Dangerous concave mirror starts fire

[JoceAndChris]

Woke up to Chris shouting about a fire in the bathroom. It turned out that the shaving mirror which was sitting on the bathroom windowsill had set fire to the window. (I've stripped the paint off it, it's just old dry pine.) It's curious, as that mirror has been sat there for months behaving itself, I suppose it's just something about the combination of the angle of the sun or the angle of the mirror.

Now there is a big hole in my 100 year old window that's going to need splicing or splining or whatever.

Wouldn't want this to happen to anyone else -check position of potentially dangerous mirrors!

Crystal droplets on light fittings wouldn't start fires, would they?

 

[biffvernon]

That has got to be this morning's most unlikely event in the universe. :shock:

 

[Flyfisher]

Probability is a funny thing. Can it be an unlikely event if it actually happened? More likely that it was inevitable given the position of the mirror and the rising sun. As proved by the fact that it happened.

I've often wondered about the dangers of shaving mirrors but this is the first time I've heard of and actual incident (not that I claim to be particularly well-informed in such matters).

Was it a 'real' fire Joce, or 'just' scorching and/or smouldering? Very frightening in either case, I imagine. Glad to hear no real harm was done.

 

[jocelyn plummer]

That did actually happen in a village nearby to us, resulting in a G2 listed being badly damaged The source of the fire was a magnifying cosmetic mirror, catching the sun and igniting the curtains. Unfortunately the owners were on holiday at the time.

 

[biffvernon]

Probability is a funny thing. Can it be an unlikely event if it actually happened?

Yes.

Consider a fair six-sided die. The probablility of it landing six up is 1/6 the probability of it landing not six up is 5/6.

Six is therefore less likely than not six and can be considered 'unlikely'. Even if it actually happened.

I still maintain that the probability of a shaving mirror causing a fire this morning is rather unlikely, but so was the whale that turned into a vase of petunias.

 

[JoceAndChris]

Aaargh! Maths!

It was bizarre, and ironic when you consider we survived a whole winter of drunken conflagration without a single igniting cinder.

Was it a 'real' fire Joce, or 'just' scorching and/or smouldering? Very frightening in either case, I imagine. Glad to hear no real harm was done.

Thanks Flyfisher, it was only scary from the point of view of what would have happened if Chris had listened to me and stayed in bed? (I have a bad cold, not laziness, you understand.) It was smouldering and smoking, maybe it just would have fizzled out in any case.

But it's sad to think about the other Jocelyn's story, and will make me think twice about where I plonk down mirrors or glasses in future.

 

[Flyfisher]

I still maintain that the probability of a shaving mirror causing a fire this morning is rather unlikely, but so was the whale that turned into a vase of petunias.

Except that given the position of the mirror and the position of the rising sun, the event was inevitable, i.e. a probability of 1.
I take your point about infinite improbability drives though :wink:

Anyway, no real harm done, which is the main thing.

 

[biffvernon]

But the position of the mirror and Sun are not a given (any more than the six facing up on the die is a given). One has to consider all possible positions of the mirror and Sun. Since there are many, P<1.
Or putting it another way, you're saying that once an unlikely event occurs, the occuarnce is certain to have happened. This is technically known as stating the bleedin' obvious.

 

[Flyfisher]

Well, the position of the sun on a particular day is certainly a given. And leaving the mirror in that particular place makes the outcome inevitable. Just because you may not realise the impact of placing the mirror in that particular position does not alter the inevitable outcome.

Probability is a human invention, used to make some sense of things for which we have insufficient knowledge.

 

[Cloudscape]

Some of this thread reminds me strongly of the tone of "The Hitchhiker's Guide to the Galaxy"... I think they had an Infinite Improbability Drive that propelled a spaceship. 8)

It might have been an urban myth, but I was told of someone who had a minor fire caused by the sun and a glass paperweight.

 

[Feltwell]

I still maintain that the probability of a shaving mirror causing a fire this morning is rather unlikely, but so was the whale that turned into a vase of petunias.

No no no, it was a missile that changed into a sperm whale and a vase of petunias, not a whale that changed into a vase of petunias. That would be silly. :wink:

 

[MdB]

No no no, it was a missile that changed into a sperm whale and a vase of petunias, not a whale that changed into a vase of petunias. That would be silly. :wink:

Now, if you are going to quote H2G2, you need to get the story correct. There were two missiles that got turned into a sperm whale and a bowl of petunias. (One crew member also received a bruise to the arm, but in order to convey a sense of intrigue and mystery, the unlucky recipient of the injury will not be named here.)

 

[Gareth Hughes]

"Oh no, not again"

 

[Schoolmarm]

:lol: :lol: :lol:

 

[JoceAndChris]

If I may wander off "The Hitchhiker's Guide" for just a moment, the solution to our potential problem is now obvious. Chris must grow a large, Henry VIII style beard.

I bet this kind of fire never happened in the days before daily shaving. You see, it was so much better in the olden days. :wink:

 

[biffvernon]

I still maintain that the probability of a shaving mirror causing a fire this morning is rather unlikely, but so was the whale that turned into a vase of petunias.

No no no, it was a missile that changed into a sperm whale and a vase of petunias, not a whale that changed into a vase of petunias. That would be silly. :wink:

I said it was rather unlikely.

If I may wander off "The Hitchhiker's Guide" for just a moment

Certainly not. Behave.

And leaving the mirror in that particular place makes the outcome inevitable.

And rolling the die in a particular way makes a six inevitable. But both die rolling and mirror placing are unpredictable and so subject to probablility theory. Chaotic systems are also inherently unpredictable and it may be the case that the same can be said for quantum mechanics. If probablility is a human invention it is so only insofar as it is a descriptor of an underlying physical reality unmediated by human intervention.

 

[biffvernon]

 

[Flyfisher]

And rolling the die in a particular way makes a six inevitable.

Precisely. Unpredictable implies unknowable, which is not the same as unknown. Mirror placing is not a chaotic system.

 

[Feltwell]

Now, if you are going to quote H2G2, you need to get the story correct. There were two missiles that got turned into a sperm whale and a bowl of petunias.

Damn, you're right, it was a bowl of petunias. The art of being a good pedant starts with being right!

If I may wander off "The Hitchhiker's Guide" for just a moment

How dare you, don't be silly.

Coming soon - "PeriodPedantry.co.uk" and "PeriodProbability.co.uk"

:wink:

 

[biffvernon]

Mirror placing is not a chaotic system.

It is when part of the Joce and Chris system.