Nitpicking, but just going with classical physics and Newton's Third Law, yes, you can do such things. If the thing you're studying emits something, and you ca

Nitpicking, but just going with classical physics and Newton's Third Law, yes, you can do such things. If the thing you're studying emits something, and you can infer the thing's state from what it emits, you can study the emissions without disturbing the thing. Similarly, looking at something doesn't change its state, since the light was already reflected / emitted. Obviously there are additional complications at such small scales, and it depends on what you're detecting (measuring / passing through magnetic fields does affect the source since it changes the field), and it depends on what you define as "change" and which quantum mechanics interpretation you subscribe to. I'm just pointing out that the thing being measured doesn't have to be the thing you're investigating, so that law in particular doesn't really imply anything.