Jao, tek su, dakle, prije dvije godine skontali da brzina svjetlosti fakat ovisi i o gustini medija kroz koje se svjetlost kreće.Magazine issue: Vol. 187, No. 4, February 21, 2015, p. 7
Ma ne kreće se kad joj ponestane sapi...Šabović Adis wrote: ↑26 May 2017, 14:19Jao, tek su, dakle, prije dvije godine skontali da brzina svjetlosti fakat ovisi i o gustini medija kroz koje se svjetlost kreće.
Đeca usedmom osnovne to znaju.
BTW, svjetlost se kreće isključivo brzinom svjetlosti.
Neće se valjda kretat' brzinom zvuka...
Ma članak je na arxivu još i ranije objavljen:Šabović Adis wrote: ↑26 May 2017, 14:19Jao, tek su, dakle, prije dvije godine skontali da brzina svjetlosti fakat ovisi i o gustini medija kroz koje se svjetlost kreće.
Đeca usedmom osnovne to znaju.
BTW, svjetlost se kreće isključivo brzinom svjetlosti.
Neće se valjda kretat' brzinom zvuka...
That the speed of light in free space is constant is a cornerstone of modern physics. However, light beams have finite transverse size, which leads to a modification of their wavevectors resulting in a change to their phase and group velocities. We study the group velocity of single photons by measuring a change in their arrival time that results from changing the beam's transverse spatial structure. Using time-correlated photon pairs we show a reduction of the group velocity of photons in both a Bessel beam and photons in a focused Gaussian beam. In both cases, the delay is several microns over a propagation distance of the order of 1 m. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves. Introducing spatial structure to an optical beam, even for a single photon, reduces the group velocity of the light by a readily measurable amount.
