4 ms·

Observation is what makes physics matter in the practical sense.

• simonh 7y ago
  Is there anything about the point being made that is inconsistent with that?
  • Koshkin 7y ago
    A theory without observables is not science.
    • simonh 7y ago
      The point being made is that all observations change the thing being observed, so you have to be very careful what you measure and how you measure it. That is all. This is a basic point in science that is often missed. As here, apparently.