# Meaning of REALLY Slow Speeds

So we have a fairly good grasp of how entities behave at extremely fast speeds (visa vi relativity etc) but what about incredibly slow speeds?

I’m a Physics student and we were covering Broglie waves. We calculated our own (using our mass and a random speed) to discover that lambda was incredibly small (2X10-36)

Since such a wave wouldn’t interact with much of anything, I calculated the needed wavelength to interact with, say, a 6cm thick door. I found a I would need to move at 2.18 x 10-31 meters / second.

But what does that physically mean? Taking a less extreme case, what would it look like if something were to move at 1 picometer / second? Are there any examples?

• This is loosely related, but MOND models that try to account for dark matter hypothesize that physics for small accelerations needs to be modified: en.wikipedia.org/wiki/Modified_Newtonian_dynamics Apr 9, 2019 at 22:35

Second of all, the Heisenberg Uncertainty Principle is pretty much useless with finding speeds primarily because the terms in that $$\Delta x$$ and $$\Delta v$$ are standard deviations.