Looking is not passive. If you want to see your reflection, the process involves lots of photons coming from a light source, bouncing off you, bouncing off a mirror perfectly, and hitting your eyes. In day to day interactions (and in many experiments), photons bouncing off of things doesn’t change the outcome a whole lot, if any.
For observing extremely small particles, we bounce a photon or an electron off just like we do looking at ourselves in the mirror. The difference is the small particle were are sending a photon at is so small that the photon sends it shooting somewhere else.
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