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Noether's Theorem and The Symmetries of Reality

PBS Space Time · 1.1M views · 2018-05-16 · 13:02

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Overview

PBS Space Time explains Noether's theorem: conservation laws such as energy and momentum are consequences of deeper symmetries. It also covers why those laws hold only under certain conditions.

On Hacker News

HN commenters point to it as an approachable explanation of how symmetries give rise to conservation laws, including the story of Emmy Noether.

Recommended by 5 HN people across 5 months · HN mentions 2018–2026

Topics

Fundamental physicsQuantum physics
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noether's theoremsymmetryconservation lawstheoretical physicsemmy noether

What people said

twiceaday · 2025-02 · Recommendation

TLDR: Do an experiment, then move 10 meters to the left (or rotate 90 degrees, or wait a few days) and do it again. The results don’t change, because the laws of physics don’t change. This realization alone is enough to produce conservation laws. Translational and rotational symmetries produce conservation of linear and angular momentum, and the time symmetry produces conservation of energy. Each symmetry you find leads to new physics. It's such an aha moment. PBS Space Time: [VIDEO]

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psychphysic · 2023-03 · Recommendation

If you like reading about Wu from a woman in physics hidden in plain sight aspect you might like the story of Emmy Noether[0]. A mathematician who worked a few doors down from Einstein and produced era defining result in physics. The connection between symmetry and conservation. Noether's theorem to this day is one of the most profound holy shit moments in many physicists education. Her life was been cut tragically short. [0] [VIDEO]

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michelpp · 2022-08 · Recommendation

PBS Space Time has done a couple of episodes on Stationary Action and Noether's Theorem that are approachable by those not yet already exposed to Langrangians: [LINK] [VIDEO] Sabine Hossenfelder also has a good episode on it: [LINK]

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Sources

Video by PBS Space Time, played through YouTube.

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