The four fundamental forces or fundamental interactions are
- Weak interaction
- Strong interaction
On Wikipedia, they are described as
the interactions that do not appear to be reducible to more basic interactions
This seems to imply that every other mechanism could be reduced to the fundamental interactions; or, put in another way, that everything is caused only by the four fundamental interactions.
However, I am a bit in doubt whether this is entirely true. Let's take for example a look at the tendency of systems to acquire the lowest possible energy state. The cause of this process is expleined here in more detail, but briefly said, it is due to the fact that every system "cycles" through every possible quantum or micro state. Since entropy is higher when thermal energy is increased, there are more such microstates with higher thermal energy (und less "other" energy types), which leads to the system giving away energy stored in heat and thus lowering internal energy.
To me, it seems like this process cannot be explained using the fundamental interactions. It rather seems to be pure mathematics which "sets" the entropy for different states.
So: Can really every process be explained only using the four fundamental interactions? Or are there exceptions, such as I explained above?