[Inaudible airport announcements] [Grey sighs] What’s the fastest way to board an airplane? I mean, you can’t just throw open the gates like funneling cattle into a chute. That’s not for us. We’re primates, after all! So let’s put our monkey brains to work to tackle this queue which is what boarding groups do: Prioritize, plainly packing primates precisely. (Primarily) Ok, we have a suggestion: pour people into the plane back to front. This is an intuitive solution to fill a cylinder. But there’s almost a law of the universe that solutions which are… …the first thing you’d think of and look sensible and are easy to implement are often… … terrible, ineffective solutions, once implemented will drag on civilization forever. :: Cough, voting systems, cough :: So it should come as no surprise that this method is… … not good and also what most airlines use to board their planes. Let’s watch it in action: The first boarding group walks to the back of the plane. Everything is smooth right until the first to go reaches their row and starts to stow. So slow. And for passenger two, while their seat is in view, there’s nothing to do. The aisle’s one queue, where all can naught but stew, stuck like glue until this guy’s through. :: Phew :: It’s bags. Bags cause most of the delay boarding a flight. Like with this: a full-stop stow. When it happens, everyone boarding the plane within and without must wait until one person finishes stowing their bag. Can you feel it? The aggregate lost seconds of human life piling up like a bounty for a delighted reaper? Of course you can. You can feel it with every bag. :: Uhhh :: What was I saying? Right, back-to-front boarding groups have a lot of full-stop stows, and very few of what you want: … pullaways and parallels and parallels and pullaways. Pullaways turn one queue into two. And parallels decrease total bag stow time and are super satisfying. The rare triple partner parallel invoking a double high-five at the sheer pleasure of its efficiency. But loading back to front lets few of these happen. Now say you weren’t just… not good at designing boarding groups,… … but you were malicious and wanted to maximize the amount of human life wasted upon a flight. What would you do? Not back-to-front but front to back — the smaller the boarding group the better. This makes almost every tedious shuffle forward result in a full stop stow,… …because most of the line waits by rows already full or outside the plane. Look familiar? This is where we acknowledge the class structure of airplanes. Real planes look like this and first class boards first, front to back, … … before the pro-conomy file in back-to-front. So, excluding pre-boarding, all airlines start with a little of the slowest boarding method you could intentionally design. Now, obviously, this video will soon reveal faster boarding procedures. And you will wonder, “why don’t airlines use the faster methods?” One possible answer is economic incentives. First class pays for perks — sometimes breathtaking perks for breathtaking amounts. And boarding first is one of them. Also, airlines give everyone loyalty points that move you up the class structure the more you fly with that airline. Which gives airlines another good reason to group people. And probably helps explain why they switched away from the older faster method you won’t believe they used to use: [Grey on microphone]: “Hey, everyone. Plane’s here. Go ahead.” Doing nothing and having people board the flight in whatever order they show up… … to get their assigned seat, is faster than organizing tidy boarding groups. This is because random people are spread, well, randomly, … … increasing the chances of pullaways and parallels, unlike the more orderly methods airlines have switched to. Man, it’s always frustrating to know that to literally have done nothing … … would be faster than the something that is done. But surely there’s a better boarding group order to be found if we can just subtract malice and add thinking to this problem. Ahh! Three groups: window, middle, aisle. In that order. This is really the same as doing random thrice, one for each column of the craft … … but the reason it’s a smidge faster is because it eliminates the other source of boarding delay: Seat shuffles. When people board randomly, seat shuffling is going to happen a bunch. And when people spill into the aisle, it slows the queue. Ordering everyone by window, middle, aisle ensures a seat shuffle will never happen. This seems like it should be a big improvement. But when you simulate boarding an aircraft with a ton of real math … (rather than just animating it in a dramatically simplified fashion) … or do actual experiments, the seat shuffle just isn’t a big deal compared to bag stowage. People wrangling their one bag that won’t possible fit, … … or trying to get onboard with three bags because they don’t think the rules should apply to them, … … who then also fiddle around getting their laptops out after stowing them. Those kinds of delays count for much more. So, Window-Middle-Aisle is maybe a smidge faster than random, which is good … … and some airlines use this method, which gets their planes turned around faster than back-to-front … … while still giving them boarding groups to play games with. The vast majority of airlines use either back to front or window-middle-aisle. So keep an eye out next time you’re boarding a flight for which is happening to you. But can we go farther? Leaving the real world: with its class systems and people, and untidiness and smells, … … ascending to the platonic plain of physics, … … where cows are spheres and people cellular automaton who will execute instructions perfectly. Here, in the Celestia, what is the theoretically fastest way to board a plane? On this level, here is what’s possible: [The Nutcracker Suite, Op. 71a: VIII. Waltz of the Flowers] To achieve this ballet, there are no boarding groups, but everyone stands in an exact order. Back-to-front in alternating rows, on alternating sides, windows in. This maximizes pullaways and parallels. Pristinely packing people in a pinch. Witnessing such glory is too much for mortal minds to bear for long… … so we are forced to descend back down into the meat world. The cacophony! The smell! Where we must stuff monkeys into a tube. Monkeys with families, where separating their young invites chaos and cleanup. Where economic incentives divide and profit. And where, even at their best, the human inability to follow instructions is breathtaking. Here, people, upon seeing ‘boarding group 123’, would flip the hell out. Let alone the impossibility of trying to get them to stand in line in order. And where even if faster, like watching seconds of a clock, people would complain it was slower. [Grey sighs] Such gifts we were not meant to have. But is there a way we can modify this perfection to improve our lot on this plane? Yes. Instead of exact order, boarding group the first would be all one side of the plane in every other row. Boarding group the second, the other side, then back, and back again. One, two, three, four. We can’t ask people for more. This shadow of the perfect method has a chance of working in the real world with benefits like: letting humans with families and friends board together, … giving airlines boarding groups they can still play with, … and still being faster than the current methods. Reaching for perfection, we will always come up short. But perhaps we can manage to get closer in the process.