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ASTR/GEOL 3300: ET Life

ASTR/GEOL 3300: ET Life. Logistics: Final exam is Monday December 13! Bring your notes, books, etc. 1:30 – 4:00 pm here. Final papers due to me electronically AT THE FINAL EXAM before 5pm ! Our Last Day IS THIS FRIDAY: Pick up old work & paper reviews!!!!!!

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ASTR/GEOL 3300: ET Life

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  1. ASTR/GEOL 3300: ET Life • Logistics: • Final exam is Monday December 13! Bring your notes, books, etc. • 1:30 – 4:00 pm here. • Final papers due to me electronically AT THE FINAL EXAMbefore 5pm! • Our Last Day IS THIS FRIDAY: • Pick up old work & paper reviews!!!!!! • We will finish our discussion of interstellar travel. • Then, Fermi’s Paradox • Implications of the Search • UFOs

  2. Pick up more reviews please Brandt, Grudzinski, Gray, Okonowsky, Townsend, Trohman, Ely, Uhle, Collette, Kaspyrzk, Rynning, McCollom, McNeill, Watson, Hazlitt, Fairbanks, Hecht, Lewis, Melville

  3. Matter/Antimatter • Isp ~105 - 107 • Might work at ~100% efficiency, mass required is reasonable • No real designs, many enormous hurdles (containment, production, radiation, efficiency) • 100 billion dollars for 1 mg!

  4. RECALL • This is for a 1000 year, one-way voyage to the nearest star. • Are there ways to do this without carrying the propellant with you? • Space is not quite empty

  5. Relativity and other weirdness • No matter who you are or where you are, how fast you’re moving and in what direction, the speed of light in vacuum always appears the same to you. • Whoa, but this has been verified many times • You can’t go more than 3 x 108 m/s • The faster you move, the slower time passes • The faster you move, the more massive you get

  6. 4 ly 10 ly 50 ly 150 ly 20,000 ly 2,000,000 ly 106 ly Perceived travel times To where? How long (to traveler) ? How far? • Alpha Centauri • Epsilon Eridani • Deneb • Pleides • Center of Milky Way • Andromeda galaxy • Virgo cluster • 2.5 y • 5 y • 10 y • 15 y • 21 y • 28 y • 30 y

  7. The Scientific Method (Chapter 2) • Science seeks natural explanations for observed phenomena: • Explanations rely solely on natural causes. • "Miracles" are not allowed. • Science advances by developing and testing hypotheses (models). • A scientific model must make testable predictions. • If tests show that the predictions are false, the model must be revised or abandoned. • Occam's Razor: • The simplest scientific model that fits all the observations is most likely the right one.

  8. Incorrect Scientific Practice • Pseudoscience ("false science"): • Masquerades as science, but does not follow the scientific method. • Commonly based on adherent belief. • Cannot be shown to be false to the satisfaction of practitioners. • Unfortunately, there are many, many, many examples.... "Extraordinary claims require extraordinary evidence." - Carl Sagan

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