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愛語導(dǎo)讀:人類首次直接探測到了引力波！證實了愛因斯坦廣義相對論的預(yù)言。引力波天文學(xué)是人類認(rèn)識宇宙的全新窗口，必將引發(fā)一場天文學(xué)的革命。  Scientists have for the first time observed ripples in the fabric of spacetime called gravitational waves, arriving at the earth from a cataclysmic event in the distant universe. It confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens an unprecedented new window to the cosmos, according to a group of scientists at a press conference in Washington on Thursday. 科學(xué)家首次探測到“時空的漣漪”-即引力波，它由宇宙深處的激變事件形成，到達地球后被探測到。周四，一組科學(xué)家在華盛頓新聞發(fā)布會上稱，這項發(fā)現(xiàn)證實了愛因斯坦1915年提出的廣義相對論，并且為人類認(rèn)識宇宙打開了一扇史無前例的全新窗口。 “This is truly scientific moonshot. We did it. We landed on the moon,” exclaimed David Reitz, executive director of the LIGO Laboratory at Caltech, at the conference in the National Press Club. “這堪比科學(xué)界的登月計劃，我們做到了，我們登上月球了！”激光干涉引力波天文臺的執(zhí)行董事大衛(wèi)賴茨在國家新聞俱樂部大聲宣布。 According to the National Science Foundation (NSF) experts, gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot be obtained from elsewhere. Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole. This collision of two black holes had been predicted but never observed. 據(jù)美國國家科學(xué)基金會（NSF）的專家稱，引力波攜帶著引人注目的其最初起源的信息，并且攜帶著其他任何地方都無法獲得的引力本質(zhì)的信息。物理學(xué)家已推斷出，探測到的引力波是在兩顆黑洞合并成一個更大的、高速旋轉(zhuǎn)的黑洞過程中，在最后若干分之一秒產(chǎn)生的。這兩個黑洞的碰撞早已被預(yù)言，但從未被觀測到。 The gravitational waves were detected on Sept 14, 2015 at 5:51 am EDT by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington. 這束引力波于2015年9月14日下午5：51分（東部夏季時）被探測到，探測儀器是分別位于路易斯安那州列文斯頓和華盛頓州漢福德的兩臺孿生引力波探測器（LIGO）。 Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and the event took place 1.3 billion years ago. About three times the mass of the sun was converted into gravitational waves in a fraction of a second -- with a peak power output about 50 times that of the whole visible universe. By looking at the time of arrival of the signals -- the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford -- scientists can say that the source was located in the Southern Hemisphere, according to a press release from NSF, which funded the research. 基于探測到的信號，LIGO科學(xué)家們估計這次碰撞的兩顆黑洞質(zhì)量分別為29顆太陽和36顆太陽，碰撞大約發(fā)生在13億年前。約3顆太陽的質(zhì)量在最后若干分之一秒轉(zhuǎn)化成引力波-以整個可見宇宙中最大輸出功率50倍的功率。據(jù)NSF（這項研究的投資方）的一篇新聞稿稱，通過觀察信號到達時間-列文斯頓探測器比漢福德探測器早7毫秒記錄了這個事件-科學(xué)家們能夠推斷源頭在南半球。 According to general relativity, a pair of black holes orbiting around each other lose energy through the emission of gravitational waves, causing them to gradually approach each other over billions of years, and then much more quickly in the final minutes. During the final fraction of a second, the two black holes collide at nearly half the speed of light and form a single more massive black hole, converting a portion of the combined black holes’ mass to energy, according to Einstein’s formula E=mc2. This energy is emitted as a final strong burst of gravitational waves. These are the gravitational waves that LIGO observed. 根據(jù)廣義相對論，一對圍繞著彼此旋轉(zhuǎn)的黑洞隨著引力波的發(fā)射而損失能量，導(dǎo)致它們在數(shù)十億年間逐漸相互靠近，在最后幾分鐘速度會大幅增加。根據(jù)愛因斯坦的方程 E=mc2，在最后的若干分之一秒內(nèi)，兩個黑洞以近乎1/2光速的速度碰撞，形成一個質(zhì)量更大的黑洞，并將結(jié)合而成的黑洞質(zhì)量的一部分轉(zhuǎn)化為能量。這部分能量會以強大引力波的形式釋放，即LIGO觀測到的引力波。 The existence of gravitational waves was first demonstrated in the 1970s and 1980s by Joseph Taylor, Jr., and colleagues. In 1974, Taylor and Russell Hulse discovered a binary system composed of a pulsar in orbit around a neutron star. Taylor and Joel M. Weisberg in 1982 found that the orbit of the pulsar was slowly shrinking over time because of the release of energy in the form of gravitational waves. For discovering the pulsar and showing that it would make possible this particular gravitational wave measurement, Hulse and Taylor were awarded the 1993 Nobel Prize in Physics. 引力波的存在最早是由約瑟夫泰勒和他的同事們于20世紀(jì)70年代和80年代證明的。1974年，泰勒和拉塞爾赫爾斯發(fā)現(xiàn)了一顆在軌道上運行的脈沖星，它位于一顆中子星附近。1982年，泰勒和約瑟夫M.韋斯伯格發(fā)現(xiàn)脈沖星軌道隨著時間推移逐步縮小，原因是能量以引力波形式發(fā)射了出去。由于發(fā)現(xiàn)了脈沖星而且這將可能使得引力波測量成為可能，赫爾斯和泰勒榮獲1993年諾貝爾物理學(xué)獎。 The new LIGO discovery is the first observation of gravitational waves themselves, made by measuring the tiny disturbances the waves make to space and time as they pass through the earth. LIGO的新發(fā)現(xiàn)是人類首次觀測到引力波本身，通過測量引力波傳播經(jīng)過地球時對時空造成的微小擾動而觀測到。 “Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein’s legacy on the 100th anniversary of his general theory of relativity,” Reitze said. “我們這次觀測到引力波，實現(xiàn)了50多年前設(shè)立的宏偉目標(biāo)-直接觀測這難以捕捉的現(xiàn)象，并且對宇宙有了更好的了解，而且值相對論100周年紀(jì)念日之時，證實了愛因斯坦遺留的理論?！辟嚧恼f。 LIGO research is carried out by the LIGO Scientific Collaboration (LSC), a group of more than 1,000 scientists from universities around the United States and in 14 other countries. More than 90 universities and research institutes in the LSC develop detector technology and analyze data; approximately 250 students are strong contributing members of the collaboration. LIGO研究項目由LIGO科學(xué)合作組織（LSC）發(fā)起，LSC是由1000多名來自美國及其他14個國家的大學(xué)的科學(xué)家組成的團體。LSC中，超過90所大學(xué)和研究機構(gòu)致力于開發(fā)探測技術(shù)和分析數(shù)據(jù)；約250名學(xué)生為這個合作組織做出了卓越貢獻。 “This detection is the beginning of a new era: The field of gravitational wave astronomy is now a reality,” says Gabriela Gonzalez, LSC spokesperson and professor of physics and astronomy at Louisiana State University. “這次探測是一個新紀(jì)元的開端：天文學(xué)的引力波領(lǐng)域現(xiàn)在成為了現(xiàn)實?！盠SC發(fā)言人，兼路易斯安那州立大學(xué)的物理天文學(xué)教授加布里埃拉岡薩雷斯說。 LIGO was originally proposed as a means of detecting gravitational waves in the 1980s by Rainer Weiss from MIT; Kip Thorne and Ronald Drever, both from Caltech. LIGO最初被提議用作探測引力波的方法是在1980年代，由麻省理工的雷納韋斯、加州理工學(xué)院的基普索恩和羅納德德雷弗提出。 “The deion of this observation is beautifully described in the Einstein theory of general relativity formulated 100 years ago and comprises the first test of the theory in strong gravitation. It would have been wonderful to watch Einstein’s face had we been able to tell him,” Weiss said. “這種探測方法在100年前愛因斯坦廣義相對論有過完美的描述，它成為強引力的最初驗證方法。如果我們有機會告訴愛因斯坦，能看到他的表情，那實在太棒了。”韋斯說。 “With this discovery, we humans are embarking on a marvelous new quest: the quest to explore the warped side of the universe -- objects and phenomena that are made from warped spacetime. Colliding black holes and gravitational waves are our first beautiful examples,” said Thorne. “有了這項發(fā)現(xiàn)，人類要開始著手一段非凡的探索：探索宇宙的彎曲面-由扭曲時空構(gòu)成的物體和現(xiàn)象。黑洞碰撞和引力波是我們漂亮的開端?！彼鞫髡f。 |
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