# Linked Questions

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### Can anyone provide a simple, inuitive explanation for Noether's Theorem? [duplicate]

I recently came across this theorem for the first time. As I understand it, what she showed was that conservation 'laws' are often simply an artifact of symmetry or invariance. For example, the ...
0answers
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### Symmetry of physical laws [duplicate]

What is the easiest explanation for how the symmetry of laws under translation in time relates to energy conservation in physics?
0answers
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### How do symmetries of nature give rise to the conservation laws? [duplicate]

In my physics textbook, the following points are given:- The Law of Conservation of linear momentum emerges from the homogenecity of space. Isotropy of Space gives rise to the Law of Conservation of ...
3answers
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### What's the interpretation of Feynman's picture proof of Noether's Theorem?

On pp 103 - 105 of The Character of Physical Law, Feynman draws this diagram to demonstrate that invariance under spatial translation leads to conservation of momentum: To paraphrase Feynman's ...
4answers
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### If all conserved quantities of a system are known, can they be explained by symmetries?

If a system has $N$ degrees of freedom (DOF) and therefore $N$ independent1 conserved quantities integrals of motion, can continuous symmetries with a total of $N$ parameters be found that deliver ...
2answers
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### Layman's version of Noether's Theorem (or the intuition behind it)

As part of a science project, I have to give a presentation to my classmates about a topic of my choice (within some constraints) - and I chose symmetry, and it's importance in physics. One important ...
2answers
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### Noether's theorem vs. Heisenberg uncertainty principle

In continuation of another question about Noether's theorem I wonder whether there exists some kind of relationship between this theorem and the Heisenberg uncertainty principle. Because both the ...
7answers
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### Why is momentum conserved (or rather what makes an object carry on moving infinitely)?

I know this is an incredibly simple question, but I am trying to find a very simple explanation to this other than the simple logic that energy is conserved when two items impact and bounce off each ...
3answers
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### What does it mean, when one says that system has N constants of motion?

For example for an isolated system the energy $E$ is conserved. But then any function of energy, (like $E^2,\sin E,\frac{ln|E|}{E^{42}}$ e.t.c.) is conserved too. Therefore one can make up infinitely ...
2answers
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### How do you find conserved quantities for linear second order ODEs?

I have a differential equation of the form $\frac{d^2 y}{dt^2} + f(t) \frac{dy}{dt} + g(t) y = 0$ where $f$ and $g$ are known functions of time. Is there a systematic (or otherwise) way of ...
4answers
860 views

### What is the Noether's theorem and how it break the law of conservation?

I was in http://worldbuilding.stackexchange.com when I read a question about how to explain magic breaking physical laws, and in one answer they talk about the Noether's theorem and how to break the ...
1answer
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### Spacetime and the conservation laws

I'm reading Peter Atkins' book, Galileo's Finger, and in the chapter on energy, he makes the points that the conservation of momentum stems from the shape of space (that it's smooth and not lumpy) and ...
2answers
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### Conservation Laws and Symmetry

The toughest of topics in physics, like Quantum Mechanics, Relativity, String theory, can be explained in layman words and many have done so. Though there is no substitute to the understanding a ...
1answer
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### What's the “deepest” reason for Noether's theorems that we have?

There are already several questions about the intuitive meaning of Noether's theorem, e.g. this & this Phys.SE posts (with not very satisfactory answers to me so far). Therefore, this time let's ...
1answer
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### Trouble Understanding the Concept of Invariance

I am reading the book by Brian Cox & Jeff Forshaw: "Why does E=MC^2". It is getting to the point of explaining what invariance is. According to Cox & Forshaw, invariance states that the laws ...