After 29 years of thinking about it, Stephen Hawking says he was wrong about black holes. The renowned Cambridge University physicist formally presented a paper on July 14 arguing that black holes, the celestial vortexes formed from collapsed stars, preserve traces of objects swallowed up and eventually could spit bits out "in a mangled form." Hawking's radical new theory caps his three-decade struggle to explain a paradox in scientific thinking: How can objects really "disappear" inside a black hole and leave no trace, as he long believed, when subatomic theory says matter can be transformed but never fully destroyed?
Hawking had previously insisted that black holes destroy all molecular fingerprints of their contents and emit only a generic form of radiation.
But at the 17th International Conference on General Relativity and Gravitation, Hawking presented mind-boggling new calculations that suggest black holes are able to cast out their contents - and that there's only one way in and one way out.
Hawking, 62, said he no longer believes a 1980s theory that black holes might offer passage into another universe, a rival explanation for identifying where matter and energy go when consumed by a black hole.
Hawking now sides with particle physicists who have long insisted that any matter swallowed by a black hole can't just disappear but must eventually generate a specific output. The latest theory offers hope that scientists one day may identify the history of what a black hole has taken in over the eons - by decoding what it emits.
"There is no baby universe branching off (inside a black hole), as I once thought. The information remains firmly in our universe," Hawking said in a speech to about 800 physicists and other scientists from 50 countries. "I'm sorry to disappoint science fiction fans, but if information is preserved, there is no possibility of using black holes to travel to other universes.
"If you jump into a black hole, your mass energy will be returned to our universe, but in a mangled form, which contains the information about what you were like, but in an unrecognizable state."
Hawking's new theory produced waves of skepticism and puzzlement from leading physics professors. Two in the front row - William Unruh of the University of British Columbia and Robert Wald of the University of Chicago - shrugged and shook their heads in disbelief as Hawking spoke.
"Hawking is completely revising his prior belief that what goes into a black hole is washed out. Now he believes that anything emitted from a black hole can be identifiable back to its source," said Wald, an expert on black holes. "He's running away from what we still believe."
Unruh said: "Part of the problem is he's providing so few details, so it's impossible to know whether we can believe these calculations. Stephen Hawking's not stupid, so we're going to take what he says seriously ... but the whole theory we're hearing seems extremely speculative."
霍金激進的新理論顛覆了他30年來爲了科學地解釋“黑洞悖論”而進行的努力：被吸入黑洞的物體怎樣才能真正“消失”，不留一點痕跡呢？長期以來他一直是這樣認爲的，而亞原子理論認爲物質的形式可以相互轉換，但不可能完全消失。
此前，霍金堅持認爲，黑洞會摧毀其中所包含的一切“微小信息”，然後只是正常向外輻射能量。
但是，在第17屆國際廣義相對論和萬有引力大會上，霍金提出了令人難以置信的新的計算結果，認爲黑洞能夠將吞噬的物質慢慢釋放出來，而且吸收和釋放的方式都只有一種。
62歲的霍金說他不再相信20世紀80年代的理論，當時的理論認爲黑洞可能可以通往另一個宇宙空間，這正好可以用來解釋被黑洞吞噬的物質和能量去了哪裏。
霍金現在站在粒子物理學家一邊，長期以來，粒子物理學家們堅持認爲任何被黑洞吞噬的物質都不會憑空消失，最後必然以一種特殊的方式釋放出來。最新的理論讓我們看到了希望：有朝一日，科學家們也許能夠通過解析黑洞釋放出的信息來確定黑洞長久以來的“吞噬史”。
霍金面對來自50個國家的大約800名物理學家和其他科學家發表了演講，他說：“（黑洞裏）沒有我曾設想過的子宇宙分支，物質信息仍然牢牢地保存在我們這個宇宙裏。我很遺憾這讓科幻迷們失望了，但如果物質信息被保存了，（我們）就不可能利用黑洞去別的宇宙空間旅行。”
“如果你跳進一個黑洞，你的物質能量將以一種‘被撕裂'的形式返回到我們的宇宙中，其中包含你以前的信息，但是已經處於無法辨認的狀態。”
霍金的新理論在物理學權威中激起了懷疑和困惑的浪潮。霍金在發表演講時，其中的兩位領軍人物——英國哥倫比亞大學的威廉·翁魯和芝加哥大學的羅伯特·沃爾德——不斷聳肩搖頭表示懷疑。
黑洞專家沃爾德說：“霍金完全改變了他自己以前的觀點，霍金以前認爲進入黑洞的一切都會被‘沖走'。現在他相信從黑洞釋放出的任何物質都能追溯到來源。他已經偏離了我們仍然堅信的理論。”
翁魯說：“部分問題在於他提供的詳細證據太少，因此我們不可能知道這些計算結果是否值得相信。斯蒂芬·霍金並不傻，因此我們會認真考慮他的話……但我們所聽到的整個理論似乎純粹來自推理。”
vortex: 旋渦流，旋風
swallow up: 淹沒，吞沒
spit out: 吐出
cap: 覆蓋，顛覆
mind-boggling: 難以置信的
eon: 永世，無數的年代
branch off: 分叉
（中國日報網站譯）