[rat156]

Hi All,

First post in the hard science side of the forums, take it easy on me please...

Anyway, I'm taking pretty pictures of RCW58 at the moment, some of the descriptions of the nebula mention that the shape is formed by light colliding with the gas from the expelled gas from earlier events. Now, I can see how this would energise the gas clouds and make them emit light, a fact that I'm now taking advantage of, but several websites describe this and other similar nebulae as "light blown", i.e. the pressure from the intense UV radiation is actually moving and shaping the gas clouds.

I was thinking about this on my drive to work this morning (where other more macro physics problems should have been entertained, but the traffic wasn't moving), how can something without mass transfer kinetic energy? How can "light pressure" actually move something?

Cheers
Stuart