system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 what is Gauge Symmetry?
gpt
Imagine you're trying to measure the length of a piece of string using a ruler. You place one end of the string at one end of the ruler, and the other end reaches the 10cm mark. However, you could also put the first end of the string at 10cm, and the other end at 20cm, and work out the difference. You still get 10cm, as the place you start measuring from does not affect the result. This means that the length of the string exhibits gauge symmetry, as it's unaffected by moving the scale that you're using to measure it.