In the universe where Harry Potter, Newt Scamander and fantastic beasts can be found, witches and wizards abound — and they can teleport from one place to the next. This ability is known as apparition. No one in the real world has this talent, especially not poor Muggles (non-magical people) like us. But while it is impossible for anyone to apparate from home to school or work, an atom is another matter. Put enough of those atoms together, and it might actually be possible to create a copy of yourself somewhere else. The only catch? The process would probably kill you.
Characters in movies and books — like the magic users in the Harry Potter series by J.K. Rowling — don’t have to obey the laws of physics. We do. That’s one reason why nobody is ever going to apparate instantly from one place to another. Such instantaneous travel would be blocked by a universal limit, the speed of light.
“Nothing can really be transported from one place to another faster than the speed of light,” says Alexey Gorshkov. He’s a physicist at the Joint Quantum Institute in College Park, Md. (In the Harry Potter world, he notes, he’d be a Gryffindor.) “Even teleportation is limited by the speed of light,” he says.
Light speed is about 300 million meters per second (some 671 million miles per hour). At speeds like that, you could get from London to Paris in 0.001 second. So if someone were to apparate at light speed, they’d move pretty quickly. There would just be a very slight delay between when they’d disappear and appear. And that delay would be bigger the farther they traveled.
In a world without magic, though, how could someone move that fast? Gorshkov has an idea. First, you would have to learn every itsy bitsy thing about a person. “It’s a full description of a human being, all your flaws, and where all your atoms are,” Gorshkov explains. That last bit is really important. Then, you would put all those data into a very advanced computer and send them somewhere else — say from Japan to Brazil. When the data arrive, you could take a pile of matching atoms — carbon, hydrogen and everything else in a body — and assemble a copy of the person in Brazil. You’ve now apparated.
There are some problems with this method of apparition. For one, scientists don’t have any way to figure out the position of every single atom in the body. But the bigger problem is that you end up with two copies of the same person. “The original copy would still be there [in Japan], and someone would probably have to kill you there,” Gorshkov says. But, he notes, the process of getting all that information about the position of every atom in your body might kill you anyway. Still, you’d be alive in Brazil, as a copy of yourself — at least in theory.
Let’s get quantum
Another way of moving data from one place to another comes from the quantum world. Quantum physics is used to explain how matter behaves at the very tiniest scale — single atoms and light particles, for example.
In quantum physics, apparition still isn’t possible. “But we do have something kind of similar, and we call it quantum teleportation,” says Krister Shalm. He’s a physicist at the National Institute of Standards and Technology in Boulder, Colo. (In the Harry Potter universe, he says, he’d be a Slytherin.)
Teleportation in the quantum world requires something called entanglement. This is when particles — say, negatively charged particles called electrons — are linked, even when they aren’t physically close to each other.
When two electrons are entangled, something about them — their position, for example, or which way they spin — is perfectly connected. If electron A in Japan is entangled with electron B in Brazil, a scientist measuring the speed of A also knows what B’s speed is. That’s true even though she’s never seen that faraway electron.
If the scientist in Japan has data on a third electron (electron C) to send to Brazil, then, Gorshkov explains, they can use A to send a bit of information about C to the entangled particle B in Brazil.
The advantage of this kind of transfer, Shalm says, is that the data are teleported, not copied. So you don’t end up with a copy of a person in Brazil and an unfortunate clone left behind in Japan. This method would move all the details about the person from Japan to a waiting pile of atoms in Brazil. Left behind in Japan would be only a pile of atoms without the corresponding information about where everything goes. “The person left over would be a blank canvas,” Shalm explains.
This would be disturbing, he adds. What’s more, scientists can’t do this very well for even a single particle. “With light [particles], it only succeeds 50 percent of the time,” he says. “Would you risk it if it only worked 50 percent of the time?” With odds like that, he notes, it’s better to just walk.
Wilder wormhole theories
There might be ways to apparate that scientists have only theorized about. One is something called a wormhole. Wormholes are tunnels that connect two points in space and time. And if Doctor Who’s TARDIS can use a wormhole, why not a wizard?
In Harry Potter and the Half-Blood Prince, Harry describes apparating as being “pressed very hard from all directions.” That feeling of pressure could be from going down the wormhole, says J.J. Eldridge. She’s an astrophysicist — someone who studies the properties of objects in space — at the University of Auckland in New Zealand. (In the Harry Potter world, she’s a Hufflepuff.). “I just don’t think a single wizard could warp spacetime enough to make one. That would require a lot of energy and mass.” Wormholes also would have to be real. Scientists think that wormholes could exist, but no one — wizard or Muggle — ever has seen one.
And then there’s the Heisenberg uncertainty principle. It states that the more someone knows about the position of a particle, the less they know about how fast the particle is going. Look at it the other way, it means that if someone knows exactly how fast a particle is going, they don’t know anything about where it is. It could be anywhere. It could, for example, have teleported somewhere else.
So if a witch knew enough about exactly how fast she was going, she would know so little about where she was that she could end up somewhere else. “When apparition is described, it says it’s like being pushed in from all sides, so this made me wonder if what’s going on is that the magic user is trying to constrain their speed and slow themselves down,” Eldridge explains. If they slow down, then the magic-user would know a lot about how fast they were going — they aren’t moving at all. But because of the Heisenberg uncertainty principle, they would know less and less about where they were. “Then the uncertainty in their position must grow so that they suddenly vanish and reappear in the direction they’re trying to restrict their [speed] to,” she adds.
Right now, though, Eldridge doesn’t know how someone would make this happen. All she knows is that it would take a lot of energy. “The only way I can think of to slow something down is to decrease its temperature,” she says. “You might need a lot of energy to cool the person down, so all the particles are frozen in place and then jump to the new location.” Freezing all your particles in place, though, is not a healthy thing to do. If it lasted more than an instant, you’d probably be dead.
So maybe it’s better to leave apparition to the quantum world — and the wizards.