Quantum Physics - Observer Effect

[Art Man]

"Quantum states are detectable but by the law of quantum mechanics, once we observe a quantum state, it changes. Nice thing is entanglement means we only have to observe one of the particles to sense the state of the others but its not two way data transfer, not yet."

Trace Dominguez with Seeker

 

"It's common to all ways of understanding quantum mechanics that I know of that observation is a sort of irreducibly violent process."

Physicist David Albert on Nour Foundation

 

"When a quantum "observer" is watching Quantum mechanics states that particles can also behave as waves. ... In other words, when under observation, electrons are being "forced" to behave like particles and not like waves. Thus the mere act of observation affects the experimental findings."

Science Daily in Google search

 

How Does Observing Particles Influence Their Behavior?

https://futurism.com/how-does-observing-particles-influence-their-behavior

Three Tricks Physicists Use To Observe Quantum Behavior

https://www.forbes.com/sites/chadorzel/2016/08/11/three-tricks-physicists-use-to-observe-quantum-behavior/amp/

 

So, this observer effect in quantum physics seems sketchy in explanation. The effect can happen with just a static object in near enough proximity to the particle to change its behavior. Additionally, the same effect happens when a human, specifically a human, observes the particle without physically interracting with it. So, my question is, is it really the act of observing that changes the particle or is it the method of observation required to observe the particle that changes it? As I understand it you need microscopes and particle accelerators, mirrors and slitted panels, and a high speed camera or other sensory instrument so that you can observe a quantum particle. Can someone more specifically and in finer detail explain all physical circumstances of making and observing a quantum particle?

Edited September 2, 2019 by Art Man

[Mordred]

Observation is a rather misleading term. Any act of measurement is an observation.  When you measure a quantum state you interfere with that state. In entanglement you have determined a wavefunction thus collapsing a superposition state. Superposition being a probability of all possible states. 

With any particle under QM the wavefunction is a probability function that the square of the amplitude gives the highest probability of locating the energy/momentum terms of a particle. Ie locating the particles position. Once you make a determination you no longer require a probability function as you have made a determination via observation/measurement.

The entanglement scenario is also of this case, for example when you entangle two electrons there is only two possible states one being the opposite of the other. Until you make a measurement you have no way of knowing the individual states but can establish a probability correlation function that describes the superposition of states and the strength of how correlated the two states are to the experimental apparatus.

Once you determine one state you automatically know the other state which collapses the probability superposition state as well as the correlation function which is also a statistical probability function.

Little side note on entangled particles. Measuring one particle doesn't affect the actual particle state of the other particle. It only affects the superposition state which is a probability state. Once determined there is no longer any probabilities involved. There is no action at a distance nor hidden variables. Nor do the two particles communicate FTL. No locality of the two particles involve the detail that the superposition wavefunction applies to both particles simultaneously. When you measure you collapse that wavefunction by making a localized determination of one of the pairs which allows you to determine the non localized state of the other particle state.

Unfortunately pop media articles don't sell well talking about probability functions puts readers to sleep so they typically romanticize what is involved with regards to the observation effect.

https://en.m.wikipedia.org/wiki/Observer_effect_(physics)

You should be able to better understand several of the lines in this link with that in mind. In particular 

Physicists have found that even passive observation of quantum phenomena (by changing the test apparatus and passively 'ruling out' all but one possibility), can actually change the measured result. A particularly famous example is the 1998 Weizmann experiment.^[2] Despite the "observer" in this experiment being an electronic detector—possibly due to the assumption that the word "observer" implies a person—its results have led to the popular belief that a conscious mind can directly affect reality.^[3] The need for the "observer" to be conscious is not supported by scientific research, and has been pointed out as a misconception rooted in a poor understanding of the quantum wave function ψ and the quantum measurement process,^[4][5][6] apparently being the generation of information at its most basic level that produces the effect.

 

Edited September 2, 2019 by Mordred

[Art Man]

1 hour ago, Mordred said:

When you measure a quantum state you interfere with that state.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Unfortunately pop media articles don't sell well talking about probability functions puts readers to sleep so they typically romanticize what is involved with regards to the observation effect.

https://en.m.wikipedia.org/wiki/Observer_effect_(physics)

You should be able to better understand several of the lines in this link with that in mind. In particular 

 

Quote

Despite the "observer" in this experiment being an electronic detector—possibly due to the assumption that the word "observer" implies a person—its results have led to the popular belief that a conscious mind can directly affect reality

 

That is exactly what I originally thought and all along the whole time since this became a huge media subject they keep playing it off as though simply observing the particles changes them, even reputable sources. They seem to purposely sidestep explaining that it is the method of observation, the equipment and physical circumstance required to observe the particles that changes them. And it does create this belief that our brains and eyes have some sort of magical power, so people do things with this belief in mind such as (when someone isn't looking). But their belief is rooted in a falsehood like so many other beliefs.

Edited September 2, 2019 by Art Man

[Mordred]

Yes unfortunately that is true and oft times it's even in the physics peer reviewed papers. The term superposition actually originates in statistics and the word entanglement is a replacement term for correlation. If you can make a correlation between two states those states are effectively entangled by that correlation.

One of the premises  of QM and the Schrodinger equation is the following.

Quote

 

Quantum superposition is a fundamental principle of quantum mechanics. It states that, much like waves in classical physics, any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state; and conversely, that every quantum state can be represented as a sum of two or more other distinct states. Mathematically, it refers to a property of solutions to the Schrödinger equation; since the Schrödinger equation is linear, any linear combination of solutions will also be a solution.

https://en.m.wikipedia.org/wiki/Quantum_superposition

The many paths of Feymann diagrams also fall into this lemma. (principle of least action ) you have the probability of all possible paths  but the particle will only take one path the path of least action.

+1 on last response one should dispense with belief when examining models. Once you believe too strongly in one model you close the book on other possibilities.

 

 

Edited September 2, 2019 by Mordred