Astronomy and physics education research and comments, field-tested think-pair-share (peer instruction) clicker questions, flashcard questions, in-class activities (lecture-tutorials), current events questions, backwards faded scaffolding laboratories, Hake gains, field-tested multiple-choice and essay exam questions, indices of discrimination, presentation slides, photos, ephemerae, astronomy in the marketplace, unrelated random sketches and minutiae.
20060426
Bon mot: black hole mass, volume, and density
"Black holes are where God divided by zero."
--Stephen Wright
Black holes are one of the end-stages of massive main sequence stars, if the core of the main sequence star exceeds the Oppenheimer-Volkov limit of 3.0 solar masses, at which gravitational forces overwhelm neutron degeneracy pressures. This results in the complete collapse of the core into a black hole. Its mass remains the same, while its size goes to zero. As density is mass divided by volume, this is where Stephen Wright's "divided by zero" takes place, resulting in an infinite density (but remember that mass is finite!).
Interactive pulsar
Neutron Stars Interactive (*.swf)
McGraw-Hill Online Learning Center
Astronomy 10 learning goal M3.5
You can control the rate at which the radio wave "lighthouse" beams are detected by separately varying the relative inclinations of the rotation axis and the magnetic poles with respect to the Earth. If only there was a way to speed up the rotation rate, in order to better approximate the typical rapid rotations of pulsars.
http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/007299181x/78778/Neutron_Nav.swf::Neutron%20Stars%20Interactive
20060425
Bon mot: theorists versus experimentalists
--Leonard Susskind
Damn the experimentalists and full speed ahead!
Meteorite scavenger hunt
Searching for Meteorites in Antarctica
Ralph P. Harvey (CWRU)
Antarctic Search for Meteorites Program, NASA, NSF
Astronomy 10 learning goal M2.1
What else are you going to find on top of all that ice and snow...well, other than penguin poop?
http://antwrp.gsfc.nasa.gov/apod/ap021226.html
20060424
Bon mot: red dwarfs
"It seems that dim stars in the universe at large are like rabbits and bureaucrats: They may not be very bright, but there are a lot of them."Red dwarfs are the "forever stars," with lifetimes that currently exceed the known age of the universe. (However, unlike rabbits and bureaucrats, red dwarfs don't breed, and those that were born have yet to die.)
--Sherwood Harrington, Mercury, 1986, no. 5
20060421
Wormholes
Total internal reflection
Promenade
Originally uploaded by HelĂ´ Bortz.
Physics 8B learning goal Q2.1
Total internal reflection off of a water-air interface.
http://www.flickr.com/photos/26036303@N00/34563452/
Partially inelastic angular collision
kill sponge bob
Originally uploaded by bryan stupar.
Physics 8A learning goal Q9.5
Transfer of angular impulse to stationary SpongeBob SquarePants.
http://www.flickr.com/photos/bryanstupar/131858646/in/pool-slocounty/