Why and how does observation change properties of things like in light wave particle duality or quantum states?
In: Physics
To observe you need to interact. How do you interact you ask? You change the system in some way, be that introducing energy or taking energy from the system.
Human observation in itself does not collapse quantum states. Maybe I’m wrong though. I’m only an armchair youtube scientist
Observation has a science meaning that’s quite different than you might be thinking from the macroscopic world. For instance, if you have a baseball throwing machine that shoots baseballs at a wall, you can “observe” it quite passively. The way that works is that light from the Sun streams down and scatters off the ball, a tiny bit of that makes it into your eyes so you can see the ball. It seems like your “observation” has no effect on the flight of the ball, making QM seem weird when it says that observation collapses the wave function.
Observation in science is any interaction that might lead to detection. To further the baseball analogy (Even though we all agree a baseball is not a quantum object), when the first photon of light from the sun interacts with the ball, or the first atom of air interacts with the ball, that’s an observation. The observation might not be collected, recorded, and analyzed by a human, but that’s not the definition.
How do we see things? Light hits the object we are looking at, bounces off the object, then comes back to our eyes.
Now what happens if the object is so small that light hitting it moves it?
Think of a pool table. In the dark. The cue ball is in your hand. There’s an 8 ball on the table. You want to find where the 8 ball is. So you throw the cue ball along the table until you hear it connect with the 8 ball. There! You just placed the 8 ball. But the cue ball made the 8 ball move. So where is it now? You knew where it just was, but now you don’t.
The cue ball is light. The 8 ball is some small particle you are trying to “see.”
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