Originated the 7-day week and the roots of the 24-hour day and 60 minute hour
Summerians
Perpetuated the calendar choices of the Sumerians, developed algebra
Babylonians
Used a 10-day week. Developed geometry
Egyptians
Atomic Theory and the Vacuum
Democritus and Leucipus
Separated science and philosophy
The Pythagoreans
Suggested the Earth rotated on its axis, and possibly was not the center of the universe
The Pythagoreans
One of the Athenian Philosophers
Socretes
deepest thinker of the Athenian philosophers. founded the first "University" - Empirical Philosophy
Plato
Founded the current scientific disciplines - founded his own university. big contributions in biology. Argued the Earth was a sphere. Argued against a heliocentric theory because of the lack of an observable stellar parallax. Also an Athenian Philosopher
Aristotle
A contemporary of Plato and Aristotle. Early developments of Mechanics in physics
Eudoxus
First serious proponent of the Heliocentric theory
Aristarchus
The greatest observational astronomer in antiquity. Developed the Stellar Magnitude scale. Produced a star catalog. Measured the distances to the sun and moon. discovered the 26000 year precession of the Earth's axis of rotation. Argued against the helioc
Hipparchus
Passed down to us much of what we know about the earlier contributions. Set down the principals of celestial navigation and Astrology
Ptolemy
Re-introduced the Heliocentric theory. Described the Solar System with the correct Sidereal periods
Copernicus
Compiled large volumes of observational data
Tycho
Used Tycho's data to discern his 3 laws of planetary motion.
Kepler
The father of modern science. Used telescope to discover the 4 brightest moons of Jupiter, the crescent phases of Venus, stars too dim to be seen with the naked eye
Galileo
Discovered the Law of Inertia and introduced the scientific method
Galileo
The father of modern physics
Newton
Three laws of motion:
*The law of inertia (An object in motion...)
*F = ma
*Conservation of Momentum - mv (Action - Reaction)
Newton
The Law of Universal Gravitation - F = G m1m2/r^2
Newton
General form of Kepler's 3rd law (M1 + M2)p^2 = a^3
Newton
The reflecting telescope and the spectrum of light
Newton
Electric charges (q/r^2) and changing magnetic fields (delta B / delta t)
Electric Field Sources
Causes a force in the direction of the field on all charges
Electric Field Effects
Moving charges (Right-Hand-Rule) and changing electric fields
Magnetic Field Sources
Causes a force on moving charges (qvB) perpendicular to the field and the direction of motion of the charge (Right-Hand-Rule)
Magnetic Field Effects
Light is composed of
Electromagnetic Waves
Accelerating charges create
Electromagnetic Waves
nucleus with negatively charged electrons orbiting around them
atoms
positively charged protons and neutral neutrons
Nuclei
number of protons
atomic number
determines the chemical element properties
atomic number
total number of neutrons and protons
atomic weight
number of neutrons determins the
isotope
when atoms gain or lose electrons
ions
same number of electrons as protons
neutral atoms
losing electrons
ionized
when electrons drop from a higher level to a vacancy in a lower level they emit
photons
quanta of light. they have momentum and energy given by their frequency times Planck's Constant. they also behave like waves
photons
Spectra - when all wavelengths are present
continuous
when hot solid objects or high pressure gasses radiate
Black Body Radiation
Spectra - when light is present at all wavelengths EXCEPT at certain wavelengths
absorption
when light passes through a diffuse gas and certain wavelengths are absorbed out of the light that continues on
absorption
when light is present ONLY at certain wavelengths
emission
when light passes through a diffuse gas and is absorbed, raising electrons to higher levels, when those electrons drop back down they emit light
emission
due to fundamental quantum effects
natural width
due to doppler shift from the motion of the emitting molecules at any temperature above absolute zero
thermal broadening
due to frequent collisions of the emitting atoms in a high pressure gas
collisional broadening
due to the splitting of levels in strong magnetic fields
zeeman effect
due to emission from a rapidly rotating star where the doppler shifts mix from emissions on different sides of the star
rotational broadening
the positioins of the lines are a characteristic function of the individual emitting elements. this allow identification of the relative composition of the source
spectral line positions
these characteristic positions are shifted by the doppler effect when the entire source is moving with respect to the observers on the earth
spectral line positions
a difference of 5 magnitudes means a factor of in brightness
100, (2.5)^difference in magnitude
the smaller the algebraic value of the magnitude the the source
brighter
magnitudes are the magnitude a star would have if it were at a distance of 10 parasecs
absolute
magnitude is the magnitude that an object appears to have
apparent
if you know both the apparent and absolute magnitudes, you can calculate the
distance
the relative brightness of stars is a function of
temperature, surface area and distance
the surface brightness varies as T^4
temperature
the total luminosity is proportional to R^2
surface area
apparent brightness is proportional to 1/d^2
distance
the spectral type classification scheme is a surface classification for stars
temperature
O B A F G K M
Oh Be A Fine Girl Kiss Me
<==hot -- cold==>
within each letter class there are sub-classes numbered 0-9 from
hotter to cooler
from kepler's and newton's laws, the masses of each star in a binary system can be determined
(M1+M2)p^2 = (r1+r2)^3 and M1/M2 = r2/r1
need to determine p, r1 and r2 to find M1 and M2
not a true binary but an optical double
optical
a true binary where both stars are clearly seen
visual
only one star is seen, but moves in an oscillatory way
astrometric
when viewed edge on-the spectral lines are alternately doppler shifted as the stars orbit one another
spectroscopic
the light shows two incompatible spectra
spectrum
the intensity of the light dims as the stars eclipse. these are usually also spectroscopic binaries as well
eclipsing
the bayer catalog divided the sky into constellations and named the stars with respect to the constellation they are in
88
named by constellation but with latin letters starting with R-Z, RR-ZZ, AA-QQ
Science Vocab 147928
