Saturday, October 29, 2005

Quote of the day:
"In a monarchy, the king and his family are the country; in a republic it is the common voice of the people. Each of you, for himself, by himself and on his own responsibility, must speak. And it is a solemn and weighty responsibility, and not lightly to be flung aside at the bullying of pulpit, press, government, or the empty catch-phrases of politicians. Each must for himself alone decide what is right and what is wrong, and which course is patriotic and which isn't. You cannot shirk this and be a man. To decide it against your convictions is to be an unqualified and inexcusable traitor, both to yourself and to your country, let men label you as they may. If you alone of all the nation shall decide one way, and that way be the right way according to your convictions of the right, you have done your duty by yourself and by your country--hold up your head. You have nothing to be ashamed of." -- Mark Twain

Monday, October 24, 2005

Watch this video clip of some white dots moving against a black background. It is extraordinary, but only if you know what you're looking at.

It's a star, whipping around the very center of our galaxy. Notice that you can't see the thing that it's whipping around. That's because it's a black hole, at the very center of our galaxy. This video clip pretty much confirms that there is a black hole at the center, which can be determined not only by the fact that you can't see it, but the speed at which the star whips by it. They estimate its mass to be about two million times that of our sun.

I had always thought that the center of the Milky Way was too dusty to see into; I don't know how they did it (though the answer seems to be "adaptive optics"). Notice the numbers on the top left; they indicate the year that each frame was taken, so you're looking at a ten-year time-lapse. And at this distance, it didn't just happen; you're looking at a star passing by a black hole about 28,000 years ago. Boggles the mind!