A new study suggests that by 2020 there will be as many as 492 million motion and gesture-tracking devices. According to researchers, gesture and motion control will become vital for certain forms of human-computer interaction in the coming years.

On Thursday Elon Musk said that his company's solar roof will likely cost less than a normal roof, including labor costs. SolarCity CEO Lyndon Rive said that the companies are aiming for 40 cents a Watt, which would put it in line with the competition.

SETI senior astronomer Seth Shostak says we should expand our search for extraterrestrial life to include sentient alien machines. According to Shostak, if we can develop artificial intelligence within a couple 100 years of inventing radio, any aliens we are likely to hear from have likely gone past that point.

The popular phrase “where there’s smoke there’s fire” is a lie. Lots of things cause smoke without fire. Smoke bombs, for example. And barbecue, which is so integral to a happy life that no reasonable person could imagine the world without it. Anyone who claims that fire always accompanies smoke is a barbecue denier.