Photons are the carriers of the electromagnetic force right? (whatever that means--I can't visualize how a particle carries a force, for me a force is something immaterial)
Can we create a powerful light source capable of exerting a force on air a create propulsion? Therefore lifting some weight against gravity?
If so, how much energy/power would we need?
Thanks!
Radiation pressure can indeed be used to power solar sails, but the pressure is minute, so it only makes sense to use it in outer space, where it isn't drowned out by the atmosphere. Generally, most proposals use solar radiation, since it is cheaply available (and can even take you inwards to, say, Venus, if you use it correctly), but the use of concentrated laser power could also work - you'd just need a humongously big laser for it, and in many cases there's easier and cheaper ways to do the same thing.
See the linked Wikipedia page for more details and examples.
