In solids, the atoms are more tightly bonded together, and the elasticĬonstants are higher. The atoms are very weakly bonded together and the elastic constants are very The stronger the bond, the higher the elastic constants. What determines the elastic constants of a material is the interatomic bond Larger in liquids than in gases is because of the elastics constants of the Sound velocity is usually larger in solids than in liquids and usually Than in solids and liquids which, of course, is not true. Therefore, by a simple densityĪrgument, one should conclude that the sound velocity is higher in gases Modulus to the mass density of the material. The square of the sound velocity is proportional to the ratio of an elastic If one solves the wave equation for the propagation of sound, one finds that Gases are the slowest because they are the least dense: the molecules in gases are very far apart, compared with solids and liquids.

Liquids are more dense than gases, but less dense than solids, so sound travels 2nd fast in liquids. The distances in liquids are shorter than in gases,īut longer than in solids. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids. it takes less time for a molecule of the solid to 'bump' into its neighborough. Because theyĪre so close, than can collide very quickly, i.e. The distances between molecules in solids are very small, i.e., solids are more dense - as compared to liquids and gases. Sound is nothing more than a local disturbance whose propagation is facilitated by the collisions between particles this disturbance propagates inĪ logitudnal wave imagine one molecule hitting the next molecule, and then that molecule hitting the next, and so forth. Not everyone agrees on the implications of the NEC experiment.Īephraim Steinberg, a physicist at the University of Toronto, said the light particles coming out of the cesium chamber may not have been the same ones that entered, so he questions whether the speed of light was broken.Why does sound travel faster in solids than in liquids, and faster in liquids than in gases (air)? Asked by: Will K Ultimately, the work may contribute to the development of faster computers that carry information in light particles. The Princeton experiment and others change these circumstances by using devices such as the cesium chamber rather than a vacuum. In everyday circumstances, an object cannot travel faster than light. However, within a single phase of matter, the inertial. The speed of everything else - rockets or inchworms - is relative to the observer, Einstein and others explained. As stated above, sound waves travel faster in solids than they do in liquids than they do in gases. The Princeton experiment and others like it test the limits of the theory of relativity that Albert Einstein developed nearly a century ago.Īccording to the special theory of relativity, the speed of particles of light in a vacuum, such as outer space, is the only absolute measurement in the universe. Wang said the effect is possible only because light has no mass the same thig cannot be done with physical objects. 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. 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. 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. Another reason is that light waves don’t need to travel through a medium like sound waves do.Light waves are able to travel through a vacuum, which means they don’t need anything to help them move along. One reason is that light waves are much shorter than sound waves. 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. There are a few reasons why light travels faster than sound. 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.

Sound travels faster than light