But What Actually Is a Particle? How Quantum Fields Shape Reality

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But what actually is a particle? When we talk about electrons, quarks, or photons — what are we really talking about? In this video, we take a journey from simple harmonic motion to quantum fields, uncovering the deep mathematical structure that underpins modern physics.

We begin with the physics of vibrations and waves, showing how the classical picture leads naturally to fields. From there, we explore what happens when quantum mechanics enters the picture, and how quantising a relativistic field leads to the profound insight that particles are simply the smallest possible vibrations of these fields.

References and Further Reading:

No-Nonsense QFT – Jakob Schwichtenberg
An excellent and intuitive introduction to the modified wave equation (Klein–Gordon equation), using a spring mattress analogy. Accessible and highly recommended for those interested in how it emerges from classical mechanics via Lagrangian methods.

Of Particular Significance (Blog) – Matt Strassler
A superb blog that explores many of the same foundational ideas covered in this video, and goes further into topics like field interactions and the Higgs mechanism. Insightful and highly readable.

Quantum Field Theory for the Gifted Amateur – Tom Lancaster & Stephen J. Blundell
A superb, detailed, and well-written introduction. Best suited for those willing to put in the work — but very accessible compared to more advanced texts.

Quantum Field Theory Lecture Notes – David Tong
A more advanced but beautifully written set of lecture notes from Cambridge. Highly recommended for deeper study.

Quantum Field Theory – Lewis H. Ryder
A clear and concise graduate-level textbook. Especially good for building physical intuition and understanding the structure of relativistic field theory.

Quantum Field Theory – Mark Srednicki
A modern and comprehensive text widely used in graduate courses. Demanding but rewarding, and an excellent long-term reference.

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