This is correct.

Even so, I may have been exaggerating, looking at the equations on the Hawking Radiation wikipedia page.

I am so spending this weekend making a Black Hole Evaporation Time Estimator app.

(PS –there's "striving for accuracy", and there's "trying to correct an error billions of orders of magnitude in size"... ! :P

Heh - true.

It's interesting to note how small they have to be, though: according to wikipedia, to radiate more than the it absorbs from the cosmic miscrowave background, the BH would have to be lighter than the moon. In other words, since the microwave background is always decreasing, all stellar-remnant BHs in the universe have always been, and are still (and for the next N times the age of the universe, will remain) increasing in size.

I misunderstood the parent to my post –sorry. My response was elaborating on the first AC who pointed out gman003's misconception – trying to add some figures.

I think a lot of people have heard that "block holes gradually evaporate", without having read any further, making the erroneous assumption about the timeframes involved is understandable.

In fact:

1. large black holes evaporate so slowly they are likely to be the most long-lived objects in the universe
2. at the current background radiation level of the universe, even small black holes absorb much more radiation than they emit, and are therefore growing at the present time
3. quasars are enormous black holes –many millions of solar masses –and are therefore calculated to be emitting radiation ("evaporating") so slowly as to result in a mathematical absurdity.

Who on earth modded this down? I just tried to add some scientific numbers to discuss the original claim!

Precisely. Black holes can't "die extremely quickly" –they evaporate unimaginably slowly. (See my other replies.) They can, however, become inactive at the drop of a hat –if & when the accretion disc becomes depleted.

Oh my apologies. To be fair, your post was ambiguous. I thought you were saying the black hole isn't consuming matter, therefore it was evaporating faster. In fact you were suggesting it is merely inactive, which is another reason the OP’s conclusion is erroneous. I hope the OP found what I wrote informative, anyway.

Nope, even then. You need to read up a little about the timeframes here.

The evaporation of black holes according to Hawking radiation is an unimaginably, incomprehensibly, comically slow process. So slow, that in this universe, the passive absorption of the cosmic microwave background is sufficient to render it irrelevant –the black hole still absorbs background photons at a greater rate than it generates radiation:

A stellar black hole of one solar mass has a Hawking temperature of about 100 nanokelvins. This is far less than the 2.7 K temperature of the cosmic microwave background. Stellar mass (and larger) black holes receive more mass from the cosmic microwave background than they emit through Hawking radiation and will thus grow instead of shrink. To have a Hawking temperature larger than 2.7 K (and be able to evaporate), a black hole needs to be lighter than the Moon (and therefore a diameter of less than a tenth of a millimeter). (wikipedia.org)

Elsewhere I have seen the figure of 10^61 times the age of the universe for the evaporation (and this is in a black-body condition: no matter absorbed whatsoever) of a BH of merely 30 solar masses. Recall we are talking about a Quasar: something hundreds of millions of solar masses and up. These things have lifetimes so vast as to render even the word "astronomical" meaninglessly trifling. Think numbers of years with more digits than you could write in your lifetime.

The irony of this comment is that it advocates abandoning precisely those checks and balances do protect the general public –namely the consistent and open practice of law, the right to a fair trial, and the presumption of innocence until proven guilty.

Dear God.

Is... is this a joke? A Gay leaked the files, therefore Gays should be banned from the military? Seriously? This is modded +5?

What is wrong with people. I am fucking sickened.

In what way does this differ from what Apple is currently doing? You have to be a bit careful when installing OS updates if your iPhone is jailbroken. That's all. When has Apple ever bricked someone's phone for "trying anything funny?" Never.

This is a crucial point. With complex codecs like H.264, there is no single standard of 'quality' even when encoding at a given bitrate. Different encoders can produce wildly different results, and as the parent says, x264 is the state of the art. (I believe CoreAVC is pretty great too, but much slower than x264, and only available on Mac OS X.)

Bingo.