# Why can we understand physical laws?

1. Jan 6, 2012

### Halfeatenpizz

I've always found it pretty amazing that human beings can understand the rules that govern the universe we live in, but is there a fundamental reason as to why they are comprehensible at all? Do they have to be rooted in logic?

If it's just something that is unknown, that's a perfectly acceptable answer. Just always wondered about it.

Also, apologies in advance if this is a naive/stupid question. I'm more of a math guy and don't have a super strong background in physics.

2. Jan 6, 2012

### Staff: Mentor

two cents:

I like to think about it in terms of building toys. There are many kinds of building toys from erector sets, to lego and all its imitators. Each can build structures that approximate the things we use today and some are better approximations than others. Math is like the building toys, we can pretty much find the math we need for a theory and we get answers that approximate reality but when we find some major issue that we can't resolve with our math. We might switch to a different math.

Math can be used to describe our universe and untold impossible universes. Physicists are searching for the right combination or best building toy.

:end two cents

3. Jan 7, 2012

### Drakkith

Staff Emeritus
This might belong in philosophy, but I'm not sure.

4. Jan 7, 2012

### Bobbywhy

Halfeatenpizz, Welcome to Physics Forums!

My two cents' worth: Yes, there IS a fundamental reason why the law of gravitation, for example, is comprehensible. When Newton described the laws (rules) that govern gravity scientists had at least two choices. They could have laughed and called him a crackpot, or they could have experimented with real masses, etc. to discover if Newton was right or not. Today we trust he was right, and that is because our experiments always prove that Nature does indeed behave just the way he described it. That is why and how physical laws are comprehensible to us.

I don't have any idea what you mean by physical laws being rooted in logic.

Last edited: Jan 7, 2012
5. Jan 8, 2012

### Halfeatenpizz

Yeah, I wasn't sure either. I was just mostly wondering if there's some commonly accepted reason for this.

6. Jan 8, 2012

### Halfeatenpizz

Sorry, I wasn't trying to be cryptic or anything. Physical laws can be described using math. Logic, in the mathematical sense, is more or less the foundations math sits on. If physics is based on mathematics and mathematics is based on logic, then physics is ultimately based on logic. It has its roots there.

Last edited: Jan 8, 2012
7. Jan 8, 2012

### ColinW

We can understand them because we invented them. So as an electrical engineer I can understand circuit theory and other simplistic "laws". However I have not a clue how to explain something as apparently simple as how two electrons repel each other! It's all very well saying a virtual photon passes between them, but what the hell does that REALLY mean? Why does this virtual photon suddenly appear? How does one electron "know" the other is approaching? There are endless questions I can ask and each time I think I have an answer to one another two appear.
These are unsettling thoughts for someone who makes a living off what little knowledge he has about his chosen field!