Parody Week: xkcd - what if?

Long Answer Section How long would it take to travel back in time to last tuesday? —CharlesOwl That’s a very good question. A lot of people would think “Duh, it’s instantaneous,” but no. That is a very narrow view, as it assumes the time travel mechanism, when in reality it all depends on the method of time travel we choose, and even then it doesn’t take into account all of the factors. For example, very lackadaisical investigation tells me that the DeLorean DMC-12 takes about fifty seconds to get from zero to a hundred miles per hour, so despite the fact that the Back to the Future time-machine’s travel mechanism happens instantaneously, since it requires the car to get up to speed, it would actually take about 30 seconds to get to last Tuesday (assuming there are no other issues); and even then, some models of DeLorean have a top speed of 85 mph, so it may even take as much as 2 minutes. That’s a shocking margin for error. Then, of course, since that time-machine doesn’t currently exist, it also means that to travel to last Tuesday from today would take upward of hundreds of years, as I would first have to make the damn thing. But I’m getting ahead of myself, let’s remove time-machine construction from the equation, as that’s an awkward variable, and not part of the question. Some time-machines don’t work so quickly. Another concept of time travel is called "The Slow Path", which involves a time-machine that puts time in reverse, at a casual speed. Of course, the problem with this mechanic is explained in the name, it is the Slow Path. The only good example in media would be ‘The Box’ from Primer, but since that movies is pretty convoluted, even on a good day, let me explain. First, you have to understand that there is linear time, that one thing occurs after another with time moving at a (somewhat) constant speed. This works with the notion of four-dimensional space, and a time-space continuum which means that I can explain it using other dimensions of space, for example: Length. Just as when you walk across a park that is 15 metres long, then want to return to your original place, you would have to walk another 15 metres in the other direction. So if linear time could be manipulated, it would make sense that to go back to last Tuesday, you would have to spend the same amount of time going backwards as you did to get here in the first place. This method would take 7 days to travel back to last Tuesday from today.    The third option for time travel, which futurists seem quite fond of, is the idea of a time-machine that works by travelling faster than the speed of light, usually devised as a train that travels around the earth to build up speed. The idea is that, since time slows down as you get closer to the speed of light, then by going faster than light, you could go backwards in time. But after thinking about for a while, I’ve realized that this idea is, retarded. As in literally, time would be retarded. It makes sense to some, but the reality is that if you were on a train that could bypass the ‘speed of light’ barrier, then after a while time would start to slow and slow and slow . . . but before it can go backwards in time, Time itself would have to STOP. And when time stops, it’s frickin’ stopped. If this came to pass, it would mean either the train’s speed would be infinite, so to others it would be imperceptible - or the train would vanish from the timeline, being literally caught up in that moment in time and disappear. No, I don’t really know where it would go from there. It could be anywhere. So in answer to the question, to travel back to last Tuesday would take somewhere between 30 seconds to 7 days, assuming you don’t get caught up into the relativistic nightmare that is time dilation. Can a train run on the moon? —Taylor Taylor No, it doesn’t have any legs. Could a warp drive get you out of a black hole? —Jeff Atwood and Joel Spolsky “Captain’s Log – Stardate 12974.9: Through a serious of unfortunate events, our ship, the USS Hawking has drifted toward a black hole. We are being dragged into the event horizon. May God have mercy on us all . . .” Black holes are so dangerous some physicists claim “Nothing can escape them’, and as a rule of thumb, it’s true. A space ship cannot escape a black hole, no matter how fast it goes, as the gravity is so great, it would pull the rocketship, and its propulsion system inwards, like a bird caught in a jet turbine. The gravity in a black hole is so dense that it bends space around itself into a twisted net that Light, Matter, Energy, Space & Time all get dragged into. According to physics, there is no way for someone to exert enough force to push themselves out of a black hole, once they’ve passed the event horizon. As it would have to travel faster than the speed of light. And nothing can do that, not even a spaceship at the ‘speed of warp’. In fact, that would probably lead to their demise even faster. However, science fiction doesn't rely upon reality. So when we allow warp drives into the scenario, things change. Warp drives don’t push themselves forward like rockets do. They create something called a ‘warp field’ which distorts space around it (to allow for faster than light travel). This means that the gravity would be displaced by the warp field, and the ship’s engines  would push against the spacetime continuum if it goes to warp, and travel faster than the speed of light. The only obstacle now is that we have no idea what it’s like inside of a black hole. Scientists have their own theories, and I have mine. But assuming the shields hold, it doesn’t matter what it’s like inside the black hole. Because according to Star Trek’s own rules, ‘warp factor’ isn’t measured in integers. It’s measured through an unspecified equation that means each measurement is much greater than the last in a curved Line Graph This means that if you turn the dial up to 11, the ship will eventually be travelling at infinite velocity, which would be pushing itself against space. Since we never specified what kind of warp engine we have, we’re allowed to assume that our ship can travel that fast. Since infinite velocity is kind of a trump card, it would therefore escape the event horizon. We don’t even have to worry about the time issues of moving at infinite speed, like out speed-of-light train, because this is Star Trek, and they have mechanisms to counter-act that kind of thing. Also, star ships can run on the moon, so it’ll be fine either way. Of course, in all likelihood, that kind of force could tear the ship apart. But this is Star Trek. They can just reconfigure the deflector to solve any other problems. What would happen if an unstoppable force hit an immovable object? —Matthew Anderson & others The fact of the matter is, this question is flawed, because when people hear words like ‘force’ and ‘object’, they think that it’s a physics problem. It’s not. It’s a language problem. The problem is, there’s no such thing as an unstoppable force, and there’s no such thing as an immovable object. I understand that it’s a hypothetical problem, but it’s not a very good one. It’s like asking:   “What would happen if my daughter had sex with the easter bunny?” It’s a fascinating question, and the answer would be important to furries everywhere, but the fact is that neither the easter bunny, nor my daughter, exist. At least, not yet . . . If the question was “what would happen if a force with infinite velocity collided with an object of infinite mass?” Then maybe we’d have something to work with. It’s still stupid, but in answer to that, there’s only two options. It would either: a) Deflect b) Explode  But the most likely happenstance is that it would explode, as we’re talking about ridiculously big forces moving at ridiculously high speed.  What if someone broke out of a hypothetical situation in your room right now? —Randall Munroe That’s a very good question, but there’s one problem with that. When you say it happens "right now" well, right now, the only hypothetical situation I am thinking of is the instance of me considering a hypothetical situation. So before I could come up with anything interesting, the only ‘someone’ in the my aforementioned hypothetical situation would be, well ME, thinking about a hypothetical situation. So, a hypothetical version of me would enter into this reality. After the initial confusion, and deciding to finish writing this post later, we’d have a bit of a chat and figure out the situation. Now there’s a lot of practical jokes and adventure that can be had with Second Matt running around (don't worry, I know that he'd agree with that name, because I would in that situation) but there’s a problem. Second Matt didn’t open a door and close it, or come through a drifting portal, no he "BROKE" out of my mind. This means that there now exists a permanent portal between reality and my mind. Thankfully, it's just the hypothetical situation he broke out of, not my imagination proper, since my mind is a dangerous place, and the last thing we need is a zombie cockroach epidemic. But there’s a lot of fun and investigation to be had with seeing the limits of this part of my imagination, seeing possible connections to a greater mindspace or even just experimenting with the objects therein of this hypothetical bedroom situation. But once we’re done with exploring that space, and all of the other business has been taken care of . . . There’s another problem that presents itself here. See, although it seems like Second Matt and myself would look identical (lending to many good practical jokes), I'm afraid that we may not look all that similar at all. Because, having come from my mind, Second Matt would be an idealized version of myself, which means that Second Matt would actually be perfect in every way. Plato calls this notion the Theory of Forms, which says that since thought does not conform to reality and matter, and can achieve insurmountable perfection in concept, then thought must be more ‘real’. I don’t know about who would be more real, but since I tend to think quite highly of myself, and believe myself to be perfect in every way. Whether or not that is true of me, it would have to be true of Second Matt because I imagined him that way. But he won’t get too high and mighty about it. I know, because I wouldn’t. We’d just figure out a way to make him look more real, or maybe make me look more like him . . . Once that’s done, I don’t really know the specifics of what would happen next, but I know some important details. For one thing, the hypothetical situation was in my bedroom, so Second Matt has somewhere to sleep. Also, if we can keep him a secret, we would (alternating who goes out in public based on a roster). We'd have to pull some ‘teleportation’ pranks on people & plan other tricks we can do; I would play a LOT more multiplayer games & we would basically ‘hang out’, doing whatever I usually do with friends, but now with Second Matt. It would be awesome! But above all else, because I am a massive word nerd, one thing we would HAVE to do, is work on a whole bunch of collaborative writing projects . . .