Our galaxy's pretty ordinary, garden-variety. So if we believe our galaxy has a super massive black hole, that tells us that most, if not all, galaxies host such a black hole at their centers.
There's a large cluster of stars that are orbiting the center of our galaxy. And by measuring the motion of stars, and in particular, their orbits, we can figure out whether or not there's a central black hole.
Proof of the black hole is a tremendous amount of mass inside a very small volume. There's 4 million times the mass of our sun within a region that's comparable to the size of our solar system.
Hatred, intolerance, poor hygienic conditions and violence all have roots in illiteracy, so we're trying to do something to help the poor and the needy.
Being poor sucks... It's hard to figure out the secrets of the universe when you're trying to figure out where you and your girlfriend are going to sleep next month.
If you go into any physics lab, everybody is depressed and feels isolated. We don't get any feedback that anybody cares about what we're doing.
Scientists and academics in particular focus on detail and the minutiae. When they talk to each other, they usually don't focus on the broad ideas; they don't focus on social interconnectedness. They focus on the task that they're doing.
Of course, relative citation frequencies are no measure of relative importance. Who has not aspired to write a paper so fundamental that very soon it is known to everyone and cited by no one?
We look at distant exploding stars called supernovae, and we've developed techniques to measure how far away they are and how fast they're moving away from us.
We've lost something that's been with us for so long, and something that drew a lot of us into mathematics. But perhaps that's always the way with math problems, and we just have to find new ones to capture our attention.
I'm sure that some of them will be very hard and I'll have a sense of achievement again, but nothing will mean the same to me - there's no other problem in mathematics that could hold me the way that this one did.
In politics, religion and other areas of culture, people disagree on the worth of competing ideas. There is no equivalent to the scientific method that can determine in a robust way which ideas match the real world, and which ones can be ruled out. S...
The atoms may be compared to the letters of the alphabet, which can be put together into innumerable ways to form words. So the atoms are combined in equal variety to form what are called molecules.
The difference between a gas and a liquid is that in the former, the atoms and molecules move to and fro in an independent existence, whereas in the latter, they are always in touch with one another, though they are changing partners continually.
When a liquid boils, the temperature has been raised to such a pitch that the evaporating molecules are sufficient in number and speed to lift off the air from the surface of the liquid and push it back en masse.
Broadly speaking, the discovery of X-rays has increased the keenness of our vision ten thousand times, and we can now 'see' the individual atoms and molecules.
I thought cryptography was a technique that did not require your trusting other people-that if you encrypted your files, you would have the control to make the choice as to whether you would surrender your files.
People are leaving trails everywhere they go; automated web crawlers tell you an awful lot about their social activities. The flow of information in fundamentally unobtrusive ways into social control organisations has risen dramatically.
In 15 years we'll have all the sequence, a list of the genes everyone has in common and those that differ among people. We know only something like a tenth of 1 percent of the sequence at the moment.
I have just joined the Board of the Population Institute because I am convinced that early stabilization of the world's population is important for the attainment of this objective.
During one or two summers, as well as part-time during the school year, I worked for a small Canadian company which developed electrical instruments for military planes.
