Exam Review Points
1) Descartes developed the Cartesian Coordinate system
2) Descartes believed in a Geometric universe, developed model for nature of motion
and matter. Set up solar system model as swirling vortices. As well as believe in
empty space theory
3) Newton studied 3 diff areas Light, Gravity and Force and develops Calculus.
4) Newton publishes his major work ‘Principia’ in 1687
5) Newton invents type of telescope called Newtonian Reflector ( mirrors instead of
lens)
6) Newton discovers colour is basic property of light and is a particle( Particle vs. Wave)
7) Hooke Suggests an inverse square law. Edmund Halley convinces Newton to publish
and basic laws called ‘Newtonian Mechanics’ in 1678 ‘Philosophaie Naturalis
Principia Mathermatica’.
8) Newton puts together theory of how motion and forces and gravity works in his 3
famous laws of physics and law for gravity.
9) Newton defines concepts as Mass, Momentum(motion), diff types of forces, Time
and Space
10)Newton’s 3 laws1) All objects in motion remain in motion ( Inertial Law) 2) Force is
proportional to mass and acceleration of an object (F=ma) 3) Force of a exerts on B,
equal & opposite of the force of B exerts n A ( Reaction Law)
11)Newton law for gravity is from Kepler’s work. Explains tides, orbits of Jupiter &
Saturn, oblateness of Earth.
12)Halley proposed using transits of Venus or Mercury to find size of solar system
13)In 1761 & 1769 this method used to measure parallax value of 1 A.U = 153 mil km
14)Halley also published first maps of wind patterns over oceans, mortality tables
15)Halley uses Newton’s law to predict the elliptical orbit of the comet ‘Halley’s Comet’
in 1682, 1531, 1607 and Dec 1658.
16)Hippachus techq in finding Longitude involved looking at eclipses of the moon.
17)Galileo discovers moons of Jupiter and uses he eclipses & positions of the moons to
tell time and Longitude. 18)John Flamsteed first royal observer at Greenwich measured positions of over 3000
stars. His catalogue published called ‘Historia Coelestis Britannica’ in 1725.
19)Two Methods used ; Lunar Distance ( Moon as a clock) and Mechanical Device
( Heavenly bodies observation)
Expanding Universe
1) Galileo observes behaviour of Saturn turns out to change shape. Later explained by
Christian Huygens as Rings of Saturn
2) Christian Huygens also discovers Saturn’s Largest Moon Titan.
3) Christian Huygens & bother grinding lenses building telescopes 45ft, 60ft and 120ft.
4) Cassini first to observe ‘gaps’ in Saturn’s rings. Now called the ‘Cassini gap’
5) Cassini & Christian observed Comets especially Halley’s Comet returns every 76 years.
6) Comet Hunters Charles Messier and Caroline Herschel. Messier complied first catalogue
of non-Stella objects ( M Catalogue) not stars or comets
7) Bode’s Law created to explain spacing of planets in 1778.
8) William Herschel accidentally discovers Uranus.
9) Bode’s Law suggests a missing planet between orbits of Mars and Jupiter.
10)In 1801 Piazza stumbled across object called Ceres. As the missing planet.
11)Herschel observes the same objects and conclude to be too small and not planets.
12)Bode’s Law leads to discovery of Asteroid Belt.
13)Newton’s Law used to analyze motions of Mercury, outer giants and Uranus’ orbit.
14)Distortions found later caused by general Relavistic effects – By Einstein.
15)John C. Adam and LeVerrier later calculated predicted path of object and in 1846
Neptune was located.
16)Percival Lowell Built himself an Observatory in Arizona. Improve quality of Observation
and High elevation and clear skies.
17)Lowell was interested in Mars after looking at Schiaparelli maps that described ‘canali’
(channels)
18) The canals on Mars turned out to be optical illusions. Lowell’s publication on Life on
Mars. Also e speculated existence of Planet X (the ninth planet). 19)In 1930 Clyde Tombaugh Discovered using Lowell’s calculations discovers Pluto (later
excludes Pluto as a planet).
20)Basic Req for Planet classification: Orbits Sun, Has sufficient Mass and Spherical in
shape & has cleared its planetary orbit.
21)In 18 Cent Chladni Suggests Meteors associated with asteroids. In 1803 Biot works out
trajectories of meteor shower and proves they are elliptical.
22)Edward Howard chemically analyzes a meteorite. Finds Basic categories of composition
( Iron, Stony-Iron or stony) also contained Nickel
23)In 1832 Comet Temple Tuttle passed Earth (33 years orbit). The Leonid Meteor shower
peaked next year 1833 (33 yr as well). Meteor showers caused by comets.
Nature of Stars
1) Newton realizes colour is fundamental property of light & cannot be changed.
2) Modern Scientific Journal the Royal Society Earliest. Astronomical Journal (ApJ) in
1849.
3) 19 Cent Prisms used to examine sunlight more closely. 1802 Wollaston Discovers
Dark Lines (7) Boundaries of Newton’s Colours of Spectrum.
4) Joseph Frauntrascope develops first simple Spectrascope to take spectra of the Sun
(Found not 7 but hundreds of thin dark lines)
5) John Herschel in 1827 discovers diff types of metals burn diff colours. Colour of
flame tells you what is burning and how hot it is.
6) Bunsen & Kirchoff – light passed through diff mediums resulting light on the other
side is changed.
7) All Matter is made of Atoms. Hydrogen (one proton and one electron) Simplest Atom.
8) Absorption and Emission in Atoms (hydrogen) Energy and colour Related. Shorter
wavelength of light HIGHER the energy.
9) Absorption: Incoming photon of wavelength & energy hits an electron within an atom
(jumped orbitals)
10)Emission: Electron falls from higher orbital to lower orbital releases energy.
11) Cascade Down: electron absorbed jump down several steps. 12)Spectroscopy: Study of EM Radiation (matter emits & absorbs radiation) Spectral
Analysis: Chemical substances (patterns of spectral lines) Spectroscope: Instrument
in spectral collect and analyze.
13)3 Types of Spectra: 1) Continuous 2) Absorption 3) mission.
14)Elements in Sun: 36 diff elements identified in solar spectra. One strong line was
Helium.
15)Absorption &Emission Lines: Same wavelength.
16)Overall properties of Continuum tell us the temperature of stars
17)Classifying Stars by Father Angelo Secchi on basis of spectral qualities. Proposed 4
diff types 1) The Sirius like white-blue 2) Solar type 3) Red (variable) 4) Red Stars.
Based on colour & patterns of bands in spectra
18)19 Cent Photography Invented. Able to collect light and compare visually.
19)In 1872 Henry Draper collects spectra of stars. Extends classification system to
types A – N.
20)Annie Jump Cannon responsible organizing Drapers types into O, B, A, F, G, K, M.
Based on temp of stars. O hottest M coolest.
21)Hetzsprung & Henry Russell Compare absolute magnitude (luminosity) of stars to
spectral type.
22)Stellar Evolution stars change overtime. Newton Believed stars as motionless &
unchanging which was proven wrong.
23)Herschel & son John catalogued over 5000 non-Stella objects by their appearance.
(Invented classification system based on appearance, rather than physical
properties.
24)Herschel found out that stars embedded in gaseous clouds.
25)Herschel Theory was: Stars
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