中国传媒大学学报（自然科学版）
中國傳媒大學學報（自然科學版）
중국전매대학학보（자연과학판）
JOURNAL OF COMMUNICATION UNIVERSITY OF CHINA(SCIENCE AND TECHNOLOGY)
2015年
2期
4-13
,共10页
真空中光速%光速不变原理%米定义%波粒二象性
真空中光速%光速不變原理%米定義%波粒二象性
진공중광속%광속불변원리%미정의%파립이상성
light speed in vacuum%principle of light speed constancy%definity of meter%wave -particle duality
1905年Einstein发表了著名的狭义相对论( SR)文章,其中说光在真空中总以不变的速度传播。然而这个光速不变性原理一直缺乏可靠的实验证明,近年来的一些研究成果倒像是证伪了这一原理。例如,美国Maryland大学的物理学家James Franson于2014年6月发表论文引起物理界的广泛关注,文章宣称已可证明光速比过去所认为的值要慢。他的论据来源于对1987年超新星SN1987A的观测,当时在地球上检测到由爆发而来的光子和中微子,而光子比中微子晚到4.7h,过去对此现象人们只作了模糊的解释。 Franson认为这可能是由光子的真空极化造成的———光子分开为一个正电子和一个电子,在很短时间内又重组为光子。在引力势作用下,重组时粒子能量有微小改变,使速度变慢。粒子在飞经168000光年的过程中(从SN1987A到地球),这种不断发生的分合将造成光子晚到4.7h。另一个例子是,2015年1月英国Glasgow大学的Padgett研究组做到了使光的运行比真空中光速( c)要慢。他们使光子经过一个专用的散射结构物,波形被改变,从而速度变慢。令人惊奇的是,光子出来后(即回到自由空间)仍以减慢了的速度行进。Franson理论和Padgett小组实验损坏了真空中光速的恒值性,使c成为“不恒定的常数”,或“不常的常数”。这种情况妨害了SR理论及现行米定义的理论基础。另外,本文比较了1993年的SKC实验和2015年的空间结构化光子实验,前者以量子隧穿和消失波为基础,后者则改变光束的横向空间结构。二者都使用相关光子对,结果都显示光子群速的变化。如今或许可以终结关于光速不变原理的讨论。……在现代物理学中波粒二象性仍是难题,但新近研究对此有新的理解,与互补原理不同；故更宜于用波理论解释粒子实验。在Padgett小组实验中,无论Bessel波束或Gauss波束光子群速均减小,表现为在1m的实验距离上迟到若干微米。……最后,本文指出近年来的光速研究为波科学带来丰富体验,为理论思维造成新机会。
1905年Einstein髮錶瞭著名的狹義相對論( SR)文章,其中說光在真空中總以不變的速度傳播。然而這箇光速不變性原理一直缺乏可靠的實驗證明,近年來的一些研究成果倒像是證偽瞭這一原理。例如,美國Maryland大學的物理學傢James Franson于2014年6月髮錶論文引起物理界的廣汎關註,文章宣稱已可證明光速比過去所認為的值要慢。他的論據來源于對1987年超新星SN1987A的觀測,噹時在地毬上檢測到由爆髮而來的光子和中微子,而光子比中微子晚到4.7h,過去對此現象人們隻作瞭模糊的解釋。 Franson認為這可能是由光子的真空極化造成的———光子分開為一箇正電子和一箇電子,在很短時間內又重組為光子。在引力勢作用下,重組時粒子能量有微小改變,使速度變慢。粒子在飛經168000光年的過程中(從SN1987A到地毬),這種不斷髮生的分閤將造成光子晚到4.7h。另一箇例子是,2015年1月英國Glasgow大學的Padgett研究組做到瞭使光的運行比真空中光速( c)要慢。他們使光子經過一箇專用的散射結構物,波形被改變,從而速度變慢。令人驚奇的是,光子齣來後(即迴到自由空間)仍以減慢瞭的速度行進。Franson理論和Padgett小組實驗損壞瞭真空中光速的恆值性,使c成為“不恆定的常數”,或“不常的常數”。這種情況妨害瞭SR理論及現行米定義的理論基礎。另外,本文比較瞭1993年的SKC實驗和2015年的空間結構化光子實驗,前者以量子隧穿和消失波為基礎,後者則改變光束的橫嚮空間結構。二者都使用相關光子對,結果都顯示光子群速的變化。如今或許可以終結關于光速不變原理的討論。……在現代物理學中波粒二象性仍是難題,但新近研究對此有新的理解,與互補原理不同；故更宜于用波理論解釋粒子實驗。在Padgett小組實驗中,無論Bessel波束或Gauss波束光子群速均減小,錶現為在1m的實驗距離上遲到若榦微米。……最後,本文指齣近年來的光速研究為波科學帶來豐富體驗,為理論思維造成新機會。
1905년Einstein발표료저명적협의상대론( SR)문장,기중설광재진공중총이불변적속도전파。연이저개광속불변성원리일직결핍가고적실험증명,근년래적일사연구성과도상시증위료저일원리。례여,미국Maryland대학적물이학가James Franson우2014년6월발표논문인기물리계적엄범관주,문장선칭이가증명광속비과거소인위적치요만。타적론거래원우대1987년초신성SN1987A적관측,당시재지구상검측도유폭발이래적광자화중미자,이광자비중미자만도4.7h,과거대차현상인문지작료모호적해석。 Franson인위저가능시유광자적진공겁화조성적———광자분개위일개정전자화일개전자,재흔단시간내우중조위광자。재인력세작용하,중조시입자능량유미소개변,사속도변만。입자재비경168000광년적과정중(종SN1987A도지구),저충불단발생적분합장조성광자만도4.7h。령일개례자시,2015년1월영국Glasgow대학적Padgett연구조주도료사광적운행비진공중광속( c)요만。타문사광자경과일개전용적산사결구물,파형피개변,종이속도변만。령인량기적시,광자출래후(즉회도자유공간)잉이감만료적속도행진。Franson이론화Padgett소조실험손배료진공중광속적항치성,사c성위“불항정적상수”,혹“불상적상수”。저충정황방해료SR이론급현행미정의적이론기출。령외,본문비교료1993년적SKC실험화2015년적공간결구화광자실험,전자이양자수천화소실파위기출,후자칙개변광속적횡향공간결구。이자도사용상관광자대,결과도현시광자군속적변화。여금혹허가이종결관우광속불변원리적토론。……재현대물이학중파립이상성잉시난제,단신근연구대차유신적리해,여호보원리불동；고경의우용파이론해석입자실험。재Padgett소조실험중,무론Bessel파속혹Gauss파속광자군속균감소,표현위재1m적실험거리상지도약간미미。……최후,본문지출근년래적광속연구위파과학대래봉부체험,위이론사유조성신궤회。
In 1905,Einstein published his famous paper of Special Relativity(SR),that the speed of light will be locally the same for all condition. But this principle be short of verification of experiment. In recent years,some results falsifying the principle of the light-speed constancy. For example,in June 2014,phys-icist James Franson of the University of Maryland,has captured the attention of the physics community by posting an article, in which he claims to have found evidence that suggests the speed of light as de-scribed by the theory of General Relativity( GR) ,is actually slower than has been thought. Franson’ s arguments are based on observations made of the supernova SN 1987A,it exploded in Feb 1987. Meas-urements here on Earth picked up the arrival of both photons and neutrinos from the blast but there was a problem—the arrival of the photons was later than expected,by 4. 7 hours. Scientists at the time attribu-ted it to a likelihood that the photons were actually from another source. But what if that wasn’ t what it was,Franson wonders,what if light slows down as it travels due to a property of photons known as vacuum polarization—where a photon splits into a positron and an electron,for a very short time before recombi-ning back into a photon. That should create a gravitational potential,between the pair of particles,which, he theorizes,would have a tiny energy impact when they recombine—enough to cause a slight bit of a sl-owdown during travel. If such splitting and rejoining occurred many times with many photons on a journey of 168000 light years,the distance between us and SN 1987A,it could easily add up to the 4. 7 hour de-lay. For another example,in Jan 2015,a team of scientists in Glasgow University has made light travel slower than speed of light in vacuum ( c) . The photons through a special mask,it changed the wave shape of photon,and slowed it to less than light speed c. But it had not just been slowed by the mask,but had continued to travel at less than light speed ( c) even after it has returned to free space. The theory of Franson and the experiment of Padgett’ s team wrecked the constancy of light-speed c in vacuum. Then,c is an “inconstant constant”,or an “not-so-constant constant”. This situation im-pair the theoretical basis of SR and the definity on meter by CGPM in 1983 . In other words,we compare the two experiments—the first article pulished in 1993,it named the“SKC experiment”;the second article pubished in Jan 2015 , it named “spatially structured photons ex-periment”. The first experiment was based on quantum tunneling effect and evanescent waves, and the second experiment was based on changing the beam’ s transverse spatial structure. Both them are using time-correlated photon pairs,and the results shows a variation of the group velocity of photons. Anyway, we may say perhaps that these experiments was the summation of discussions about the constancy of light speed c in free space. …… Now, the particle - wave duality still the magic ghost in modern phys-ics. Recent advances in study shows,the quantum objects can behave beyond the wave-particle duality and the complementarity principle would stimulate new conceptual examination and exploration of quan-tum theory at a deeper level. Then we are very reasonable if we expect to understand the photon’ s experi-ment that explaned by the wave’ s theory. In the article of Padgett’ s team,it shows a reduction of the group velocity of photons in both a Bessel beam and photons in a Gaussian beam. In both cases,the delay is several micrometers over a propagation distance of 1m. …… Finally,the study on light velocity in re-cent years has a great deal of experience on wave sciences,and bring the new chance on theoretical think-ing.
