Edge.org
Lee Smolin
Physicist, Perimeter Institute; Author, Time Reborn
Our Concept Of Nature
"If an event or process has internal properties, you cannot learn about them by interacting with it or measuring it. If there are internal properties, they are not describable in terms of position, motion, charges or forces, ie in the vocabulary physics uses to talk of relational properties.
You might, however, know about a process's internal properties by being that process."