Why the Infinite Improbability Drive Is Really, Really Improbable

An aerospace engineer from NASA on why science fiction can be so inspiring and so disappointing.

by Elisabeth Sherman

Imagine a world in which your favorite science fiction stories are a reality: A steaming cup of tea materializes before your eyes as you zip through space using an improbability drive with a portal gun tucked snugly into your belt. Sounds great, right? Unfortunately — and sorry to spoil the fantasy — it’s best to not get too excited about a post-scarcity universe or a hyperspeed commute. Many of the gadgets we’ve grown accustomed to seeing on screen violate the physical laws of this universe, which means that unless you have access to another universe (please get in touch if so), you’ll have to settle for something Newtonian.

In an effort to get over our disappointment with reality, we spoke to Marc Millis, a former aerospace engineer at NASA’s Glenn Research Center and the founder of the Tau Zero Foundation, and Dr. Adam Bruckner, a professor of Aeronautics and Astronautics at the University of Washington, about three of science fiction’s most iconic gadgets. They explained precisely why these tools have to stay in the fictional box. It’s a total bummer but also very informative — and that’s something.

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The Infinite Improbability Drive

In Hitchhiker’s Guide to the Galaxy, the spaceship Heart of Gold — which will lend its name to the SpaceX Mars Mission ship — uses an “Improbability Drive” to skip traveling through hyperspace by “using probability” to arrive at random locations throughout the universe. This means that if you enable the drive, it will take you somewhere completely unexpected every single time. You never know where you’ll end up. It makes for a good adventure, but it’s not exactly practical.

Weirdly enough, there is a kernel of scientific foundation for this type of device. Bear with me, because its a little tricky to grasp: According to the books, the drive was inspired by the fact that although particles are supposed to appear near the nucleus of an atom, there’s an infinitesimally small chance that these particles will sometimes be found far away from their point of origin. The scientists who built the Heart of Gold then theorized that the same concept could be applied to space travel, allowing a body to travel between locations without passing through the intervening space. Thus the improbability drive was born.

“Quantum physics actually shows that a particle might not be exactly where [one] would expect it to be. On the tiny scales that quantum physics describes, there’s something called the ‘probability distribution function’ for a particle’s location. It shows where the particle is most likely to be [but] that region extends out to farther distances, albeit with diminishing probability,” explained Millis.

Bruckner confirms that using probability to get anywhere deliberately would be futile because “with probabilities, there is no determinism.” But even if you wanted to build a spaceship that used probability as part of its operating system, you wouldnt have much luck.

“Your entire spaceship, which is macroscopic, would have to behave like a quantum particle. Every single atom in this spacecraft would be forced to behave like every other atom,” he explained. “Macroscopic things cannot be made to behave like one atom or one electron.”

As for the chance that humans could somehow figure out a way to control probability? We aren’t ready for that level of power yet, so don’t even think about it.

“If we could come up with a way to be anywhere in any multiverse, what would differentiate us from the concept of a God? We would be everywhere and know everything,” Dr. Bruckner warns.

The Portal Gun

Rick Sanchez’s portal gun — which he uses to shoot holes in the fabric of spacetime, allowing himself and Morty to enter different universes — violates the laws of physics within this universe, but that’s only half the problem. The rest of the problem is that there is no way to know whether or not other universes would be bound by the same physical laws as our own.

“There’s no way to prove that all universes obey all the same physical laws or use quantum mechanics,” said Dr. Bruckner. “Nothing says that another universe grew out of a Big Bang.”

According to the multiverse theory, some universes outside of ours could be exactly the same, while others could be just slightly different. Maybe history took a different path; maybe you and I were never born. This idea certainly reflects how alternate universes are treated on Rick and Morty — just watch the episode “Close Rick-Counters of the Rick Kind.” However, that’s pretty much the only thing about the portal gun that matches up with known scientific theories.

“The closest thing I know in physics to “portals” are wormholes,” Millis says. Scientists speculate that wormholes are connections between widely separated regions of space, but the concept is still hypothetical; they haven’t been observed in space yet. If wormholes do provide a shortcut between locations in the universe, then it’s reasonable to speculate that a super-genius like Rick would find a way to harness this power to transport him into other worlds. Still, Rick would have to have great aim, because as Millis points out, a common confusion with the term “multiple dimensions” is that it’s naively assumed to mean multiple sets of familiar 3D spaces. Multiple dimensions can also mean that space has other characteristics.” They might not all be three dimensional — even time may operate differently.

Last year, scientists at CERN’s Large Hardron Collider speculated that it might be possible for gravity to “leak” into extra dimensions through miniature black holes, which they tried to detect to using the LHC. That means it would take a massive particle collider operating at trillions of electric volts to produce even a mini black hole. A hand held device that could do the same is out of the question…for now.

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The Replicator

The United Federation of Planets found a way to eliminate hunger from the planets under its benevolent wings, thanks in large to the replicator, a device that rearranges particles into molecules and molecules into objects. It’s a conceivable technology, because as Einstein’s famous E=mc2 equation proved, matter is just another form of energy, which would allow objects with mass to be created out of said energy. Scientists say this is not a totally insane notion and that there are two potential methods for making the replicator a reality.

Scientists working with the European Strategy Forum for Research Infrastructure are building ELI, or the Extreme Light Infrastructure. ELI, a high-powered laser so powerful that if you shot one of its beams into so-called empty space (remember, quantum mechanics stipulates there is no such thing as empty space because super tiny particles are floating around us literally everywhere), it would stop particles from colliding and annihilating each other. What does this have to do with making tea materialize out of thin air? If particles don’t get annihilated, they end up with mass in what was once an empty region of space. So it’s not food quite yet, but it still creates objects where there weren’t objects before.

In a much more practical and far simpler experiment, scientists at NASA are working on a 3D printer that can produce food. Their aim is provide astronauts with a device that can produce sustenance for them during long voyages. In 2013, a version of the device produced a pizza in twelve minutes.

Such a device might land us humans one step closer to Gene Roddenberry’s fantasy of a Utopian future: If the printer ever becomes widely available to the public, it could eliminate starvation, provide relief from food shortages, and give impoverished communities the food and water resources they so desperately need.

Plus, it would give me another reason to brag about how important and influential Star Trek turned out to be, which is of course, the most important thing here.

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