How to have an object's scale be affected by proximity to empty? I have a collection of cubes that are parented to a spinning circle. I would like the cubes to increase in scale as they pass through an empty and then shrink again so that the cubes at the front are bigger and highlighted more. 



Q: How can I do this with animation nodes?
You can either use Object controller falloff or Point Distance falloff to get proximity effect.
In your case you have animated cubes outside Animation Nodes. So we only care about scales of cube inside Animation nodes. Then here is how to do:



Or we can also build entire setup inside Animation nodes: