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Week of Mar 26
Week of Apr 2
Week of Apr 9
Week of Apr 16
Week of Apr 23
Readings: BDSV Ch. 1, "Scale of the Universe" tutorial
Make sure to bring your PRS transmitter to class!
We'll review distance scales, and then talk about time scales: the age of the universe and how we know what the age is from the expansion of the universe. We'll explore the idea that looking out is looking back in time, and define what's meant by "the observable universe". I'll cover more or less the material in the text, although not exactly in the same order.
Readings: BDSV Ch. 1
We'll complete Chapter 1's "big picture" tour of what we know about the universe. We'll talk about motion of objects, and scales of velocity: motion of the Earth in the solar system and the Milky Way. We'll then talk about very large scales of motion. Finally, we'll talk about the history of matter and energy in the universe, and the "life cycles" of galaxies, stars and planets. Most of these topics we'll be coming back to later in the semester.
Readings: BDSV Ch. 2.1, 2.2; and the "Seasons" tutorial. Try some of the interactive figures on the Mastering Astronomy website! Also please start to play with the SkyGazer software if you have not already.
We will start to get oriented to the sky, and talk about how the patterns in our sky appear, and change with the Earth's rotation and orbit. We'll first talk about constellations, the "celestial sphere", and the local sky, and define various terminology that we'll need to describe positions of objects. We'll look at how the local sky changes daily, due to the rotation of the Earth, and how it changes over the course of a year, due to the Earth's orbit around the Sun. Finally, we'll look at the reasons for seasons.
Readings: BDSV end of Ch. 2.2, 2.3, "Phases of the Moon" and "Eclipses" tutorials.
We will discuss more features of the sky visible to us. First, we'll consider how the precession of the Earth's axis causes very long term changes in the local sky. Next, we'll talk about the Moon: we'll see how the phases of the Moon work, and why we see only one face of the Moon. Then we'll talk about solar and lunar eclipses.
Quiz 1 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
During the rest of the class time, Bill Ebenstein and your observing TA, Ariana Minot, will demonstrate the telescopes.
Readings: BDSV Ch. 2.4, S1.1; we will also touch on parts of Chapter 3.
We'll talk about the motions of the planets in the sky, and how the apparent retrograde motion can be explained in a Copernican system. In this context, we'll discuss parallax, and how the ancients did not embrace a Sun-centric model because of lack of observable stellar parallax. In the second part of the lecture will start to discuss celestial timekeeping: astronomical time periods and calendars based on the motion of celestial objects.
Readings: BDSV Ch. S1.2
After some review, I'll introduce celestial coordinates (dec and RA), the standard way to describe an object's position on the celestial sphere. We'll then do a tutorial using SkyGazer software. If you have a laptop computer, please bring it to class, with the SkyGazer software installed.
Readings: BDSV Ch. S1.2, S1.3
After making some "personal celestial spheres" out of styrofoam, we'll continue by discussing how the local sky looks at various latitudes. Finally we'll cover some principles of celestial navigation: how to determine your latitude and longitude using objects in the sky.
Readings: BDSV Ch. 3, especially 3.3
Quiz 2 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
In the lecture we'll cover a bit of history: from Copernicus' sun-centric model, Tycho's tour de force naked eye observations, and Kepler's interpretation of Tycho's measurements in terms of elliptical orbits of the planets. We'll then state Kepler's three laws of orbital motion and discuss some of their implications.
Readings: BDSV some of Ch. 4.3, 5.3, "Energy" tutorial
Guest lecturer: Roger Wendell
Today's lecture will cover some basic concepts of matter and energy: we'll discuss different kinds of energy, the concept of "conservation of energy", and the idea that mass is a form of energy. Next, we'll talk about matter: we'll cover atomic structure, phases of matter, and energy in atoms. Many of you will already have been exposed to at least some of this material at some point, but these concepts are so crucial to further understanding of our universe, that it's essential to go over them.
Readings: BDSV Ch. 4.1-4.3, "Motion and Gravity" tutorial
Guest lecturer: Roger Wendell
Material to be discussed includes how to describe motion, using concepts of velocity, acceleration, mass, force and momentum, and Newton's Laws of Motion. You will see what weightlessness means, and how an object can orbit the Earth rather than fall into it. Finally some further conservation laws will be covered: conservation of momentum and conservation of angular momentum.
Readings: BDSV Ch. 4.4, some of 4.5, "Orbits and Kepler's Laws" tutorial
We'll cover Newton's universal law of gravitation, and see how Kepler's laws follow from Newton's. We'll then delve a bit deeper into the properties of orbits: we'll look at bound and unbound orbits, geosynchronous orbits, and escape velocity.
Readings: BDSV Ch. 5.1-5.2, 5.4, "Light and Spectroscopy" tutorial
This class will introduce what we know about the nature of light. We'll introduce some wave concepts and terminology, and show how light can behave as both a wave and as a particle. We'll discuss the electromagnetic spectrum, and the ways in which light can interact with matter. We will start discussing how electromagnetic spectra can bring information about astronomical objects, by considering absorption and emission lines.
Readings: BDSV Ch. 5.5, "Doppler Shift" tutorial
After a brief review of spectra, we will talk about thermal radiation and continue the discussion of how we can learn about astronomical objects from their electromagnetic spectra. We will then discuss the Doppler effect: waves from a source moving toward the observer have a higher frequency, and waves from a source moving away have a lower frequency. For light waves, that means that light from receding sources is redshifted, and light from approaching sources is blueshifted. The wavelength shift depends on the velocity, so this phenomenon allows us to measure the velocities of stars (along the line of sight). We'll look at several examples of the use of Doppler shift in astronomy: rotation rates of stars and galaxies, binary stars, Hubble's Law.
Readings: BDSV Ch. 14.1, 14.2, "The Sun" tutorial
Quiz 3 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
We will discuss the Sun, our very own star. After introducing some terminology, we'll talk about how the Sun shines. We'll look at how we have evidence of fusion processes deep inside the Sun via detection of neutrinos.
Readings: BDSV Ch. 14.3, 15.1
We'll briefly cover a few more features of the Sun: magnetic fields, sunspots, flares, and their consequences. We'll then move on to properties of stars, and discuss luminosity and apparent brightness, absolute and apparent magnitude, and spectral types.
Guest lecturer: Prof. Ronen Plesser
The midterm will be 50 minutes long and will be in a style similar to that of the quizzes, although it will include one or two longer problems in addition to multiple-choice and short-answer problems. It will be closed-book. The material you'll be responsible for includes basically everything so far.
Readings: BDSV Ch. 15.2, 15.3, "Hertzsprung-Russell Diagram", "Stellar Evolution" tutorials
We will discuss the Hertzsprung-Russell diagram: the plot of luminosity vs surface temperature of stars. We'll show how different classes of stars show up as different groupings on this diagram. We'll then talk about star clusters, and how we can use them to determine stellar properties and learn about stellar evolution.
Readings: BDSV Ch. 16 (in less detail), 17.1-17.4
We will describe the lives of stars, from formation to death. The life trajectory of a star is determined primarily by its initial mass, and we'll look at the typical histories of both lower and higher mass stars.
Readings: BDSV Ch. 18.1-18.3, some of S4.3, S4.4
We'll discuss the bizarre properties of various stellar "corpses". Low mass stars end up as cooling, inert white dwarfs, prevented from further collapse by electron "degeneracy pressure". They can sometimes revive, sometimes catastrophically, by accreting matter from a companion star. Neutron stars result when the inert core of a high mass star collapses, and protons and electrons get squeezed so much that they form neutrons. These have even more bizarre properties than white dwarfs, and can be observed as pulsars. Black holes take gravitational collapse to the ultimate limit: when a neutron star cannot support itself by neutron degeneracy pressure, it collapses to a black hole, from which even light cannot escape.
Readings: BDSV Ch. 19.1, 19.2, 19.4
Quiz 4 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
We will discuss what is known about the Milky Way, our own Galaxy: we'll cover the anatomy of the Galaxy, the star-gas-star cycle, rotation of objects around the Galaxy, and the supermassive black hole at the Galactic center. Note: I missed slides 27-30 from lecture, due to the animation that froze my laptop, but they contain some ideas you need to know (section 19.2 in BDSV). Animations can be found on the links below.
Readings: BDSV Ch. 19.3, 20.1, some of 21.1-21.2
We will look at classifying galaxies, by first trying it out with a bag o' galaxies, and comparing the results to standard galaxy types. We'll then briefly talk about galaxy formation.
Readings: BDSV Ch. 15.1, 20.2, 20.3, "Measuring Cosmic Distances", "Hubble's Law" tutorials
We will discuss how we know the distances to objects on various distance scales (the "cosmic distance ladder"). We'll then talk about how measurements of galactic distances and recession velocities lead to Hubble's Law, and some of the consequences of Hubble's Law.
Readings: BDSV Ch. 22.1-22.3, "Detecting Dark Matter in Spiral Galaxies" tutorial
We will discuss some of the evidence for the existence of dark matter in galaxies (from rotation curves) and in clusters of galaxies (from orbital velocities, x-ray emission and gravitational lensing). We'll then consider large-scale structure formation in the universe, and the role of dark matter in it.
Readings: BDSV Ch. 22.2
Quiz 5 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
We will discuss some of the possible candidates for dark matter (MACHOS, WIMPs, modified gravity), and ongoing research to identify the nature of the dark matter. Much of this material is not in your textbook.
Readings: BDSV S2
We will discuss Einstein's postulates of special relativity, their consequences, and how we need to revise our everyday concepts of space and time to accommodate them.
Readings: BDSV S3.1-3.3
We will cover Einstein's theory of general relativity, which includes gravity and acceleration: we'll cover the equivalence principle, define spacetime and spacetime curvature, and explore how gravity can be considered to arise from the curvature of spacetime.
Readings: BDSV S3.4, S3.5, Ch. 18.3, "Black Holes" tutorial
We will discuss experimental evidence for the validity of Einstein's theory of general relativity, and future tests. We'll revisit black holes in the context of what we now know about spacetime. Finally, we'll briefly cover some speculative topics: wormholes and warp drive.
Readings: BDSV Ch. 22.4, "Fate of the Universe" tutorial
We will discuss what's known about the fate of the universe. Current measurements indicate an expansion which is speeding up, and which is as yet unexplained: "dark energy" is the name given to the mysterious source of this expansion.
Readings: BDSV Ch. 23.1, 23.2
We will look at what's known about the very beginning of time. We'll look at different eras since the Big Bang, and what's known about them based on current knowledge of physics, and examine the observational evidence for the Big Bang.
Readings: BDSV 23.3, 23.4
Quiz 6 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
We will discuss the idea of an inflationary period early in the history of the universe, and how it solves various cosmological problems. Then we'll talk about the "Concordance Model": the current best guess of the composition and evolution of the universe based on various different observations.
Readings: BDSV Ch. 7.2, 8, "Formation of the Solar System" tutorial
We will now zoom back in to solar system scales, and discuss various features of our own solar system, and the current best theories about how it formed.
Guest lecturer: Prof. Reyco Henning, UNC
Readings: BDSV Ch. 7.3
We will discuss types of exploration missions to the planets of our solar system, and illustrate with a few examples, focusing in more detail on the current Mars rover missions.
Readings: BDSV Ch. 7.1, 9.1, 11
We will look in more detail at some features of the terrestrial and jovian planets, including interiors, internal heat, and magnetic fields; for the jovian planets, we'll also look briefly at moons and rings.
Readings: BDSV Ch. 13, "Detecting Extrasolar Planets" tutorial
We will discuss various techniques for detecting the presence of extrasolar planets, and what we've learned about solar systems beyond our own, including some hot-off-the-press results.
Readings: BDSV Ch. 10.6, 12.4, 24.1
Quiz 7 The quiz will be 15 minutes long and will consist of several multiple choice and a few short answer problems. It will be closed-book. The material you'll be responsible for includes:
We will discuss some of Earth's features that make it unique in the solar system, and the history of life on Earth. We'll briefly discuss mass extinctions, asteroid/comet impacts, and the future of life on Earth.
Readings: BDSV Ch. 24.2-24.5
We will discuss the search for life on the other planets of our solar system, and then the search for life elsewhere in the universe. Course evaluation will be today.
Selected topics will be reviewed for the final (you can suggest topics for review on Monday's minute questionnaire-- I'll try to cover the most frequently requested ones).
