What subjects should I study before Quantum Mechanics?

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Discussion Overview

The discussion revolves around the foundational subjects and historical context necessary for understanding Quantum Mechanics, particularly through the lens of blackbody radiation and Wien's Displacement Law. Participants explore the depth of knowledge required in thermodynamics and electromagnetism, as well as recommendations for relevant literature.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Historical

Main Points Raised

  • One participant suggests that understanding Wien's Displacement Law requires knowledge of thermodynamics and electromagnetism, questioning the sufficiency of an undergraduate course.
  • Another participant recommends "Concepts of Modern Physics" by Arthur Beiser as a helpful resource for the OP's studies.
  • A different participant emphasizes the historical development of Quantum Mechanics, referencing Oliver Darrigol's book and noting that an undergraduate degree may not fully prepare someone for the complexities discussed in it.
  • Concerns are raised about the glossing over of historical developments in many QM textbooks, with a suggestion that a historical perspective is often lacking in standard courses.
  • One participant mentions "Quantum Concepts in Physics" by Malcolm Longair as a valuable resource that provides a historical narrative of the development of quantum phenomena.
  • Another participant notes that reading Longair's earlier works led them to Darrigol's book, indicating a progression in understanding through these texts.
  • A participant humorously suggests that the journey to understanding Quantum Mechanics may take at least five years, prompting a plan to start with an online course in undergraduate thermodynamics.

Areas of Agreement / Disagreement

Participants express a range of views on the necessary background for studying Quantum Mechanics, with no consensus on the exact depth of knowledge required or the best resources. Some advocate for a historical approach, while others focus on technical prerequisites.

Contextual Notes

Participants highlight the limitations of undergraduate courses in preparing students for the historical and conceptual complexities of Quantum Mechanics. There is also mention of the evolving nature of disciplines like statistical mechanics during the time of early quantum theorists.

yosimba2000
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I'm interested in learning Quantum Mechanics the way it was discovered, and that seems to be from blackbody radiation, which itself seems to be first quantified by Wien's Displacement Law.

So Wikipedia says Wien derived this law by "considering adiabatic expansion of a cavity containing waves of light in thermal equilibrium. He showed that under slow expansion or contraction, the energy of light reflecting off the walls changes in exactly the same way as the frequency."

I'm assuming I need to understand thermodynamics, and maybe electromagnetism. But to what depth should I know these subjects before attempting to understand Wien's Law? Would an undergraduate course suffice?

Also, any additional subjects would you recommend?
 
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yosimba2000 said:
I'm interested in learning Quantum Mechanics the way it was discovered, and that seems to be from blackbody radiation, which itself seems to be first quantified by Wien's Displacement Law.

So Wikipedia says Wien derived this law by "considering adiabatic expansion of a cavity containing waves of light in thermal equilibrium. He showed that under slow expansion or contraction, the energy of light reflecting off the walls changes in exactly the same way as the frequency."

I'm assuming I need to understand thermodynamics, and maybe electromagnetism. But to what depth should I know these subjects before attempting to understand Wien's Law? Would an undergraduate course suffice?

Also, any additional subjects would you recommend?

hello there,
from what you say I believe you should have a look at the book "concepts of modern physics" by arthur beiser, here's the link for a brief look:

<Link to copyrighted material removed.>

I used this book during university, so I hope it will enlighten you.
 
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Oops, missed your reply.

Thanks, I'll look into that book!
 
One of the best places I've found to learn the (complete) historical development of QM is Oliver Darrigol's: From c-numbers to q-numbers. However, I feel an undergraduate course, or even an undergraduate degree in physics will not prepare the reader for everything in that book. This is not unlikely. We should remember the scientists developing quantum mechanics were skilled professional physicists, so it would be unlikely that Planck or Einstein just thought of quantizing matter and QM developed full grown as Athena did from the head of Zeus.
Most developments in the early chapters of QM textbooks are glossed over. Darrigol shows Planck and Einstein were uncomfortable and even skeptical of introducing the early quantum ideas.
Darrigol;s book can probably be read for historical flavor, without full understanding, though, perhaps by interested undergraduates/graduate students.

The time invested in a QM course in graduate school usually is spent to develop calculation skills and less from a historical perspective. Many textbooks start with spin, an intrinsically QM subject, and avoid the historical development altogether. I see many posts in these forums that support this approach, which I disagree with.

You can learn Wien's law from Beiser, but to link it all to the concept in Wikipedia regarding adiabatic expansion of a black body cavity would require a good all-around undergraduate and maybe graduate program in thermodynamics, (statistical mechanics wa,s just starting to be a discipline in Planck's time see Darrigol), classical electrodynamics, the cavity was modeled by harmonic oscillators, and classical mechanics.

I hope the above post does not discourage, but encourage the OP poster. I think the section where Planck shares his feelings that he was at one time the only one that tried to reconcile the black body radiation spectrum entropy with classical statistics, he did not have to worry about someone beating him to publication, was illuminating
 
"Quantum Concepts in Physics: An Alternative Approach to the Understanding of Quantum Mechanics" by Malcolm Longair is an interesting book. Use Amazon to look at the detailed table of contents.

https://www.amazon.com/dp/1107017092/?tag=pfamazon01-20

"Written for advanced undergraduates, physicists, and historians and philosophers of physics, this book tells the story of the development of our understanding of quantum phenomena through the extraordinary years of the first three decades of the twentieth century. Rather than following the standard axiomatic approach, this book adopts a historical perspective, explaining clearly and authoritatively how pioneers such as Heisenberg, Schrödinger, Pauli and Dirac developed the fundamentals of quantum mechanics and merged them into a coherent theory, and why the mathematical infrastructure of quantum mechanics has to be as complex as it is. The author creates a compelling narrative, providing a remarkable example of how physics and mathematics work in practice. The book encourages an enhanced appreciation of the interaction between mathematics, theory and experiment, helping the reader gain a deeper understanding of the development and content of quantum mechanics than any other text at this level."
 
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Reading Longair's earlier book including the chapter he does in quantum mechanics led me to Darrigol's book which is more complete. Longair's ne book that you cite promises to be a good source.
 
Sounds like a 5 year journey AT LEAST!

Better get started, then. I think I'll find an OCW on undergraduate thermodynamics!
 

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