Researchers at the University of Central Florida, USA, have developed a way to control the speed of light. Not only can they speed up a pulse of light and slow it down, they can also make it travel backward.
The results were published recently in the journal Nature Communications.
This is coming as a research team that set out to examine the myth of the ‘sugar rush’: can sugar really put you in a better mood?
Using data collected from 31 published studies involving almost 1300 adults, Dr Konstantinos Mantantzis at Humboldt University of Berlin, Dr Sandra Sünram-Lea at Lancaster University, and Dr Friederike Schlaghecken and Professor Elizabeth Maylor in the University of Warwick’s Department of Psychology investigated the effect of sugar on various aspects of mood, including anger, alertness, depression, and fatigue.
They also considered how factors such as the quantity and type of sugar consumed might affect mood, and whether engaging in demanding mental and physical activities made any difference.
The researchers found that :
Professor Elizabeth Maylor, from the University of Warwick, commented:
“We hope that our findings will go a long way to dispel the myth of the ‘sugar rush’ and inform public health policies to decrease sugar consumption.”
Dr Konstantinos Mantantzis, from Humboldt University of Berlin, who led the study, said:
“The idea that sugar can improve mood has been widely influential in popular culture, so much so that people all over the world consume sugary drinks to become more alert or combat fatigue.
“Our findings very clearly indicate that such claims are not substantiated — if anything, sugar will probably make you feel worse.”
Dr Sandra Sünram-Lea added:
“The rise in obesity, diabetes and metabolic syndrome in recent years highlights the need for evidence-based dietary strategies to promote healthy lifestyle across the lifespan. Our findings indicate that sugary drinks or snacks do not provide a quick ‘fuel refill’ to make us feel more alert.”
This achievement is a major step in research that could one day lead to more efficient optical communication, as the technique could be used to alleviate data congestion and prevent information loss. And with more and more devices coming online and data transfer rates becoming higher, this sort of control will be necessary.
Previous attempts at controlling the speed of light have included passing light through various materials to adjust its speed. The new technique, however, allows the speed to be adjusted for the first time in the open, without using any pass-through material to speed it up or slow it down.
“This is the first clear demonstration of controlling the speed of a pulse light in free space,” said study co-author Ayman Abouraddy, a professor in UCF’s College of Optics and Photonics. “And it opens up doors for many applications, an optical buffer being just one of them, but most importantly it’s done in a simple way, that’s repeatable and reliable.”
Abouraddy and study co-author Esat Kondakci demonstrated they could speed a pulse of light up to 30 times the speed of light, slow it down to half the speed of light, and also make the pulse travel backward.
The researchers were able to develop the technique by using a special device known as a spatial light modulator to mix the space and time properties of light, thereby allowing them to control the velocity of the pulse of light. The mixing of the two properties was key to the technique’s success.
“We’re able to control the speed of the pulse by going into the pulse itself and reorganizing its energy such that its space and time degrees of freedom are mixed in with each other,” Abouraddy said.
“We’re very happy with these results, and we’re very hopeful it’s just the starting point of future research,” he said.
Source: Rael-Science Post