When entertainment and science meet, coolness can result. A fresh example comes from "Fantastic Four," a sci-fi adventure film opening this week. Its studio, 20th Century Fox, promotes the superhero thriller with four videos explaining the science behind the fiction on screen. In the promos (see one below), physicist Michio Kaku talks about the realities and near-possibilities of alternate dimensions and other fantasies.

Even the characters' powers, like invisibility, are more realistic than you might think. "Metamaterials interact with light in bizarre ways," Kaku says in one clip. "See this Pyrex glass that seemingly disappears right before our eyes. The Pyrex and the oil have what we call the same refractive index." Elsewhere in the real world, the U.S. military is working on Iron Man-style suits with exoskeletons (motorized, wearable frames) that could lift hundreds of pounds. The super-strength frames also will have have communications, night vision and a display showing battle information graphics in real time.

A similar project at Panasonic aims at a version for private industry that weighs just over 13 pounds and lets wearers carry an additional 33 pounds. A much larger style could help workers carry up to 220 pounds. Developing powerful, long-life batteries that can be worn comfortably is the biggest challenge for real-life Iron Man suits. Other futuristic research at the Pentagon involves body-cooling vests, helmets that sense hidden threats and liquid armor that hardens when bullets hit – showing again that truth can be as exciting and imaginative as action movies.

Professor says: "They [filmmakers] need to get it right enough that the audience buys into and doesn't stop and question the suspension of disbelief." -- James Kakalios, University of Minnesota physicist

Panasonic says: "We expect that exoskeletons, or power-assist suits, will be widely used in people's lives in 15 years." -- Mio Yamanaka, spokesperson in Osaka, Japan

Research executive says: "We're all about augmenting human strength and endurance. To do that you have to wrap a robot around a person." – Nathan Harding, chief executive of Ekso Bionics in Berkeley, Calif.