A Way to Know If We're in a Simulation

This was inspired by a dream I had that was mildly unsettling.  In the dream, you were in a house with a few old-school moving pictures on the wall - the kind that required a handcrank to animate except the owner found a way to keep the pictures moving on their own for a long time, to the point the owner had long passed away and the pictures were still moving.  Over time, the mechanical devices keeping the pictures moving start to wear out, and the pictures start to slow down.  What becomes odd is that if you look closely enough, you start to notice that every so often, a frame goes missing or blacks out, as if the universe flickered and the camera captured a moment of nothingness.

Of course, that dream could have been a lot of other things, such as mechanical issues with the camera that shot the footage, but what it got me wondering was 1) if the universe was a simulation with a frame rate, 2) whether we could capture the flickers in between the frames to prove it.  This is assuming of course that the kind of simulation we're in is digital with discrete frames, but even if it were analog, we'd start to see stutters where the change was no longer continuous.

The main obstacle is that you are bound in this universe with the same frame rate, so anything you record would be lined up with the universe's frame rate such that you cannot capture any of the gaps between the frames.  Even if you had the highest frame rate camera imaginable, you can't make it faster than time itself.  In other words, time itself is our frame rate.

So how do we break "outside of time" and record it? Lucky for us, time can slow down based on general relativity.  In other words, we record from one region of time-space that is moving faster and point the camera at another region of time-space that is slower.  In other words, point the camera at a black hole.  Time near a black hole slows down to the point even light "disappears" by stopping (not because it gets sucked in).  We wouldn't literally film the black hole itself (that would just be black); we would film the stuff nearest it to the point of being almost frozen in time but enough for us to still see some movement if we sped the footage up.

If the universe is a simulation with some sort of frame or refresh rate, what we should see then is some kind of stutter or missing frames as time slows to almost standstill - like a video that is lagging or music that begins to skip.  If there is no refresh rate, it should be infinitely divisible.  It doesn't disapprove that we're in a simulation if we don't find a refresh rate, but it would eliminate one possibility.