Symmetry of the Universe

It turns out that our universe also has symmetries. A symmetry of the universe is the transformation that doesn’t affect the laws of physics. To understand, consider an empty universe. If we throw a ball, it moves in a straight line at a constant speed. Repeating this experiment elsewhere in the universe yields the same result: the ball behaves identically. This suggests that the universe exhibits translational symmetry, meaning the laws of physics remain unchanged regardless of location. Similarly, the universe is also symmetric under rotations. Orienting ourselves differently does not affect the ball's motion. Additionally, it is also symmetric through time. Performing the experiment at different times yields the same outcome, as the laws of physics do not change over time. These symmetries impose constraints on the behavior of objects.

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