Physics and its basic laws is useful:
there are suspensions (heavy) with a single bulb and well in these ampoules resist as long as the others.
shows that a heavy suspension during an impact, undergoes a much lower acceleration than the same shock on a light suspension (in the ratio of weights or masses) !!
Give a kick in a balloon or a truck, they do not have the same acceleration in the shock !!
Also as the hot filaments to 2200 ° C suffer as the acceleration that they have undergone, this objective experimental observation, of resistance on heavy luster,
scientifically proves that the shocks of not above the ceiling or others (cleaning, head shot) are the sufficient cause to shorten the duration of the filaments !!
On my handhelds, for decades, I found this phenomenon, a small shock: life shortened, a good shock, dead!
So increase the luster by ten and hang it with an intermediate rubber !!
Several lamps on the same wire in parallel with the same voltage will not be different from a single and magnetic, too, in the Earth's magnetic field, except big magnet against the bulb, will not change much.
If elsewhere there is a big self, big motor, big transformer, powerful thyristor, the brutal cuts of current on these machines with inductance, make overvoltages (1000V) which can weaken the filament, like the lightning which kills a lamp in a microsecond or the aging of 800 hours, (halogen less clear), as I could see at home!