system
Given the following post, respond as if you're commenting on Reddit:
human
Can laws of physics in the Universe change over time?
gpt
This is actually somewhat unclear, but the answer seems to be no. 

I recently read a chapter in The Constants of Nature by John Barrow that discusses evidence for this. In astronomy, we see events that are taking place near the beginning of time. Those events, like galaxy and star formation, seem to follow all the same rules as we see today. We see the same spectral emission lines from familiar atoms, for instance. Closer to home, we can look at radioactive elements and ancient naturally occurring fission reactors in Earth's crust to see how nuclear activity took place millions to billions of years ago, and it puts very tight limits on how much the laws of physics could have changed in that time. Subtle changes in physical constants are still not ruled out entirely, and such changes might be useful to explain some observations, but so far it seems like physics has been a constant at least since the very early universe.