In an argument re an incandescent bulb, yeah those things, will flicker at 100Hz or 50Hz given a 50Hz mains power. The reasoning is the peak and trough of the sine wave both deliver a peak in candescence ie two peaks per cycle therefore 100Hz flicker?? Will be settled by experiment soon as we find a shop that sells incandescent bulbs, the pimple face kid in the hardware franchise does not know what a incandescent bulb is...lol. So my reasoning is correct??