Mechanical Resonance on Atomic Size Scalee ```Name: Andy Status: student Grade: 9-12 Country: United Kingdom Date: Summer 2011 ``` Question: I'm thinking about resonance. In particular about the resonate frequency of products (eg the singer breaking the glass by singing a note at the resonate frequency of the wine glass). I understand the theory of resonance, but was wondering what happens if you resonate a an element in gas form - eg oxygen - in a fixed volume box/container? What happens to the oxygen, does it break down? Or polarize? Is heat produced? If heat is produced what happens when you stop resonating - does it get very cold as a result? Replies: Andy, Temperature is defined as molecular vibrations at an atomic level. So yes, if you were to vibrate an oxygen atom, that, by definition, would be raising its temperature. Conversely, one way scientists cool atoms to extremely cold temperatures (very near absolute zero), is to hit them with lasers to stop those vibrations. I suggest you read about the molecular definition of temperature (or if you are ambitious, read about quantum thermodynamics) for more information. Hope this helps, Burr Zimmerman In order to have a resonance, it is necessary to have a restoring force acting on the target -- the forces holding the glass together in your first example. Unless the pressure of a gas is very high, there are no restoring forces to overcome the impinging force. Now everything has its exceptions. If the gas is at sufficiently high pressure that it is a liquid there are restoring forces, but these behave by forming bubbles if the impinging pressure exceeds the vapor pressure of the liquid at the temperature. But that is an extreme example. If the gas is contained in a box, the box can resonate, and the gas will respond accordingly. But that really is not the gas resonating, it is the gas responding to volume changes in the box. To give a complete answer to your question, the conditions of the "experiment" would have to be more precisely defined. Vince Calder Click here to return to the Physics Archives

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