This signifies that each vertical dotted line is 20ns apart, so the ripple you see has a frequency of something like 50MHz.
Unless you have a 50MHz buck converter (which would be very exotic --- the fastest common ones are around 1/10th that), that looks more like something may be inadvertently oscillating and/or you're picking up strong RF noise from possibly something in...
https://en.wikipedia.org/wiki/6-meter_band#Radio_control_hob...
And "leared" -- the (unintentional?) pun made me click.
>And "leared" -- the (unintentional?) pun made me click.
I assume it's a reference to the "Quality Learing Center" in Minnesota, one of the questionable daycares at the center of the alleged Somali daycare fraud scandal. Ever since some of the expose videos about it came out it's become a meme to say "lear" instead of "learn".
Cannot it be a noise from imperfect switching? The switching occurs at lower frequency, and the noise is high frequency.
I guess he also believes that 50 MHz or so signals can be measured reliably on a 40 MHz (on paper at least) scope.