Revisiting Entropy

I think after considering the various narrative constraints, I am beginning to agree more with the assumptions and conclusions Darkmirage set forth in his rant about infinite energy via time traveling. Oh, spoilers for Madoka Magica onward, I apologize.

It’s one of those persistent paradoxes in which some other issues have to be reconciled in your model of time traveling in order to make sense of it all. In that sense, the physics is not as important.

Time traveling by itself can be consistent with the Second Law. Certainly, the arrow of time can go forward as usual, and traveling to the future is something all of us do. One form of time travel is just going to the future faster than everybody else.

The reverse situation, too, can be tied to some kind of mechanism in which the net total entropy is a positive value. The question thus becomes more in the lines of conservation of mass-energy, and, as always, linearity of states.

There are good reasons to assume that the typical groundhog day mechanism implies a single, linear outcome of cause and effects, in which one cause at a certain time propagates consequences irrelevant of each “reset.” Here, Homura’s resets are played fast and loose; it seems that she can reset at will, even if Madoka survives the bewitching eve and the big bad witch of the west is slain. More importantly, it doesn’t seem QB maintains memory of Homura.

So what does that mean? It means Yuki Nagato is still better than QB. It also means that we don’t know what gets transplanted back in time. It may very well be that nothing “physical” gets passed back, and we can’t really say anything about it until we know more about soul gems and souls.

TL;DR: The Big Reveal episode teaches us very little, if anything, new that we didn’t know before, about the xenophysics of Madoka.

So why am I slowly changing my position? I think if QB’s race can create a system where people can travel to the past with that sort of information, they would have came up with a way to pass the information on reducing entropy to an earlier point in their civilization. In other words, while Homura is a determined little girl who is driven by undying hope and love, there’s nothing stopping an entire race from doing the same. Thankfully, I don’t see how we can take any of the known setting elements out of its presentation and make an argument that bypasses the black box of the soul gem. And so until they explain that to us, we’re going to be in the dark. At least the objection of “a wizard did it” only applies in the time traveling mechanism, but maybe wizards like the taste of white mascot animals with ears coming out of their ears, and that is what makes them so.

No Responses to “Revisiting Entropy”

  • Iconograph

    She could of course be a Level 5.

  • Kurogane

    Possibly the real black box here is Kyubey’s wish-granting ability.

    Look at Homura’s wish. She wished, in the most vague sense, to be able to protect Madoka from her inevitable Fate and got a pimpin’ time-space manipulation ability in return.

    However, as DM argued, if their wish-granting ability was so powerful, how come they didn’t just wish entropy away or use the time-travel tech to go back in time to solve it.

    This somehow implies that either:

    1. Kyubey’s wish-granting ability is a “black box” that accurately reads the hopes and wishes of the wisher, liberally breaking laws of physics and/or causality to grant it. It also implies that they do not have full control over that ability as well. Perhaps the ability is tied to a key. A key called “emotions”.

    2. This is all a huge Xanatos Gambit by Kyubey to infinitely collect massive amounts of energy.

  • omo

    I don’t think the wish-giving ability is the black box. I just assumed QB was able to accomplish whatever the girls asked for using means ordinary to QB. There wasn’t any reason to assume that technologically, QB cannot do any of it.

    I would say the black box is one layer deeper, as in how QB was able to do all those things.

  • jpmeyer

    The wishes have been awkward for us because every time we learn about something that was granted by a wish, or the results of a specific wish, we immediately think of the sort of points DM makes (not just about entropy, but even things like “Wait, how did Homura knock Sayaka out like that?”

    (Which is another example of my major criticism of this show: it has everything backwards when it comes to over-discussing what should not be discussed and under-discussing what should be discussed.)

  • omo

    I agree with that assessment generally. I think it has largely to do with the way Urobochi attempted to engineer geek instincts to mislead. While the desired effect may have been achieved, the trad-eoff was a less-than-smooth execution.


    I don’t think that Kyubei is the one granting the wishes. I think that the girls grant their own wishes and Kyubei just acts as a catalyst by releasing their sould (and harnessing them for power in the process). Kyubei didn’t grant Homura time traveling ablities, so he can’t use them himself, so there isn’t a contradiction (assuming that I’m reading what your objection is correctly).

  • omo



    I understand your reading and it is a plausible one. I just take it a bit further and assume that however the QB race accomplishes it, they can move back in time by some mean. The technology is there. Even if they have to coerce a human girl to do it for them.

    The real opposing theory to that is the personal reality one, in which some proclaims that Homura lives alone in some kind of contrived spacetime/universe/MatrixEgg setup divorced from the plot reality. That’s also a possible read.

  • LoliHat

    QB said that humans could somehow reverse entropy, and that his race is just using the girls for that end. Considering that conceit, traveling back through time as a (unintended?) side effect related to that isn’t much of a stretch.

    I don’t get out of shape about the entire entropy thing since QB’s explanation came across as not so much violating the laws of thermodynamics, but of humans, and teenage girls in particular, being some type of energy accumulators that the QB race is just harnessing.

  • LoliHat

    Again, I am reminded of Madoka’s mother’s speech. Her mother said that it is better to make mistakes when young then as an adult. In the previous loops, Madoka acted like and adult…and things did not end well. In this loop, she is acting like a child. This suggests that her not being a strong adult in this loop will be a game changer…that is *if* she doesn’t start acting like a strong adult…

  • omo

    QB said that humans could somehow reverse entropy, and that his race is just using the girls for that end.
    Where does he say that? I must’ve missed it.

  • Kurogane Shiroikaze

    I think he misread the part where Kyubey says that humans have the most potential for magic.

  • LoliHat

    Just re-watched the scene from ep. 9.

    QB does say that the souls of humans are capable of reversing entropy, and that his race have figured out how to harness that.

  • omo

    Ah. Well we know QB uses the souls or soul energies for something. I’ll just chalk it up to verbal syntax over translation.

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