今日主題:Model Black Hole Re-Creates Stephen Hawking Prediction / 黑洞模型
洪欣老師推薦:托福聽力最好的課外教材:60-Second Science
康康精選托福會考的主題,堅持每天精聽一定會進步的哦!!
建議方法:
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍,直到寫出85%以上的字)
3. 最後check文稿,看哪聽不出來,單字沒背過,還是發音不熟。
4. 堅持天天聽,就能每天進步哦。
#科學人SSS
MP3音檔 (按右鍵可下載聽):喜歡的同學,幫忙推或按讚哦~~
http://online1.tingclass.net/voaspe/…/20160928sa_science.mp3
只有音檔怎夠,聽不懂地方,不用怕,康康幫你準備好中英文稿了:
中英文稿:
Black holes got their name because light can't escape them, beyond a certain radius—the event horizon. But in 1974 Stephen Hawking proposed that quantum effects at the event horizon might cause black holes to be…not completely black.
黑洞得名的原因是光無法逃脫於一個特定的介面——視界。在1974年,史蒂芬•霍金提出,視界裡的量子效應,可以使黑洞不完全“黑”。
"Hawking said that pairs of particles should be created at the event horizon." Jeff Steinhauer, a physicist at the Israel Institute of Technology. "One particle exits the black hole and travels away, perhaps to Earth, and the other particle falls into the black hole."
“霍金表示,視界可以產生成對的粒子”以色列理工學院的物理學家傑夫•施泰因豪爾說道。“正粒子遠離黑洞逃逸,可能是沿著地球,而反粒子則被黑洞吞噬。”
Ideally, we could just study those exiting particles…which make up the so-called Hawking radiation. But that signal is too weak. We can't see it against the universe's background radiation. So Steinhauer built a model of a black hole instead. Which traps not photons, but phonons—think of them as sound particles—using a gas of rubidium atoms, flowing faster than the speed of sound.
理想情況下,我們可以研究這些週邊的粒子….這些粒子構成了霍金輻射。但是信號太弱了。在宇宙輻射背景下,我們根本看不到它發出的輻射。所以施泰因豪爾構建了一個黑洞模型。這個黑洞模型不僅能吸收光子,還能吸收聲子——姑且認為聲子就是聲音粒子——使用的銣原子氣體,銣原子的運動速度比聲音的速度要快。
"And that means that phonons, particles of sound, trying to travel against the flow are not able to go forward. They get swept back by the flow. It's like someone trying to swim against a river which is flowing faster than they can swim. And the phonon trying to go against the flow is analogous to a photon trying to escape a black hole."
這意味著聲子無法對抗銣原子繼續前進。它們會被氣流阻回。這就仿佛有人想要逆流而上,但是河水的速度快於他的游泳速度。聲子試圖逆流逃離就如同光子想要逃離黑洞一樣。
Steinhauer doesn't actually pipe sound particles into the device. He doesn't need to. He merely created the conditions under which quantum effects predict their appearance. "So the two swimmers can come into existence simultaneously without anybody supplying energy to create them."
施泰因豪爾實際上並沒有用管道將這些粒子輸入裝置。因為他根本不用這樣做。他只是營造了產生量子效應的環境。“所以,兩個粒子可以同時存在,而不需要任何裝置來提供能量。”
He ran the test 4,600 times—the equivalent of six days—and took pictures of the results. And indeed, he saw a correlation between particles emanating into and out of the model black hole…an experimental demonstration of Hawking radiation. The results appear in Nature Physics.
施泰因豪爾測試了4600次——耗時6天,並對測試結果拍照。他發現了逃逸粒子和被吸入黑洞粒子之間的關係……相當於霍金輻射的演示實驗。該研究結果發表在《自然物理》雜誌上。
Steinhauer also determined that the partner particles had a quantum connection, called entanglement…which could help theorists investigating the information paradox. "So there's the question of where does information go, if one throws it into a black hole?" This study can't answer that. But, he says, "it helps give hints, to direct physicists towards the new laws of physics, whatever they might be."
施泰因豪爾還判定成對粒子之間存在量子關聯,這可以説明理論學家研究資訊悖論。所以,現在的問題是,如果一個粒子吸入黑洞,那麼資訊將去往何處?研究並沒有給出我們答案。但是施泰因豪爾表示,研究給我們提供了線索,指導物理學家研究新的物理學定律。
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