Slashdot Mirror


User: wganderson12

wganderson12's activity in the archive.

Stories
0
Comments
2
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 2

  1. Re:That kind of thing has been done actually on 12-Year-Old Rewrites Einstein's Theory of Relativity · · Score: 2

    I think Feynman's real talent, the talent shared by many of the physicists I know who make real fundamental breakthroughs, is the ability to _understand_ physical problems in terms that even a 12 year old could understand. That is to say, to pare away the unnecessary complexities and reduce the problem to the simplest form that encapsulates the essence of the question. Once you can do that, you can explain what's happening in terms even a 12 year old can understand, because that's how you understood it in the first place.

  2. Re:I'm not qualified to read this article. on Why Some Supermassive Black Holes Have Big Jets · · Score: 3, Informative

    Black holes are regions of spacetime from which light cannot escape (nor can any other known form of matter or energy). The boundary of that region is called an event horizon. In classical General Relativity, there is a singularity inside the black hole. For a spinning black hole (described by the Kerr spacetime), this singularity is a ring around the axis of rotation, if that makes you feel any better. But in the end, talking about the motion of the singularity is meaningless - space and time do not exist in any normal sense at the singularity - it is called a singularity because the definitions of space and time break down there (the curvature of spacetime becomes infinite). If there is no space and no time, what does it mean to "rotate"? In fact, it is the spacetime at and outside the horizon that carry angular momentum (as compared to an observer at infinity). What that means is that objects near a rotating black hole which feel that they are locally "at rest" will still be rotating around the black hole from the perspective of an observer very far away from the black hole because the spacetime itself is being dragged around the black hole. Finally, for the record, singularities in spacetime are widely believed by physicists to indicate a failure of the General Theory of Relativity to describe extremely high curvature regions and not actual physical objects in our universe. We hope that if we can ever reconcile General Relativity and Quantum Mechanics that the resulting theory will be singularity free. Does that clarify things?