To a computer, words and sentences appear like data. But AI researchers want to teach computers how to actually understand the meaning of a sentence and learn from it.

One of the best ways to test the capability of an AI to do that is to see whether it can understand and follow a set of instructions for a task that it’s unfamiliar with. Regina Barzilay, a professor of computer science and electrical engineering at MIT’s computer science and AI lab, has attempted to do just that — teaching a computer to play Sid Meier’s Civilization.

In Civilization...

By Yun Xie, Ars Technica

Since the 1970s, chemists have worked on storing solar energy in molecules that change state in response to light. These photoactive molecules could be the ideal solar fuel, as the right material should be transportable, affordable, and rechargeable. Unfortunately, scientists haven’t had much success.

One of the best examples in recent years, tetracarbonly-diruthenium fulvalene, requires the use of ruthenium, which is rare and expensive. Furthermore, the ruthenium compound has a volumetric energy density (watt-hours per liter) that is several...