Physicist does the math on Star Trek’s “Picard maneuver”

“And after I drew one or two diagrams, I started noticing, ‘Hey, I think I’ve thought about something like this before,’” said de Aguiar Alves.

Three images, not two

The idea behind the Picard maneuver comes from the way a faster-than-light spaceship would outrun its own light. If the spaceship were going at a constant, faster-than-light speed, then another ship at rest would see two images, corresponding to two different times when light from the ship could reach them.

But in the story, Picard’s ship isn’t going at a constant speed. He speeds up to warp speed, then stops close to the enemy ship. The Stargazer accelerates twice… and that changes the timing. After diagramming things out, de Aguiar Alves found that the enemy ship would see three images of the Stargazer, not two.

Left: The thin gray lines show what would be seen from the Ferengi vessel at different time points. At some times, as many as three images of the Stargazer will be visible.
Right: Adding another burst of warp speed can boost the number of Stargazer images to five.

While the details were wrong, de Aguiar Alves was impressed that the episode reproduced the core textbook idea mostly accurately. “The main thing they got perfectly, and I think it is a great illustration.”

Physicists don’t expect faster-than-light space travel to ever be possible. But because light travels more slowly in substances like water, the math of faster-than-light travel is still useful. When a particle travels faster than light can in water, its shockwave emits a characteristic glow called Cherenkov radiation, the blue light seen in nuclear reactors.

For de Aguiar Alves, the motivation was a more elusive physical phenomenon, called the memory effect. First theorized for gravitational waves, the memory effect happens when a wave passes by a particle and leaves a lasting effect on its motion. Theoretical physicists expect it to happen when ordinary electromagnetic waves pass a particle, too, but it requires very specific circumstances and is very hard to detect. Recently, a physicist at the Niels Bohr Institute has argued that the effect should be more dramatic in a medium like water with a limited speed of light. Wanting to understand this better inspired de Aguiar Alves to try to picture how a memory-effect-influenced electron would be detected, and the diagrams he drew helped him picture the Star Trek scenario as well.

“You get a lot of intuition very quickly, and pretty much for free, by just doodling,” said de Aguiar Alves.

Matt von Hippel is a freelance science writer based in Copenhagen, with a background in particle physics. In addition to journalism, he blogs weekly at 4gravitons.com.