High School How do I explain quantum superposition?

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Quantum superposition can be effectively explained through the behavior of photons interacting with polarizers, illustrating how states can exist simultaneously until measured. The concept of wave-particle duality is often misapplied, as it was recognized as a flawed approach in the development of quantum mechanics. Schrodinger's cat is frequently misunderstood; it was intended to critique the absurdity of superposition rather than exemplify it. The double-slit experiment serves as a more accurate demonstration of superposition, showcasing how particles can exhibit wave-like behavior. Understanding superposition can be simplified by discussing the superposition of waves with different wavelengths, leading to the creation of new waveforms.
Bianca Meske
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I'm a student trying to explain quantum superposition without using Schrodinger's cat. Instead, I'm trying to use the principal of wave particle duality to explain how a particle can be in multiple states (and locations) at once before it is observed due to wave properties. However, I'm unsure how to do this effectively and simply for others to understand. Any ideas?
 
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Bianca Meske said:
I'm a student trying to explain quantum superposition without using Schrodinger's cat.
Good. Schrodinger's cat is not an example of superposition, it is an example of how not to use superposition. Many popular "explanations" of the cat misunderstand what Schrodinger was doing when he described the thought experiment; in fact he was arguing that the idea of a cat in a superposition of dead and alive was absurd, and therefore that something was wrong with the then-current (almost a century ago) understanding of QM because it seemed to predict that result. We have many older threads here about this.
Instead, I'm trying to use the principal of wave particle duality to explain how a particle can be in multiple states (and locations) at once before it is observed due to wave properties.
Not so good. Wave-particle duality was recognized as a wrong turn in the development of quantum mechanics at about the same time that Schrodinger proposed the cat. Again, many oversimplified presentations of the theory miss this, and we have many threads about it.
However, I'm unsure how to do this effectively and simply for others to understand. Any ideas?
Some of the best examples of superposition come from photons directed at polarizers. The states "vertically polarized" and "horizontally polarized" can be written as superpositions of "polarized 45 degrees left" and "polarized 45 degrees right"; and the two 45 degree states can be written as superpositions of vertically polarized and horizontally polarized.

When a photon approaches a polarizing filter set at some arbitrary angle then no matter what the polarization of that photon is, we can rewrite it as a superposition of "polarized at the polarizer angle" and "polarized perpendicular to the polarizer angle". Same angle makes it through every time, perpendicular never does.
 
So can the double slit experiment be used accurately to explain superposition or no?
 
So, you just want to explain superposition? Just so it can be understood (by the average person) what that is even referring to?
You don't care how to explain it, as long as it is explained?
 
Bianca Meske said:
I'm a student trying to explain quantum superposition without using Schrodinger's cat. Instead, I'm trying to use the principal of wave particle duality to explain how a particle can be in multiple states (and locations) at once before it is observed due to wave properties. However, I'm unsure how to do this effectively and simply for others to understand. Any ideas?

Let's go back a few steps. Can you explain the "usual" superposition of waves? For example, if I take two waves of slightly different wavelengths, I can produce a superposition of those waves to produce a new wave.

Are you able to "explain" that?

Zz.
 
Time reversal invariant Hamiltonians must satisfy ##[H,\Theta]=0## where ##\Theta## is time reversal operator. However, in some texts (for example see Many-body Quantum Theory in Condensed Matter Physics an introduction, HENRIK BRUUS and KARSTEN FLENSBERG, Corrected version: 14 January 2016, section 7.1.4) the time reversal invariant condition is introduced as ##H=H^*##. How these two conditions are identical?

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