Cambridge, Massachusetts - When you shine a light on a conducting surface like silicon or graphene, that light jump-starts certain electrons into high-energy states and kicks off a cascade of interactions that happens faster than the blink of an eye. Within just a few femtoseconds - a thousand trillionth of a second - these energized electrons can scatter among other electrons like balls on a billiard table, quickly dissipating energy in an ultrafast process known as thermalization.

Cambridge, Massachusetts - Governments often offer subsidies to consumers for clean-technology products, from home solar panels to electric vehicles. But what are the right levels of subsidy, and how should they be calculated? As a new paper co-authored by MIT researchers shows, governments can easily make subsidies too low when they ignore a basic problem: Consumer demand for these products is usually highly uncertain.

Cambridge, Massachusetts - Two MIT researchers have developed a thin-film material whose phase and electrical properties can be switched between metallic and semiconducting simply by applying a small voltage. The material then stays in its new configuration until switched back by another voltage. The discovery could pave the way for a new kind of “nonvolatile” computer memory chip that retains information when the power is switched off, and for energy conversion and catalytic applications.

Ann Arbor, Michigan - The metaphor is an old one in Western civilization—the head represents rationality and the heart represents emotion. The link is often made in speech and literature by pointing at one's head (thinking) or at one's chest (feeling).

Cambridge, Massachusetts - Customer service calls can be frustrating for consumers and agents alike. But MIT spinout Cogito believes it can use behavioral analytics to make those experiences less onerous.

Baltimore, Maryland - A Johns Hopkins Bloomberg School of Public Health analysis of registered medical marijuana users found that a hodgepodge of law and policy changes since 2001 had varying effects on the number of people consuming what in many states remains an otherwise illegal drug for its purported health benefits.