Good point about the light hours thing. It sort of kills the hypothesis.

I agree with drethelin that the 6 hour mark doesn't have to correspond with Quirrel's last day of school. However, in the last story arc, Quirrel talks like his time limit is only a short time away, perhaps only a month. Of course, he could be talking about his inevitable firing from the defense professor position.

Sorry, I didn't mean to suggest that Quirrel went away to the plaque when he was in zombie mode, nor to suggest that it had become a Horcrux. Instead, what I am suggesting is that Quirrel is always in the plaque and is operating his body by remote control. If it takes some effort to do so, he might let the body go slack when he doesn't need to be doing anything.

As for the horcrux, this could always be a different, but perhaps related, spell.

I was re-listening to the podcast of Chapter 20 (Bayes's Theorem) when I was struck by an idea. It builds on another idea I heard in this same forum. The original idea was that Quirrel had Horcruxed the Pioneer plaque and that, due to the nature of magic, his Horcrux passing beyond a distance of 6 light hours would lead to his death due to a limitation on magic's ability to affect things more than 6 hours into the past - which would be needed for faster than light communications.

Having now re-listened to that chapter, I've picked up some new clues. Harry had made the suggestion that it might be possible to add an entire human mind's worth of information to the Pioneer plaque by creating a portrait or arranging for a terminally ill person's ghost to be attached to it before launch. Quirrel of course denied that he had done anything like that through a bit of misdirection. This leads many to speculate that he had Horcruxed the probe, downloading a copy of himself into it for posterity.

I had the idea that perhaps he downloaded himself into the probe and then started to operate his body by remote control. When his body goes limp, it's because he's not at the 'controls' at that moment. Once the probe passes beyond 6 light hours, it will become impossible for him to continue to tele-operate his body any longer and he will be trapped on the probe for the rest of its flight time. I believe he is revealing an important clue in the following paragraph:

"Sometimes," Professor Quirrell said in a voice so quiet it almost wasn't there, "when this flawed world seems unusually hateful, I wonder whether there might be some other place, far away, where I should have been. I cannot seem to imagine what that place might be, and if I can't even imagine it then how can I believe it exists? And yet the universe is so very, very wide, and perhaps it might exist anyway? But the stars are so very, very far away. It would take a long, long time to get there, even if I knew the way. And I wonder what I would dream about, if I slept for a long, long time..."

Is he contemplating the eons that await him while the probe moves on to 'some other place'? Does he plan to put his mind on hold, to sleep, for most of that flight time?

Here's my first attempt. It was meant to be about confirmation bias. On rereading it, it seems more like it's about finding the positives in bleak situations. I guess that's important, too.

Nothing much happened this week, you tell your mum at week's end. Because 'nothing' never gets mentioned, when talking to your friend.

Because inside all that nothing, there are things both here and there. If a room is mostly empty, You'll find a table or a chair.

On Monday you did nothing, except you stubbed your toe.

On Tuesday you did nothing, but it begain to snow.

On Wednesday you did nothing, except you found that money.

On Thursday you did nothing, except you spilled that hunny.

On Friday you did nothing, except you cleaned that fluff.

But now remembering your empty week, do you think of all that stuff?

So telling your friend about that room, Or your mum about your week. Now that room is full of stuff. Your week is not so bleak.

If it's true that intelligence correlates with height, I wonder if it is because childhood nutrition affects height? Perhaps childhood nutrition also affects brain development. Interesting.

Could this constraint apply in other ways? Suppose magic is the result of something that responds to the wishes of witches, as suggested at one point. If that something is Earth-based, perhaps a wizard on an outbound spacecraft would stop being able to do magic when he reaches 6 light-hours out. An interesting experiment.

Harry might be able to realistically do an experiment similar to this as a first year if there is a magic spell that lets you communicate with an object. He could use a spell to accelerate that object to a very high speed and then check in on it as it approaches the 6 light-hour point.

I hadn't realised I could. I've just done so. I didn't write any kind of note to that effect. Is one needed for a spelling edit?

Ah. In that case, your comment makes a lot of sense. I apologise for the confusion.

Thanks for both pieces of advice. Apparently what karma goes around comes around, because I'm back up to 2/3 or what I had before the misadventure started. I'm at peace.

Nice read. That's exactly what I should do. Someone else made a similar comment about definition issues. In retrospect, the conversation on Facebook could have been wrapped up very fast.