Transformations and SymmetryPlanets

So far, all the symmetries we looked at were visual in some sense: visible shapes, images or patterns. In fact, symmetry can be a much wider concept: immunity to change.

For example, if you like apple juice just as much as you like orange juice, then your preference is “symmetric” under the transformation that swaps apples and oranges.

In 1915, the German mathematician Emmy Noether observed that something similar is true for the laws of nature.

For example, our experience tells us that the laws of Physics are the same everywhere in the universe. It doesn’t matter if you conduct an experiment in London, or in New York, or on Mars – the laws of Physics should always be the same. In a way, they have .

Similarly, it shouldn’t matter if we conduct an experiment while facing North, or South, or East or West: the laws of nature have .

And finally, it shouldn’t matter if we conduct an experiment today, or tomorrow, or in a year. The laws of nature are “time-symmetric”.

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Transformations and SymmetryPlanets