Let me give this a try. I suspect that the magnitude of energy delivered by the UV rays is not quite enough to allow ignition of a small region of the gasoline. It reminds me of the ignition of gunpowder where a flame can be placed upon a small amount of powder and it takes some time before ignition occurs.
I have always felt that if you consider a small volume of the material you would have the following occur. Heat or explosive effect is generated within the volume of material, but the energy escapes through the surface area of that volume. If the heat is reduced too much after flowing through the surface, then it can not cause the adjacent volume to ignite. Just my two cents worth....maybe wrong but this is what I have always thought. Dave -----Original Message----- From: mixent <[email protected]> To: VORTEX <[email protected]> Sent: Sun, Apr 22, 2012 6:02 pm Subject: [Vo]:Ignition Hi, Here's a little conundrum that has troubled me for some time. ake a cup of gasoline and place it in open sunlight. It will slowly evaporate. ring a flame near it and it will suddenly ignite. Why don't the UV rays from sunlight cause ignition? Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
