How do you know the Earth Rotates? How do you measure the distances to objects in the Solar System and nearby stars? What is the Nature of Light?
|
|
- Vincent Carr
- 6 years ago
- Views:
Transcription
1 How do you know the Earth Rotates? How do you measure the distances to objects in the Solar System and nearby stars? What is the Nature of Light?
2 How do you know the Earth Rotates?
3 How do you know the Earth Rotates? In 1851, Léon Foucault proved the Earth s rotation directly. A pendulum swinging on the Earth feels the rotation due to the Coriolis Force. FC = -2 m Ω x v Versions of the Foucault Pendulum now swings in the Panthéon of Paris and the Houston Museum of Natural Science v=49jwbrxcpjc
4 How do you know the Earth Rotates?
5 What is the effect? The coriolis force is a =2v ω magnitude is a =2vω sin θ maximum particles motion is perpendicular to Earth s rotation (e.g., straight up if you re on the equator), and zero when parallel (e.g., straight up when you re at the pole) everywhere else we can take an average that sin θ 1 2 so that a cor vω
6 What is the effect? A particle feels this effect for the time it is in flight. If the particle is in flight for a time Δt, the velocity will be altered by a fractional amount v v a cor t v ω t where ω -1 = 1 day / 2π ~ 4 hrs ~ 14,000 s So, if travel time, Δt << 14,000 s, then no visible effect. Example: During WW1, Germans used a huge artillery gun to bombard Paris from a distance of 120 km. Gun had a muzzle velocity of 1.6 km/s, and shells reached an altitude of 40 km with a flight time of Δt = 170 s. The deflection is then d = 1 2 a cor( t) 2 vω( t) 2 /2 2km
7 Coriolis Force affects wind patterns Blue: flow from high to low pressure Red: Coriolis force in Northern Hemisphere
8 Coriolis Force affects wind patterns Blue: flow from high to low pressure Red: Coriolis force in Northern Hemisphere Coriolis Force affects rotation of weather patterns - you need to include the effects of atmospheric pressure. As air flows into low-pressure regions it is deflected to one side or the other (depends on the hemisphere). Cyclones rotate clockwise in southern hemisphere; hurricanes rotate counterclockwise in northern hemisphere (shown here)
9 How do you know the Earth Rotates? Hurricane Gustav Aug 31, 2008
10 How do you know the Earth Rotates? Hurricane Gustav Aug 31, 2008 Coriolis Force affects rotation of weather patterns (cyclones rotate clockwise in southern hemisphere; hurricanes rotate counter-clockwise in northern hemisphere).
11 How do you know the Earth Rotates? Hurricane Ike Sept 4, 2008
12 How do you know the Earth Rotates? Hurricane Ike before making landfall
13 In Kepler s day through the 19th century, we had only relative distances to the Sun and Planets. Estimated Mean Distances of the Planets from the Sun (in Astronomical Units) Kepler 21st Century Mercury Venus Earth Mars Jupiter Saturn
14 In Kepler s day through the 19th century, we had only relative distances to the Sun and Planets. Estimated Mean Distances of the Planets from the Sun (in Astronomical Units) Kepler 21st Century Mercury Venus Earth How would you measure the Mars absolute distance to other planets?! Jupiter Saturn
15 Parallax: same idea as triangulation, derived from Greek parallaxis, the value of an angle. Example: How far is Rudder Tower from the Albritton Bell Tower? h=138 ft θ=5 o D
16 Parallax: same idea as triangulation, derived from Greek parallaxis, the value of an angle. Example: How far is Rudder Tower from the Albritton Bell Tower? D = [ h / tan(θ) ] for h=138 ft and θ=0.5 o, D= ft h=138 ft θ=5 o D
17 Parallax: same idea as triangulation, derived from Greek parallaxis, the value of an angle. Another example: how far away is a car by its headlights? D 2θ 2w D = [ w / tan(θ) ] for w = 1 m and θ=0.5 o, D=114.6 m for w = 1 m and θ=5 o, D=11.4 m
18 Parallax: same idea as triangulation, derived from Greek parallaxis, the value of an angle. Another example: how far away is a car by its headlights? 2θ 2w D D = [ w / tan(θ) ] You subconsciously do this all the time. Your brain judges how fast an oncoming car is going by the change in its angular size. for w = 1 m and θ=0.5 o, D=114.6 m for w = 1 m and θ=5 o, D=11.4 m
19 Parallax: same idea as triangulation, derived from Greek parallaxis, the value of an angle. 2B d p d = B / tan(p)
20 First observation Parallax unmoving background stars 1 AU Position of star on first observation d = 1 AU / tan(p) 1 / p (radians) AU 57.3 / p (degrees) / p (arcsec) AU Define: 1 parsec = x 10 5 AU d = 1 / p(arcsec) pc.
21 Parallax unmoving background stars 1 AU Position of star 180 days later 180 days later d = 1 AU / tan(p) 1 / p (radians) AU 57.3 / p (degrees) / p (arcsec) AU Define: 1 parsec = x 10 5 AU d = 1 / p(arcsec) pc.
22 Cygnus Parallax Example: The distance to 61 Cygni. In 1838, after 18 months of observations, Friedrich Bessel announced a parallax angle to this star of arcseconds. This corresponds to: d = 1 / = 3.16 pc. 21st century value is 3.48 pc.
23 Estimated Mean Distances of the Planets from the Sun (in Astronomical Units) Kepler 21st Century Mercury Venus Earth Mars Jupiter Saturn
24 The Answer: with Parallax View from Pacific Ocean N Mars View from United Kingdom
25 The Answer: with Parallax View from Pacific Ocean N Mars View from United Kingdom Tried by Jean Richer in Got an answer that 1 AU = 87 million miles. (Present-day answer: 1 AU = 93 million miles.) But, Richer s data had lots of systematic errors, and no one took this seriously.
26 Venus comes much closer to the Earth than Mars. But, when Venus is at its closest approach, it s lost in the Sun s glare, so can t see background stars. But, can use the time that Venus begins transits. View from Pacific Ocean N Venus View from United Kingdom
27 Venus comes much closer to the Earth than Mars. But, when Venus is at its closest approach, it s lost in the Sun s glare, so can t see background stars. But, can use the time that Venus begins transits.
28 Venus comes much closer to the Earth than Mars. But, when Venus is at its closest approach, it s lost in the Sun s glare, so can t see background stars. But, can use the time that Venus begins transits.
29 Venus comes much closer to the Earth than Mars. But, when Venus is at its closest approach, it s lost in the Sun s glare, so can t see background stars. But, can use the time that Venus begins transits. View from Pacific Ocean N Venus I see Venus begin Transit at Time T1 View from United Kingdom
30 Venus comes much closer to the Earth than Mars. But, when Venus is at its closest approach, it s lost in the Sun s glare, so can t see background stars. But, can use the time that Venus begins transits. I see Venus begin Transit at Time T2 View from Pacific Ocean N Venus I see Venus begin Transit at Time T1 View from United Kingdom
31 Venus comes much closer to the Earth than Mars. But, when Venus is at its closest approach, it s lost in the Sun s glare, so can t see background stars. But, can use the time that Venus begins transits. I see Venus begin Transit at Time T2 View from Pacific Ocean N Venus I see Venus begin Transit at Time T1 View from United Kingdom Royal Society sponsored an exhibition in 1768 to Tahiti to measure Venus transit of the Sun. This led to a measurement of the AU within 10% of the present-day value. Subsequent observations of Mars, Venus, and asteroids confirmed and refined this measurement. Humanity now had a yardstick for the AU.
32 Parallax Cygnus Example: The distance to 61 Cygni. In 1838, after 18 months of observations, Friedrich Bessel announced a parallax angle to this star of arcseconds. This corresponds to: d = 1 / = 3.16 pc. 21st century value is 3.48 pc. 1 parsec = x 10 5 AU = 3.09 x m = 1.92 x miles =3.26 lightyears (lyr).
33 Parallax Cygnus Example: The distance to 61 Cygni. In 1838, after 18 months of observations, Friedrich Bessel announced a parallax angle to this star of arcseconds. This corresponds to: d = 1 / = 3.16 pc. 21st century value is 3.48 pc. 1 parsec = x 10 5 AU = 3.09 x m = 1.92 x miles =3.26 lightyears (lyr). Therefore, d(61 Cygni) = 10.3 lyr!
34 The Wave Nature of Light Double-Slit Experiment of Thomas Young ( )
35 Constructive Interference Destructive Interference
36
37 Light Propagation Direction Coherent Light From Single Slit Destructive Interference Barrier with Double Slits Screen Constructive Interference Intensity Distribution of Fringes
38 The Wave Nature of Light d sinθ = { nλ (n-1/2) λ (n=0,1,2,3... ), constructive interference (n=0,1,2,3... ), destructive interference Young found that blue light has λ = 400 nm = 4000 Å red light has λ = 700 nm = 7000 Å where 1 Å = m (1 Ångstrom)
39 Radiation Pressure S Like all waves, light carries both energy and momentum in the direction of propagation. The amount of energy carried is described by the Poynting vector: S = (1/μ0) E x B where S has units of W m -2 (energy per unit area). The average Poynting vector is given by the time-average E and B fields. <S> = (1 / 2μ0) E0B0 where E0 and B0 are the amplitude of the waves.
40 Radiation Pressure The Radiation Pressure depends on if the light is absorbed or reflected. Absorption, force is in direction of light s propagation: (absorption) Reflection, force is always perpendicular to surface (reflection)
41 Radiation Pressure, as a means of space travel?!! v=eq2datxcft0&feature=fvw v=wfa1ggulknk&nr=1
42 Thermal Radiation (Blackbody Radiation)
43
44 The temperature of lava can be estimated from its color, typically K.
45 Blackbody Radiation Any object with a temperature above T=0 K emits light of all wavelengths with varying degrees of efficiency. An IDEAL emitter is an object that: 1. Absorbs all light energy incident upon it and 2. Emits this energy with a characteristic spectrum of a Black Body. Stars and Planets are approximately blackbodies (as are gas clouds, and other celestial objects).
46 Thermal Radiation: Hotter objects emit more light at all frequencies. Hotter objects emit photons with higher average energy (higher frequencies).
47 Blackbody Radiation T=10,000 K T=8000 K T=5800 K T=3000 K
48 Blackbody Radiation Observed Spectra of Vega-type Star Solar-type Star T=10,000 K T=8000 K T=5800 K T=3000 K
49 Blackbody Radiation Observed Spectra of Vega-type Star Solar-type Star Here Stars Look almost exactly like blackbodies T=10,000 K T=8000 K T=5800 K T=3000 K
50 Blackbody Radiation Observed Spectra of Vega-type Star Solar-type Star Lots of absorption from atoms in the stars atmospheres (more next week) Here Stars Look almost exactly like blackbodies T=10,000 K T=8000 K T=5800 K T=3000 K
51
52 Hottest stars (blue): T=50,000 K Coldest stars (red): T=3,000 K Sun: T=5,800 K
53 During Influenza Season, many airports around the world screen for people with temperatures using Infrared cameras:
54 Thermal Radiation: Wien s Law The peak wavelength (in meters) is related to the temperature (in Kelvin) as: λ = (0.0029/T)
55 Blackbody Radiation Wilhelm Wien ( ) received the Nobel Prize for his contribution to our understanding of Blackbody Radiation. Through experimentation, Wien discovered that the peak emission of a wavelength, corresponds to a wavelength λmax which relates to the temperature as: λmax T = m K Wien s Displacement Law!
56 Blackbody Radiation Wilhelm Wien ( ) received the Nobel Prize for his contribution to our understanding of Blackbody Radiation. Through experimentation, Wien discovered that the peak emission of a wavelength, corresponds to a wavelength λmax which relates to the temperature as: λmax λmax T = m K Wien s Displacement Law!
57 Note: as T increases, the blackbody emits more radiation at all wavelengths. Blackbody Radiation Josef Stefan ( ) Ludwig Boltzmann ( ) Related the Luminosity of a Blackbody to the Surface Area of the object: L = A σ T 4 For a sphere: L = (4π R 2 ) σ T 4 Stefan-Boltzmann constant: σ = x 10-8 W m -2 K -4
58 Example: Luminosity of the Sun, L =3.839 x W Radius of the Sun, R = x 10 8 m Using: L = (4π R 2 ) σ T 4 T = L ( ) 1/4 = 5777 K 4π R 2 σ Radiant Flux (or surface flux) = L / Area = L / (4π R 2 ) for a sphere Fsurf = σ T 4 = x 10 7 W m -2 Wien s Displacement Law: λmax = ( m K) / T = x 10-7 m = nm
59 The Problem with Blackbody Radiation: Classical Physics (before 20th century) could not explain it! Lord Rayleigh ( ), born John William Strutt, 3rd Baron Rayleigh), did initial research into blackbodies. Awarded Nobel Prize in Considered a hot oven (blackbody) of of size, L, at temperature, T, which would then be filled with E/M radiation (light). E/M waves must satisfy E=0 at wave edges. Standing waves of λ = 2L, L, 2L/3, 2L/4, 2L/5,... In Classical Physics, each mode (different standing wave) should receive equal energy amount, kt, where k, is Boltzmann s constant. Rayleigh s derivation gave: E Bλ(T) 2c kt / λ 4 Bλ : Intensity (units of Energy per second per area per wavelength) c : speed of light 0 L BUT, when you integrate this over all wavelengths, it diverges to infinity, called the ultraviolet catastrophe!
60 The Problem with Blackbody Radiation: Classical Physics (before 20th century) could not explain it! 5 4 Log Intensity A more complete derivation provided by Rayleigh and James Jeans in Rayleigh-Jeans: Bλ(T) 2c kt / λ ,000 Wavelength [nm]
61 The Problem with Blackbody Radiation: Classical Physics (before 20th century) could not explain it! 5 4 Experiments showed this! Log Intensity A more complete derivation provided by Rayleigh and James Jeans in Rayleigh-Jeans: Bλ(T) 2c kt / λ ,000 Wavelength [nm]
62 The Problem with Blackbody Radiation: Classical Physics (before 20th century) could not explain it! 5 4 Experiments showed this! Wien developed this empirical relation : Bλ(T) (a / λ 5 ) e -b/λt Log Intensity A more complete derivation provided by Rayleigh and James Jeans in Rayleigh-Jeans: Bλ(T) 2c kt / λ ,000 Wavelength [nm]
63 The Problem with Blackbody Radiation: Quantum Physics solves it! Max Planck ( ), German Physicist, solved the mystery of blackbody radiation with the following radical suggestion. A standing E/M wave could not acquire just any arbitrary amount of energy. Instead, the E/M wave can only have allowed energy levels that were integer multiples of a minimum wave energy. This minimum energy, a quantum, is given by E=hν=hc / λ, where h is the Planck constant, h= x J s. This gives the formula for the intensity of blackbody radiation: Bλ(T) = 2hc 2 / λ 5 (e hc/λkt - 1) or Bν(T) = 2hν 3 / c 2 (e hν/kt - 1) This result greatly influenced the development of Quantum Mechanics.
64 The Problem with Blackbody Radiation: Quantum Physics solves it! Similarly, the specific energy density, uλ, of E/M radiation is the energy per unit volume between λ and λ+dλ. uλ dλ = (4π / c ) Bλ(T) dλ = 8πhc / λ 5 (e hc/λkt - 1) dλ Similarly, the specific energy density, uν, is the E/M energy per unit volume between ν and ν+dν. uν dν = (4π / c ) Bν(T) dν = 8πhν 3 / c 3 (e hν/kt - 1) dν
65 Blackbody Radiation T=10,000 K T=8000 K T=5800 K T=3000 K
66 Blackbody Radiation Observed Spectra of Vega-type Star Solar-type Star T=10,000 K T=8000 K T=5800 K T=3000 K
67 Blackbody Radiation Observed Spectra of Vega-type Star Solar-type Star Here Stars Look almost exactly like blackbodies T=10,000 K T=8000 K T=5800 K T=3000 K
68 Blackbody Radiation Observed Spectra of Vega-type Star Solar-type Star Lots of absorption from atoms in the stars atmospheres (more next week) Here Stars Look almost exactly like blackbodies T=10,000 K T=8000 K T=5800 K T=3000 K
69 What have we learned? The effect of the coriolis force is one way we can prove the Earth is Rotating. We measure the distances to planets and nearby stars using Parallax. Light acts like a wave which carries energy and can exert radiation pressure. At sources radiate light as blackbodies following a Planck Function, which specifies the amount of light emitted per frequency and is dependent only on the object s temperature.
Friday, September 9, How do you know the Earth Rotates?
How do you know the Earth Rotates? How do you know the Earth Rotates? How do you know the Earth Rotates? In 1851, Léon Foucault proved the Earth s rotation directly. A pendulum swinging on the Earth feels
More informationStellar Astrophysics: The Continuous Spectrum of Light
Stellar Astrophysics: The Continuous Spectrum of Light Distance Measurement of Stars Distance Sun - Earth 1.496 x 10 11 m 1 AU 1.581 x 10-5 ly Light year 9.461 x 10 15 m 6.324 x 10 4 AU 1 ly Parsec (1
More informationLight. Geometric Optics. Parallax. PHY light - J. Hedberg
Light 1. Geometric Optics 1. Parallax 2. Magnitude Scale 1. Apparent Magnitude 2. Describing Brightness 3. Absolute Magnitude 3. Light as a Wave 1. Double Slit 2. The Poynting Vector 4. Blackbody Radiation
More informationElectromagnetic Radiation.
Electromagnetic Radiation http://apod.nasa.gov/apod/astropix.html CLASSICALLY -- ELECTROMAGNETIC RADIATION Classically, an electromagnetic wave can be viewed as a self-sustaining wave of electric and magnetic
More informationTake away concepts. What is Energy? Solar Radiation Emission and Absorption. Energy: The ability to do work
Solar Radiation Emission and Absorption Take away concepts 1. 2. 3. 4. 5. 6. Conservation of energy. Black body radiation principle Emission wavelength and temperature (Wien s Law). Radiation vs. distance
More informationChemistry 795T. Lecture 7. Electromagnetic Spectrum Black body Radiation. NC State University
Chemistry 795T Lecture 7 Electromagnetic Spectrum Black body Radiation NC State University Black body Radiation An ideal emitter of radiation is called a black body. Observation: that peak of the energy
More informationChemistry 795T. Black body Radiation. The wavelength and the frequency. The electromagnetic spectrum. Lecture 7
Chemistry 795T Lecture 7 Electromagnetic Spectrum Black body Radiation NC State University Black body Radiation An ideal emitter of radiation is called a black body. Observation: that peak of the energy
More informationDetermination of Stefan-Boltzmann Constant.
Determination of Stefan-Boltzmann Constant. An object at some non-zero temperature radiates electromagnetic energy. For the perfect black body, which absorbs all light that strikes it, it radiates energy
More informationThe Death of Classical Physics. The Rise of the Photon
The Death of Classical Physics The Rise of the Photon A fundamental question: What is Light? James Clerk Maxwell 1831-1879 Electromagnetic Wave Max Planck 1858-1947 Photon Maxwell's Equations (1865) Maxwell's
More informationLIGHT. Question. Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light.
LIGHT Question Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light. What kind of information can we get from light? 1 Light
More informationLight and Matter(LC)
Light and Matter(LC) Every astronomy book that I ve seen has at least one chapter dedicated to the physics of light. Why are astronomers so interested in light? Everything* that we know about Astronomical
More informationA star is at a distance of 1.3 parsecs, what is its parallax?
Stars Spectral lines from stars Binaries and the masses of stars Classifying stars: HR diagram Luminosity, radius, and temperature Vogt-Russell theorem Main sequence Evolution on the HR diagram A star
More informationX Rays must be viewed from space used for detecting exotic objects such as neutron stars and black holes also observing the Sun.
6/25 How do we get information from the telescope? 1. Galileo drew pictures. 2. With the invention of photography, we began taking pictures of the view in the telescope. With telescopes that would rotate
More informationThe Nature of Light I: Electromagnetic Waves Spectra Kirchoff s Laws Temperature Blackbody radiation
The Nature of Light I: Electromagnetic Waves Spectra Kirchoff s Laws Temperature Blackbody radiation Electromagnetic Radiation (How we get most of our information about the cosmos) Examples of electromagnetic
More informationElectromagnetic Radiation.
Electromagnetic Radiation http://apod.nasa.gov/apod/astropix.html CLASSICALLY -- ELECTROMAGNETIC RADIATION Classically, an electromagnetic wave can be viewed as a self-sustaining wave of electric and magnetic
More informationModern Physics, summer Modern physics. Historical introduction to quantum mechanics
1 Modern physics 2 Gustav Kirchhoff (1824-1887) Surprisingly, the path to quantum mechanics begins with the work of German physicist Gustav Kirchhoff in 1859. Electron was discovered by J.J.Thomson in
More informationProperties of Electromagnetic Radiation Chapter 5. What is light? What is a wave? Radiation carries information
Concepts: Properties of Electromagnetic Radiation Chapter 5 Electromagnetic waves Types of spectra Temperature Blackbody radiation Dual nature of radiation Atomic structure Interaction of light and matter
More informationChapter 3 Energy Balance and Temperature. Topics to be covered
Chapter 3 Energy Balance and Temperature Astro 9601 1 Topics to be covered Energy Balance and Temperature (3.1) - All Conduction (3..1), Radiation (3.. and31) 3...1) Convection (3..3), Hydrostatic Equilibrium
More informationThermal Radiation of Blackbodies Lab Partner 1 & Lab Partner 2 12 May 2011
Thermal Radiation of Blackbodies Lab Partner 1 & Lab Partner 2 12 May 2011 We report on experiments investigating the thermal radiation from a blackbody. By finding the electromagnetic spectra emitted
More informationpoint, corresponding to the area it cuts out: θ = (arc length s) / (radius of the circle r) in radians Babylonians:
Astronomische Waarneemtechnieken (Astronomical Observing Techniques) 1 st Lecture: 1 September 11 This lecture: Radiometry Radiative transfer Black body radiation Astronomical magnitudes Preface: The Solid
More informationChemistry 431. Lecture 1. Introduction Statistical Averaging Electromagnetic Spectrum Black body Radiation. NC State University
Chemistry 431 Lecture 1 Introduction Statistical Averaging Electromagnetic Spectrum Black body Radiation NC State University Overview Quantum Mechanics Failure of classical physics Wave equation Rotational,
More informationChapter 3 Energy Balance and Temperature. Astro 9601
Chapter 3 Energy Balance and Temperature Astro 9601 1 Topics to be covered Energy Balance and Temperature (3.1) - All Conduction (3..1), Radiation (3.. and 3...1) Convection (3..3), Hydrostatic Equilibrium
More informationDynamics of the Earth
Time Dynamics of the Earth Historically, a day is a time interval between successive upper transits of a given celestial reference point. upper transit the passage of a body across the celestial meridian
More informationASTR-1010: Astronomy I Course Notes Section IV
ASTR-1010: Astronomy I Course Notes Section IV Dr. Donald G. Luttermoser Department of Physics and Astronomy East Tennessee State University Edition 2.0 Abstract These class notes are designed for use
More informationName and Student ID Section Day/Time:
AY2 - Overview of the Universe - Midterm #1 - Instructor: Maria F. Duran Name and Student ID Section Day/Time: 1) Imagine we ve discovered a planet orbiting another star at 1 AU every 6 months. The planet
More informationToday in Astronomy 142: observations of stars
Today in Astronomy 142: observations of stars What do we know about individual stars?! Determination of stellar luminosity from measured flux and distance Magnitudes! Determination of stellar surface temperature
More informationSources of radiation
Sources of radiation Most important type of radiation is blackbody radiation. This is radiation that is in thermal equilibrium with matter at some temperature T. Lab source of blackbody radiation: hot
More informationMidterm Study Guide Astronomy 122
Midterm Study Guide Astronomy 122 Introduction: 1. How is modern Astronomy different from Astrology? 2. What is the speed of light? Is it constant or changing? 3. What is an AU? Light-year? Parsec? Which
More informationQuantum Mechanics (made fun and easy)
Lecture 7 Quantum Mechanics (made fun and easy) Why the world needs quantum mechanics Why the world needs quantum mechanics Why the world needs quantum mechanics Why the world needs quantum mechanics Why
More informationDeducing Temperatures and Luminosities of Stars (and other objects ) Electromagnetic Fields. Sinusoidal Fields
Deducing Temperatures and Luminosities of Stars (and other objects ) Review: Electromagnetic Radiation Gamma Rays X Rays Ultraviolet (UV) Visible Light Infrared (IR) Increasing energy Microwaves Radio
More informationExam #1 Covers material from first day of class, all the way through Tides and Nature of Light Supporting reading chapters 1-5 Some questions are
Exam #1 Covers material from first day of class, all the way through Tides and Nature of Light Supporting reading chapters 1-5 Some questions are concept questions, some involve working with equations,
More informationModern physics. Historical introduction to quantum mechanics
2012-0-08 Modern physics dr hab. inż. Katarzyna ZAKRZEWSKA, prof. AGH KATEDRA ELEKTRONIKI, C-1, office 17, rd floor, phone 617 29 01, mobile phone 0 601 51 5 e-mail: zak@agh.edu.pl, Internet site http://home.agh.edu.pl/~zak
More informationToday. Spectra. Thermal Radiation. Wien s Law. Stefan-Boltzmann Law. Kirchoff s Laws. Emission and Absorption. Spectra & Composition
Today Spectra Thermal Radiation Wien s Law Stefan-Boltzmann Law Kirchoff s Laws Emission and Absorption Spectra & Composition Spectrum Originally, the range of colors obtained by passing sunlight through
More informationStructure & Evolution of Stars 1
Structure and Evolution of Stars Lecture 2: Observational Properties Distance measurement Space velocities Apparent magnitudes and colours Absolute magnitudes and luminosities Blackbodies and temperatures
More information3.3 The Wave Nature of Light
3.3 The Wave Nature of Light Much of the history of physics is concerned with the evolution of our ideas about the nature of light. The speed of light was first measured with some accuracy in 1675, by
More informationAstronomy The Nature of Light
Astronomy The Nature of Light A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am Measuring the speed of light Light is an electromagnetic wave The relationship between Light and temperature
More informationSTSF2223 Quantum Mechanics I
STSF2223 Quantum Mechanics I What is quantum mechanics? Why study quantum mechanics? How does quantum mechanics get started? What is the relation between quantum physics with classical physics? Where is
More informationTycho Brahe ( )
Tycho Brahe (1546-1601) Foremost astronomer after the death of Copernicus. King Frederick II of Denmark set him up at Uraniborg, an observatory on the island of Hveen. With new instruments (quadrant),
More informationThe Nature of Light. Chapter Five
The Nature of Light Chapter Five Guiding Questions 1. How fast does light travel? How can this speed be measured? 2. Why do we think light is a wave? What kind of wave is it? 3. How is the light from an
More informationWelcome to Phys 321 Astronomy & Astrophysics II. Course Instructor: Prof. Bin Chen Tiernan Hall 101 1
Welcome to Phys 321 Astronomy & Astrophysics II Course Instructor: Prof. Bin Chen Tiernan Hall 101 bin.chen@njit.edu 1 NJIT Astronomy Courses The Physics Department has an undergraduate minor and a concentration
More informationCoriolis Effect - the apparent curved paths of projectiles, winds, and ocean currents
Regents Earth Science Unit 5: Astronomy Models of the Universe Earliest models of the universe were based on the idea that the Sun, Moon, and planets all orbit the Earth models needed to explain how the
More informationsummary of last lecture
radiation specific intensity flux density bolometric flux summary of last lecture Js 1 m 2 Hz 1 sr 1 Js 1 m 2 Hz 1 Js 1 m 2 blackbody radiation Planck function(s) Wien s Law λ max T = 2898 µm K Js 1 m
More informationTemperature, Blackbodies & Basic Spectral Characteristics.
Temperature, Blackbodies & Basic Spectral Characteristics. Things that have one primary temperature but also exhibit a range of temperatures are known in physics as blackbodies. They radiate energy thermally.
More informationUseful Formulas and Values
Name Test 1 Planetary and Stellar Astronomy 2017 (Last, First) The exam has 20 multiple choice questions (3 points each) and 8 short answer questions (5 points each). This is a closed-book, closed-notes
More informationA Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise. The Solar Flux
When you compare gamma ray photons with photons of radio waves, which of the following is true? Gamma rays have a shorter wavelength and less energy Gamma rays have a shorter wavelength and same energy
More informationRadiation from planets
Chapter 4 Radiation from planets We consider first basic, mostly photometric radiation parameters for solar system planets which can be easily compared with existing or future observations of extra-solar
More informationWhat is it good for? RT is a key part of remote sensing and climate modeling.
Read Bohren and Clothiaux Ch.; Ch 4.-4. Thomas and Stamnes, Ch..-.6; 4.3.-4.3. Radiative Transfer Applications What is it good for? RT is a key part of remote sensing and climate modeling. Remote sensing:
More informationModern Physics (Lec. 1)
Modern Physics (Lec. 1) Physics Fundamental Science Concerned with the fundamental principles of the Universe Foundation of other physical sciences Has simplicity of fundamental concepts Divided into five
More informationLecture 3: Emission and absorption
Lecture 3: Emission and absorption Senior Astrophysics 2017-03-10 Senior Astrophysics Lecture 3: Emission and absorption 2017-03-10 1 / 35 Outline 1 Optical depth 2 Sources of radiation 3 Blackbody radiation
More informationAstronomy 150 K. Nordsieck Spring Exam 1 Solutions. 1. ( T F ) In Madison the North Star, Polaris, is situated almost exactly at the zenith.
Astronomy 150 K. Nordsieck Spring 2000 Exam 1 Solutions True or False (Circle T or F) 1. ( T F ) In Madison the North Star, Polaris, is situated almost exactly at the zenith. False. Polaris is near the
More informationIn class quiz - nature of light. Moonbow with Sailboats (Matt BenDaniel)
In class quiz - nature of light Moonbow with Sailboats (Matt BenDaniel) Nature of light - review Light travels at very high but finite speed. Light is electromagnetic wave characterized by wavelength (or
More informationCHAPTER 3 The Experimental Basis of Quantum
CHAPTER 3 The Experimental Basis of Quantum 3.1 Discovery of the X Ray and the Electron 3.2 Determination of Electron Charge 3.3 Line Spectra 3.4 Quantization 3.5 Blackbody Radiation 3.6 Photoelectric
More informationTopics Covered in Chapter. Light and Other Electromagnetic Radiation. A Subatomic Interlude II. A Subatomic Interlude. A Subatomic Interlude III
Light and Other Electromagnetic Radiation Topics Covered in Chapter 1.Structure of Atoms 2.Origins of Electromagnetic Radiation 3.Objects with Different Temperature and their Electromagnetic Radiation
More informationLight and Other Electromagnetic Radiation
Light and Other Electromagnetic Radiation 1 Topics Covered in Chapter 1.Structure of Atoms 2.Origins of Electromagnetic Radiation 3.Objects with Different Temperature and their Electromagnetic Radiation
More informationATMO/OPTI 656b Spring 2009
Nomenclature and Definition of Radiation Quantities The various Radiation Quantities are defined in Table 2-1. Keeping them straight is difficult and the meanings may vary from textbook to textbook. I
More informationASTRONOMY QUIZ NUMBER 1
ASTRONOMY QUIZ NUMBER. You read in an astronomy atlas that an object has a negative right ascension. You immediately conclude that A) the object is located in the Southern Sky. B) the object is located
More informationAST 2010: Descriptive Astronomy EXAM 2 March 3, 2014
AST 2010: Descriptive Astronomy EXAM 2 March 3, 2014 DO NOT open the exam until instructed to. Please read through the instructions below and fill out your details on the Scantron form. Instructions 1.
More informationRecall: The Importance of Light
Key Concepts: Lecture 19: Light Light: wave-like behavior Light: particle-like behavior Light: Interaction with matter - Kirchoff s Laws The Wave Nature of Electro-Magnetic Radiation Visible light is just
More informationAy 20 Basic Astronomy and the Galaxy Problem Set 2
Ay 20 Basic Astronomy and the Galaxy Problem Set 2 October 19, 2008 1 Angular resolutions of radio and other telescopes Angular resolution for a circular aperture is given by the formula, θ min = 1.22λ
More informationLecture 2 Global and Zonal-mean Energy Balance
Lecture 2 Global and Zonal-mean Energy Balance A zero-dimensional view of the planet s energy balance RADIATIVE BALANCE Roughly 70% of the radiation received from the Sun at the top of Earth s atmosphere
More information5. Light-matter interactions: Blackbody radiation
5. Light-matter interactions: Blackbody radiation REMINDER: no lecture on Monday Feb. 6th The electromagnetic spectrum Sources of light Boltzmann's Law Blackbody radiation The cosmic microwave background
More informationAstronomy 7A Midterm #1 September 29, 2016
Astronomy 7A Midterm #1 September 29, 2016 Name: Section: There are 2 problems and 11 subproblems. Write your answers on these sheets showing all of your work. It is better to show some work without an
More informationThe atom cont. +Investigating EM radiation
The atom cont. +Investigating EM radiation Announcements: First midterm is 7:30pm on Sept 26, 2013 Will post a past midterm exam from 2011 today. We are covering Chapter 3 today. (Started on Wednesday)
More informationCHAPTER 3 The Experimental Basis of Quantum Theory
CHAPTER 3 The Experimental Basis of Quantum Theory 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Discovery of the X Ray and the Electron Determination of Electron Charge Line Spectra Quantization As far as I can
More informationModel of Stars 5 Oct
Outline Test 1 Model of Stars 5 Oct Missouri Club on Fri Questions on parallax Hot plate model of a star Thermal radiation Hertzsprung Russell diagram Missouri Club for Hwk 4 Test 1: Average 15 (60%) Test
More informationLecture 8. > Blackbody Radiation. > Photoelectric Effect
Lecture 8 > Blackbody Radiation > Photoelectric Effect *Beiser, Mahajan & Choudhury, Concepts of Modern Physics 7/e French, Special Relativity *Nolan, Fundamentals of Modern Physics 1/e Serway, Moses &
More informationAY2 Winter 2017 Midterm Exam Prof. C. Rockosi February 14, Name and Student ID Section Day/Time
AY2 Winter 2017 Midterm Exam Prof. C. Rockosi February 14, 2017 Name and Student ID Section Day/Time Write your name and student ID number on this printed exam, and fill them in on your Scantron form.
More informationMIDTERM PRACTICE EXAM
MIDTERM PRACTICE EXAM PART I Multiple Choice Answer all questions in this part [60 pts] Directions (1-30): For each statement of question, select the word or expression that best completes the statement
More informationGuiding Questions. Measuring Stars
Measuring Stars Guiding Questions 1. How far away are the stars? 2. What is meant by a first-magnitude or second magnitude star? 3. Why are some stars red and others blue? 4. What are the stars made of?
More informationThe Nature of Light Interaction of Light and Matter
The Nature of Light Interaction of Light and Matter Dariusz Stramski Scripps Institution of Oceanography University of California San Diego Email: dstramski@ucsd.edu IOCCG Summer Lecture Series 25 June
More information5. Light-matter interactions: Blackbody radiation
5. Light-matter interactions: Blackbody radiation The electromagnetic spectrum Sources of light Boltzmann's Law Blackbody radiation why do hot things glow? The cosmic microwave background The electromagnetic
More informationAstronomy 1102 Exam #1 Chapters 1,2,5,6 & 16
Astronomy 1102 Exam #1 Chapters 1,2,5,6 & 16 Chapter 1 Degrees- basic unit of angle measurement, designated by the symbol -a full circle is divided into 360 and a right angle measures 90. arc minutes-one-sixtieth
More informationModule 5 : MODERN PHYSICS Lecture 23 : Particle and Waves
Module 5 : MODERN PHYSICS Lecture 23 : Particle and Waves Objectives In this lecture you will learn the following Radiation (light) exhibits both wave and particle nature. Laws governing black body radiation,
More informationChapter 7. Quantum Theory and Atomic Structure
Chapter 7 Quantum Theory and Atomic Structure Outline 1. The Nature of Light 2. Atomic Spectra 3. The Wave-Particle Duality of Matter and Energy 4. The Quantum-Mechanical Model of the Atom 3 September
More informationVisit for more fantastic resources. Edexcel. A Level. A Level Physics. Astrophysics 1 (Answers) Name: Total Marks: /30
Visit http://www.mathsmadeeasy.co.uk/ for more fantastic resources. Edexcel A Level A Level Physics Astrophysics 1 (Answers) Name: Total Marks: /30 Maths Made Easy Complete Tuition Ltd 2017 1. Amongst
More informationEmission Temperature of Planets. Emission Temperature of Earth
Emission Temperature of Planets The emission temperature of a planet, T e, is the temperature with which it needs to emit in order to achieve energy balance (assuming the average temperature is not decreasing
More informationEarth: the Goldilocks Planet
Earth: the Goldilocks Planet Not too hot (460 C) Fig. 3-1 Not too cold (-55 C) Wave properties: Wavelength, velocity, and? Fig. 3-2 Reviewing units: Wavelength = distance (meters or nanometers, etc.) Velocity
More informationLecture Outline. Energy 9/25/12
Introduction to Climatology GEOGRAPHY 300 Solar Radiation and the Seasons Tom Giambelluca University of Hawai i at Mānoa Lauren Kaiser 09/05/2012 Geography 300 Lecture Outline Energy Potential and Kinetic
More informationStellar Composition. How do we determine what a star is made of?
Stars Essential Questions What are stars? What is the apparent visual magnitude of a star? How do we locate stars? How are star classified? How has the telescope changed our understanding of stars? What
More informationAST 101 INTRODUCTION TO ASTRONOMY SPRING MIDTERM EXAM 1 TEST VERSION 1 ANSWERS NOTE: Question 20 Fixed
AST 101 INTRODUCTION TO ASTRONOMY SPRING 2008 - MIDTERM EXAM 1 TEST VERSION 1 ANSWERS NOTE: Question 20 Fixed Multiple Choice. In the blanks provided before each question write the letter for the phrase
More informationLecture 12. Measurements in Astronomy. Using Light. ASTR 111 Section 002. In astronomy, we need to make remote and indirect measurements
Lecture 12 ASTR 111 Section 002 Measurements in Astronomy In astronomy, we need to make remote and indirect measurements Think of an example of a remote and indirect measurement from everyday life Using
More informationExam# 1 Review Gator 1 Keep the first page of the exam. Scores will be published using the exam number Chapter 0 Charting the Heavens
Exam# 1 Review Exam is Wednesday October 11 h at 10:40AM, room FLG 280 Bring Gator 1 ID card Bring pencil #2 (HB) with eraser. We provide the scantrons No use of calculator or any electronic device during
More informationThe Stefan-Boltzmann law is an example of a power law.
Stefan-Boltzmann law The Stefan-Boltzmann law, also known as Stefan's law, states that the total energy radiated per unit surface area of a black body in unit time (known variously as the black-body irradiance,
More informationastronomy A planet was viewed from Earth for several hours. The diagrams below represent the appearance of the planet at four different times.
astronomy 2008 1. A planet was viewed from Earth for several hours. The diagrams below represent the appearance of the planet at four different times. 5. If the distance between the Earth and the Sun were
More informationGoal: The theory behind the electromagnetic radiation in remote sensing. 2.1 Maxwell Equations and Electromagnetic Waves
Chapter 2 Electromagnetic Radiation Goal: The theory behind the electromagnetic radiation in remote sensing. 2.1 Maxwell Equations and Electromagnetic Waves Electromagnetic waves do not need a medium to
More informationSpectroscopy Lecture 2
Spectroscopy Lecture 2 I. Atomic excitation and ionization II. Radiation Terms III. Absorption and emission coefficients IV. Einstein coefficients V. Black Body radiation I. Atomic excitation and ionization
More informationAST 105 Intro Astronomy The Solar System
NEXT: TERRESTRIAL ATMOSPHERES Mercury AST 105 Intro Astronomy The Solar System Moon Venus Mars Earth Terrestrial Atmospheres: Which planet has the most atmosphere? Is it the largest? Closest? Fastest Rotator?
More informationAst 241 Stellar Atmospheres and Interiors
Ast 241 Stellar Atmospheres and Interiors Goal: basic understanding of the nature of stars Very important for astronomers Most of (known) mass and luminosity from stars Normal galaxies To understand galaxies
More informationPart I. Quantum Mechanics. 2. Is light a Wave or Particle. 3a. Electromagnetic Theory 1831 Michael Faraday proposes Electric and Magnetic Fields
Quantized Radiation (Particle Theory of Light) Dr. Bill Pezzaglia Part I 1 Quantum Mechanics A. Classical vs Quantum Theory B. Black Body Radiation C. Photoelectric Effect 2 Updated: 2010Apr19 D. Atomic
More informationHow big is the Universe and where are we in it?
Announcements Results of clicker questions from Monday are on ICON. First homework is graded on ICON. Next homework due one minute before midnight on Tuesday, September 6. Labs start this week. All lab
More informationTorben Königk Rossby Centre/ SMHI
Fundamentals of Climate Modelling Torben Königk Rossby Centre/ SMHI Outline Introduction Why do we need models? Basic processes Radiation Atmospheric/Oceanic circulation Model basics Resolution Parameterizations
More informationExam 1 Astronomy 114. Part 1
Exam 1 Astronomy 114 Part 1 [1-40] Select the most appropriate answer among the choices given. 1. If the Moon is setting at 6AM, the phase of the Moon must be (A) first quarter. (B) third quarter. (C)
More informationSunlight and its Properties Part I. EE 446/646 Y. Baghzouz
Sunlight and its Properties Part I EE 446/646 Y. Baghzouz The Sun a Thermonuclear Furnace The sun is a hot sphere of gas whose internal temperatures reach over 20 million deg. K. Nuclear fusion reaction
More information! p. 1. Observations. 1.1 Parameters
1 Observations 11 Parameters - Distance d : measured by triangulation (parallax method), or the amount that the star has dimmed (if it s the same type of star as the Sun ) - Brightness or flux f : energy
More informationQM all started with - - The Spectrum of Blackbody Radiation
QM all started with - - The Spectrum of Blackbody Radiation Thermal Radiation: Any object, not at zero temperature, emits electromagnetic called thermal. When we measure the intensity of a real object,
More informationChapter 10 Planetary Atmospheres: Earth and the Other Terrestrial Worlds Pearson Education, Inc.
Chapter 10 Planetary Atmospheres: Earth and the Other Terrestrial Worlds 10.1 Atmospheric Basics Our goals for learning: What is an atmosphere? How does the greenhouse effect warm a planet? Why do atmospheric
More informationDirected Reading. Section: Viewing the Universe THE VALUE OF ASTRONOMY. Skills Worksheet. 1. How did observations of the sky help farmers in the past?
Skills Worksheet Directed Reading Section: Viewing the Universe 1. How did observations of the sky help farmers in the past? 2. How did observations of the sky help sailors in the past? 3. What is the
More informationEnergy. Kinetic and Potential Energy. Kinetic Energy. Kinetic energy the energy of motion
Introduction to Climatology GEOGRAPHY 300 Tom Giambelluca University of Hawai i at Mānoa Solar Radiation and the Seasons Energy Energy: The ability to do work Energy: Force applied over a distance kg m
More informationChapter 5 Light and Matter: Reading Messages from the Cosmos. How do we experience light? Colors of Light. How do light and matter interact?
Chapter 5 Light and Matter: Reading Messages from the Cosmos How do we experience light? The warmth of sunlight tells us that light is a form of energy We can measure the amount of energy emitted by a
More informationIn-Class Question 1) Do you think that there are planets outside the solar which would be habitable for human life?
The Habitability of Worlds Lecture 31 NASA: The Visible Earth In-Class Question 1) Do you think that there are planets outside the solar which would be habitable for human life? a) 1 (yes, definitely)
More information