[Просто о сложном] Преодоление скорости света
Недавно ученые из исследовательского института в Принстоне посмели покуситься на знаменитый постулат. Вот как описывает эти эксперименты газета «Санди Тайме»: «Мощный импульс света пропускался через шестисантиметровую «колбу», заполненную специально приготовленным газообразным цезием. И приборы показали невероятную вещь – пока основная часть света шла со своей обычной скоростью, какие-то шустрые фотоны успевали добежать до противоположной стены лаборатории, находящейся примерно в 18 метрах, и отметиться на расположенных там датчиках».
Физики подсчитали и, как говорится, прослезились. Если частицы-торопыги пролетали 18 метров за то же время, что нормальные фотоны путешествовали сквозь шестисантиметровую «колбу», это значит, что скорость торопыг в 300 раз превышала скорость света! Все это полностью противоречило теории Эйнштейна.
Чтобы как-то оградить авторитет великого физика, исследователи из Принстона выдвинули предположение, что «быстрые фотоны» вовсе и не проходят расстояние от источника света до датчиков, а как бы исчезают в одном месте и мгновенно возникают уже в другом. То есть налицо так называемый эффект нуль-транспортировки, или телепортации, о которой так много писали фантасты в своих романах.
Дальнейшие эксперименты и вовсе поставили физиков в тупик. Выяснилось, что некоторые частицы прибывают в точку назначения даже раньше, чем включается источник света. Это разрушало уже не только постулаты теории относительности, но и фундаментальные представления о природе времени, которое, как принято считать, течет только в одну сторону и не может быть повернуто вспять.
Фотоны-торопыги нахально нарушали основополагающие законы физики, в том числе наши представления о причинно-следственных связях. Причина (включение источника света) в этих опытах наблюдалась уже после ее следствия (срабатывание датчика от долетевшего фотона).
Логичным здесь было бы только одно объяснение – «колба» с газообразным цезием работает как своеобразная машина времени, посылающая часть световых фотонов в прошлое, что и позволяет им достигать датчиков раньше, чем включается источник света.
Эксперименты ученых из Принстона не могли не привлечь внимания их коллег.
Руководители Итальянского государственного исследовательского совета сообщили, что недавно им тоже удалось разогнать микроволны со скоростью на 25 процентов быстрее скорости света.
Поэтому они уверены, что сообщение американцев полностью достоверно.
Поэтому они уверены, что сообщение американцев полностью достоверно.
А вот еще одно интересное сообщение – Из Университета Кобленца. Понтер Нимц и Альфонс Штапьхофен пропускали фотоны света через две зеркальные призмы, находящиеся на расстоянии метра друг от друга. И приборы неожиданно показали, что при определенных условиях частицы прибывали к месту назначения так, будто двигались со скоростью, превышающей скорость света. Удивительный эффект, по мнению немецких ученых, показывает, что в их установке время оборачивается вспять – и луч света оказывается в пункте назначения еще до того, как начинает свой путь. Но ведь к тем же выводам пришли и специалисты из Принстона!
tainy.net Оригинал статьи был здесь www.sunday-times.co.uk The Sunday Times
June 4, 2000
In research carried out in the United States, particle physicists have shown that light pulses can be accelerated upto 300 times their normal velocity of 186,000 miles per second.
The implications, like the speed, are mind-boggling. On one interpretation, it means that the light will arrive at it's destination almost before it has started it's journey. In effect, it is leaping forward in time.
Exact details of the findings remain confidential because they have been submitted to Nature, the international scientific journal, for review prior to publication.
The work was carried out by Dr. Lijun Wang, of the NEC research institute in Princeton, who transmitted a pulse of light towards a chamber filled with specially treated caesium gas.
Before the pulse had fully entered the chamber it had gone right through it and travelled a further 60ft across the laboratory. In effect, it existed in two places at once, a phenomenon Wang explains by saying it travelled 300 times faster than light.
The research is already causing controversy among physicists. What bothers them is that if light could travel forward in time, it couyld carry information. This would breach one of the basic principles in physics - causality, which says that a cause must come before an effect. It would also shatter Einstein's theory of relativity since it depends in part on the speed of light being unbreachable.
This weekend Wang said he could not give details but he confirmed : "Our light pulses did indeed travel faster than the accepted speed of light. I hope it will give us a much better understanding of the nature of light and how it behaves."
Cr. Raymond Chiao, professor of physics at the University of Berkeley who is familiar with Wang's work, said he was impressed by the findings. "This is a fascinating experiment," he said.
In Italy, another group of physicists has also succeeded in breaking the light speed barrier. In a newly published paper, physicists at the Italian National Research Council described how they propagated microwaves at 25% above normal light speed. The group speculates that it could be possible to transmit information faster than light.
Dr. Guenter Nimtz, of Cologne University, an expert in the field, agrees. He believes that information can be sent faster than light and last week gave a paper describing how it could be done to a conference in Edinburgh. He believes, however that this will not breach the principle of causalty because the time taken to interpret the signal would fritter away all the savings.
"The most likely application for this is not in time travel but in speeding up the way signals move through computer circuits", he said.
Wang's experiment is the latest and possibly the most important evidence that the physical world may not operate according to any of the accepted conventions.
In the new world that modern science is beginning to perceive, sub-atomic particles can apparently exist in two places at the same time - making no distinction between space and time.
Separate experiments carried out by Chiao illuistrate this. He showed that in certain circumstances photons - the particles of which light is made = could apparently jump between two points separated by a barrier in what appears to be zero time. The process, known as tunnelling, has been used to make some of the most sensitive electron microscopes.
The implications of Wang's experiments will arouse fierce debate. Many will question whether his work can be interpreted as proving that light can exceed it's normal speed - suggesting that another mechanism may be at work.
Neil TUrok, professor of mathematical physics at Cambridge University, said he awaited the details with interest, but added : "I dout this will change our view of the fundamental laws of physics."
Wang emphasises that his experiments are relevant only to light and may not apply to other physical entities. But scientists are beginning to accept that man may eventually exploit some of these characteristics for inter-stellar space travel.
www.urigeller.com
(AP) Scientists have apparently broken the universe's speed limit. For generations, physicists believed there is nothing faster than light moving through a vacuum -- a speed of 186,000 miles per second. But in an experiment in Princeton, N.J., physicists sent a pulse of laser light through cesium vapor so quickly that it left the chamber before it had even finished entering. The pulse traveled 310 times the distance it would have covered if the chamber had contained a vacuum. Researchers say it is the most convincing demonstration yet that the speed of light -- supposedly an ironclad rule of nature -- can be pushed beyond known boundaries, at least under certain laboratory circumstances. "This effect cannot be used to send information back in time," said Lijun Wang, a researcher with the private NEC Institute. "However, our experiment does show that the generally held misconception that 'nothing can travel faster than the speed of light' is wrong." The results of the work by Wang, Alexander Kuzmich and Arthur Dogariu were published in Thursday's issue of the journal Nature. The achievement has no practical application right now, but experiments like this have generated considerable excitement in the small international community of theoretical and optical physicists. "This is a breakthrough in the sense that people have thought that was impossible," said Raymond Chiao, a physicist at the University of California at Berkeley who was not involved in the work. Chiao has performed similar experiments using electric fields. In the latest experiment, researchers at NEC developed a device that fired a laser pulse into a glass chamber filled with a vapor of cesium atoms. The researchers say the device is sort of a light amplifier that can push the pulse ahead. Previously, experiments have been done in which light also appeared to achieve such so-called superluminal speeds, but the light was distorted, raising doubts as to whether scientists had really accomplished such a feat. The laser pulse in the NEC experiment exits the chamber with almost exactly the same shape, but with less intensity, Wang said. The pulse may look like a straight beam but actually behaves like waves of light particles. The light can leave the chamber before it has finished entering because the cesium atoms change the properties of the light, allowing it to exit more quickly than in a vacuum. The leading edge of the light pulse has all the information needed to produce the pulse on the other end of the chamber, so the entire pulse does not need to reach the chamber for it to exit the other side. The experiment produces an almost identical light pulse that exits the chamber and travels about 60 feet before the main part of the laser pulse finishes entering the chamber, Wang said. Wang said the effect is possible only because light has no mass; the same thig cannot be done with physical objects. The Princeton experiment and others like it test the limits of the theory of relativity that Albert Einstein developed nearly a century ago. According to the special theory of relativity, the speed of particles of light in a vacuum, such as outer space, is the only absolute measurement in the universe. The speed of everything else -- rockets or inchworms -- is relative to the observer, Einstein and others explained. In everyday circumstances, an object cannot travel faster than light. The Princeton experiment and others change these circumstances by using devices such as the cesium chamber rather than a vacuum. Ultimately, the work may contribute to the development of faster computers that carry information in light particles. Not everyone agrees on the implications of the NEC experiment. Aephraim Steinberg, a physicist at the University of Toronto, said the light particles coming out of the cesium chamber may not have been the same ones that entered, so he questions whether the speed of light was broken. Still, the work is important, he said: "The interesting thing is how did they manage to produce light that looks exactly like something that didn't get there yet?"
www.cbsnews.com
June 4, 2000
Eureka! Scientists break speed of light
Scientists claim they have broken the ultimate speed barrier : the speed of light.In research carried out in the United States, particle physicists have shown that light pulses can be accelerated upto 300 times their normal velocity of 186,000 miles per second.
The implications, like the speed, are mind-boggling. On one interpretation, it means that the light will arrive at it's destination almost before it has started it's journey. In effect, it is leaping forward in time.
Exact details of the findings remain confidential because they have been submitted to Nature, the international scientific journal, for review prior to publication.
The work was carried out by Dr. Lijun Wang, of the NEC research institute in Princeton, who transmitted a pulse of light towards a chamber filled with specially treated caesium gas.
Before the pulse had fully entered the chamber it had gone right through it and travelled a further 60ft across the laboratory. In effect, it existed in two places at once, a phenomenon Wang explains by saying it travelled 300 times faster than light.
The research is already causing controversy among physicists. What bothers them is that if light could travel forward in time, it couyld carry information. This would breach one of the basic principles in physics - causality, which says that a cause must come before an effect. It would also shatter Einstein's theory of relativity since it depends in part on the speed of light being unbreachable.
This weekend Wang said he could not give details but he confirmed : "Our light pulses did indeed travel faster than the accepted speed of light. I hope it will give us a much better understanding of the nature of light and how it behaves."
Cr. Raymond Chiao, professor of physics at the University of Berkeley who is familiar with Wang's work, said he was impressed by the findings. "This is a fascinating experiment," he said.
In Italy, another group of physicists has also succeeded in breaking the light speed barrier. In a newly published paper, physicists at the Italian National Research Council described how they propagated microwaves at 25% above normal light speed. The group speculates that it could be possible to transmit information faster than light.
Dr. Guenter Nimtz, of Cologne University, an expert in the field, agrees. He believes that information can be sent faster than light and last week gave a paper describing how it could be done to a conference in Edinburgh. He believes, however that this will not breach the principle of causalty because the time taken to interpret the signal would fritter away all the savings.
"The most likely application for this is not in time travel but in speeding up the way signals move through computer circuits", he said.
Wang's experiment is the latest and possibly the most important evidence that the physical world may not operate according to any of the accepted conventions.
In the new world that modern science is beginning to perceive, sub-atomic particles can apparently exist in two places at the same time - making no distinction between space and time.
Separate experiments carried out by Chiao illuistrate this. He showed that in certain circumstances photons - the particles of which light is made = could apparently jump between two points separated by a barrier in what appears to be zero time. The process, known as tunnelling, has been used to make some of the most sensitive electron microscopes.
The implications of Wang's experiments will arouse fierce debate. Many will question whether his work can be interpreted as proving that light can exceed it's normal speed - suggesting that another mechanism may be at work.
Neil TUrok, professor of mathematical physics at Cambridge University, said he awaited the details with interest, but added : "I dout this will change our view of the fundamental laws of physics."
Wang emphasises that his experiments are relevant only to light and may not apply to other physical entities. But scientists are beginning to accept that man may eventually exploit some of these characteristics for inter-stellar space travel.
www.urigeller.com
Faster Than The Speed Of Light?
February 11, 2009 9:42 PM(AP) Scientists have apparently broken the universe's speed limit. For generations, physicists believed there is nothing faster than light moving through a vacuum -- a speed of 186,000 miles per second. But in an experiment in Princeton, N.J., physicists sent a pulse of laser light through cesium vapor so quickly that it left the chamber before it had even finished entering. The pulse traveled 310 times the distance it would have covered if the chamber had contained a vacuum. Researchers say it is the most convincing demonstration yet that the speed of light -- supposedly an ironclad rule of nature -- can be pushed beyond known boundaries, at least under certain laboratory circumstances. "This effect cannot be used to send information back in time," said Lijun Wang, a researcher with the private NEC Institute. "However, our experiment does show that the generally held misconception that 'nothing can travel faster than the speed of light' is wrong." The results of the work by Wang, Alexander Kuzmich and Arthur Dogariu were published in Thursday's issue of the journal Nature. The achievement has no practical application right now, but experiments like this have generated considerable excitement in the small international community of theoretical and optical physicists. "This is a breakthrough in the sense that people have thought that was impossible," said Raymond Chiao, a physicist at the University of California at Berkeley who was not involved in the work. Chiao has performed similar experiments using electric fields. In the latest experiment, researchers at NEC developed a device that fired a laser pulse into a glass chamber filled with a vapor of cesium atoms. The researchers say the device is sort of a light amplifier that can push the pulse ahead. Previously, experiments have been done in which light also appeared to achieve such so-called superluminal speeds, but the light was distorted, raising doubts as to whether scientists had really accomplished such a feat. The laser pulse in the NEC experiment exits the chamber with almost exactly the same shape, but with less intensity, Wang said. The pulse may look like a straight beam but actually behaves like waves of light particles. The light can leave the chamber before it has finished entering because the cesium atoms change the properties of the light, allowing it to exit more quickly than in a vacuum. The leading edge of the light pulse has all the information needed to produce the pulse on the other end of the chamber, so the entire pulse does not need to reach the chamber for it to exit the other side. The experiment produces an almost identical light pulse that exits the chamber and travels about 60 feet before the main part of the laser pulse finishes entering the chamber, Wang said. Wang said the effect is possible only because light has no mass; the same thig cannot be done with physical objects. The Princeton experiment and others like it test the limits of the theory of relativity that Albert Einstein developed nearly a century ago. According to the special theory of relativity, the speed of particles of light in a vacuum, such as outer space, is the only absolute measurement in the universe. The speed of everything else -- rockets or inchworms -- is relative to the observer, Einstein and others explained. In everyday circumstances, an object cannot travel faster than light. The Princeton experiment and others change these circumstances by using devices such as the cesium chamber rather than a vacuum. Ultimately, the work may contribute to the development of faster computers that carry information in light particles. Not everyone agrees on the implications of the NEC experiment. Aephraim Steinberg, a physicist at the University of Toronto, said the light particles coming out of the cesium chamber may not have been the same ones that entered, so he questions whether the speed of light was broken. Still, the work is important, he said: "The interesting thing is how did they manage to produce light that looks exactly like something that didn't get there yet?"
www.cbsnews.com
