system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What causes the strobe-like trail of lights (not a smear of light, but a staccatto - - - - - - - -) we see along the path of moving LED lights? Automobile headlights and tail lights, for example.
gpt
Some LED headlights and tail lights aren't on 100% of the time.  They work on a 'duty cycle'. So at 50% duty cycle, the LED is on 50% of the time.  This is very typical of LED tail lights, as they will be at 25% or so duty cycle as tail lights, and 95% to make them brighter when you apply the brakes.