Yeah, basically we normally blast things with photons to measure them, whether that’s in a complex microscope or you just turning on the light, so you can see your measuring stick.

Now, photons are themselves quanta. So, for measuring quanta, we’re blasting quanta at quanta. It’s not quite like throwing a tennis ball at another, because there’s no hard collisions at the quantum level, but the quanta do still interact and kind of push each other around.

So, any time you measure a quantum, you also push it around, which means what you just measured is not anymore true. As a result, you can only determine a probability of where it might now be.