I think that one of the issues that we have at the board is the differing level of education that people have in the sciences. I would like this thread to be a very general dicussion of the relationship between scientific theory/law.
Rather than talk in the abstract, can we discuss a point that has come up on another board I use:
Is it too difficult for you to grasp? I understand that there is no hierarchy between the two in terms of their uses to science. But prior to a law being declared a law, it is a theory. A theory is a hypothesis supported by evidence (though still not proven, only assumed to be true in order to further experimentation). Prior to Newton establishing his Law of Gravity, he had to test it. During that testing phase, the Law of Gravity was merely a working theory of his. It had to be because there's no other way for us to get a law than to gather evidence to support it. This does not necessarily follow that all theories can become laws, but all laws were at one point... theories. This is why we haven't come up with any scientific laws in a long, long time. Laws only cover the most basic things, theories are more complex and the more complex the more impossible they are to prove.
As an opening question - if theories never become law, how is it that laws were at one time theories?
What you've presented is a very idealised view of how things work.
In practice many of the "laws" we have were never really theories, except possibly in the mind of the originator, before they were published. Newton made his observations, thought about them a bit, and published his work including assorted "laws" of motion. Many modern theories (such as General Relativity) are actually more sound than what we call laws (such as Newtons Law of Gravitation - which is superceded by the theory of General Relativity).
Scientists are much more careful about using the word "law" these days. It has hints of finality that science has long since found to be untenable ... there have been too many instances of what were thought to be final answers to questions that have proved to be very much less than final.
I always considered laws to simply be relationships or observations. For example newtons laws of motion are all observations about massive bodies. He observed that bodies in motion remained in motion unless a force acted upon them for example. Even the quantative law of F=ma is simply an observation that acceleration and force are proportional. Theories on the other hand are models constructed around the observable facts. That would make "laws" a special term for observable facts and relationships, and as Mr Jack said a term thats a relic of past times.
I think that's largely right. Certainly for things like Newtons laws of motion. Though some laws, such as some formulations of the Second Law of Thermodynamics are more of the attempt to explain those observations that is closer to theory - heat can never of itself flow from a cold state to a hotter one is an observation, a change in a closed system can only occur if its possible for entropy to increase is more theoretical (though contra my namesake who has also posted on this forum, nonetheless true).
Thank you all for your feedback - (is there a way to reply to all?).
My understanding of the situation is as you have all described it, however I have not done a good job of explaining it to someone on another site (I also thought it would be a useful discussion for those who are new to the sciences on this site)
Well I certainly understand how someone who is new to science could be confused by terms such as fact, law and theory. If layman definitions are used it would be easy to think that there were things that are definately true (facts and laws), and things we guess might be true (theory). "Law" does sound much better than "observation" does though.