Are there any good, preferably tutorial, papers on equivalence classes with regards to theories of physics, and how they relate to units?(adsbygoogle = window.adsbygoogle || []).push({});

Specifically, I'm looking for something that discusses that if you formulate the laws of physics in feet, then convert the units to inches, you haven't changed any observable aspects of the theory, that the laws of physics expressed in "inches" are equivalent to the laws of physics expressed in feet.

Very basic stuff, but I see confusion on this topic all the time,usually related to the issue of varrying fundamental constants.

(On the topic of varying constants - We have Duff proposing similar ideas, but his explanations aren't particularly to those who don't already grasp the point of equialence classes, and I think there are some problems in general with his presentation, as a lot of people seem fit to disagree with some of what he says in the literature).

Ideally, such a paper would go on to explain that the equivalence class relationship is a mathematical one, and that it applies irrespective of whether you call an inch and inch, or whether you call an inch a foot, i.e. that the point is that the theories themselves are mathematically equivalent, regardless of how you name things.

But I'll take whatever I can find at this point...

**Physics Forums - The Fusion of Science and Community**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Equivalence classes

Loading...

**Physics Forums - The Fusion of Science and Community**