Black Hole Emits a 1,000-Light-Year-Wide Gas Bubble 145
PhrostyMcByte writes "12 million light-years away, in the outer spiral of galaxy NGC 7793, a bubble of hot gas approximately 1,000 light-years in diameter can be found shooting out of a black hole — one of the most powerful jets of energy ever seen. (Abstract available at Nature.) The bubble has been growing for approximately 200,000 years, and is expanding at around 1,000,000 kilometers per hour."
How can a black hole emit anything? (Score:4, Interesting)
Re:How can a black hole emit anything? (Score:5, Interesting)
No, but the combination of gravity and magnetism means they can whip up a lot of stuff outside the event horizon and direct it outward along the poles.
Further, stuff that does fall in adds it's angular momentum to that of the hole, and a spinning black hole has both an inner and outer event horizon. Stuff can fall through one and still escape the other, IIRC, removing angular momentum from the hole.
200,000 years (Score:3, Interesting)
Is that 200,000 years from now, or 200,000 years from 12 million years ago? (since it's that many lightyears away)
Re:How can a black hole emit anything? (Score:3, Interesting)
This means that theory is not something verifiable through observation, but a systematic method of understanding complex reality in a way that is parsimoniously comprehensible. If competing theories have also yet to be disproved then there is no 'right' theory, only a trade off between utility and falsifiability -> the more general the theory, the less well it is defined concretely through variables and hypothesis -> the better it is at abstracting reality and the worse it is at being falsifiable.
The point being that a "theory" is neither the super-hypothesis that you seem to think it is, nor is it the half-witted conjecture that the gpp thinks it is.
It is a multidimensional abstraction of reality that, while useful for explanation and at some point empirically disprovable, must reside at some level of abstraction and thus make trade offs between its usefulness and dis-provability.
Re:How can a black hole emit anything? (Score:4, Interesting)
Actually, in philosophy of science, falsifiability has been dead for decades, thanks to the Quine-Duhem Thesis. The Quine-Duhem Thesis states that a theory never makes a prediction in isolation, but does so in conjunction with auxiliary hypotheses and propositions about initial conditions. This means that when we are faced with an observation that apparently falsifies our theory, we always have the option of "explaining away" the observation by rejecting at least one of our auxiliary hypotheses or propositions about initial conditions. (This does lead to the theory becoming more ad hoc.)
Falsifiability has pretty much been replaced by Bayesianism. Bayesianism uses Bayes' Theorem (used in many spam filters, btw), and allows us to talk about an observation confirming or disconfirming a theory. Confirmation does not mean "prove," it only means "makes more likely to be true." Same thing with disconfirmation: "makes less likely to be true," not "falsifies." This is a better fit with actual scientific practice, since scientists tend to look for evidence that confirms their theory, not evidence that fails to falsify it. But for some odd reason, philosophically aware scientists haven't gotten the memo about all of this, and they are still talking about an account of theory confirmation that's been dead for about 50 years.
Philosophers also think that you are never required to accept the results of a non-deductive argument (including the results of abduction, aka the scientific method), and you always have the option of withholding judgment. However, if you do accept a well-confirmed theory as being true, most epistemologists (who study knowledge) would agree that you are justified.