P. O. Box 953, Topanga CA 90290 david(*)alumni.caltech.edu
Field Guide to the San Andreas Fault
What is the San Andreas Fault? Where is it? How can I see? What does it do to the landscape? Will an earthquake make California fall into the ocean? What risks does it pose? Should I worry about it? What towns lie on the fault? When is the "big one" coming? These any many other questions about the infamous San Andreas Fault will be discussed in an all color presentation. Topics covered include plate tectonics, continental drift, fault activity, the origin of volcanos, the geologic future of California and much more. Click here to see the book on which this presentation is based: Field Guide to the San Andreas Fault
Click here to see the book on which this presentation is based: Color and Light in Nature
Intelligent Life in the Universe
Are we alone?
Is there life in space? Where would we find it? Would we recognize it if we came across it? What have studies of our own solar system told us about life? Does all life have to depend on carbon? Has the Earth been visited? How would we communicate with an alien civilization? Is life common in the Universe or are we alone? What are we doing now to find life in space? These and many other aspects of the latest thinking about life in the Universe will be discussed. I will not discuss UFOs, alien abductions, time-travel, or warp-drives unless provoked!
Asteroid Impacts on Earth
What are the chances and what could we do about it?
Asteroids and meteoroids strike the Earth everyday but most are too small to survive passage through the atmosphere. Only those larger than a few tens of meters across can reach the ground and these are rare. The last one was in 1908 near Tunguska, Russia when an asteroid or comet nucleus caused a10 megaton airburst that flattened trees in an area larger than Washington D.C. About 60 million years ago an object estimated to be 6 miles across struck the Yucatan area of Mexico near Chicxulub. The billion megaton explosion created a 110 mile wide crater and is thought to have been the cause of the Cretaceous-Tertiary Mass Extinction that killed most higher life forms including the dinosaurs. What are the chances of getting hit by a civilization-disrupting asteroid? How much warning time would there be? What is the status of our asteroid surveys? Who is in charge of protecting the Earth from asteroids? Come to the talk and find out.
Tides: Pulse of the Planet
More than just water going up and down
What are tides and why do we have them? What does the Moon have to do with it? Do other planets have tides? How do tides affect life on Earth? Why do some places have two high tides each day, and other have only one? Where are the largest tides in the world? The smallest? Do lakes have tides? What do Saturn's Rings have to do with tides? What do tidal forces do in other places in the Universe? If we dropped Britney Spears into a Black Hole, what would happen? These and many other aspects of tides in the Universe will be discussed.