Gadgets & Gizmos: The Transporter

ST-Beam

“Beam me up, Scotty.”

Nobody on Star Trek ever actually said those words. But the phrase has become part of our culture anyway. The concept of instantaneous (or near-instantaneous, at least) transportation is tantalizing: who wouldn’t like to be able to cross a continent, or travel from the Earth’s surface to a ship in orbit, simply by stepping onto a platform and saying, “Energize.”

We are a long way from being able to skip the commute and simply beam to work in the morning. But the concept is no longer pure science fiction like it was in the 1960s.

The Star Trek approach to matter transmission relied on Einstein’s famous mass-energy equivalence. Basically, the idea was that physical objects could be converted to energy, and that energy could be “beamed” from one location to another, where the energy would then be converted back into its original, material form. The problem with this approach is that mass-energy conversion is unfortunately not practical for real-world applications involving ordinary objects, because the amount of energy involved is staggering. If all of the matter contained in a human body were converted to energy, the results would literally be explosive.

The atomic bombs that devastated Hiroshima and Nagasaki converted only a very small percentage of their total mass into energy. Those explosions were the energy released by a mere 700 mg of matter. A human adult weighing 135 lb (62 kg, or 62,000,000 mg) has about 88,571 times that much mass.

Try to imagine 88,571 atomic bombs, all identical to the ones that destroyed Hiroshima and Nagasaki, exploding simultaneously in the same laboratory. Now, try to imagine controlling that much energy.

It is possible that, at some point in the far distant future, we may find a way to control that much energy without destroying the laboratory — and everything else within a hundred kilometres — in the process. But there are other problems with this approach. The Star Trek vision of matter transmission was essentially like saying, “We can ‘beam’ an ice cube by melting it, directing the steam to another location, and then cooling that steam to turn it back into an ice cube.”

The problem is that converting matter to energy isn’t like converting steam to ice. 100% conversion only takes place if the particles are completely annihilated, as in a matter-antimatter reaction (which is a topic for another post).

But there are easier ways to approach the problem of matter transmission, and two of them are currently in their early development stages.

A group at the Hasso Plattner Institute in Brandenberg, Germany, has created a device called “Scotty” (named in honour of the Enterprise chief engineer) that uses a 3D scanner to “read” an object. The object is then destroyed by the scanner, and the data is transmitted to a 3D printer in another location, which then recreates the object. (Want to read their paper?) This device makes it possible to, in effect, “fax” a physical object to somebody else.

The object received on the other end is a re-creation, not the original object, and the device can only transmit items that can be constructed by a 3D printer. (So it is not possible to, for example, use Scotty to send a package of medical supplies to the International Space Station, because the 3D printer would be unable to “print” the actual medicines.) Still, this has the potential to revolutionize the shipping industry as 3D printing technology becomes more sophisticated: sending an encrypted data packet is much faster, and much cheaper, than sending a physical item.

The other approach to matter transmission is “quantum teleportation” which is based on a principle of quantum mechanics known as “quantum entanglement.” Entire books can be — and in fact have been — written on the subject of entanglement. But basically, what quantum entanglement means is that under certain conditions, subatomic particles can become linked together so that their individual quantum states can only be described in terms of the combined whole, rather than describing each particle as a separate entity. Essentially, once particles are entangled, they no longer behave independently. Measuring the state of one entangled particle will tell you the states of both particles.

(You can see how it works here or here.)

And the critical point here is that the distance between the particles is irrelevant. Two entangled particles can be on different continents, and they will still continue to behave as a single quantum system. Measuring one of these particles will still tell you about the other one, and the second particle does not need to be in the same room (or even the same galaxy, for that matter).

Einstein described this as “spooky action at a distance” and he never did accept this consequence of quantum theory. Nonetheless, it has been validated in experiment after experiment. Like so much of quantum theory, it might be counterintuitive, but it works.

But how does this make teleportation possible? Well, to start, it’s important to remember that what is being transmitted is the information that makes up the quantum state of the particles, not the particles themselves. First, scientists entangle, then physically separate, two photons. Once linked in this way, any change made to one of the photons will have an effect on the other.

Then, at the starting location, the qubits (quantum bits, or the data that makes up the quantum state) of the particle to be teleported is measured. This measurement is then transmitted to the final location, where the other entangled photon is already determined by the measurement at the starting point (thanks to quantum entanglement). This allows the quantum state to be transferred to a second particle, which is now identical to the first.

This is a long way from “Beam me up, Scotty.” While we have succeeded in teleporting elementary particles, there are significant technological challenges involved in mapping the complete quantum states of every particle that makes up a human body. But the key point is that these are technological challenges — not theoretical issues.

In other words, teleportation falls into the category of “It could become possible, if we can ever build a powerful enough computer.”

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“But is it REALLY impossible?”

I have not failed. I have just discovered 10,000 ways that won't work. ~ Thomas Edison

I have not failed. I have just discovered 10,000 ways that won’t work. ~ Thomas Edison

I was the kind of student who gave teachers a headache. I was always asking questions. Too many questions. Smart questions. Dumb questions. Annoying questions. Even questions that my teachers clearly figured should not be asked.

To their credit, they did their best. But privately, they probably considered me to be a major you-know-what in the you-know-where.

The day I locked horns with my physics teacher about the possibility of travelling faster than the speed of light is a case in point.

This question was important to me. If faster-than-light travel was truly impossible, that would make any kind of contact with extra-terrestrial intelligence a virtual impossibility.

And I really wanted to meet a Vulcan.

So I demanded to know WHY supraluminal travel was impossible.

He attempted to explain why special relativity establishes c as the ultimate speed limit of the universe. I countered with a list of inventors who did not let the fact that their ideas were considered “impossible” stop them from developing their inventions. He tried to explain the difference between a theoretical impossibility and an engineering challenge. I pointed out the way that new theories can re-write the worldview of old theories. He told me I was missing the point of Einstein’s theory. I asked him why Einstein’s word should be considered the “last word.”

That was when he told me the discussion was over.

In retrospect, I cannot blame him for that. After all, he had a lesson plan to work through, and he couldn’t afford to spend the entire class arguing with me about the speed of light. But I thought he was wrong then, and I still think he was wrong now.

He wasn’t wrong about relativity. But I believe he was wrong in treating Einstein’s work as the final word on the subject. Our knowledge of the universe is incomplete; we have no way to know what kind of discoveries (both theoretical and experimental) might be made in the next decade — never mind the next century. And if there is one thing to be learned from the history of science, it is that no scientist, no matter how brilliant, can hope to have the “last word” in his — or her — discipline.

And as I discovered in university, real scientists understand this only too well.

Some things probably are impossible, in the literal sense of the word. But many are merely “impossible for now”, or “impossible, given our current understanding of physics.” Even fifty years ago, such common technologies as wifi and bluetooth (to say nothing of more esoteric advances like nanotechnology or quantum teleportation) would have been considered “impossible”.

In the 1950s, before Yuri Gagarin’s historic trip into space, a manned moon landing was widely believed to be pure science fiction. But Gagarin’s inaugural spaceflight in 1961 was quickly followed by Neil Armstrong and the successful Apollo mission eight years later.

Even after Apollo, the idea that humans could survive for extended periods away from Earth was generally considered to be pure fantasy — at least until the International Space Station was launched in 1998. Now, in 2015, an actual extraterrestrial colony on Mars is only eight years in the future (assuming the Mars One project continues on schedule, of course).

And so, in just over 60 years, science fiction becomes scientific reality.

In a world where alleged impossibility is often merely temporary, where many of yesterday’s impossibilities are today’s commonplace tools, I think we have to ask what the word “impossible” really means. Absolute impossibility is, I suspect, a rarity; most of what we consider “impossible” is merely “relative impossibility”, or “impossible for us, right now, given our current level of development.”

And as for the future? It hasn’t been written yet.