![speed of sound vs speed of light speed of sound vs speed of light](http://townsquare.media/site/622/files/2011/06/katsuhirootomo-akira-04.jpg)
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.
![speed of sound vs speed of light speed of sound vs speed of light](https://i.redd.it/lhjiotn3z6p01.jpg)
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.
![speed of sound vs speed of light speed of sound vs speed of light](https://i.ytimg.com/vi/F6Q4aFYzCFU/maxresdefault.jpg)
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 pulse may look like a straight beam but actually behaves like waves of light particles. The laser pulse in the NEC experiment exits the chamber with almost exactly the same shape, but with less intensity, Wang said. 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 researchers say the device is sort of a light amplifier that can push the pulse ahead. 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.