The focal ratio of brightness level in a vacuum is the absolute f number limit point of the population . Nothing will go faster than 299,792 kilometers per second ( 186,000 mile per second ) , harmonize to Einstein ’s employment , as it would need an infinite amount of Energy Department to do so .

However , that does n’t mean that light ca n’t be beaten in terminal figure of speed under the right set of destiny . In water , for example , light is slow up down to 225,000 kilometers per second ( 139,800 miles per secondment ) , which is still middling zippy , but can be beat by speck ( e.g. in a atomic nuclear reactor ) and leave inCherenkov light .

But 225,000 klick per 2nd is far from the slowest that light has ever move . In 1998 , scientists were able to slow it to just 17 metre per second , or an embarrassing 61.2 kilometer ( 38 miles ) per time of day .

slow up light was not the ultimate heading of the experimentation . The squad were groovy to learn Bose - Einstein Condensate ( BEC ) , a state of matter first hypothesized by Albert Einstein based on the workplace of theoretical physicist Satyendra Nath Bose . When a gas of boson – subatomic force - carrying corpuscle that have integer twirl – are cooled to temperatures approaching absolute zero , they organize asingle quantum physical object , often compared to itacting as a single particle .

" The moving ridge function of a BEC corresponds to the ground nation of a macroscopic quantum object , " onepaper explicate . " In other Scripture , a collection of atoms in a BEC behaves as a single quantum entity . "

In this strange novel state of matter , first created in the real worldin 1995 , you get a macroscopic looking at at quantum behavior .

It has plenty of eldritch properties , includingzero viscosity . You get some of this stuff in a drinking glass , it will crawl up theside of the field glass . They can sustain vortex that can be used to createanalog black hole , and explode in a way like to a supernova , termed abosenova . It ’s pretty unmortgaged why you ’d need to study this stuff and nonsense .

In 1998 , scientist from the Rowland Institute for Science create a BEC by supercooling Na atoms in a vacuum bedchamber . First they send away laser irradiation ( moving at theusual swiftness of light ) at the atomic number 11 , slowing down the particles as they absorb photon . Now slack , they were put in another array of optical maser , where the speck were knocked back in whatever direction they came from , further slowing ( and chill ) the swarm of atoms , kept in place by a sinewy magnetised landing field .

Once this was done and a cloud of condensation was formed , the squad kindle one laser across the breadth of it to set up quantum hinderance , while a second laser was fired across its length . Under these conditions , the light was slowed dramatically .

" We prevail a light speed of 17 [ meters per second ] for pulse propagation in an corpuscle cloud ab initio fix as an almost pure Bose Einstein condensation ( condensate fraction is ⩾90 percent ) , " the team wrote of their experimentation . " Whether the cloud remains a condensate during and after pulse extension is an issue that is beyond the reach of this Letter . "

While satisfying , the team realized they could do better .

" Soon after , we succeeded in stopping a short pulse completely in an atomic cloud cooled to a temperature just above the passage temperature for BEC , " the team explains on theHau research lab website . " At the time when the light pulse is slowed , compressed , and comprise within the nuclear sampling , we turn off the dominance laser theater of operations abruptly and then turn it back on at a later sentence . When the control laser is turned back on , the light pulsation is regenerate : we can stop and controllably regenerate the weak impulse . "

The alphabetic character is published inNature .