Very little about the Swan makes any sense whatsoever. The Swan was apparently built in 1979 by the Dharma Initiative to contain a huge pocket of electromagnetic energy that they had uncovered. This pocket of electromagnetic energy could have catastrophic effects for the rest of the world if unleashed. As such, they built a system by which they discharge a buildup of this energy (it presumably fills a capacitor) every 108 minutes. This capacitor is discharged by entering a code (4 8 15 16 23 42) into a computer, which then activates the system which discharges the energy. This system is built into a station called the Swan, which resembles a military bunker. The initial plan was to have two-man teams run the Swan, which worked until the Dharma Intiative was destroyed by the Others in an event known as the Purge. After this, Desmond Hume, who was stranded on the Island after being shipwrecked during a trip around the world, took over duties at the Hatch along with a member of the Dharma Initiative who survived the Purge, until he accidentally killed him (which, "coincidentally", led to the crash of Oceanic 815). Desmond is later relieved by the survivors of Oceanic 815, who take over the duties of running the computer. At the end of the second season, John Locke decides not to enter the code into the computer, causing a huge burst of electromagnetic energy to be released. Desmond then activates the failsafe system in the Swan, which destroys the station and disperses the electromagnetic energy for good.

Now, let us review why this is contrived and non-sensical:

1. Why would you ever design a manual system to do a regular task that is necessary to save the world? What if something happens that prevents the people in the station from entering the code? They could sleep through the alarm that activates when the code needs to be entered, or trip trying to get to the computer to enter the code, or any other number of things that could potentially happen when you have to repeat a task 12-13 times a day for 25+ years.

2. Even if you made a system that has to have a person activate it every 108 minutes, why would you use a code? It seems to me that putting in a code seems kind of pointless, because it's not like you want the method by which to save the world to be secret or complicated. You would almost certainly want it to be simple and intuitive.

3. Why would you only have one computer devoted to running this program that dispersed the electromagnetic energy? If that computer ever crashed, or was damaged, or anything, then the world could well end (incidentally, it was shot once, but thankfully repaired before the time limit was up). It seems incredibly stupid not to have some type of failsafe...

4. Oh wait, they do have a failsafe. The failsafe destroys the hatch and...permanently disperses the pocket of electromagnetic energy. That seems to be a great idea until you ask the obvious question of why on Earth they didn't just disperse the energy in the first place if they had the ability to do so. When you can simply press a button that saves the world by permanently stops the electromagnetic energy from destroying the world, why make a button that you have to press every 108 minutes for the rest of eternity. IT MAKES NO SENSE. It would be like... Actually, I cannot think of an analogy for how dumb this is.

There are quite a few more flaws with The Swan (such as the lack of a link to the outside world, why it was run by a private corporation, why nobody had checked on it in a significant number of years, etc.), but it is clearly a ridiculous storyline.

Now, a talented writer could come up with a series of contrived explanations to make this contrived plotline make sense. For instance, even though I am not a talented writer, I could easily come up with an explanation to problem number 1 by saying that the odd temporal anomalies on the island would wreak havoc with a fully automated system. Does this sound dumb and contrived? Yes. But the point is that there theoretically could be semi-decent explanations to the numerous issues with the plot.

The funny thing is that the complete lack of sense revolving around The Swan and numerous other plotlines (such as everything to do with The Light in Season Six) is that it is integral to the show. The reason for this stems from the theme of faith that is present throughout Lost. Throughout the plot of The Swan, there is an argument between the characters over whether it makes any sense to enter the code again and again and again because the whole setup makes no sense. True, they do notice that there is some mysterious force inside the station (the huge pocket of electromagnetic energy attracts metal), but that still doesn't really serve to detract from the utter senselessness of the situation. This leads numerous characters to disbelieve in the necessity of entering the code, and with the introduction of evidence that the whole thing might be a social experiment, John Locke, the man who believes more than anyone in the power of the Island, experiences a crisis of faith that ultimately leads him to not enter the code, thus causing the EM pocket to be released, thus forcing Desmond to activate the failsafe. The aftermath of this event leads to Locke renewing his faith in the Island.

And this gets into the truly fantastic thing about Lost, namely that we, as viewers, are also always experiencing Locke's trial in faith in the Island and its mysteries. As the plot of Lost got more and more outrageous, between The Swan, the Others and their implausible power in the rest of the world, the ability to move the Island, everything to do with variances in time, and of course, the entire sixth season, people steadily stopped watching the show. The reason most commonly cited is that the plot was getting too ridiculous and long-winded; i.e. the plot had gone overboard and viewers lost faith in the show. Viewers were forced to make leaps of faith throughout the show and accept that the forces on the Island had the capability to do things that transcended what we saw on the screen. And thanks to tremendous production and acting, it by and large worked. So even though anyone who discussed Lost with a non-fan sounded like a raving lunatic, those who watched the show through all six seasons inevitably accepted that the powers on the Island transcended the character's experiences and that the nonsensical plot made sense on another level.