AST101PPT(exam3)

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Unformatted text preview: Welcome back to Astronomy 101 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The questions on mid-term 2... • A. were easier than • C. were harder than I • B. were about what I • D. what mid-term? I was expecting was expecting was expecting Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What is the Sun made of? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. August Comte 1798-1857 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Isaac Newton Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • White light is a mixture of all the colors of the rainbow Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Visible light is just a small part of the electromagnetic spectrum • Light is a form of electromagnetic radiation Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • There is electromagnetic radiation all around us... • Radio waves are passing through our bodies... • The light in the room is radiation... • You’re emitting infrared radiation right now Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Light is a wave and is characterized by • Wavelength • Frequency • All electromagnetic radiation travels at the same speed: 300,000 km/s • The speed of light! Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The speed of a wave is given by speed = wavelength x frequency • Since the speed is constant, increasing the frequency decreases the wavelength • Similarly decreasing the frequency increases the wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of these waves has the shortest wavelength? (A) (B) (C) (D) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of these waves has the longest wavelength? (A) (B) (C) (D) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which color has the shortest wavelength? • A. Red • B. Green • C. Yellow • D. Blue Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which color has the highest frequency? • A. Red • B. Green • C. Yellow • D. Blue Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The different frequencies of light make up the electromagnetic spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of the following is a form of light? • A. radio waves • C. blue light • B. x-rays • D. all of the above are a form of light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of the following travels the slowest? • A. radio waves • C. blue light • B. x-rays • D. they all travel at the same speed Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Light comes in packets called photons • Each photon travels at the speed of light and is characterized by a frequency and wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The energy carried by a photon is proportional to it’s frequency • Energy = Planck’s constant x frequency • The higher the frequency, the higher the energy of the photon • The higher the energy, the more damage a photon can do Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which color has the highest energy? • A. Red • B. Green • C. Yellow • D. Blue Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Red, Orange,Yellow, Green, Blue, Indigo,Violet Least Energy Most Energy Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. EM Spectrum of Light p 45-47 • • Work with a partner • Discuss the concepts with one another • Come to a consensus answer you both agree on Read the instructions and questions carefully Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of the following has the shortest wavelength? • A. a photon of • C. an x-ray • B. blue • D. a radio wave ultraviolet light electromagnetic radiation Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of the following would be true about comparing gamma rays and radio waves? • A. a photon of • C. an x-ray • B. blue • D. a radio wave ultraviolet light electromagnetic radiation Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Participation Credit • Answer the question on your index card • Make sure you carefully explain your reasoning • Write your name and SUID on your card and put it in the boxes by the doors at the end of class Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Energy Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Energy can be transferred from one object to another • Energy can be transformed from one type of energy to another • The total amount of energy in the universe is conserved Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • There are three kinds of energy • Kinetic energy: the energy of motion • Radiative energy: the energy carried by light • Potential energy: stored energy which can be converted later Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What about heat? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Heat is the total kinetic energy of many individual particles • Temperature measures the average kinetic energy of the particles Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Less thermal energy More thermal energy Same temperature since the average speed is the same Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Lower temperature Higher temperature The particles are moving faster so the temperature is higher Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. I would rather stick my hand in... • A. the air in oven at 450° F (232° C) • B. a pot of boiling water at 212° F (100° C) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which has a higher temperature? • A. the air in oven at 450° F (232° C) • B. a pot of boiling water at 212° F (100° C) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which contains more energy? • A. the air in oven at 450° F (232° C) • B. a pot of boiling water at 212° F (100° C) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • In astronomy, we measure temperature in Kelvin • 0 K = -273 C • 300 K = 27 C • 373 K = 100 C Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Potential Energy Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Gravitational energy is an example of potential energy • An object in a gravitational field has more potential energy when it is higher than when it is lower • This gravitational potential energy can be converted into kinetic energy Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. When I let go of the ball • A. Its gravitational potential energy will stay the same and its kinetic energy will increase • B. Its gravitational potential energy will decrease and its kinetic energy will increase • C. Its gravitational potential energy will decrease and its kinetic energy will stay the same • D. Its gravitational potential energy will stay the same and its kinetic energy will stay the same Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Welcome back to Astronomy 101 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Matter Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Matter is made of atoms • Atoms are made of: • positive protons, • neutral neutrons, • negative electrons Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The number of protons is the atomic number and determines which element we have • Number of protons and neutrons is the atomic mass number • The same element can have different atomic masses (called isotopes) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Nucleus Electron cloud Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Normal atoms are electrically neutral • The number of negative electrons balances the number of positive protons • When there is an imbalance, we get static electricity Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Nucleus Electron cloud Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The atomic number of this atom is (A) one (B) two (C) four (D) six Neutron Proton Electron cloud Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The atomic mass number of this atom is (A) one (B) two (C) four (D) six Neutron Proton Electron cloud Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. That atom was Helium-4 (2 protons, 2 neutrons) If I add two neutrons... • A. I still have helium, but have a different isotope (Helium-6) • B. I have a different element (Lithium-6) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. That atom was Helium-4 (2 protons, 2 neutrons) If I add one proton and one neutron... • A. I still have helium, but have a different isotope (Helium-6) • B. I have a different element (Lithium-6) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. How do light and matter interact? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Light that passes through matter is transmitted • Light bounces off matter is reflected or scattered • Light gets turned into another form of energy when it hits matter is absorbed • If we heat an object up, it can emit light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The visible spectrum Hot, dense sources like a light bulb produce a continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Intensity Spectral Curve Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. At what color does this object’s spectral curve peak? Intensity • A. Red • B. Green • C. White • D. Blue Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What color does this object appear to be? Intensity • A. Red • B. Green • C. White • D. Blue Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Is this object emitting infrared light? Intensity • A. yes • B. no Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. At what color does this object’s spectral curve peak? Intensity • A. Red • B. Green • C. White • D. Blue Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What color does this object appear to be? Intensity • A. Red • B. Green • C. White • D. Blue Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. At what color does this object’s spectral curve peak? Intensity • A. Red • B. Green • C. White • D. Blue Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What color does this object appear to be? Intensity • A. Red • B. Green • C. White • D. Blue Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Intensity 7500K 6000K Light from a hot, dense object produces a continuous spectrum called a black body spectrum 4500K Wavelength (nm) An object is emitting all colors of visible light looks white Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The hotter an object the more blue it appears • The cooler an object the more red it appears • The peak of the spectral curve tells us the temperature of the object Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Intensity 7500K 6000K 4500K Wavelength (nm) How hot is the filament in a regular light bulb? • A. 7500 K • B. 6000 K • C. 4500 K • D. It is impossible to tell Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Hotter objects emit photons with a higher average energy • The hotter an object, the more radiation is emitted from each square meter of it’s surface • If we keep the temperature constant, but make the object bigger the total energy emitted will be larger Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which is has the highest temperature? (A) Lava (B) Light Bulb Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which is has the highest energy output? (A) Lava (B) Light Bulb Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which spectral curve corresponds to which object? • A. Curve 1 is the lava and curve 2 is the light bulb • B. Curve 1 is the light bulb and curve 2 is the lava Intensity Curve 1 Curve 2 Wavelength Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The lava’s spectral curve peaks at a longer wavelength because its temperature is lower • However the lava has a larger surface area, so its energy output (intensity) is greater • If two objects are the same size, the hotter object will glow brighter at all wavelengths Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Black Body Radiation p57-60 • • Work with a partner • Discuss the concepts with one another • Come to a consensus answer you both agree on Read the instructions and questions carefully Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which star has the highest temperature? C A B Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which best describes how Star A would appear as compared to Star B? • A. Star A would appear more red that Star B • B. Both stars would appear more red than blue • C. Both stars would appear more blue than red • D. Star A would appear more blue than Star B Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which star emits light with the longer peak wavelength? • A. Star A • B. Star B • C. Both stars peak at the same wavelength • D. None of the above are possible Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which star is the has the highest temperature? Star B Star A Star C Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which star is the largest? Star B Star A Star C Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Continuous spectrum Hot, dense sources like a light bulb produce a continuous black-body spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Are there any other types of spectrum? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Emission spectrum The atoms in a cloud of hot gas emit light at particular frequencies Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Why do we see an emission spectrum? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Electrons can have different amounts of energy • The energy levels in a particular atom are at fixed discrete values Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Ionization Level Second excited state Energy First excited state Ground state Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • We measure atomic energy levels in electron volts (eV) • • The energy in a can of coke is 3.6 x 10 1 eV = 1.60 x 10-19 Joules 21 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Electrons in atoms can only have energies at precisely the energies of the atomic levels • They cannot take any other energies in between these levels Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Let’s look at a Hydrogen electron Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 1.9 eV 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Excited electrons emit energy in a transition • The energy is carried away by a photon • The amount of energy emitted must be exactly the difference between two levels Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV Is this transition physically realistic? A. yes B. no Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV Is this transition physically realistic? A. yes B. no Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV Is this transition physically realistic? A. yes B. no Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV Is this transition physically realistic? A. yes B. no Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV Is this transition physically realistic? A. yes B. no Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV What is the energy of the photon emitted? A. 0.7 eV C. 10.2 eV B. 1.9 eV D. 12.1 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV What is the energy of the photon emitted? A. 0.7 eV C. 10.2 eV B. 1.9 eV D. 12.1 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV What is the energy of the photon emitted? A. 0.7 eV C. 10.2 eV B. 1.9 eV D. 12.1 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 10.2 eV 0 eV What is the energy of the photon emitted? A. 0.7 eV C. 10.2 eV B. 1.9 eV D. 12.1 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The differences between the energy levels determine what colors of light the atom can emit • The last transition had an energy of 1.9 eV • frequency = 4.6 x 10 Hz • wavelength = 650 nm 14 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.0 eV 12.8 eV 12.1 eV 10.2 eV 0 eV 2.8 eV 2.6 eV 1.9 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Let’s look at Sodium Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Sodium has different energy levels to Hydrogen 5.2 eV 4.1 eV 3.2 eV 2.1 eV 0 eV 2.1 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Hydrogen Lamp Sodium Lamp Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The emission spectrum is an atom’s “fingerprint” Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Mercury Lithium Cadmium Strontium Calcium Sodium Wavelength of emitted light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What happens if we look at a hot, dense source through a cloud of cooler gas? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 11eV 5 eV 10.2 eV 0 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 20 eV 1.9 eV 13.6 eV 12.8 eV 12.1 eV 10.2 eV 10.2 eV 0 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Atoms can only absorb photons of a specific energy • The differences between the energy levels determine what colors of light the atom can absorb Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Continuous spectrum Electron in cool gas cloud Absorbtion spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Continuous spectrum Electron in cool gas cloud Absorbtion spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Continuous spectrum Electron in cool gas cloud Absorbtion spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Atoms in the gas absorb photons from the incident light • The atoms absorb light at particular frequencies according to their allowed transitions • The other frequencies of light are not absorbed pass through the gas Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The colors of light that are not absorbed are transmitted through the gas • The absorbed frequencies are then emitted in random directions, causing these frequencies are scattered • The scattered light results in dark lines in the spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The photons in emission lines are created when electrons fall to lower energy levels • The lines in absorption spectra are caused by electrons absorbing a photon and rising to a higher energy level Hydrogen absorption spectrum Hydrogen emission spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Light and Atoms p63 - 67 • • Work with a partner • Discuss the concepts with one another • Come to a consensus answer you both agree on Read the instructions and questions carefully Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. (A) (B) + + Which atom would be emitting light with the greatest energy? (C) + (D) + Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. (A) + (B) This atom can emit violet, green, yellow and red light + Which electron emits red light? (C) + (D) + Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. (A) + (B) This atom can emit violet, green, yellow and red light + Which electron emits violet light? (C) + (D) + Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The electron has become ________ tightly bound to the nucleus and has ________ light in the process (A) less, emitted (B) less, absorbed (C) more, emitted + (D) more, absorbed Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The electron has become ________ tightly bound to the nucleus and has ________ light in the process (A) less, emitted (B) less, absorbed (C) more, emitted + (D) more, absorbed Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Welcome back to Astronomy 101 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. In astronomy, we encounter three types of spectra Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. CEmission Spectrum Absorption Spectrum ontinuous Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Continuous spectrum Hot, dense sources like a light bulb produce a continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Emission spectrum The atoms in a cloud of hot gas emit light at particular frequencies Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Absorption spectrum The cooler cloud of gas absorbs light from the hot dense source at specific frequencies determined the composition of the gas Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. When we pass light from the Sun through a prism, we see the spectrum shown on the right. This is a... • A. dark line absorption spectrum • B. bright line emission spectrum • C. continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Types of Spectra p61 - 62 • • Work with a partner • Discuss the concepts with one another • Come to a consensus answer you both agree on Read the instructions and questions carefully Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Imagine that you are on the surface of Earth (below the atmosphere) and are observing the Sun. Which of the following spectra would you observe by analyzing the sunlight? • A. dark line absorption spectrum • B. bright line emission spectrum • C. continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. If you analyze the light from a low density object (such as a cloud of interstellar gas), which type of spectrum do you see? • A. dark line absorption spectrum • B. bright line emission spectrum • C. continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Consider an absorption spectrum produced by shining light from a hot, dense source through a cooler cloud of gas. What has happened to the light that is missing from the dark lines in the spectrum? • A. it has disappeared from the universe • B. it is absorbed by the gas, which keeps getting hotter and hotter • C. it is absorbed by the gas and then re-emitted in random directions Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Imagine that you are looking at two different spectra of the Sun. One spectrum is obtained from a telescope high above the Earth’s atmosphere. The other is obtained by a telescope on the surface of the Earth. Which spectrum is obtained by the telescope in space? (A) (B) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Participation Credit: What type of spectrum would you see and why? (A) Viewing a star through a cloud of interstellar gas (B) Viewing the cloud of gas itself Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What causes black body spectra? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Imagine a photon being emitted inside a hot, dense object (e.g. metal bar) • The photon is initially emitted with a specific transition energy... • ...but this photon is inside the object, so we can’t see it Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • All the atoms in the object are vibrating because they are hot • The photon bounces around randomly inside the object exchanging energy with the other atoms • When it finally escapes from the poker so we can see the photon has different energy Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The energy of a photon tells us it’s frequency • When we look at the frequencies of all the photons emitted, we notice a pattern • This is the black-body spectrum of the object • The peak of the spectrum depends only on the temperature of the object Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. So now we can measure temperature and chemical composition using light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Telescopes Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Optical Telescopes • Light collecting area: how much light the telescope can collect at one time • Angular resolution: the smallest angle over which two stars appear to be distinct Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Eye vs Telescope • A 10 m telescope will collect a million times more light than the human eye • The angular resolution of the human eye is about 1 arcminute • The angular resolution of the Hubble Space Telescope is 0.05 arcseconds Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Refracting Telescopes • Glass lenses focus the light from distant objects Lens • Limited by the size of the lenses Eyepiece Focus Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Largest Refracting Telescope 102 cm (40”) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Reflecting Telescopes • Uses curved mirrors to focus the light • Can be made much larger than refracting telescopes Secondary mirror Focus Primary mirror Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Largest Reflecting Telescope 10.4 m (410”) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. We don’t want to limit ourselves to visible light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • We can use the entire electromagnetic spectrum to observe the Universe • Telescopes have to use different technologies to focus different frequencies of electromagnetic waves Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The Chandra X-ray telescope uses metal rings to focus the incoming rays Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Observing electromagnetic waves at different frequencies gives us different views of the Universe NASA/CXC/SAO NASA/Hubble VLA/NRAO Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. So we put some telescopes in space Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Telescopes p 49 - 51 • • Work with a partner • Discuss the concepts with one another • Come to a consensus answer you both agree on Read the instructions and questions carefully Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. When we observe supernova remnant LMV N132D, we see the spectrum shown on the right. This is a... • A. dark line absorption spectrum • B. bright line emission spectrum • C. continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. When we observe Quasar PKS 0405-123 through interstellar gas, we see the spectrum shown on the right. This is a... • A. dark line absorption spectrum • B. bright line emission spectrum • C. continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What type of spectrum does the quasar emit? • A. dark line absorption spectrum • B. bright line emission spectrum • C. continuous spectrum Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. William Thomson, 1st Baron Kelvin Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Hermann von Helmholtz Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Kelvin and Helmholtz proposed that the Sun generated energy by gravitational contraction • As the Sun’s gas shrinks, it’s gravitational potential energy is turned into heat • This method could keep the Sun hot for 25 million years Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. There is a problem with the theory of gravitational contraction... Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. These rocks are over 2.5 billion years old Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The Sun is 4.5 billion years old Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Albert Einstein Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. E= 2 mc Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Energy in the Sun is generated by nuclear fusion... • which turns mass into energy... • ...but it requires extremely high temperatures and densities to occur • Fusion is the only source of energy that could sustain the Sun for 4.5 billion years Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Let’s journey to the center of the Sun Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 13.6 eV 12.8 eV 12.1 eV 100 eV 10.2 eV 0 eV Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • When an atom loses an electron it becomes ionized Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • If many of the atoms in a gas are ionized, the gas becomes a plasma • Plasma conducts electricity and responds to magnetic fields Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Solar wind: ionized particles ejected from the Sun at high speeds Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Corona: the outer atmosphere of the Sun. Extends several million km Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The Sun’s corona has a temperature of 1,000,000 K. Does it mostly emit: (A) Visible Light (B) Infrared Light (C) X-rays (D) Ultraviolet Light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Chromosphere: the middle layer of the Sun’s atmosphere Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The Sun’s chromosphere has a temperature of 10,000 K. Does it mostly emit: (A) Visible Light (B) Infrared Light (C) X-rays (D) Ultraviolet Light Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Photosphere: the layer of the Sun we see with our eyes 6000 K Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which has a higher temperature? (A) An incandescent light bulb (B) The surface of the Sun (C) They are both the same temperature Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Power is the amount of energy radiated in one second • A regular light bulb is rated at 100 Watts • The Sun’s luminosity is 3.8 x 10 Watts • 1 second of the Sun’s output would provide 26 us with enough energy for 500,000 years Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Ranking Task for Participation Credit Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Inside the Sun temperatures rise reaching 15,000,000 Kelvin at the core • The core density is 100 times that of water • Core pressures are 200 billion times atmospheric pressure Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Fusion Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Fusion combines four hydrogen nuclei into one helium nucleus • This is called the proton-proton chain • A helium nucleus is about 0.7% lighter than four hydrogen nuclei • This missing mass becomes energy according to E = mc2 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which plot below most accurately shows how the amounts of hydrogen and helium in the Sun change over time? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Every second 600 millions tons of H becomes 596 million tons of He • • The Sun has been burning hydrogen for 4.5 The mass of the Sun is 2 x 1027 tons billion years and has enough fuel for another 6.5 billion years Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. A high energy photon is produced by a nuclear reaction at the center of the Sun. Which diagram best represents how that photon’s energy escapes from the Sun’s radiative zone? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Welcome back to Astronomy 101 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of the following best represents the temperature of the Sun from the core to the photosphere? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Which of the following best represents the density of the Sun from the core to the photosphere? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Nuclear fusion in the core of the Sun generates gamma-ray photons • The Sun is so dense, it can take hundreds of thousands of years for the photons to reach the photosphere • By the time photons escape, their energies form a black body spectrum with a temperature of about 5000K Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. A high energy photon is produced by a nuclear reaction at the center of the Sun. Which diagram best represents how that photon’s energy escapes from the Sun’s radiative zone? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Photons bounce around randomly inside the Sun making their way outwards • In the radiation zone, photons carry energy from the deepest layers to the upper layers • In the upper layers, the material is cooler and less dense • In the convection zone, hot gas rises and cooler gas sinks carrying heat to the surface Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The surface of the Sun is like a thick fog with hot material rising and cool material sinking Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The location indicated by the arrow is darker because... (A) hotter material is rising (B) hotter material is sinking (C) cooler material is rising (D) cooler material is sinking Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Joseph von Fraunhofer Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. KH 390 400 h g Gf e d 450 h F c 500 h b 4-1 D E 550 C a 3-1 600 650 B A 750 700 wavelength in nm Hydrogen Sodium Unknown Helium Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The Sun is made of 74% hydrogen and 24% helium • The remaining 2% is composed of other heavy elements • The Sun is made up of elements left over from the Big Bang, elements formed from dying stars, and elements created in supernovae Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Sunspots are cool, darker regions on the Sun’s surface Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • They are due to strong magnetic fields which inhibit convection Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The graph below show the black body curves for a normal region of the photosphere and a sunspot. Which corresponds to a sunspot? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. When these magnetic field lines snap they can release huge amounts of energy Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Fortunately we are protected by the Earth’s magnetic field Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Is the electromagnetic spectrum the end of the story? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Gravitational Waves Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • In Einstein’s theory of gravity matter tells space how to curve and space tells matter how to move The mass of the Sun curves the space around it The planets follow the shortest path in the curved space Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Nothing can travel faster than the speed of light... Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. The Sun is eight light minutes from the Earth. If the Sun’s energy output suddenly changed... (A) we would know right away (B) we would know in less than eight minutes (C) we would know in exactly eight minutes (D) we would know in more than eight minutes Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • When massive objects move around, the curvature of space changes • Information about this change travels out at the speed of light as ripples in spacetime • We call these ripples gravitational waves • Gravitational waves contain information about the sources that generated them Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Gravitational wave stretch and squeeze the distance between freely falling objects • Fortunately for us, gravitational waves are very weak • But that makes them very hard to detect Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Gravitational waves are not just a different wavelength, they are a different spectrum! • Their detection would give us insight into fundamental physics and astronomy! Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. EM imaging Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. T. Creighton Multi-band imaging Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. T. Creighton Multi-modal observation Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. T. Creighton • To generate detectable gravitational waves we need a lot of matter moving very fast • When stars run out of fuel, there is no heat pressure to balance the force of gravity • Stars more about four times the mass of the Sun explode in a supernova and their cores collapse down to a neutron star Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Neutron Stars 1.4 times the mass of the Sun compressed into a ball the size of Manhattan We know binary neutron stars exist, as we have seen their radio emissions Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • As the stars orbit around each other they lose energy in the form of gravitational waves • This causes the stars to inspiral into each other Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Binary Black Holes Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Sources of Gravitational Waves Continuous Sources: spinning neutron stars Compact binary coalescence (CBC): inspiral, merger and ringdown of black holes and neutron stars Short bursts: supernovae, unmodeled transient sources Stochastic sources: gravitational wave background from the big bang Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. gravitational wave strain The graph below show a gravitational wave emitted by a source target by LIGO. By looking at the shape of the wave as a function of time, match the wave to its source (A) Exploding Star time → (B) Spinning neutron star (C) Coalescing Black Holes (D) The Big Bang Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. gravitational wave strain The graph below show a gravitational wave emitted by a source target by LIGO. By looking at the shape of the wave as a function of time, match the wave to its source (A) Exploding Star time → (B) Spinning neutron star (C) Coalescing Black Holes (D) The Big Bang Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. gravitational wave strain The graph below show a gravitational wave emitted by a source target by LIGO. By looking at the shape of the wave as a function of time, match the wave to its source (A) Exploding Star time → (B) Spinning neutron star (C) Coalescing Black Holes (D) The Big Bang Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Detecting Gravitational Waves Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • The strength of a gravitational wave is given by the strain h(t) = change in length / length • Typical strains on Earth for astrophysical sources are: h G ENS 4r c 10 21 Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Proxima Centauri 4.2 light years Imagine measuring this distance to a precision of ten microns! Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Mirror Beam splitter Laser Mirror Photodiode Michelson interferometer Gravitational waves stretch and squeeze the detector’s arms Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. LIGO Livingston Observatory LIGO Hanford Observatory Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Abbott et al, Rep. Prog. Phys. 72, 076901 (2009) Virgo Near Pisa, Italy GEO600 Hannover, Germany Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Have we seen anything? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. 1972 Observing the universe with gravitational waves is a tremendous challenge Construction of LIGO facilities 1994 Weiss’ design for a first-generation gravitational-wave interferometer: LIGO 2002 Initial LIGO begins “science runs” Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Noise limits sensitivity Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Sensitivity Progress Neutron star binaries visible in Milky Way (~ 50 kpc) Andromeda (~700 kpc) Virgo Cluster (20 Mpc) September 2002 March 2003 September 2005- Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. No detections (yet) Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. What’s going on now? Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. We are building Advanced LIGO Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. • Advanced LIGO will see 1000x more volume of the Universe than Initial LIGO • We expect to see tens or even hundreds of gravitational-wave events per year • We will open a new window on the universe Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. Copyright 2011 Duncan Brown. Copyright images used under "fair use" (17 United Stated Code, Section 107). Distribution or reproduction of this material outside blackboard.syr.edy is prohibited. ...
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