I don't know, I still think the phrase is apt. People complaining they are "just a pawn" are usually as much complaining they don't have any control (the chess master is in control) as they are complaining they are weak. And while your pawns are "valuable" in that, while you can't afford to throw them away, they are…

Our wavelength range makes a lot of sense. It is centered around the peak wavelength of the sun. Animals that see in IR tend to use it for night vision (when the peak wavelengths are in the IR) but even then their range mostly overlaps with ours. It is likely that aliens would therefore have similar ranges to us…

Actually, power storage is one of the biggest problems for solar power. Unlike fuel burning power plants which can decrease or increase their power output as needed, solar power output is only dictated by the sun. If you want to use solar power at night you need some way to store that energy and giant batteries just…

One substantially issue that wasn't mentioned is the problem of light collecting area. The earth only receives so much sunlight per surface area. By placing trees in a skyscraper that is (for example) 100 stories tall effectively increases tree density by a factor of 100 and therefore decreases the amount of light…

One other obvious problem is light collecting area. The earth only gets so much sunlight per surface area. By placing trees on a hundred stories (for example) you've essentially increased the tree density per surface area by a factor of 100 which means you have decreased the amount of sunlight available to each tree…