The next installment in the popular astronomy talks series Dr. Knop Talks Astronomy is on Saturday, and you’re invited! Here are the details:

Talk Title: Neptune and Vulcan: Dark Matter in the Solar System

Date: Saturday, April 18, 2009

Time: 10:00 AM Pacific Time (SL Time)

Location: The large amphitheater on the sim named StellaNova SLURL: http://slurl.com/secondlife/StellaNova/213/210/32/

Abstract: The cosmological Dark Matter is one example of a more general thing that we might call “dark matter” with lowercase letters— that is, something that has not been observed directly, but whose existence we infer because of its gravitational effects. In the 19th century, there was dark matter in the Solar System: Uranus was showing deviations in its orbit that could not be explained by the action of the Sun and the other known planets. That led to the discovery of Neptune. Similarly, deviations in the orbit of Mercury led to the postulated planet Vulcan inside Mercury’s orbit. However, it turned out that Vulcan didn’t exist at all, and that the answer to the question of Mercury’s orbit was a modification of our theory of gravity.

This science talk is intended for the general public. All are welcome. It’s part of a series of popular talks called Dr. Knop Talks Astronomy. Dr. Knop was on one of the teams that discovered the accelerating expansion of the universe. Feel free to ask questions or make comments. Produced in association with the Meta Institute for Computational Astrophysics (MICA).

For more information, see http://mica-vw.org/

Link on the Official SL Events calendar: https://secure-web2.secondlife.com/events/event.php?id=2595217&date=1240038000