Ast Nov 2007 HOW DID THE PLANETS FORM ? ( Before about 1700 this would have been an idle question – not enough was known about physics and chemistry.)
Ast Nov 2007 FACTS TO EXPLAIN -- Nearly circular orbits, same plane -- Move in same direction -- Spacing of the orbits, distr. of mass -- Most planets rotate same direction -- Terrestrial vs. gas-giant planets -- Gas-giants have moons -- Asteroid belt -- etc.
Ast Nov 2007 NEWTONIAN ORBITS, 1700: “Calculate backward in time” ???
Ast Nov 2007 GEORGES-LOUIS LECLERC DE BUFFON, 1707— Naturalist -- Precursor to evolution theory -- Non-biblical history of Earth (Earth 75,000 years old?) Movie trivia: Jefferson in Paris (1995) Brotherhood of the Wolf (2001)
Ast Nov 2007 Comte de Buffon’s theory (c. 1770): tidal forces
Ast Nov 2007 IMMANUEL KANT 1724—1804 German (Prussian) philosopher
Ast Nov 2007 PIERRE SIMON DE LAPLACE 1749— Famous mathematician and physicist -- Mechanique Celeste -- Theory of probability -- Minister of the Interior (but later turned against Napoleon) -- etc.
Ast Nov 2007 LAPLACE 1796: Exposition du System du Monde ( a book for ordinary people! )
Ast Nov 2007 “NEBULAE”: mysterious glowing clouds in space
Ast Nov 2007 KANT AND LAPLACE SUGGESTED THAT NEBULAE WERE PLANETARY SYSTEMS BEING FORMED: “THE NEBULAR HYPOTHESIS”
Ast Nov 2007
Buffon proposed a “catastrophic” theory; but The nebular hypothesis was an “evolutionary” theory. ( explain )
Ast Nov 2007 Buffon proposed a “catastrophic” theory; The nebular hypothesis was an “evolutionary” theory. The practical difference is enormous.
Ast Nov 2007
AGE OF THE EARTH (AND THE SOLAR SYSTEM)
Ast Nov 2007 AGE OF THE EARTH (AND THE SOLAR SYSTEM) c. 1750, The Bible: maybe 6000 years (depending on who was interpreting it)
Ast Nov 2007 AGE OF THE EARTH (AND THE SOLAR SYSTEM) c. 1750, The Bible: maybe 6000 years (depending on who was interpreting it) 1770, Buffon, cooling of the Earth: 75,000 years
Ast Nov 2007 AGE OF THE EARTH (AND THE SOLAR SYSTEM) c. 1750, The Bible: maybe 6000 years (depending on who was interpreting it) 1770, Buffon, cooling of the Earth: 75,000 years 1850, fossils: millions of years?
Ast Nov 2007 AGE OF THE EARTH (AND THE SOLAR SYSTEM) c. 1750, The Bible: maybe 6000 years (depending on who was interpreting it) 1770, Buffon, cooling of the Earth: 75,000 years 1850, fossils: millions of years? 1880, salt in ocean: even older?
Ast Nov 2007 AGE OF THE EARTH (AND THE SOLAR SYSTEM) c. 1750, The Bible: maybe 6000 years (depending on who was interpreting it) 1770, Buffon, cooling of the Earth: 75,000 years 1850, fossils: millions of years? 1880, salt in ocean: even older? 1890, Kelvin, cooling of both the Earth and the Sun: 30—100 million years
Ast Nov 2007 AGE OF THE EARTH (AND THE SOLAR SYSTEM) c. 1750, The Bible: maybe 6000 years (depending on who was interpreting it) 1770, Buffon, cooling of the Earth: 75,000 years 1850, fossils: millions of years? 1880, salt in ocean: even older? 1890, Kelvin, cooling of both the Earth and the Sun: 30—100 million years 1910, RADIOACTIVITY: billions of years!
Ast Nov 2007 RADIOACTIVE DATING OF METEORITES: THE SOLAR SYSTEM IS 4.6 – 4.7 BILLION YEARS OLD. ( 4.65 x 10 9 = 4,650,000,000 years )
Ast Nov 2007
EARLY ATMOSPHERE DIDN’T HAVE MUCH O 2.
Ast Nov 2007
NEXT: THINGS THAT GO BOOMP IN THE NIGHT COSMIC IMPACTS
Ast Nov 2007 IMPACT CRATERS ON THE MOON, MARS, MERCURY
Ast Nov 2007
... AND SMALLER METEOROIDS, OF COURSE. ( ALL SIZES )
Ast Nov 2007 FLASHES SEEN ON MOON! (?)
Ast Nov 2007
NE Arizona, 50,000 years old
Ast Nov 2007 Australia, 300,000 years old
Ast Nov 2007 Northern Quebec, 1 million years
Ast Nov 2007 Northern Canada, 200 million years old
Ast Nov 2007
GEOLOGISTS’ K-T BOUNDARY, 65 MILLION YEARS AGO (“CRETACEOUS – TERTIARY”)
Ast Nov 2007 GEOLOGISTS’ K-T BOUNDARY, 65 MILLION YEARS AGO (“CRETACEOUS – TERTIARY”) DINOSAURS R.I.P.
Ast Nov 2007
IRIDIUM-RICH LAYER IN ROCKS
Ast Nov 2007 SO WHAT? WHY IS IRIDIUM IMPORTANT? ( explain )
Ast Nov 2007 THE CHICXULUB EVENT, 65 MILLION YEARS AGO
Ast Nov 2007 EFFECTS OF A BIG IMPACT -- BLAST WAVE IN THE AIR -- SEISMIC (earthquake)
Ast Nov 2007 EFFECTS OF A BIG IMPACT -- SEISMIC (earthquake) -- TSUNAMI (see picture)
Ast Nov 2007
EFFECTS OF A BIG IMPACT -- SEISMIC (earthquake) -- TSUNAMI (see picture) -- PLANETARY CONFLAGRATION
Ast Nov 2007 EFFECTS OF A BIG IMPACT -- SEISMIC (earthquake) -- TSUNAMI (see picture) -- PLANETARY CONFLAGRATION -- LONG LONG WINTER
Ast Nov 2007 EFFECTS OF A BIG IMPACT -- SEISMIC (earthquake) -- TSUNAMI (see picture) -- PLANETARY CONFLAGRATION -- LONG LONG WINTER ---- ALTOGETHER, BIBLICAL IN SCOPE. ----
Ast Nov 2007 ASTEROIDS
Ast Nov 2007 COMET NUCLEUS
Ast Nov 2007 MENTION HOW TO ESTIMATE FREQUENCY OF EVENTS
Ast Nov 2007
SIBERIA 1908: THE TUNGUSKA EVENT PHOTO TAKEN 20 YEARS LATER
Ast Nov 2007 Vela satellite Sept. 1979: a mystery
Ast Nov 2007