Sure, the problems with the physics are right in there with bothersome things that Harry says that you could still justify, starting with the non sequiturs about conservation of energy when McGonogall turns into a cat.

I disagree with su3su2u1 (the tumblr author) about levitation; that doesn't violate conservation of energy if it's mediated by a force, and why shouldn't it be? On the other hand, turning into a cat violates conservation of mass (or would appear to, and that should be easy to check with a bathroom scale), which (via E = mc²) translates into a huge energy violation. But bringing up the quantum Hamiltonian? FTL signalling? Su3su2u1's analysis is correct.

The justification for this is that Harry is 11 and has only a vague idea about how physics actually works. But then it's hard to tell what we should learn from Harry and what we should ignore. (For that matter, I don't even know if Eliezer knows better than Harry or not.)

I have come to the conclusion that keeping the ultimate Source of Magic an unknown (for the scope of HPMoR) was probably a premise taken by EY early on. Otherwise we would have seen much more experiments to discover it (and more foreshadowing). That many (me included) have been waiting for it patiently is probably more a sign of our wishful thinking and neglect of evidence to the contrary than an oversight by EY.

ADDED: I wonder whether there is such a thing as negative foreshadowing, i.e. indications the some information will not be revealed later. Could be a smart literary device to reduce disappointment in these cases. Can one make reader go "Aha, Harry's quote about the difficulty of experimets fits nicely to Hermiones final remark that their schedule will take six years when taking outside view estimates into account"...

I am among those with a sympathetic view of Snape. This was a satisfying chapter for me.

Draco's not stupid. I don't know how much of the circumstances around the graveyard scene are going to become public, but enough information has already been released to paint a picture of Mysterious Circumstances involving Hermione and Quirrell (and the dead). Knowing that, if Harry -- a kid with an uncanny talent for showing up in the center of Mysterious Circumstances, and with close links to both Hermione and Quirrell -- shows up and tells you he has a horrible secret that will make you hate him, is it that hard to put the pieces together even without hearing the secret explicitly? Not conclusively, of course, but enough for strong suspicion?

Brains are flexible, so why can't psychopaths learn empathy using different circuitry? If sufficiently motivated, that is.

Harry has to some extent undone the work of Merlin. Merlin's interdict ensures that the most powerful magics slowly die out of the world as wizards and witches die with their secrets. Harry's scheme for immortality in the magical world puts a stop to the losses, and allows magical knowledge to be kept as it is re-discovered, however slowly. Previously the loss rate exceeded the discovery rate. I think that is about to be reversed. And the Interdict of Merlin was put in place to avoid a prophesied destruction of the world.

Ch. 80

And when (the legend continues) the Seers continued to foretell that not enough had yet been done to prevent the end of the world and its magic, then (the story goes) Merlin sacrificed his life, and his wizardry, and his time, to lay in force the Interdict of Merlin.

So what would he have been doing? Saving victims of accident so that they end up being fine after a small hospital stay? Miraculously curing terminally ill people? I find it unlikely that he could do anything else with long-term benefits without anyone catching on. But yeah, I like that alternate character interpretation of Flamel.

The fact that he's wearing it at all stuns me. It needs to be maintained by a coven of the greatest wizards around.

Imagine: Harry dies (heart attack, stroke, stabbed by Goyle, whatever) Handless amnesiac Voldemort appears, dies of human transfiguration sickness after a few deeply confused minutes Horcrux network activates.
Best case, this amnesiac being can't figure out how to possess anyone. Medium case, somebody gets possessed by the clueless shade.
Worst case: network was built to supplement current memories with dump of previous ones (we can see by the part where Voldemort Confounds himself before the Mirror that he had thought about the concept of changing his mental state), and the Dark Lord is back in business

I've argued before that HPMOR probably includes some kind of mind/body dualism. It occurs to me that an interesting experiment is about to be performed.

The body of Hermione Granger has been infused with the life and magic of Harry Potter. I assume for narrative reasons that Hermione will wake up as Hermione. But a copy of Harry could wake up in Hermione's body instead.

The mechanisms behind a person' life force, magic force, and mind are unknown to us. We don't also don't know whether or to what extent these aspects of a person are separate or connected. It should be assumed throughout this post that I am talking about the minds of magical people, and that muggles could be a separate case.

If Hermione wakes up as Hermione after being resurrected by Harry's life force and magic force I will conclude:

1. A mind is probably not made up only of a person's life force and/or magic force. The only exception I can think of is if the mind runs on a substrate of your life and/or magic force but the Patronus 2.0 or resurrection process strip that information out of the projected life and magic, passing the substrate but not the pattern on it.

2. Either the mind has at least something to do with the body OR magic will, upon resurrection, retrieve the mind that is supposed to go with the body OR Harry's intent is sufficient to establish what was supposed to happen here.

3. Related to #1, atomic souls in the sense of "an animating force that contains a person's life, magic, and mind all in one non-physical object that persists beyond that person's death" would be ruled out. Life beyond death would not be ruled out, but souls could not be things with no smaller components if they exist at all.

4. I would update to consider possibilities like "your mind is just your brain but magic stores it in other dimensions or on a magical substrate when required" more likely than I previously did.

If Hermione wakes up as a copy of Harry in Hermione's body I will conclude:

1. Mind/body monism is almost certainly false. Your mind is not your brain in any sense; the brain is at best an interface that the mind uses or a home that it resides in. Monism could only be rescued if magic turned Hermione's brain into Harry's brain during the resurrection process.

2. Your mind either is inseparable from your life and/or magic or it is a pattern on a life/magic substrate that is transmitted with that subtrate through the Patronus 2.0 resurrection process.

3. I will update to consider atomic souls as described above to be more likely than I previously did.

Separately, in a world with mind/body monism, I wonder whether regeneration as a magic that always transfigures you back into yourself would prevent learning. Probably not. Magic tends to have the intended effect rather than a strictly mechanistic one.

(edited for formatting and grammar)

I've argued before that HPMOR probably includes some kind of mind/body dualism. It occurs to me that an interesting experiment is about to be performed.

The body of Hermione Granger has been infused with the life and magic of Harry Potter. I assume for narrative reasons that Hermione will wake up as Hermione. But a copy of Harry could wake up in Hermione's body instead.

The mechanisms behind a person' life force, magic force, and mind are unknown to us. We don't also don't know whether or to what extent these aspects of a person are separate or connected. It should be assumed throughout this post that I am talking about the minds of magical people, and that muggles could be a separate case.

If Hermione wakes up as Hermione after being resurrected by Harry's life force and magic force I will conclude:

1. A mind is probably not made up only of a person's life force and/or magic force. The only exception I can think of is if the mind runs on a substrate of your life and/or magic force but the Patronus 2.0 or resurrection process strip that information out of the projected life and magic, passing the substrate but not the pattern on it.

2. Either the mind has at least something to do with the body OR magic will, upon resurrection, retrieve the mind that is supposed to go with the body OR Harry's intent is sufficient to establish what was supposed to happen here.

3. Related to #1, atomic souls in the sense of "an animating force that contains a person's life, magic, and mind all in one non-physical object that persists beyond that person's death" would be ruled out. Life beyond death would not be ruled out, but souls could not be things with no smaller components if they exist at all.

4. I would update to consider possibilities like "your mind is just your brain but magic stores it in other dimensions or on a magical substrate when required" more likely than I previously did.

If Hermione wakes up as a copy of Harry in Hermione's body I will conclude:

1. Mind/body monism is almost certainly false. Your mind is not your brain in any sense; the brain is at best an interface that the mind uses or a home that it resides in. Monism could only be rescued if magic turned Hermione's brain into Harry's brain during the resurrection process.

2. Your mind either is inseparable from your life and/or magic or it is a pattern on a life/magic substrate that is transmitted with that subtrate through the Patronus 2.0 resurrection process.

3. I will update to consider atomic souls as described above to be more likely than I previously did.

Separately, in a world with mind/body monism, I wonder whether regeneration as a magic that always transfigures you back into yourself would prevent learning. Probably not. Magic tends to have the intended effect rather than a strictly mechanistic one.

(edited for formatting and grammar)