honk

I was relaxing in the bar, calmly enjoying my beer. Outside, the traffic was horrible. The intersection was almost blocked and the drivers were angry. A car blew its horn. I thought I saw the lights in the bar blink. It was obviously just a brain glitch. Surely the lights can't dim when a car is honking outside, can they? A great thought came to my mind. What if they actually could? I mean, when a lightning bolt hits a powerline or transformer station, the lights most certainly blink. They dim a little. The same thing happens when someone in the building is welding - the welder draws a lot of current so the line voltage decreases significantly. The question is, when a tram or trolleybus or even a train goes past the building, does it create enough of a disturbance for the lights to noticeably blink? In most cases, I guess it doesn't. But do the lights blink unnoticeably? Possibly. It's not necessarily an electrical disturbance that can cause the lights to blink. Air currents for instance do modify the light output of all devices, be them incandescent lamps, fluorescents, LEDs, whatever, simply because light output is dependent on temperature, no matter how slightly. Me shouting at the lightbulb can potentially alter its output. By how much, that's another discussion. It's certainly not noticeable, but is it measurable? If it's not directly measurable, is it at least statistically measurable? How many photons a second does a lightbulb's output vary with when a car honks outside? I don't know. Fewer than air currents cause? Electrical disturbances from people turning their TV on or off in the next building? I don't know. It's an interesting thought. My guess is about 5.