Because Arthur collects electrical and muggle things! We encounter very few wizards who have the slightest interest in muggles, let alone collecting muggle artefacts. He has no need to do it, but he enjoys it and finds it fascinating. I doubt he would not collect some working electrical objects, knowing his interest in them.
Why? The Weasleys don’t need electricity, and besides, as Kara says:
Fine, then where does the magic stop? Hermione says incredibly clearly in GoF that electrical items won't work - there's simply too much magic around. In the middle of the Atlantic Ocean they would work because there's no magic. The likening of magic to radiation, is, in my view, incredibly accurate. The more sources there are and the more radioactive/strong they are, the more radiation there is the area and the further you have to go to 'escape' it.
Are we? I’m not trying to be flippant, but you seem to be working on the assumption that “magic WILL leak” Why?
Why should the adjacent properties in Grimmauld Place have problems? Why should magic “leak” from one place to another? It’s magic, not radiation.
If you say magic shouldn't leak then what makes these places so special? What's stopping it from leaving? The fact that INSIDE those places it is magical shows that it spreads around, as there's not a spell being cast by a person constantly on every square foot yet the place is still magical. I'm fairly sure in HBP Dumbledore can 'feel' the magical enchantments around the locket's protective devices.
I quickly drew up this diagram to try and explain my point (apologies for the poor quality).
Essentially the pink blobs are magical spells, whether in the form of wizards casting them or moving staircases, enchantments etc. The grey box indicates the magical place. Firstly, if magic doesn't leak then the entire house wouldn't be magical, and one would be able to use electrical devices in it. Obviously not every single inch can be enchanted.
You are saying it doesn't leak outside the magical place, but I think it must. What is stopping it from spreading? Nothing!
Yes, that is true and is canon from what Hermy said.
The presence of concentrated magic prevents electronic technology from working.
We're saying exactly the same thing here, what I'm trying to work out is why the magic is only limited to those magical places and why it doesn't spread around.
I admit that I have no proof of cause and effect. But the previous paragraph is a useful theory and it can be easily tested. All we need to do is find one occasion in canon where an electrical item is shown working in a magical location and the theory fails.
Of course “concentrated magic” is a very woolly term, but that's deliberate on my part, as it gives authors some leeway. Factors may be: “power” of spells cast, number of spells cast, number of “permanent” spells, number of magical items and devices, number and type of concealment charms, I could go on, but, my motto is "when in doubt, make something up (and be prepared to justify it)".
And, by the way, finding something hard to believe does not make it untrue. I have that problem all of the time (often about people who manage to get elected to public office).
I made a second post as I was getting confused doing it all in one.
But he was interested in electricity! No wizard ever has a need for an electrical item, but Arthur collects them. If he wanted to find out how they worked he would want working ones, would he not? We have no evidence that all of Arthur's collection was broken, but there is none to say any of it worked, either.
Originally Posted by Karaley Dargen
He and his family lived there for weeks with wizards all over the place. None of the electric lights would have worked, the fridge wouldn't have worked, the TV wouldn't have worked... unless the items were enchanted by the Ministry (a possible explanation, but no facts to back it up) then the items in his house should of stopped working. We must assume they didn't.
Apart from that, you refer to the Quidditch World Cup Campsite as an instance where many wizards were in the same place over a stretch of time. However, this is quite remote, with only the Roberts Family possibly living there – and we don't even know where exactly they usually live. Most of all though, we don't know what kind of electricity they use there, and whether or not it worked during that time. The poor man was constantly being obliviated – do you think he remembers whether his radio worked in the evening?
That is what I'm getting at. A spell so powerful as to stop all magic entering and leaving? We know that extra defences have to be put in place to protect the OOTP safe houses: if no magic could enter or leave with a basic anti-magic-leak-shied then this would't be needed.
Grimmauld Place is shielded from sight – I'm sure that it has some sort of shield that prevents the magic from leaking out, too. Possibly there are Ministry rules – if you want to start putting spells on your house (like the concealment charms in GP, or the household spells in the Burrow), you have to put up an anti-magic-leak shield.
Yes, that is true.
I don't get the point you made earlier about giants and dragons. I can put my cheese in a plastic bag to keep it from smelling up the fridge, but if I put a mouse in there alongside it, it'll just bite a hole in the bag and get out, probably with the cheese. Magic itself and magical creatures are completely different things...