In 2013 the Boulder Cosmology Group met at 7PM for DVD lectures on the second and fourth Wednesdays of the month and reading discussions on third Mondays at the Meadows Branch of the Boulder Public Library.
See http://www.sackett.net/cosmologyAll.htm for a list of all materials covered in the Cosmology Group since it began meeting in 2003.
01/07/2013 Book Discussion: From Eternity to Here: The Quest for the Ultimate Theory of Time, by Sean Carroll. Parts I and II (first 118 pages). Book notes from Jeff.
Note: we are meeting on the first Monday because the third Monday in January is a holiday.
DVD lectures numbered below in the schedule through March 13, are viewed two per meeting on “Dark Matter, Dark Energy: The Dark Side of the Universe” by CalTech Professor Sean Carroll.
15. 01/09/2013 The Geometry of Space
Precise measurements of the cosmic microwave background let us measure the total energy density of the universe by observing the geometry of space. We find that the energy in matter alone is not enough, confirming the need for dark energy.
16. 01/09/2013 Smooth Tension and Acceleration
Dark energy is smoothly distributed throughout the universe and its density is nearly constant, even though the universe is expanding. Unlike gas under pressure in a container, dark energy is a kind of "negative pressure"—or tension—that imparts an accelerated expansion to the universe.
17. 01/23/2013 Vacuum Energy
The density and distribution of dark energy remain the same across all of spacetime, but what exactly is dark energy? There are many possibilities, the simplest of which is vacuum energy—an constant amount of energy in every cubic centimeter of space itself. Vacuum energy is equivalent to Einstein's idea of the cosmological constant.
18. 01/23/2013 Quintessence
Another idea about dark energy is that it results from a new field in nature, analogous to the electromagnetic field but remaining persistent as the universe expands. This field is called quintessence. It would be observationally distinguishable from the cosmological constant.
02/11/2013 Book Discussion: From Eternity to Here: The Quest for the Ultimate Theory of Time, by Sean Carroll. Part III (pages 119 to 258).
Note: we are meeting on the second Monday because the third Monday in February is a holiday.
19. 02/13/2013 Was Einstein Right?
We have inferred the existence of dark matter and dark energy from the gravitational fields they cause. In this lecture, we explore proposals that a modified theory of gravity might allow us to dispense with the need for invoking dark stuff. However, this turns out to be very difficult in practice.
20. 02/13/2013 Inflation
Before we had observational evidence that the universe is accelerating, cosmologists considered the possibility of a period of rapid acceleration at very early times—a scenario known as inflation.
21. 02/27/2013 Strings and Extra Dimensions
We know about the dark sector because of gravity, and string theory is an ambitious attempt to unify gravitation with the other forces of nature into a theory of everything. String theory promises a theory of quantum gravity, but it also predicts extra, unseen spatial dimensions that are difficult to test.
22. 02/27/2013 Beyond the Observable Universe
The speed of light and the age of the observable universe are finite. That means we can't see the whole universe because our vision can only stretch so far. The "multiverse"—a hypothesis of regions where conditions are very different from those we see in our observable universe—may help explain properties of dark energy.
23. 03/13/2013 Future Experiments
Astronomers are designing new observatories to probe the acceleration of the universe and other cosmic phenomena. Physicists are also looking forward to new experiments that will dramatically improve our understanding of particles and forces, and how ordinary matter fits in with dark matter and dark energy.
24. 03/13/2013 The Past and Future of the Dark Side
The concordance cosmology is an excellent fit to a variety of data, but it presents us with deep puzzles: What are dark matter and dark energy? Why do they have the densities they do? Our own universe seems unnatural to us. That's good news, as it is a clue to the next level of understanding.
03/18/2013 Book Discussion: From Eternity to Here: The Quest for the Ultimate Theory of Time, by Sean Carroll. Part IV (pages 259 to 376). Book notes from Jeff.
DVD lectures numbered below in the schedule through June 12, are viewed two per meeting on “Black Holes Explained” by University of California, Berkeley Professor Alex Filippenko.
1. 03/27/2013 A General Introduction to Black Holes (The first Filippenko lecture)
Widely featured in novels, movies, and other media, black holes are not just entertaining plot devices, they're real. Learn how the idea of black holes was proposed more than two centuries ago, and how more recently Einstein's general theory of relativity gave a firm theoretical basis for them.
2. 03/27/2013 The Violent Deaths of Massive Stars
Discover how black holes can form from stars that are much more massive than the sun. After exhausting their nuclear fuel, these behemoths end in a colossal explosion called a supernova, leaving behind a superdense neutron star, or in some cases something even denser: a black hole.
3. 04/10/2013 Gamma-Ray Bursts—The Birth of Black Holes
Trace the story of gamma-ray bursts. Long a mystery, these intense eruptions of high-energy radiation from random spots in the sky are now thought to be associated with the formation of black holes in distant galaxies. Their visibility from so far away means they are truly titanic explosions.
4. 04/10/2013 Searching for Stellar-Mass Black Holes
If black holes emit no light, how are they detected? Investigate the different clues that establish strong evidence for black holes. For example, a star orbiting an unseen object that exceeds the 3-solar-mass limit for neutron stars is probably circling a black hole.
04/15/2013 Book Discussion: The Lightness of Being: Mass, Ether, and the Unification of Forces, by Frank Wilczek. Chapters 1 to 8. Book notes from Jeff.
5. 04/24/2013 Monster of the Milky Way and Other Galaxies
This lecture presents the most compelling evidence to date for black holes—found in the core of most galaxies. There, stars and gas clouds typically orbit at high speeds, signaling the presence of a central, supermassive black hole, millions to billions of times the mass of the sun.
6. 04/24/2013 Quasars—Feasting Supermassive Black Holes
Quasars are another astronomical mystery explained by black holes. Explore the history of these star-like objects that long baffled astronomers, until observers realized they were seeing matter falling into supermassive black holes during the early era of galaxy formation.
7. 05/08/2013 Gravitational Waves—Ripples in Space-Time
Gravity waves are an unexplored new window for studies of black holes. Learn how these hard-to-detect vibrations are the predicted ripples in the fabric of space-time that should result from violent phenomena such as the merging of two black holes.
8. 05/08/2013 The Wildest Ride in the Universe
What happens if you fall into a black hole? Take a wild ride into the supermassive black hole at the center of the Milky Way Galaxy with a vivid computer simulation showing the strange effects you would experience before being crushed to incredible density.
05/20/2013 Book Discussion: The Lightness of Being: Mass, Ether, and the Unification of Forces, by Frank Wilczek. Chapter 9 to the end of the book. Book notes from Jeff.
9. 05/22/2013 Shortcuts through the Universe and Beyond?
Mathematically, black holes seem to connect our universe with others through a gateway called an Einstein-Rosen bridge—nicknamed a wormhole by physicist John Wheeler, who also coined the term black hole.
10. 05/22/2013 Stephen Hawking and Black Hole Evaporation
Learn why black holes may not be completely black. In 1975, physicist Stephen Hawking showed that they can evaporate via a quantum tunneling process
11. 06/12/2013 Black Holes and the Holographic Universe
The "no-hair" theorem says that black holes are utterly simple and preserve almost no information about what went into them. Discover why some physicists believe that the supposedly lost information is contained just outside the black hole in a form that resembles a hologram.
12. 06/12/2013 Black Holes and the Large Hadron Collider
Professor Filippenko closes by looking at the possibility that a new particle accelerator called the Large Hadron Collider will produce microscopic black holes. Discover why there is no danger that they will devour the Earth, and why there is no risk from any known black holes in space.
06/17/2013 Book Discussion: Gravity's Fatal Attraction: Black Holes in the Universe, by Mitchell Begelman and Martin Rees. We will discuss the first four chapters of the book at this meeting.
06/26/2013 A Leonard Susskind lecture on the Higgs mechanism: “Demystifying the Higgs Boson”. If you want to watch the video in full screen mode, use this link.
07/10/2013 A Lawrence Krauss lecture on “Why Is There Something Rather Than Nothing?”
07/15/2013 Book Discussion: Gravity's Fatal Attraction: Black Holes in the Universe, by Mitchell Begelman and Martin Rees. We will discuss chapters five through eight of the book at this meeting. Note: Professor Begelman attended the July 15 discussion!
07/24/2013 A Sean Carroll lecture on “Particles, Fields and the Future of Physics”.
08/14/2013 A Sean Carroll Cosmology for Particle Physicists lecture at CERN on “Our Homogeneous and Isotropic Universe” given on May 9, 2005.
08/19/2013 Book Discussion: Gravity's Fatal Attraction: Black Holes in the Universe, by Mitchell Begelman and Martin Rees. We will discuss the rest of the book at this meeting.
08/28/2013 A Sean Carroll Cosmology for Particle Physicists lecture at CERN on “Dark Matter” given on May 10, 2005.
09/11/2013 First half of a Sean Carroll Cosmology for Particle Physicists lecture at CERN on “Dark Energy” given on May 11, 2005.
09/16/2013 Book Discussion: The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, by Leonard Susskind. Part I.
09/25/2013 Second half of a Sean Carroll Cosmology for Particle Physicists lecture at CERN on “Dark Energy” given on May 11, 2005.
10/09/2013 A Sean Carroll Cosmology for Particle Physicists lecture at CERN on “Thermodynamics in the Early Universe” given on May 12, 2005.
10/21/2013 Book Discussion: The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, by Leonard Susskind. Parts II and III.
10/23/2013 A Sean Carroll Cosmology for Particle Physicists lecture at CERN on “Inflation and Beyond” given on May 13, 2005.
11/13/2013 Selected DVD lectures from Professor David M. Meyer, Experiencing Hubble: Understanding the Greatest Images of the Universe.
11/18/2013 Book Discussion: The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, by Leonard Susskind. Part IV.
11/27/2013 Selected DVD lectures from Professor David M. Meyer, Experiencing Hubble: Understanding the Greatest Images of the Universe.
12/11/2013 Selected DVD lectures from Professor David M. Meyer, Experiencing Hubble: Understanding the Greatest Images of the Universe.
12/16/2013 Book Discussion: Symmetry and the Beautiful Universe, by Leon Lederman. First third of the book (through Chapter 5). Book notes from Jeff.
For more information, e-mail group leader Jeff Grove: firstname.lastname@example.org.
This is http://www.sackett.net/cosmologySchedule2013.htm, last updated January 20, 2014.