A metal working friend told me recently that in Australia we're not meant / allowed to use fluorescent lights above lathes, as the flicker can disguise movement.
Yeah gas discharge lamps (CFL, neons, halides) will flicker at twice the mains' frequency on a single-phase circuit, makes it very dangerous to use them as e.g. factory lighting. You can mitigate that by using 3-phase power supplies, high-frequency controller, or by supplementing the basic lighting with incandescent bulbs around machinery.
The stroboscopic effect is really fun right until you're in a place with lots of moving parts at a multiple of the strobe frequency.
OTOH it's also used to fine-tune engine timing and such: set a stroboscope at a fraction of the frequency you want, the engine is properly tuned when everything looks completely stopped. Makes it very easy to notice mistiming.
Some turntables include a strobing light and rings of dots around the edge for different speeds. If it's spinning at the correct speed the corresponding dots will stand still.
Absolutely - the way he described it sounded like a horrendous accident waiting to happen, especially for smaller / home shops where the operator may not be aware of the problem. He was under the expectation that LEDs solved this problem, though he is using drop-in LED tubes that may have some better persistence through the off-cycles.
I do some occasional wood-turning, but usually augmented with ambient daylight - along with the dubious safety advantage of having a very noisy electric motor.
Plus I'm old enough to have used a timing light hanging off a distributor on my first car. Try explaining that to the kids of today. ; )
This is slightly worrying.