[Chode]

bouncing a photon or other particle against it, the state of the particle is changed.

but aren't photons bouncing off of it anyway whether they go into my eye or not?

i guess my point is, i am not doing anything but looking at it,not trying to measure it - not affecting it in any way, scattered photons of light either enter my eye or they don't through nothing of my doing, if they enter my eye and i see them, how does that change it's state?

that is why i ask is he using the words measure and observe interchangeably

[ETL]

I’m far from an expert on the subject, but, as the piece I posted a little while ago points out, there are several interpretations of QM.

Interpretations of Schroedinger’s Cat
http://www.freerepublic.com/focus/chat/3114541/posts?page=22#22

[ETL]

but aren't photons bouncing off of it anyway whether they go into my eye or not? i guess my point is, i am not doing anything but looking at it,not trying to measure it - not affecting it in any way, scattered photons of light either enter my eye or they don't through nothing of my doing, if they enter my eye and i see them, how does that change it's state?

"Confusion about the Uncertainty Principle It's very common for the uncertainty principle to get confused with the phenomenon of the observer effect in quantum physics, such as that which manifests during the Schroedinger's cat thought experiment. These are actually two completely different issues within quantum physics, though both tax our classical thinking.

The uncertainty principle is actually a fundamental constraint on the ability to make precise statements about the behavior of a quantum system, regardless of our actual act of making the observation or not. The observer effect, on the other hand, implies that if we make a certain type of observation, the system itself will behave differently than it would without that observation in place."

http://physics.about.com/od/quantumphysics/f/UncertaintyPrinciple.htm

[ETL]

but aren't photons bouncing off of it anyway whether they go into my eye or not? i guess my point is, i am not doing anything but looking at it,not trying to measure it - not affecting it in any way, scattered photons of light either enter my eye or they don't through nothing of my doing, if they enter my eye and i see them, how does that change it's state?

"The observer effect refers to situations in science where the act of observing a system has an impact on the system being observed. Checking pressure in a tire, for example, is done by causing a release of air which, in turn, causes a slight change in the tire pressure. This is a classic example. Scientists (especially psychologists) have to be especially careful when planning their research methods to avoid interfering with the results they intend to get.

In the realm of quantum physics, there's a more powerful form of the observer effect, as exhibited by the Schroedinger's Cat thought experiment and the quantum double slit experiment. It appears that in cases like these, the very act of making the measurement doesn't just modify the system, but actually results in fundamentally different physical behaviors within the system.

Also Known As: Quantum Observer Effect

Examples:

The quantum Zeno effect is an especially powerful example of the observer effect in action within quantum mechanics."

http://physics.about.com/od/physicsmtop/g/ObserverEffect.htm