Debunking the Princess Leia lie

By Kate Repantis

Like many alumni, Daniel Smalley ’05, MEng ’06, SM ’08, PhD ’13 is a Star Warsenthusiast. But when he watches the first episode in the Star Wars series, Smalley is academically miffed.

In the movie, R2-D2 delivers a seemingly holographic yet also 3-D message from Princess Leia pleading for Obi-Wan Kenobi’s help. “There’s a violation of physics here,” Smalley says.

“The way we interpret that movie scene is, R2-D2 is creating an image in space that can be seen from every angle, just like a real physical object,” he explains. “A real physical object shoots [light] photons in all directions.” But the Princess Leia message is not real—she’s a display created by light, which travels in a straight line. In reality, the princess would only be seen by the film’s other characters if they stared at her from the exact same direction—down the barrel of R2-D2’s projector.

Spurred on by this and further pop culture slights to physics, like that of Iron Man’s gauntlet, which appears in both 3-D and holographic form (“It almost ruined the movie for me,” he remembers), Smalley formed the Electro-Holography Research Group as a new professor at Brigham Young University after graduating from MIT.

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