The phrase "act of observing" is correct and usable in written English.
It can be used when discussing the process or action of watching or noticing something carefully.
Example: "The act of observing nature can lead to a deeper understanding of environmental changes."
Alternatives: "process of observation" or "observation activity".
The sculptures were not an expression of the observed landscape but of the act of observing it.
In Moselle's film, her presence has a clear effect; the act of observing something changes it.
The act of observing an untouched culture, of course, inevitably touches it.
Just like the adage that the act of observing a phenomenon changes it, the act of trapping and retaining data creates the potential for it to be compromised.
According to Bohr and his supporters it is the act of observing a particle that "forces" it into a definite state.
A fourth-degree invasion-of-privacy charge refers to the act of observing someone, without consent, "under circumstances in which a reasonable person would know that another may expose intimate parts or engage in sexual penetration or sexual contact".
"I manipulate an audience in the best way possible, which is to assist them in the act of looking, of observing".
Or else the very act of our observing the face fixed its position.
Sometimes the act of physically observing food will make you realize you're hungry.
According to Heisenberg, the very act of observation changes the thing observed; Peter J. Davison's shrewd set — a kind of blond-plywood bullring built within the proscenium, where some of the audience are seated so that we can look at them looking down on the proceedings as they look out at us — em-phasizes that act.
Quantum physics has taken this further with 'the Observer Effect,' (also related to Heisenberg's Uncertainty Principle) which states that the act of observation changes what is observed.
