史蒂芬·霍金：这世上根本没有黑洞

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，你刚才是说，我不会被黑洞所吞噬？

你还说，那黑洞有可能，会在出现之后就不断扩大，蓬勃发展，就像当年大卫·哈塞尔霍夫（David Hasselhoff）的演艺事业以飞速迅猛壮大一般？

说来这也是一件有意思的事：每当一个新词诞生，我们都以为自己很清楚它的意思。拿“黑洞”举例，每当有人提到这个词，我们就会立刻想到一个无穷大的黑色虚无，将滑落进去的一切吞噬。

但现在，史蒂芬·霍金（Stephen Hawking）在他刚刚发表的一篇名为《黑洞的信息存储与气象预报》（Information Preservation and Weather Forecasting for Black Holes）的论文中，宣称黑洞并不存在——此语一出，石破天惊，立即掀起一片质疑与不解。

不妨让我们来看看他的原话：“事件视界的缺失意味着‘黑洞’——一种能使光永远无法逃离的物理环境——其实并不存在。”

听上去，这话已经说的很清楚了。这世上从来没有什么黑洞，因为光总有可能逃逸出来。

但霍金继续说道：“不过，可见视界仍然是存在的，并且可以持续存在一段时间。而这就意味着，传统的黑洞概念可以被重新定义为拥有亚稳定边界的引力场。”

所以说还是有黑洞的了？只是，我们需要稍稍修改一下之前给它下的定义。那么，到底什么是霍金所说的“可见视界”呢？

嗯，它的定义是这样的：可见视界是“一种表面，当试图逃出黑洞内核的光线处在它的附近时，光线便会处于悬停状态”。

但是，一旦光线处于悬停状态，他们也将如同影片《铁面人》（The Man in the Iron Mask（1998））中的“铁面犯人”一般，被囚禁在密不透风的牢笼里，永远无法逃脱。这样来看，光线的结局必然也将和传统黑洞理论所得出的结论一样——任何东西，一旦消失在黑洞中，那里便将是它永远的归宿。

想到这里，一阵无力感涌上心头，于是，我转而试着去搜寻科学杂志《自然》（Nature）上对黑洞的解释。而那上面则说，至少在理论上（是的，我们不得不承认，所有这些假说都还停留在理论层面），黑洞是有可能在某种特定的情况下消失的。

不过，这杂志上刊载的来自加拿大埃德蒙顿大学的物理学家唐·佩奇（Don Page）的一席话又让人倍感沮丧，他说，一些极小的微粒仍旧存在从黑洞里逃逸的可能。

噢，准备好欢呼了吗？

别急，他还没说完呢。这之后他又说，即使是这些微粒成功逃逸，“那将比想着把一本已被你烧成灰烬的书恢复成原样的尝试还糟”。

哈，这感觉我倒是似曾相识呢！