Atoms and Stars, Fall 2002 (Bowen)
Information sheet for Final Exam
- SPEED OF LIGHT.
- Roemer 1676 and eclipses of Io (moon of Jupiter) 16 min leads
to 186,000 mi/sec with today's radius of earth's orbit
- ASTRONOMY.
- Ptolemy c. 140 AD Geocentric, planets on spheres
- Nicholas Copernicus (1473 - 1543) Heliocentric, simpler arrangement of
spheres. Possible Arabic influence. Conflict with Catholic church primarily
after his death.
- Tycho Brahe (1546 - 1601) Danish nobleman, decades of accurate astronomical
data, relationship with Kepler.
- Johannes Kepler (1571 - 1630) 3 laws (ellipse, equal areas, r2
proportional to t3) based on Brahe's data for Mars. Tortuous path to
discoveries, many false starts, changes of direction. Poor health, few friends,
hard on himself.
- Galileo (1564 - 1642) Telescope, moons of Jupiter, sunspots, horns of Venus:
basis for arguing for Copernican universe. Pope = Simplicius? Experiments done
later to confirm hypotheses. Inclined planes, law of odd numbers, inertia, speed
of fall independent of mass. Trial and conviction (Bellarmine), house arrest,
still new work - strength of beams, publishing work with inclined planes.
Movement of science to France (René Descartes) and England (Francis
Bacon).
-
Isaac Newton (1642-1727) Principia Mathematica Philosphia Naturalis.
Three laws of motion: body at rest tends to stay at rest, F = ma, action and
reaction. Gravitation F = Gm1m2/r2. Calculus (Leibnitz
controversy) and geometry to show Kepler's three laws followed. Same law worked
for moon's orbit and force of gravity on earth. Clockwork universe (not accepted
today because of Quantum Mechanics and Heisenberg Uncertainty Principle).
Gravitation action at a distance, contradicted Descarte mechanical universe but
today most forces due to exchange of particles.
- Motivated to show God working in world (natural explanations for mechanics and astronomy were not yet
extensive enough to support a 100% natural approach to the world?)
- Einstein 1904 - 1910 Special and General Relativity. Special is constant
speed of light, General is gravity comes from bending of space-time, bending of
light.
- AU Astronomical Unit radius earth orbit 93 M mi, light year distance light
travels one year
- Stars, planets ("wanderers"), galaxies (spiral, elliptical,
irregular), super galaxies (groups of , nebula (clouds), comets (orbits),
asteroids (one pass-by).
- Big Bang about 15 BYA further away = faster receding, get speed from
relativistic shift in atomic spectra, age from distance / speed, also microwave
background is cooled light, can see light warms up coming through nebula so
comes from far away. Age of earth from radioactive dating
- CHEMISTRY.
- Four Aristotle elements: air, earth, fire, water. C, H, N, O
elements (cannot be broken down but not the case in 20th century), CO2,
CO, H2O, NO2 molecules (atoms combine - Dalton) Vs mixture
in any ratio without forming molecules (cinnamon-sugar, dough)
- Stephen Hale, 1727 many different types of "air"
- Antoine Lavoisier (1743 - 1794) different types of "air",
electrolysis of water, H and O. Modern terms (oxygen, air, hydrogen etc),
burning is combination with oxygen. Importance of gases.
- John Dalton (1766 - 1844) and Atomic Theory of Matter (misread Principia?)
Law of Definite Proportions. Air empty space with a few atoms, equal volumes
equal numbers, gas weight is relative atom/molecule weight.
- Ludwig Boltzmann (1844 - 1906) applied Atomic Theory to gas of Newtonian
atoms, invented Statistical Mechanics (with J. Willard Gibbs), explains Second
Law of Thermodynamics - "energy runs downhill."
- EXPANDING CIRCLES COLLIDING
-
1865 James Clerk Maxwell electricity and magnetism combine to explain light as
e-m radiation. Also Boltzmann and Newton (uniting terrestrial and celestial).
- Kansas School Board - 1999 removed Evolution, Geologic Time Scale (5
BY), Big Bang and Continental Drift from state requirements, became "local
choice" (no other areas treated this way). 2001, action reversed by
newly elected members.
- Archimedes. Screw pump, weight less by amount of displaced water, work on
lever, screw, block and tackle, war machines