe Missing? What evidence do astronomers have that 90% of the universe is dark? This traveling talk requires that the audience be familiar with physics and algebra at the high school level. This is an ideal talk for high school physics classes after they have learned about circular motion with a radial acceleration of a = v^2/R and understand Newton's law of universal gravitation F=GMm/R^2. This is the only traveling talk that requires the audience to understand equations.
• Light Pollution: How Seeing the Stars Will Save You Money: We can not see the Milky Way from the Washington Metro area anymore, but this spectacle could return. In fact, it can be done in such a way as to save millions of dollars-for towns, county, and state government-while putting more light on the ground where we humans need to see at night and in the spectral band (color) at which humans have our peak visual acuity. IDA, International Dark Sky Association.
• Solar Eclipses Solar Eclipse in general and the eclipse of 11 July 1991 and the eclipse of  26 February 1998 in particular are the subject of this talk and slide presentation.
• Chesapeake Bay Crater 35.5 ± 0.6 million years ago, when Washington, DC and Richmond VA were on the coast, an object hit the earth on the continental shelf in the Atlantic ocean, N 37° 17'  W 76° 1', causing a crater 85 km in diameter.  After sea level fell, this crater would help form the Chesapeake Bay.  The impact site is now called the lower Chesapeake Bay in Virginia.  The Chesapeake Bay Bolide: Modern consequences of an Ancient Cataclysm.
• Ancient Sky Watchers of  Guatemala, Mexico, Belize, El Salvador, and Honduras, the Maya.  The Maya had a better solar year determination (tracking of the winter solstice) than the Europeans did in 1582AD before 900AD, how did they do this?

Send e-mail to Harold Williams at Harold.Williams@montgomerycollege.edu
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web page by Dr. Harold Williams last modified 10:56PM September 26, 2005.