Astronomy Essential Cosmic perpective quiz chapter 5 Flashcards
What does light from the sun do?
warms the earth, drives the wind and rain, and powers photosynthesis in plants and so the food the chain
What can light from distant objects tell us?
their composition temperature, speed and other things
how do we experience light?
by asorbing it in our eyes to see and in our skin as heat , radient energy A kind of KE
What do humans use up to as?
100-w light bulb
What was galileo able to measure?
the speed of sound but was unable to measure the speed if light, because the speed of light was about million times faster
what was Roemer successful at? and what was he able to realize?
measuring the speed of light. and he was able to realize the reason for the 16 minute transit delays when jupiter was at conjuction was because it took 16 minutes for the light to traverse the earths orbit
What did maxwell derive?
4 equations relating electricity and magnetism that theroretically joined them.. His theory predicted the spped of EM waves produced by accelerating charges. The speed came out as the speed of light
what was maxwells theory arent? prediction?
Maxwell predicted em waves of frequencies beyond visible light confirmed when hertz found radio waves and roentgun discovered x rays
True statment
The visible part of of the spectrum /rainbow from lowest to ighest requency: red, orang, yellow, blue, green, violet
what is the EM spectrum from lowest to highest?
Radio, microwave IR visible UV xrays Gamma rays
Less radiation and frequencies arent
typically harmful to us , but those of higher frequencies are
What are the four properties of waves
wavelength (distance from peak to peak) frequency (how frequently they pass by amplitude (how strong) and speed (how fast through the median
what is light , sound and water?
light is transverse wace the variation is transverse to the wave direction . sound is a longitude wave (the variation is froward and back water waves are surface waves, transverse and longitudinal combined (a kind of circlar motion
because light is tranverse what does it produce?
polarization
what is the equation for waves?
transverse or longitude v=Kf
true statement
as A goes up then f goes down. long A means low frequency. To change v requires that you change the medium
what are the different frequencies we perceive?
sound/light as differing pitch/color. We perceive differing amplitudes of sound /light as differing loudness/brightness
what are sound, water and wire waves known as?
Mechanical waves since their waving is due to disturbing the medium. Em waves arent mechanical waves, but they are transverse since the electric field varies in a direction perpendicular to the velocity direction
what is the four wave phenonmena light exibits?
reflection, refraction, diffraction, and interference , so light is a wave
what is reflection, reffraction, diffraction, and interference?
reflection is the bending of waves (such as through glass of water) diffraction is the spreading out of wavess (such as at small openings) and interference is the adding of waves at the same point ( such as water waves from dropped stones in a pond)
what is constructive interference and destructive?
is where the peaks of two waves add to make a more pronounced wave. Destructive interference is where the peak meets through and the waves cancel
what does adding more sound do to wave? what does reducing noise to a machine operator do?
adding more sound can make things quieter. You can reduce the noise a machine operator hears by adding the same engine noise inverted.
what did newton explain?
light by treating it as a particle, but thomas young, showed that light is a wave because it produced the multiple peaked 2 slit interference pattern
what does light exihibit?
Light exhibits other phenomena implying that its a particle called a photon. Since light also exhibits the phenomena of waves, light is a wave particle thing A “wavicle”
What other phenomena does light exhibit?
photoelectric effect, uv tanning low light photography and the plank energy distribution curve for glowing hot bodies.
what is the photelectric effect?
If you shine frequency low intensity light (dim blue light) on a piece of metal then electrons are produced right away. if you shine low frequency high intensity light (bright red light) then no electrons are produced.
what happens if light were acting like a wave?
then you would expect electrons to be produced for any color light and after a ling time after they finally absorb enough energy ( say its a blue photon) then it knocks an electron out right away. So light is a particle.
what does Low uv intensity light cause?
tanning, but intense visible light does not. So light is a particle
what happens if light were a wave?
then low light photographs should show the whole image but dimly. what actually appears are bright dots randomly scattered around. So , light is a particle.
true statement about the color distrubution
to describe the color distribution of light coming from hot dense gases, treating light as a wave didnt work. So planck treated light as a particle, but thought it was just a trick.
what happens when the wave and particle aspects of light are joined?
The energy of one particle of light E=hf (where h is planck constant , is proportional to the frequency (f of its wave.
what are the 4 ways that light and matter interact?
emission(light bulb) absorbtion, (black wall) transmission(window) and reflection/scattering mirrors and normal walls
what do transparent objects and opaque lights do?
transparent objects transmit the light and opaque objects absorb the lights
what does red glass do and green lawn?
red glass transmits red light while absorbing other colors while a green lawn scatters green, absorbing the others,
what do we see with color?
the true color of a non glowing object is the color we see when white light is shining on it.
What about white and black colors?
White and black colors are considered although white is what we see there is lots of red, blue, and green while black is what we see when there’s little if any light
what do we read better?
we read better black letters on a white background than reversed although black is the lack of light
what do atoms and neuteal neutons have?
an atom has positive charged protons and neutral neutrons in the nucleus and negative charged electrons outside the nucleus.
what are protons and neutrons composed of?
quarks
how much massive are protons than neutrons and are they the same mass charge?
protons are 2000x massive and have the same mass charge.
what are the chemical elements?
H, He, C, O Si, Fe, Au, Ag, Pb and u
what are the protons that are distinguished?
each element is distinguished by the number of protons in the nucleus. H and 1 proton , He has 1 proton 2, c 6 & O 8 protons
what are the numbers for H and He in atomic numbers?
H has atomic number 1 and He has atomic atomic 2
what does normal He have?
2 neutrons in addition to the 2 protons so has an atomic mass number of 4: he 4
What are the elements of differing number on neutrons called?
isotopes
what are the three isotopes of carbon called? and what do they have?
c-12, c-13, and c-14. c-, 12 has 6 p and 6 n , c-13 has 6p and 7 n while c-14 has 6p and 8n
atoms where electrons don’t balance protons are called?
ions
read equation about protons and neutrons
0 with 8 neutrons is neutral, with 9 is 0>-1 with 7 is 0>+1
what can atoms and molecules do?
atoms can join to make compounds (chemically bonded different atoms) and molecules (covenantly bonded)
what is atomospheric o2 and salt
a molecule, but not a compound. Table salt NacI is a compound but not a molecule (its ironically bonded. h20 is both a compound and molecule
what are the four phases of matter?
solid, liquid, gas and plasma
what are stars made up of? and what is its state?
stars are made up of plasma, and plasma is the most common state of matter
evaporation is going from?
liquid to gas, what happens more often on moons and comits is sublimation:solid to gas.
what is pressure?
pressure is force/area. a 200 lb force with two 20 square inch hands produces a pressure of 200/40=5lbs/in>2 or 5 psi. suing just one hand (same force then pressure in psi 1o.
what is the atmospheric pressure? and what is the weight?
14.7 psi. the weight of air in 1 square inch to the top of the atmosphere is 14.7 lbs
what is the inner core of the earth like?
the inner core of the earth is hotter than the outer liquid core, but due to the much greater pressure its solid
what will standing water do?
standing water will evaporate away even if below boiling temperature because some of the water will be going fast enough
what do atoms have?
mass energy by E=mc2 KE by virtue of their motion, and potential energy by virtue of their arrangement
what do electons in an atom have?
electrons in an atom have only certain allowed energy levels quanitzed like you can only step on certain heights of a ladder
an electron volt is an energy of?
1.6x10>-19J
a h election on level ( the ground state) can absorb a photon of?
10.2 ev or 12.1 or 12.8 but nothing in between
a h electron on level 2 drops to level 1 by emitting?
10.2 Ev
A light coming from an object tells us about that object?
for example we can distinguish a lemon from a lime by its color
what example can we take from spreading light out by its colors?
If we see the spectral lines of hydrogen in a spectrum then we we conclude hydrogen is present
What example can we take for when molecules and Ions produce different spectral lines than their neural atoms?
atomic oxygen o produces different spectral lines than molecular 02 orionized oxygen o+
What happens within a spectrum?
within a spectrum one might find bright lines corresponding to extra energy or dark lines corresponding to losses of energy
spectroscopy
is the process of obtaining a spectrum the and reading
the information it contains
A spectrum of mars should contain?
two broad lumps, one corresponding to the reflected visible sunlight and the other corresponding to the planetss emmited thermal energy
Small peaks in the UV could correspond?
to hot gas in the upper martian atmosphere and small dips in the near IR could correspond to the presence of carbon dioxcide
There are three basic kinds of Spectra?
continuous (smooth, all colors, what comes from a hot dense gas) emission (discrete bright lines from a hot, low density gas,) and absorption (discrete dark lines from a realitivly cool, low density gas
Typically a ______ from a consists of all three
Spectrum
____/____ lines result from _____/_____ transitions of electrons on low density gases where the particles are essentially independent from eachother
Emission/Absortion and downward / upward
The continuous spectrum results from the jumbled result of _______; solids, _____,____
dense materials/ liquids or dense gases
A _______ is an idealized _____ that is a perfect _____: it absorbs all the _____ incident upon it, reflecting none. The object then radiates the energy in characteristic ______ _____
Blackbody-object-absorber-radiation-planck curve
No real ______ is a perfect______ but approx so.
object—–blackbody
As you ____ something up then it gets ______ and _____. For example as a ____dies down then it gets gradually ______as its color shifts from say yellow to orange or red.
- heat
- brighter
- bluer
- fire
- dimmer
_________ law : _____, the hotter the brighter
- F=T>4
if the _____ is two three ten times as hot in _____ then it will ___ 16/81/ 10,000 times as much ______
- blackbody
- kelvins
- emit
- energy
____ law : max =contant /T the ______ the _____ As the _____ in kelvins goes up then the ______ of maximum ____ gets ______ (to bluer color
- Wiens law
- hotter
- bluer
- temperature
- wavelength
- emission
- shorter
A blue white star peaks in the Uv and is hotter than than the sun while a reddish star peaks in the _____ and is cooler than the sun
- IR
The ______ _______ in ____ results in a trains pitch being ____ as it approaches and ___ as it recedes 1
- the doppler affect
- sound
- higher
- lower
The ______ ______ results from the bunching together of the ______when the source is ________ and the _________out of the _____ when the source is receding.
- doppler affect
- wavecrests
- approaching
- spreading
- wavecrests
______ light sources are said to be ______ shifted while ____ light sources are red shifted.
- approaching
- blue
- receding
The ________ only tells us how ____an object is moving towards or away but it doesnt indicate how fast its ______ cross ways.
- doppler shift
- fast
- moving
to detrimine the ______velocity you need to know how much its ____ in _____ and how ____ away it is
- transvere
- moving
- angle
- far
to determine the ________ of a star you need the _____ to get the radical velocity and the _____ and _________ to get the tansverse velocity.
- total velocity
- doppler data
- distance
- angular motion
If as star is spinning then part of the star is moving ______ us (blueshifted) and part is moving _____ from us (redshifted) which causes the spectral line to ______
- toward
- away
- broaden
if there are two stars co-orbiting to close to seperate in the _______then one can often see ___ of ________ in the spectrum that shift back and forth periodically.
- spectogragh
- pairs
- spectral lines
if one of the two objects is much bigger than the other ( such as a ____ or _____ then you’lll only see one _____ shifting back and forth. This is how _____ have been discovered orbiting other stars.
- star or sun
- spectal line
- planets
