# Where is the symmetry in the universe

If particle physicists are on the trail of symmetries, then they don't want to turn the universe or turn it upside down, but are on the trail of the laws of nature that apply to it.

Our universe is not particularly symmetrical. Our earth is only almost a perfect sphere, it is flatter at the poles than at the equator. And there is only one earth, for example, here. If we shifted our whereabouts by 10 light years, we would not find a second earth. Compared to such a shift, the universe is not symmetrical.

It looks different with the laws of nature. Physicists assume that these should apply here on the spot as well as 10 light years away. It shouldn't matter how our laboratory is turned when we investigate the laws of nature. As a rule, the same laws apply in the mirror image. And tomorrow the world should not be ruled by any other natural law than yesterday. It is such assumptions of symmetry that provide physicists with numerous conditions for how the laws of nature can look. Because they have to be built in such a way that they behave symmetrically.

Let's look at the individual symmetry assumptions again in detail:

Which laws of nature do you think a physicist finds who walks through the world with his head tilted to one side throughout his life? The same as his upright colleague. Because no matter how you turn the universe: The same laws of nature should apply. The laws of the universe are rotationally symmetrical.

Rotational Symmetry: A cube can be rotated in many ways without changing its appearance.

Even if you sometimes don't believe it: that thing in the bathroom in the morning is your own reflection and looks a lot like you. Because we humans are by and large built in mirror symmetry. And most of the laws of physics would not have to be rewritten if we lived in a mirrored version of our universe.

Kaleidoscope patterns like this one are created by multiple reflections.

It is 8:15 pm. The weather report was just running. Next up is the forecast for the physical laws of tomorrow. How strong will gravity be? Will there be atoms at all tomorrow? Or is everything completely different for a change? Absurd notion? Right! Because we assume that the universe obeys the same physical laws today, yesterday and tomorrow. The laws in the universe are symmetrical with a shift in time.

The apple never falls far from the tree.