Black holes – truly exotic objects. Do they really exist? They seem now to be mostly accepted in the scientific community. That certainly was not the case for so many years. I remember when I was going to UCLA and taking an astrophysics class when the idea of black holes was so fascinating to the students that they jammed the hall and corridors trying to suck in every word from our professor. It sure was interesting.
Too much to explain right here about black holes, but now it is believed they are at the center of galaxies and help in the birth of new galaxies and on the other hand destroy stars in its own galaxy.
This short video depicts some of the actions thought to be exhibited by black holes.
What’s an extremely powerful source of energy in the universe? It’s a quasar and it mystified astrophysicists and astronomers for a long time after they were discovered in the late 1950′s. Their discovery by radio telescopes was baffling because there were no visible objects that corresponded to their sources.
A quasar is now known to be an extremely powerful and very distant active galactic nucleus. Quasars were first identified as being high redshift sources of electromagnetic energy. They emit radio waves and visible light, that are point-like and similar to stars. This is rather unexpected and you would expect extended sources of energy and light since they are galaxies.
The original controversy over the nature of these powerful objects now in the past since now there is a scientific consensus that a quasar is a compact region 10-10,000 Schwarzschild radii. That’s the radius across the central super massive black hole at the center of a galaxy.
The coming year 2009 is The International Year of Astronomy. A lot has been planned to celebrate the 400th anniversary of Galileo turning his new telescope to the heavens. Many of the names planning the online community portion of it may be familiar to you: Pamela Gay, Fraser Cain, Chris Lintott, and Phil Plait. Check out this fantastic trailer as a promotion for IYA 2009.
This is an example that visually shows that even our Sun is tiny compared to some other objects in the sky. Here is a video (via digg) that shows how small we (the earth) really are. It vividly shows size comparisons of a few monstrosity objects lerking around in our galaxy. If an imaginary spaceship got anywhere near these huge monsters they would be sucked into them so fast due to tremendous gravitational forces they would be vaporized from the heat probably before they hit.
A size comparison1 of the Sun to VV Cephei A (the supergiant of the binary star system VV Cephei) can be found at Wikipedia. VV Cephei A is 1600-1900 times the size of the Sun and 275,000-575,000 times as luminous.
If you imagine the Sun as a one millimeter dot, VV Cephei A is nearly two meters in diameter.
Earth imagined as a one millimeter dot makes VV Cephei A 207 meters in diameter!
When you realize that most or at least many of the quazillions of stars in the universe have planets around them it makes earth and us seem minuscule compared to them.
