Death Spiral First Evidence Of Black Hole

Porfiry writes "NASA's Hubble Space Telescope may have, for the first time, provided direct evidence for the existence of black holes by observing the disappearance of matter as it falls beyond the "event horizon." An event horizon is the mysterious region surrounding a black hole that forever traps light and matter straying nearby. By definition, no astronomical object other than a black hole can possess an event horizon. The discovery comes from a detailed statistical analysis of a 1992 observation of one of the first black holes ever discovered, Cygnus XR-1, which lies 6,000 light-years from Earth in the summer constellation Cygnus the Swan."

And Tackhead sends in this related information: "The folks at the Chandra X-Ray Observatory appear to have detected event horizons by comparing the X-ray luminosity of the accretion discs surrounding black-hole-based X-ray novae versus neutron-star-based X-ray novae during their phases of dormancy. X-ray novae are caused by ignition of fusion in the accretion discs of hot gas drawn from companion stars near black holes or neutron stars. While the novae were dormant, the discs surrounding black hole companions were observed and found to be 100 to 1000 times fainter than those surrounding neutron star companions. The conclusion: 'something' must be consuming the energy that would otherwise be expected from the disc; the most likely candidate being an event horizon."

Comments

Re:Still more indirect "evidence"

[sachsmachine]

I'm not entirely sure this isn't a troll,but... it's either this or finish an essay on Bertrand Russell.

What is your criterion for direct evidence? Part of the idea of a black hole is that I can't really see it in front of me, since it's black. Any good view of evidence would treat visual perceptions as different in degree, rather than kind, from evidence of the sort that these telescopes have turned up. I see tables in front of me all the time, but the way by which I should argue for the existence of tables and the way by which I should argue for the existence of black holes is precisely the same.

What you say about laws applying everywhere is absolutely meaningless. I can create a list of laws for *any* universe that I can describe, no matter how chaotic it may appear -- there may be a whole lot of non-computable functions in those laws, and the list might not be finite, but that doesn't mean that universe is any less bound by laws.

What's unusual about the laws in this universe is that there seem to be relatively few of them, and they're relatively simple -- at least compared to what they might be. There's no reason, though, why they *must* be so simple, or must be equally simple everywhere; the fact that we expect them to be is merely more evidence of the simplicity.