I know the first part....

For the second, my point was the possibility of photosynthesis....well not really....perhaps utilising light as an energy source is the better way to put it. I'm thinking from an astrophysical context. Think about constructing solar cells on the moon for example. On earth we can place them anywhere, but on the moon, light has much limited distribution 'cause it isn't scattered......actually i'm not sure, hence the question....Do you get what i mean?