Wave Particle Duality & Uncertainty Principle: Which Came First?

In summary, the concept of wave-particle duality, which is a heuristic term, came before the uncertainty principle and it was primarily developed by De-Broglie's Phd thesis in 1924. However, the uncertainty principle was a result of the fully developed quantum theory by Dirac in December 1926. The wave particle idea led to different versions of quantum mechanics, Schroedinger's equation and wave mechanics, which were later shown to be the same theory by Dirac. Waves can sometimes behave like particles and vice versa, but this is not a general principle as there are many circumstances where this is not the case. The issue of the Dirac Delta function was fixed by Von-Neumann in 1932.
  • #1
RQwtq
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Which of them comes first,(I mean the concept or the theory)? Did Heisenberg come up with the idea of uncertainty principle because of the discover of the wave particle duality?

Thanks for paying attention~
 
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  • #2
What do you mean by "wave-particle" duality? It's usually a heuristic, rather than a specific technical term. Do you mean ##[x,p]=i\hbar##?
 
  • #3
Is it true that waves sometimes behave like particles and particles sometime behave like waves? If it's true, that is what I meant...
 
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The wave particle duality is actually incorrect - its neither wave nor particle - its quantum stuff. Concepts like that were part of the ideas prior to the full birth of QM that happened in December 1926 when Dirac came up with his transformation theory that basically goes by the name QM today.

The uncertainty principle follows from that fully developed theory - its a theorem about non-commuting observables.

Historically Heisenberg came up with the uncertainty principle 1925-1927. The wave particle duality probably dates from De-Broglies Phd thesis in 1924 - so it likely came first. But I want to emphasise its incorrect.

Thanks
Bill
 
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  • #5
I'm working on a chemistry video for homework. I want to say that it is wave-particle duality that led Heisenberg to come up with the idea. But, really, I'm not sure about it, so I'm here to ask...Now I'm even more confused:confused:
 
  • #6
RQwtq said:
I'm working on a chemistry video for homework. I want to say that it is wave-particle duality that led Heisenberg to come up with the idea. But, really, I'm not sure about it, so I'm here to ask...Now I'm even more confused:confused:

It wasn't.

It followed from the matrix mechanics he developed about that time.

The wave particle idea led to Schroedinger's equation and wave mechanics.

They were two different versions of QM.

It was suspected they were in fact the same theory.

Dirac succeeded in showing that in December 1926:
http://www.lajpe.org/may08/09_Carlos_Madrid.pdf

There were a couple of mathematical technicalities that needed elaboration due to what's called the Dirac Delta function. Von-Neumann fixed that issue in 1932 when he published his famous Mathematical Foundations of Quantum Mechanics.

Thanks
Bill
 
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  • #7
Ok, that's much easier to be understood. Thank you
 
  • #8
RQwtq said:
Is it true that waves sometimes behave like particles and particles sometime behave like waves? If it's true, that is what I meant...

Yes that's true - but its not a generally applicable principle because there are many circumstances where its neither.

Thanks
Bill
 
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  • #9
thanks
 

FAQ: Wave Particle Duality & Uncertainty Principle: Which Came First?

1. What is wave-particle duality?

Wave-particle duality is the concept that particles can exhibit both wave-like and particle-like behavior, depending on how they are observed or measured. This means that at the quantum level, particles can have properties of both waves and particles.

2. How does the uncertainty principle relate to wave-particle duality?

The uncertainty principle, proposed by Werner Heisenberg, states that it is impossible to know both the position and momentum of a particle with absolute certainty. This is because the act of measuring one property affects the other property, leading to uncertainty. In the context of wave-particle duality, the uncertainty principle shows that particles can behave as waves because their position and momentum cannot be precisely determined at the same time.

3. Which came first, wave or particle behavior?

Wave and particle behavior are both fundamental properties of particles at the quantum level. Therefore, it is not accurate to say that one came before the other. Instead, particles can exhibit both behaviors simultaneously depending on how they are observed or measured.

4. How does the double-slit experiment demonstrate wave-particle duality?

The double-slit experiment is a classic experiment that demonstrates the wave-like behavior of particles. When a single particle is fired at two slits, it creates an interference pattern on the other side, similar to how waves behave when passing through two slits. This shows that particles can behave as waves, supporting the concept of wave-particle duality.

5. Does wave-particle duality have any practical applications?

Yes, wave-particle duality has many practical applications in modern technology. For example, the principles of wave-particle duality are crucial in the development of quantum computing, which has the potential to greatly increase computing power. It is also essential in fields such as nanotechnology and medical imaging, where the behavior of particles at the quantum level plays a significant role.

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