A new Star Wars movie has arrived in theaters to make us dream. Full of technology and adventures, it’s willing to show us the depth of the galaxy – united with the force, of course.
But as a scientist at Duke, I cannot stop trying to explain the laws of nature, and one question comes to my mind when thinking of the Jedi: Where is the force in the universe?
If the force exists and the Jedi can feel it, our devices should be able to detect it, shouldn’t they? In order to try to understand what and where the force is in the landscape of science, remember the definition that Master Obi Wan gave to Luke in the first movie, “A New Hope.”
“The force is what gives the Jedi its power. It’s an energy field created by all living things. It surrounds us. It penetrates us. It binds the galaxy together.”
Is there in the universe an energy field with these characteristics? There are two things in the universe that could fit that description, and both come from the dark side: dark energy and dark matter.
These two concepts are not really well-known nowadays. They are called dark because they don’t emit light. They constitute 69 percent and 27 percent, respectively, of the content of the universe. You can tell that the dark side really rules the galaxy. They both are distributed all through the universe, although there are differences: Dark matter is attractive gravitationally, and therefore forms lumps, while dark energy is repulsive.
In any case, neither has been directly detected yet. Dark energy was postulated in the late 20th century to explain some observations from 1998 that pointed out that the universe is accelerating its expansion. It should be some sort of repulsive pressure that pulls the universe apart, making it grow faster and faster.
But dark energy does not bind the galaxy together. If it continues as it is doing now, dark energy will pull the universe so intensely it will break it, tearing galaxies apart. Dark energy cannot be the force.
In the case of dark matter, the most likely candidate is the so-called WIMPs (weakly interactive massive particles). These are described as very heavy particles that don’t interact through the electromagnetic force. This lack of interaction makes dark matter undetectable (or at least it has not yet been detected). From what we know of dark matter, it should be penetrating us without us noticing it. Dark matter is attractive gravitationally. Indeed, the movement and formation of galaxies can’t be explained with the amount of matter we observe from stars, and we need the existence of dark matter to explain it. Yes, dark matter surrounds us, penetrates us and binds the galaxy together.
Is dark matter the Jedi force?
Well, dark matter should penetrate living creatures as well as water, rocks or even stars. But Obi Wan could be referring to baryonic matter (the one made out of ordinary atoms, like you and me) when he said living things. In a poetic form, he could be talking about the matter we can see, the type of matter that can create life (5 percent of the content of the universe). If he meant that the force penetrated ordinary matter, then he could be talking about dark matter.
But may a Jedi use the force?
The way we interact with things is through the forces. These forces are the electromagnetic force, the gravitational force and two nuclear forces. But we are all made out of atoms, so whatever sensor the Jedi has to feel the force (be it dark matter or not) we should be able to build detectors, also made out of atoms, to detect it, too. And we can’t detect dark matter yet.
Well, these days scientists at the CERN laboratory in Switzerland seem to have found a new, exotic type of particle. Will it be dark matter? Are we about to feel the force?
Whatever happens, may the science be with you.
Andres Aragoneses, originally from Spain, is a postdoctoral physics researcher at Duke University.