Lecture 1 Flashcards
Darwinian definition of life
A system capable of evolution by natural selection
3 lines of evidence indicating bio life should be common in the universe:
1) Organic mols common beyond earth
2) Life originated quickly (e.g. on earth)
3) Life has high degree of adaptability despite earth’s changing conditions
Primitive vs Modern Astronomy
Primitive: Empirical observations explained by making up stuff
Modern: Uses natural laws to find explanations
Democritus vs Aristotle
Democritus: Atoms made up 4 main elements (water, earth, fire, air). Same processes that created out world could have created others.
Aristotle: 4 elements only on earth and 5th (quintessence) in heaven. Earth is unique.
Epicurus
Metrodorus
Titus Lucretius Carus
Epicurus: Infinite worlds both like and unlike Earth
Metrodorus: Unnatural to have infinite universe but only one living world
Titus: Nothing in universe is unique and alone so other Earths must have different men and beasts
Thomas Aquinas
Christian theology; God could create many worlds but obviously created just one
Giordano Bruno
Jailed and burned at stake for claiming many suns exist and many earths revolve around them like the planets in our solar system
Karl Gauss
Joseph von Littrow
William Whewell
Gauss: Suggests planting trees in right triangle to demonstrate pythagorean theorem to aliens
Littrow: Suggests lighting fires in kerosene-filled trenched to communicate
Whewell: Against aliens because
outer planets - Water gases and vapour
inner planets - Very hot water
moon - Lacked water and atmosphere
Secchi
Schiaparelli
Percival Lowell
Secchi: Sees channels on Mars
Schiaparelli: Seasonal variation on channels
Lowell: Suggests “channels” (canals) are large-scale engineering structures
Nikola Tesla
Guido Marconi
Tesla: Sends out radio noise to space, listens for reply
Marconi: Listens for radio signals from Mars on a boat in remote oceanic location
Fred Hoyle and Chandra Wickramsinghe
Argues that life (including viruses) fall to Earth from space
Geocentric models of:
Anaximander
Pythagoras and Aristotle
Anaximander: Celestial sphere with Earth at centre
Pythagoras/Aristotle: Developed geocentric model later adopted by Ptolemy
Solar vs Lunar eclipses
Solar: Useful for knowing angle of orbit
Lunar: Useful for knowing size of Earth (thru shadow of earth on moon)
Scientific method
Make observations Ask question Suggest hypothesis Make prediction Perform test
Model
Theory
Law
Model: System of hypotheses. Makes specific, testable predictions.
Theory: System of models known to work.
Law: Theory that explains many experiments.
