Black Holes

The Physics Classroom. Retrieved June 11, 2009 from: http://www.physicsclassroom.com/Class/circles/index.cfm

Ando, D. An Introduction to Black Holes. Retrieved June 11, 2009 from: http://design.lbl.gov/education/blackholes/index.html

4. Why is there no light coming from a black hole?

5. What kind of evidence is used to support the idea that black holes exist?

This animation shows the motion of stars over a period of eight years, as they orbit the supermassive black hole at the center of our galaxy. The black hole, which contains a few million times the mass of the Sun, is invisible in this infrared image, though its gravitational effect is apparent! Its location, marked above by the yellow cross, coincides with a mysterious and highly variable source of radio waves and x-rays known to astronomers as Sagittarius A*.

Centaurus A is the nearest example of an active galactic nucleus (AGN), located only 10 million light years from us. The black hole at the center of this galaxy is thought to be around 60 million times the mass of our Sun; material around it gets shot off in the form of huge jets which travel at nearly the speed of light and are easily visible in this Chandra x-ray image. Many of the small dots surrounding the central AGN are thought to be microquasars, smaller black holes which shoot off jets of their own as they rip material from companion stars.

Curios About Astronomy? Ask an Astronomer page. Retrieved June 11, 2009 from

http://curious.astro.cornell.edu/blackholes.php

6. Given what you know about scientific inquiry, why is the lack of direct evidence for black holes a problem for scientists?

7. Why might black holes be important?

8. How is the search for black holes similar to the quest to view microscopic objects?

National Aeronautics and Space Administration. Retrieved June 11, 2009 from

http://www.jwst.nasa.gov/

Bad Astronomy: If the Sun collapses into a black hole, the Earth and all the other planets will get sucked in.

Good astronomy: If the Sun were to collapse into a black hole, we would feel no difference in the gravity as measured at the Earth.

http://www.badastronomy.com/bad/misc/black_hole_sun.html

http://www.sciencedaily.com/releases/2010/08/100818085938.htm

http://www.sciencedaily.com/releases/2010/07/100721145103.htm

http://www.sciencedaily.com/releases/2010/07/100701183530.htm