UK friends, help me understand

A discussion on my UK editors list has degenerated (as the good threads usually do :-) into something totally unrelated to work, namely electrical wiring.

Specifically, and this has me completely confused, the assertion by several members that they've been told by electricians that to comply with the new ("new" = four years old) electrical regulation called Part P, all the fixed lights in their house have to be on a single circuit (and all the plugs have to be on a single separate circuit). Looking up Part P myself, I find that it's suggested model plan does nothing of the sort; it puts all fixed lights on each *floor* on one circuit and all plugs on each floor on one circuit. Now, that still seems like overkill to me; why not do what we do here in the US, and have them circuited room by room? That way if the lights go out in the kitchen, I don't trip over everything in the dark on my way to the fuse box.

Which brings up the part that REALLY confuses me. All these folks are claiming that every time one of the lightbulbs blows, the CIRCUIT BREAKER TRIPS! WHAAAAA? Why on earth would the circuit breaker trip when a lightbulb goes *out*. We're not talking explosive decompression or implosion here, just an ordinary incandescent lightbulb has the tungsten coil inside fail and it stops generating light. Why on EARTH would that make the breaker trip, ESPECIALLY if that means every light in the floor (or house, since I don't doubt that these folks are telling the truth, just that what their builders are doing is actually the requirement of the code). This makes NO sense to me.

Can someone wise in the way of volt and amp explain?

(no subject)

Well, well, well. No sooner did the final (and unexpected) escrow check from the house sale finally arrive (now to figure out how to get redactrice her share...) than I spent a good part of my share!

I was hoping to spend the afternoon having coffee with a new acquaintance and possibly winning a new convert to "Fjords", but instead I found myself driving around Takoma Park on a cold, rainy day trying to find an open auto mechanic. Eventually I would up at the defrocked Shell station on 193 and Carroll, which proved willing to take a look at my car and try to figure out what was making the truly horrific grinding noise at the front left wheel (and making the brakes feel a bit dodgy).

Turns out something (I suspect the HUGE pothole on the 123-to-495 offramp) snapped by left front axle and either that or driving on it completed the ruin of my front left wheel bearing and hub (which I think had been bad for some time). Three hours and $400 later... :-(

Text messaging (which I'd discovered, thanks to ban_leodhasach my phone is unexpectedly able to do), allowed me to warn my prospective gaming partner that we would have to postpone our meeting to another day. And I had two books with me (good thing, since I finished one!) But a great deal less fun (and more cold!) than how I had hoped to spend the day!