Given the risks of aiming such a powerful beam of high-intensity radiation at an Earth ground station, as well as the cost of building billions of dollars in infrastructure to collect the energy in space, the efficiencies you can get from terrestrial solar power seem a safer bet--at least for now.

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During my tour, he also showed how that same wall can be used to beam in 2D or 3D video from the Web, including the International Space Station.

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