Uploaded March 2026 | Updated September 2026, 3 weeks ago

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According to our best theories of physics, the fundamental building blocks of matter are not particles, but continuous fluid-like substances known as 'quantum fields'. David Tong explains what we know about these fields, and how they fit into our understanding of the Universe.

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David Tong is a professor of theoretical physics at Cambridge University, specialising in quantum field theory.

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