史蒂芬·霍金：這世上根本沒有黑洞

Wait, so my life may not have disappeared down a black hole after all?

There is a chance for it to emerge and bloom like the career of David Hasselhoff?

It's charming when a phrase enters the language and we think we all know what it means. In the case of "black hole," we think of an infinity of black nothingness that swallows everything that slips into it.

But now, in a new paper called "Information Preservation and Weather Forecasting for Black Holes," Stephen Hawking has cast the cat among the black, holey pigeons and caused a scattering of incomprehension.

His precise words were: "The absence of event horizons mean that there are no black holes -- in the sense of regimes from which light can't escape to infinity."

It seems clear. There are no forever and ever holes of blackness. There is always the chance that light might emerge.

Hawking continued, however: "There are however apparent horizons which persist for a period of time. This suggests that black holes should be redefined as metastable bound states of the gravitational field."

So there are black holes. It's just that we should redefine them a touch. So what's this apparent horizon?

Well, it's "a surface along which light rays attempting to rush away from the black hole's core will be suspended."

But if they're suspended, they will never emerge, stuck in solitary confinement like the Man in the Iron Mask. The result is surely still the same. Once something disappears into a black hole, it's done for.

At times of existential stress like these, I turn to Nature magazinefor help. It suggests that, at least in theory (and, let's face it, this is all theory), black holes might at some point disappear.

However, the magazine offers a dispiriting set of words from Don Page, a physicist from the University of Edmonton in Canada. It might be possible that particles could emerge from black holes, he said.

Oh, cry of joy.

However, if particles did "it would be worse than trying to reconstruct a book that you burned from its ashes."

Ah, now that's a feeling I'm familiar with.

等等，你剛才是說，我不會被黑洞所吞噬?

你還說，那黑洞有可能，會在出現(xiàn)之后就不斷擴大，蓬勃發(fā)展，就像當年大衛(wèi)·哈塞爾霍夫(David Hasselhoff)的演藝事業(yè)以飛速迅猛壯大一般?

說來這也是一件有意思的事：每當一個新詞誕生，我們都以為自己很清楚它的意思。拿“黑洞”舉例，每當有人提到這個詞，我們就會立刻想到一個無窮大的黑色虛無，將滑落進去的一切吞噬。

但現(xiàn)在，史蒂芬·霍金(Stephen Hawking)在他剛剛發(fā)表的一篇名為《黑洞的信息存儲與氣象預(yù)報》(Information Preservation and Weather Forecasting for Black Holes)的論文中，宣稱黑洞并不存在——此語一出，石破天驚，立即掀起一片質(zhì)疑與不解。

不妨讓我們來看看他的原話：“事件視界的缺失意味著‘黑洞’——一種能使光永遠無法逃離的物理環(huán)境——其實并不存在。”

聽上去，這話已經(jīng)說的很清楚了。這世上從來沒有什么黑洞，因為光總有可能逃逸出來。

但霍金繼續(xù)說道：“不過，可見視界仍然是存在的，并且可以持續(xù)存在一段時間。而這就意味著，傳統(tǒng)的黑洞概念可以被重新定義為擁有亞穩(wěn)定邊界的引力場。”

所以說還是有黑洞的了?只是，我們需要稍稍修改一下之前給它下的定義。那么，到底什么是霍金所說的“可見視界”呢?

嗯，它的定義是這樣的：可見視界是“一種表面，當試圖逃出黑洞內(nèi)核的光線處在它的附近時，光線便會處于懸停狀態(tài)”。

但是，一旦光線處于懸停狀態(tài)，他們也將如同影片《鐵面人》(The Man in the Iron Mask(1998))中的“鐵面犯人”一般，被囚禁在密不透風的牢籠里，永遠無法逃脫。這樣來看，光線的結(jié)局必然也將和傳統(tǒng)黑洞理論所得出的結(jié)論一樣——任何東西，一旦消失在黑洞中，那里便將是它永遠的歸宿。

想到這里，一陣無力感涌上心頭，于是，我轉(zhuǎn)而試著去搜尋科學雜志《自然》(Nature)上對黑洞的解釋。而那上面則說，至少在理論上(是的，我們不得不承認，所有這些假說都還停留在理論層面)，黑洞是有可能在某種特定的情況下消失的。

不過，這雜志上刊載的來自加拿大埃德蒙頓大學的物理學家唐·佩奇(Don Page)的一席話又讓人倍感沮喪，他說，一些極小的微粒仍舊存在從黑洞里逃逸的可能。

噢，準備好歡呼了嗎?

別急，他還沒說完呢。這之后他又說，即使是這些微粒成功逃逸，“那將比想著把一本已被你燒成灰燼的書恢復成原樣的嘗試還糟”。

哈，這感覺我倒是似曾相識呢!