Hermione’s Stone (1)

Harry Potter and the Prisoner of Azkaban

A couple of weeks ago now my family and I were watching said film. We’ve seen it many times so each viewing is an opportunity to spot something new. It was the scene where the our three heroes are in Robbie Coltrane’s cottage and a stone smashes a nearby pot. Hermione picks it up. It is notable by the fossilised ammonite it has. Knowing the story by now, I thought to myself, “I wonder if Hermione puts the stone in her pocket then, later (or earlier), having travelled back in time, she throws it back at herself”.

When we finally reached the scene of throwing, it was clear that Hermione had actually picked up the stone atop a giant pumpkin. OK, problem solved, mischief managed.

But, hey. What if she HAD pulled the stone from her pocket, thrown it through the window, smashed the pot and then her past-self picked it up ?

This raises an interesting question, amongst many:

If this did happen, where did Hermione’s Stone come from ?

[in principle it didn’t need to be the stone, it could have been a clod of earth, or something smaller like a molecule, picked up on her shoe, deposited at the scene, then picked up on her shoe again]


Hermione and the Fossilised Stone

To try to understand this more clearly I drew some sketches on paper, then eventually diagrams in Powerpoint so I could illustrate it here.


You’ll note that I’ve tried to simplify the process’s characteristics, so H is Hermione, s is the stone, ti are time intervals and the arrows represent the apparent flow of events or causality.  By doing this we not only start to understand what might be going on with Hermione’s Stone, s, but also other features. The time t1 is somewhat trivial, but at this point serves to illustrate that stuff went on before the ‘stone incident’.The time represented by t2 is that between picking up the stone and the point at which Hermione spins the ‘Time Turner’ in the infirmary, with Harry. Now, at this point in events the two go back in time ‘rapidly’ to a time t3 before the ‘stone incident’ to allow them enough time to reach the cottage. You’ll note that I’ve initially characterised this as -t2 and -t3, the minus-sign representing the direction of time-travel i.e. backwards. So, now the two have stopped travelling back, they join the ‘normal flow of time’ (or at least that local to Hogwart’s). Time flows forward t3 until the ‘stone incident’ at which point our time-travelling Hermione has released the stone (to be picked up by her former self) and carries on her way with Harry, under the normal flow of time, by t2 then t4. t4 represents an arbitrary length of time after the infirmary, let’s say until the end of the film.

This is the final iteration of the diagram, in which H walks off into the future (and the next film) after time t4, but not necessarily in line with where she came in. Could this be the ‘new universal line’ ?

Stone Circle ?

So what did happen to the stone ?

Well, it would appear that the stone is stuck in some sort of ‘time loop’ or ‘stone cycle’, constantly cycling around between ‘just before the stone incident’, at (t1-t3), and the ‘infirmary time-turning event’ at time (t1+t2), then back again.

Did the stone exist before this point ?

If not, has it been spontaneously created ? (remember we’re in a magical world)

If so, was there an initial cycle, where Hermione picked up the stone, then subsequently recycles the stone, or indeed does she end the cycle in some future iteration, by not putting it in her pocket. Then it gets really confusing. Unless, perhaps at each cycle a new universe is created. Does that work ?

Worse still, in such nonsense, has causality been broken, do paradoxes ensue, are multiple universes created ? In an ammonite’s shell, does it suggest that TIME TRAVEL IS NOT POSSIBLE  ?

(or not in this sense, at least)

That’s ruined the film and Doctor Who for me in one go !


OK, now we’re left with more questions than we started with. But hey.

Conserving the Illusion

For the sake of Doctor Who, let’s assume time travel i.e. going back in time, is possible in some form.

Looking at the diagrams again, what struck me was that during the the period (t1-t3) to (t1+t2) there are more than one Hermiones in the universe (whatever universe that happens to be). There are not only the two Hermiones (and Harrys) walking through the film in ‘the normal flow of time’ but also the Hermione and Harry travelling back in time. There, but in reverse, if you will.

Three Hermiones, three Harrys and up to three Stones !

Hold on. Wouldn’t that break the ‘Law of Conservation of Energy’ ?

(if it exists in the magical universe)


Next on Hermione’s Stone: Minus Signs


About Dr_JAH

Independent Researcher
This entry was posted in Maths, Physics, Problem Solving, Science, Space, Uncategorized. Bookmark the permalink.

1 Response to Hermione’s Stone (1)

  1. Pingback: Hermione’s Stone (2) | Dr. JAH

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