Discussion: Spacetime Waves Churn Around a ...

[Fraser]

SUMMARY: Astronomers from Harvard and MIT have detected evidence for hot iron gas that seems to be riding a ripple of spacetime around a black hole. The team used NASA's Rossi X-Ray Timing Explorer to watch how the X-rays eminating from a black hole 40,000 light-years away seem to flicker. They matched this to the light being radiated by iron gas, and found that the two kinds of radiation were in synch. One explanation, predicted by Einstein more than 80 years ago, is that the black hole churns up space and time as it rotates many times a second. We're seeing the X-rays and light from the iron gas after they've journeyed through this swirl of spacetime.

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[GOURDHEAD]

Astronomers from Harvard and MIT have detected evidence for hot iron gas that seems to be riding a ripple of spacetime around a black hole.

Could this effect more likely be due to intense magnetic fields coupled with relativistic speeds of orbiting material as a function of orbit "radii" and the corresponding variable resolution of conservation of angular momentum specific to the speeds at each radius? The Lense-Thirring precession effect should "compactify" spacetime near the event horizon in the direction of rotation and stretch spacetime radially outward in a continually decreasing (perhaps quantum effect limited) fashion against the direction of rotation. It seems that we should expect to see some sort of spiralling effect. There should not be a single ripple and spacing between ripple crests should be an indicator of total energy and how relativistic mass increases were distributed to maintain conservation of angular momentum. If spacetime were to be warped, the black hole should have to supply the energy thus causing it to radiate energy and lose mass. Could this be coupled to the virtual particle dance alleged to be going on near the black hole?

Here is a link describing the alleged effect. I remain confused and without conviction.

[Greg]

I actually like this conclusion about the findings. It makes perfect sense that black holes would spin just as their parent stars would, especially after a supernova. One of the problems I have had with detecting emissions around a black hole is why we can see any light near the even horizon at all. Related to this is why black holes tend to be such sloppy eaters, ultimately ejecting alot of the mass that orbits around it. The Lense-Thirring precession explains this nicely. Any matter that had a trajectory straight down the chute would be deflected into orbit by the twisted space time fabric. Undoubtedly some matter will collide with already orbiting matter in the process ejecting light which we can detect. The Fe band broadness and QPO frequency effects fit in nicely with the model. Maybe I am wrong, but in contrast, I think other explanations will have to be quite arbitrarily contrived and based on conjectures about unknown properties of electro-magnetism or gravity to explain these findings.

[Matthew]

We can see light near the event hosizon because the escape velocity is less that c up until you hit the event horizon. It th that light cannot escape, but before that light can albiet loosing a lot of energy.

Greg, I believe that black holes can only "eat" so much before the pressure near the black hole is so great that other matter is pushed away.

[wstevenbrown]

The article appears to attribute all of the line-broadening to gravitational effects. Does anyone doubt that the near neighborhood of the event horizon (emitting x-rays and shorter) is ionized? Rapidly-orbiting ions cause magnetic fields. I would bet that the parts of the disc nearest the event horizon 1) have a braided fine structure from local magnetic field effects 2) have an overall magnetic field intense enough to cause Zeeman splitting. Thus the iron line is at least double, possibly fourfold, and each of the splits are fuzzed wider by gravity. Antoniseb posted an article ca, 2 mo. ago which was an exploration of what might be learned from the spectral lines of infalling iron near a collapsed object. :huh: Best regards--Steve

[antoniseb]

Originally posted by matthew@Jan 11 2005, 05:39 AM
I believe that black holes can only "eat" so much before the pressure near the black hole is so great that other matter is pushed away.

More to the point, a black hole can absorb matter as rapidly as it can fall in, but the accretion disk is composed of particles travelling at a large fraction of the speed of light, and every collision is a relativistic one. It is the x-rays and gravity waves from this disk that radiates most of the energy away from a black hole, and the magnetic effects that shoot jets out the poles is the next largest loss of energy from the vecinity of the black hole.