Every day I’m one of a few people who decide to walk to school from a free parking area in order to save a few bucks. Recently, I’ve been thinking about Star Trek, and in particular about how nice it would be to have the transporter, especially since it rains literally all the time. When I get to class it often looks like I decided to shower that morning with my clothes on for a change. But the more I considered the Star Trek transporter as a replacement to my wet walk, the less appealing it became.
There is a frequently discussed problem in Star Trek over their transporters. I’m sure many of you are familiar with it, it goes something like this: if people are being disassembled piece by piece, transported across the across the universe and then reassembled, it’s not really you on the other side. Rather, it seems likely that the you that went into the transporter dies instantly and then some other person with all your memories is simply created on the other side.
The transporter problem becomes a heavy topic really fast; it often ends up with a discussion over what consciousness is and arguing whether persistence of consciousness is necessary to stay the same person. And just when you’ve convinced yourself that persistence of consciousness is necessary, you find yourself awake late at night, scared that you’re going to fall asleep and an impostor who looks just like you and has all your memories is going to wake up tomorrow morning, put on your shoes and socks, and go about your day.
Anyway, philosophical considerations aside, I think we’ll be safe from the dangers of transporters for a while yet. The reason? Bandwidth. Say we manage to get a complete atom-by-atom 3D scan of a person. That sort of thing seems like it would take up a lot of hard drive space. It would be a ridiculous amount of data, and I want to know exactly how much data it would be. For each atom we’ll need two pieces of data: the position in 3D space and what type of atom it is. We certainly don’t want any of these atoms to have their locations saved out of place, so we’ll use the highest resolution possible: the Planck length. (Yes, the universe has a highest effective resolution, yes the reason is a quantum mechanical effect, and yes, I’m simplifying things a bit.) It turns out that we need roughly 400 bits to store the data for each atom. Now times that by the average number of atoms in our body, and we get our answer — one human is about three billion zettabytes of data. As a comparison, the total amount of data ever produced in the history of computers is probably under five zettabytes of data. And I didn’t even make up the word zetta, it’s an official International System of Units prefix meaning a billion trillion of something. It’s just that things are so rarely that big that it doesn’t get used much.
If we wanted to build a data centre to store all the data for that one person, it would be, as it turns out, pretty big. I mean, it would fit inside Greenland — but just barely. It would be a 10-foot-thick layer of the densest storage units money can buy covering the entire island, but it’s technically doable.
But there’s a better solution: why store the data at all? Why not just beam the person’s data directly to the reassembler as he’s being scanned? Well, using a single fibre optic cable, we can transmit a huge amount of data in a short amount of time — about 40 billion bytes per second. We’d be able to get all of our bodily data from one place to another in only 20 times the current age of the universe! I think in that case I would be a little late for school. Well, what if we just used more fibre optics?
If we had a giant bundle of a thousand billion optic cables — the bundle being a kilometre tall and a kilometre wide — and each cable was sending data at record speeds, it would still take 100 days to teleport across. So I’m still definitely going to be late.
But hey — at least I’d be dry.
