Scientists have created the world's thinnest balloon, made of a single layer of carbon just one atom thick.The fabric that the balloon is made of is leakproof to even the tiniest airborne molecules. It could find use in "aquariums" smaller than a red blood cell, through which scientists could peer at molecules, researchers suggested.The balloon is made of graphite, as found in pencils, which is made of atom-thin sheets of carbon stacked on top of each other known. The sheets are known as graphene.Graphene is highly electrically conductive, and scientists are feverishly researching whether it could find use in advanced circuitry and other devices."We were studying little graphene trampolines, and by complete accident, we made a graphene sheet over a hole. Then we started studying it, and saw that it was trapping gas inside," said researcher Paul McEuen, a physicist at Cornell University in Ithaca, N.Y.By experimenting further with bubbles made of graphene, McEuen and his colleagues found the membranes were impermeable to even the smallest gas molecules, including helium."It's amazing that something only an atom thick can be an impenetrable barrier. You can have gas on one side and vacuum or liquid on the other, and with a wall only one atom thick, nothing would go through it," McEuen told LiveScience.
The short answer is "no", but it is a qualified "no" because there are odd ways of interpreting the question which could justify the answer "yes". Light is composed of photons so we could ask if the photon has mass. The answer is then definitely "no": The photon is a massless particle. According to theory it has energy and momentum but no mass and this is confirmed by experiment to within strict limits. Even before it was known that light is composed of photons it was known that light carries momentum and will exert a pressure on a surface. This is not evidence that it has mass since momentum can exist without mass. [ For details see the Physics FAQ article What is the mass of the photon? ]. Sometimes people like to say that the photon does have mass because a photon has energy E = hf where h is Planck's constant and f is the frequency of the photon. Energy, they say, is equivalent to mass according to Einstein's famous formula E = m...
Comments