history of astronomy
atom facts
- usually same number of electrons as protons - + and + repel - -and - repel - + and - attract - H= one proton HE= two proton ... # of protons defines types of atom
what theory did Einstein publish in 1905? 1915? What distinguishes these theories
-1905: Special Relativity: what happens when there is a constant movement linking the event and the observer. -1915: General Relativity: brings in gravity and what happens as the speed of any movement increases or decreases. -both deal with how an observer and an event are related.
what process forms new elements
-H atoms in space were pulled together by gravity until the pressure becomes so great that it fuses atoms together to form He ... nuclear reactions -larger than iron = supernovas
what is Charles Messier known for
-around 1770 he began to map out the fuzzy patches, trying to establish a pattern of the universe. -mapped 110 objects
Hubble
-had doppler shift, telescope, and cepheid stars as tools HE OBSERVED -all distant galaxies are moving away from us: older and farther galaxies were moving faster: universe was expanding, there was a beginning point
what ideas did Newton have for the universe
-his telescope showed stars moved and gravity was a force between all objects - nothing was at rest -no limits to the universe, infinite in both space and time -helped with the church because of the idea of infinite and eternal
what evidence do we have that the universe is expanding
-light was red-shifted, Doppler Effect.
Copernicus
-lived in the 16th century -heliocentric model: sun centered -circular orbits -not taken seriously by the church -knew he could only improve Ptolemaic system with flawed alternative
Ptolemy
-lived in the 2nd century -geocentric model: earth centered -circular orbits with epicycles: going around earth and itself -foundation on which our future understanding of the universe was built on
once the core of a star is mostly iron, what happens
-smaller stars: starts to die, elements go into space as the star cools leaving behind a hot iron core (white dwarf star). which cools into a brown dwarf that no longer emits light -large stars: crush the iron core until it implodes causing a dramatic explosion. may form dense neutron stars or pulsars.
orbit
-the path of an object as it revolves around another object in space -continuous state of free-fall ex: cannon shot perfectly
who watched over scientists in the past... who watches over scientists today...
...church ...other scientists
why does the moon follow us... why does it look so big... why does it look "on fire"
...distance ...on horizon, compares it to other things ...GBIV is filtered through atmosphere
1. Doppler Shift occurs when there is motion between the observer and the source 2. Doppler Shift occurs in both sound and light waves 3. if an object is moving toward an observer the frequencies are shifted to lower freq 4. the larger the speed between source and observer the larger the shift 5. if a star is moving away it is red shifted
1. T 2. T 3. F 4. T 5. T
what are the two death blows to the Ptolemaic model
1. jupiter had moons: heavenly bodies clearly orbits something other than the moons 2. there were shadows seen on venus: clear that they were the result of venus orbiting the sun
main functions of a telescope
1. magnify (eyepiece) 2. funnel light (bigger the better)
know!!
1.) astronomers put spectrometers (like our diffraction gradings) on telescopes and found what stars of made of 2.) our sun (special to us because of proximity) is like many others: lots of hydrogen, helium, and some other elements 3.) UV = strong/highest frequencies
what is the doppler shift?
19th century -shift to higher frequency when moving toward -blue shift - colors shift towards blue (moving towards) ROYGBIV -shift to lower frequency when moving away -red shift - colors shift towards red (moving away) ROYGBIV
Gaileo saw what moons
4 moons orbiting jupiter (Io, Europa, Ganymede and Callisto) (same as we see today)
what is the title of the best seller stephen hawking wrote
A Brief History of Time
Kepler "tweaked" ...
Copernicus's circular orbits to elliptical
who wrote stephen hawking's universe
David Filkin
"cosmological constant"
Einstein's fudge factor to show that general relativity doesn't slow expanding universe ... biggest blunder of his life
Newton's Law of Universal Gravitation
Fg = G (m1m2)/r²
KISS
Keep It Simple Stupid -beautiful in simplicity (Copernicus model had more beauty than Ptolemy)
this type of star... revolutionized the way astronomers measured distances
Leavitt found Cepheid stars - every kind had same brightness - used parallax (used to determine distance to nearby stars: thumb with switching eyes)
the Greeks observed what five wandering stars
Mercury, Venus, Mars, Jupiter, Saturn (same as we see today)
can white light be separated and if so what colors
ROYGBIV.... every color in between!
Tycho Brahe
an extremely careful observer *(great data taker)* who had all the instruments to help him map the sky and planets very precisely; his data helped Kepler *(thinker)* discover that planets must have elliptical orbits around the sun
satellites on earth
artificial: 2218 natural: 1 (moon)
Copernicus v Ptolemy
competing models
Hoyle
developed stellar nucleosynthesis, said stars create hydrogen, helium, +more, up through iron
what did stephen hawking have to do with the book
he was a scientific adviser and inspiration
what does newton's law of universal gravitation represent
how to calculate the size of gravity, NOT how it works
what is the problem with Newton's universe
if gravity was acting on everything why do the stars stay apart? wouldn't everything be pulled into one spot?
where do all of the elements form
in stars: need immense heat and pressure
what happened in 1840 that changed the universe
it was finally confirmed that there were individual stars within galaxies and other galaxies
Did Galileo invent the telescope
no
are advances in science always connected to advances in technology
no; sometimes it is, but not always (ex. Copernicus and Ptolemy model)
what is a wandering star
planets
type of telescope that can be big
reflecting
type of telescope that can't be big
refracting
why can we see only one side of the moon
rotates 1, spins 1
definition of science
science cannot promise eternal truths; only the elimination of false hypothesis and the establishment of what is currently the most likely explanation of an aspect of reality
what are the three pieces of evidence that proved the Earth was not flat
stick and shadows experiment, boats and the horizon lines, eclipses
Galileo used what tool to prove the Heliocentric theory to be correct
telescope
science is not
the truth
general relativity
the warping of space, time, +more
steady state universe
universe is infinite and unchanging -pretty much everyone believed this (including Einstein)
scientific models
use to communicate and predict
retrograde motion
when a planet doubles back on itself
