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A major scientific/engineering achievement 精选

已有 13061 次阅读 2016-2-12 01:43 |系统分类:海外观察

For new readers and those who request to be “好友 good friends” ,  please read my 公告first.

Here are some facts:

1.    Unless you are a professional astronomer,then I am willing to bet with high probability that you have never heard of the term LIGO. I didn’t until this morning  via my e-mail from the President of theMIT (see below)

2.    As a scientist/engineer you probably have heard of the three kinds of   telescopes:   the most familiar Light telescope that most of us associate with telescope, and  the lesser known radio telescope and the x-ray telescope. All three kinds of telescopes are based on electromagnetic waves.

3.    Einstein in his discovery of the general theory of relativity in 1915 (one hundred  years ago) predicted the existence of another kind of wave, called  gravitational waves which are caused by masses (such as a star) moving  around the universe. But the effect of gravitational wave is so small  ( 10-21  tijmes smaller than ordinary EMwaves) even with huge  mass as a star that it was impossible to measure and detect until recently.

4.    LIGO is an acronym that  stands for Laser Interferometer Gravitational-wave Observation - a project 40 some years in the making that was  jointly  worked on by MIT and Caltech and sponsored by the US National  Science Foundation to detect such gravitational waves.

5.    Today  (Feb 11, 2016 almost exactly one hundred years later after  Einstein) at a live news conference jointly held by NSF, MIT and CalTech https://www.youtube.com/user/VideosatNSF/live.  it was announced that a gravitationalwave created some 1.3 billion years ago by the collision of two black holes was successfully detected ” beyond any reasonable doubt”.  http://news.mit.edu/2016/ligo-first-detection-gravitational-waves-0211. It was estimated that about 60,000 persons watched this news conference live on a worldwide basis..

6.    The phrase “beyond any reasonabledoubt” is a triumph of modern engineering and physics since the GW telescope is ground based . To detect the smallest  movement one must eliminate ALL kinds of earth bound vibrations and noises  unimaginable to most of us.

7.    Unfortunately the You Tube video is not available in China. But I am sure news  of such magnitude will be reported worldwide and in China.  The President of MIT thought so highly of this discovery and invention  that he announced it in a letter to ALL alumina https://outlook.office.com/owa/projection.aspx

8.    The significance of this fourth kind of telescope promise huge future  astronomical discoveries just like neutronstar and quasars were discovered by radio and x-ray telescopes during the past70 years.  They will change completely our view of the universe.

9.    More GW telescopes all over the world are scheduled to come on line in the  next few years now that it validity has been proven.

I includethe text of the letter of the President of MIT announcing this discovery  below:

Feb 11, 2016

Dear MIT graduate,

 At about 10:30 this morning in Washington, D.C., MIT, Caltech and the  National Science Foundation (NSF) will make a historic announcement in  physics: the first direct detection of gravitational waves, a disturbance of  space-time that Albert Einstein predicted a century ago.

 You may want to watch the announcement live now. Following the NSF event, you can watch our on-campus announcement event.

 You can read an overview of the discovery here as  well as an interview with  MIT Professor Emeritus Rainer Weiss PhD '62, instigator and a leader of the  Laser Interferometer Gravitational-Wave Observatory (LIGO) effort.

The beauty and power  of basic science
 I do not typically write to you to celebrate individual research  achievements, no matter how impressive; our community produces important work  all the time. But I urge you to reflect on today’s announcement because it  demonstrates, on a grand scale, why and how human beings pursue deep  scientific questions – and why it matters.

 Today's news encompasses at least two compelling stories.

 First is the one the science tells: that with his theory of general  relativity, Einstein correctly predicted the behavior of gravitational waves,  space-time ripples that travel to us from places in the universe where  gravity is immensely strong. Those rippling messages are imperceptibly  faint; until now, they had defied direct observation. Because LIGO  succeeded in detecting these faint messages – from two black holes that  crashed together to form a still larger one – we have remarkable evidence  that the system behaves exactly as Einstein foretold.

 With even the most advanced telescopes that rely on light, we could  not have seen this spectacular collision, because we expect black holes  to emit no light at all. With LIGO's instrumentation, however, we  now have the "ears" to hear it. Equipped with this new sense,  the LIGO team encountered and recorded a fundamental truth about nature  that no one ever has before. And their explorations with this new tool have  only just begun. This is why human beings do science!

 The second story is of human achievement. It begins with Einstein: an  expansive human consciousness that could form a concept so far beyond the  experimental capabilities of his day that inventing the tools to prove its  validity took a hundred years.

 That story extends to the scientific creativity and perseverance of Rai  Weiss and his collaborators. Working for decades at the edge of what was  technologically possible, against the odds Rai led a global  collaboration to turn a brilliant thought experiment into a triumph  of scientific discovery.

 Important characters in that narrative include the dozens of outside  scientists and NSF administrators who, also over decades, systematically  assessed the merits of this ambitious project and determined the grand  investment was worth it. The most recent chapter recounts the scrupulous care  the LIGO team took in presenting these findings to the physics community.  Through the sacred step-by-step process of careful analysis and peer-reviewed  publication, they brought us the confidence to share this news – and they  opened a frontier of exploration.

 At a place like MIT, where so many are engaged in solving real-world  problems, we sometimes justify our nation's investment in basic science by  its practical byproducts. In this case, that appears nearly irrelevant. Yet  immediately useful "results" are here, too: LIGO has been a strenuous  training ground for thousands of undergraduates and hundreds of PhDs – two of  them now members of our faculty.

 What's more, the LIGO team's technological inventiveness and creative  appropriation of tools from other fields produced instrumentation of  unprecedented precision. As we know so well at MIT, human beings cannot  resist the lure of a new tool. LIGO technology will surely be adapted and  developed, "paying off" in ways no one can yet predict. It will be  fun to see where this goes.

*        *        *

The discovery we  celebrate today embodies the paradox of fundamental science: that it is  painstaking, rigorous and slow – and electrifying, revolutionary and  catalytic. Without basic science, our best guess never gets any better, and  "innovation" is tinkering around the edges. With the advance of  basic science, society advances, too.

 I am proud and grateful to belong to a community so well equipped to  appreciate the beauty and meaning of this achievement – and primed to unlock  its opportunities.

 In wonder and admiration,

 L. Rafael Reif


Note added 2/15/2016 I did not realize that there is a group of people  in China that do not believe in Einstein's theory of relativity until  I was informed by my  friends. Now that this GW discovery event is    known and acknowledged worldwide, I see they have chosen to delete  one of their ridiculous comment on this blog article in order to appear  more reasonable.

As the old saying goes:"you are certainly entitled to your opinions and beliefs, but you are not entitled to your own facts". One can always     shout louder and more passionately, but that is religion not science. You should follow the rules of science and present your own theory and evidences to refute the established thoery if you want the rest of the world to believe in yours.




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