Answer 2: The skin of the bag will begin to shine, but the shape of the bag remains to be squashed state yet.
Thank you for your response.
I am sorry to be late to answer to you. I was waiting for other's responses too.
I am very sorry if my wording was insufficient in the first blog.
I wished to mean a bag having skin like an aluminum foil.
Its metallic optical reflectance is 100%. It is not a black-body.
So that the photons injected from the laser equippment will be reflected back completely elastically.
As a reaction, I believe that the entire surface of the interior of the bag must feel a radiation pressure.
So, if the weight of material constituting the bag is sufficiently light practically, then the bag must be inflated until a balance between the reaction pressure from the skin and the whole inflow of the radiation pressure from the laser equippment is reached. My opinion is for Answer 3.
Please refer to a physics dictionary if you would like.
And do you know about "Solar Sail" which is being planned by Planetary Society?
February 21, 2013