I think of a scientific theory as a system of describing the nature and behavior of certain physical objects. Theories can turn out to be more or less correct. Some, such as the theories of special and general relativity and quantum mechanics, have been shown to be highly accurate except in some extreme situations. Others, such as theories about global warming or earthquake prediction, are not so well-established. Similarly, theories about economics or psychiatry tend to have limitations and are often controverted.
So saying something is a theory does not tell you how accurate it is. Creationists like to say that evolution is “just a theory” to imply that it is not likely to be accurate, but some theories are highly accurate. I don’t think that a scientific “law” is something which is more than “just a theory.” As others have stated, laws seem to mean theories which involve equations. In reality, the things we call laws often have limitations as well. I don’t know what creationists think would be an alternative to a scientific theory; there is really no such thing as a completely incontrovertible “scientific fact.” Of course, they take the Bible to be incontrovertible fact.
Isaac Asimov: “Creationists make it sound as though a ‘theory’ is something you dreamt up after being drunk all night.”
This is incorrect. A theory is a hypothesis that has withstood the test of time. Theories do not subsequently turn into laws. They are two completely different things.
A law is a summary of observations with no explanation thereof. A theory attempts to explain observed behavior.
For example, in chemistry, you have such diverse observations that are summarized by laws like the gas laws (including Boyle’s Law, etc.), the Law of Definite Proportions, the Law of Multiple Proportions, and the Law of Conservation of Mass, as well as observations such as Brownian motion.
All of these various laws and observations can be successfully explained with atomic theory.
Exactly.
There will never be another scientific Law unless the entire culture of science flips on its head. Theories will remain Theories forever, if current practice continues.
There will be lots of new Laws, describing in mathematical terms things we didn’t have a complete model of before. But they won’t be Theories getting promotions (as discussed above, that’s just not how it works), and will probably be dense, esoteric, and boring as hell to lay-people as the places that science advances to becomes more and more specialized.
Thank you. When typing the post, I almost went back and added “(at least)” between “has” and “two meanings.” I was in a hurry, so I decided to leave it and see how long it took someone here to come up with more. 
Can you name any new Laws (capital L, named as such) in any field which have been added since, say, Einstein?
Oh, that’s easy. Godwin’s law. Murphy’s law. There are a whole bunch of them.
When you put it like that, you include rule-of-thumb type laws such as Moore’s Law.
Is there, in fact, a theory or theories that explains Newton’s laws?
Nice one. But here’s Wikipedia’s page of List of scientific laws named after people. Not a lot of modern examples there. And half of them sound like Big Bang Theory episode titles.
Depends of whether you consider the Theory of Relativity an explanation.
I was thinking of things like the Caldeira-Leggett model, the Sakuma–Hattori equation, or the Yang–Baxter equation.
They aren’t named as laws, but neither are things like the Navier-Stokes equations or the Scrodinger equation, but I’m not as scientifically inclined as others here, so I’ll leave it to others to compare laws vs. rules vs. equations. But I don’t think the distinction is of the same nature as laws vs. theories.
Yeah, well how many laws do you need?
All the easy ones were gobbled up early. Still, I don’t think people are as likely to claim that something is a “law” these days, and are more likely to just call it “So-and-so’s Equation”.
I read an article several months ago about how Science would do itself a service by changing its nomenclature to conform to what the general public assigns to meanings. They gave examples like “theory” which to the general public means something to not give much weight to, while for science it means something much more significant. They also pointed out that “positive feedback” is a BAD thing for science but a good (positive) thing to the general public, so saying that CO2 creates positive feedback makes the general public completely misunderstand what is trying to be said.
The article had several examples and it made me realize why people often have no idea what I’m saying.
Short version:
No. It’s just Science being all Sciency and not conforming to the general usage of common words.
This whole discussion revolves around a very common misapprehension—that words in English have definite, universally understood meanings. In the common vernacular, a “theory” is equated with a “Wild-Ass Guess.” In scientific usage, a “Theory” is a systematic attempt to consolidate all observations in a defined field into a cohesive unity. All experimental evidence must be accounted for, leaving nothing out. It must be “falsifiable,” in the sense that, in principle, a test result might prove the theory insufficient. It must make predictions, but it is not essential that we have the technology or ability to test the predictions.
In short, a scientific “Theory,” capital “T”, is an extremely rigorous elucidation of the field it was created to explain.
What are commonly referred to as “Laws” are usually nothing more than Theories, after all. For example, when chemistry was getting started, diligent researchers noticed that the total mass of all the reagents going into the reaction equaled the total mass of the products of the reaction. After many experiments, the “Law of Conservation of Mass” was formulated.
In a similar vein, experiments dealing with energy found that, while energy could be converted from one form to another, as Potential -> Kinetic -> Thermal etc., the [FONT=Trebuchet MS]Total energy of a closed system remained constant. Thus, the “Law of Conservation of Energy” was formulated.[/FONT]
Except both “Laws” are wrong. They are very good approximations to reality, but once nuclear energy was understood, it became obvious that energy was being given off by radioactive substances, seemingly from nowhere. Einstein’s E=mc[sup]2[/sup] showed that mass and energy can be inter-converted, therefore we now speak of the Conservation of Mass-Energy.
Many other Conservation “Laws” have been shown to be close approximations to the effects they describe. They have been broadened to include a wider range of observations, or combined with other conservation laws to better correspond to reality.
It turns out that there is nothing particularly magical about calling some conjecture a “Law” rather than “only a Theory.” As pointed out above, it is largely a matter of semantics.
Um, so, translated into English… a law is an observation, a theory is an agreed-upon explanation, an equation is a recent observation, and a fact is a theory by some arrogant dead guy who doesn’t understand the political correctness of modern science? Is that about right?
Actually, the reference to “fact” in the OP
(that was nudged out of the thread very early with the discussion of Laws), is a separate issue–and plays on the different ways that we talk about evolution, as well.
In the arena of evolution, for example, there are two separate ways to discuss it.
One is the fact of evolution. This is simply a statement that evolution occurs. It is a fact. Evolution does occur.
The other is the Theory of Evolution, (or, more realistically, the several theories of evolution), that is the set of hypotheses that attempt to explain the way in which evolution occurs. Most often, it is a reference to the prevailing theory, Darwin’s theory of natural selection as modified by Dobzhansky’s application of Mendelian genetics to Darwin’s work, with any number of challenges and improvements relying on increased knowledge of genetic and molecular processes in the context of ecological pressures. (So we call it Darwin’s.)
So we wind up with two separate statements that are both accurate, but mean something different.
Evolution is a fact, i.e., it is a phenomenon that does occur.
Evolution is a theory, i.e., Darwin’s theory of natural selection is the prevailing scientific description, (to the best of our current knowledge), of the mechanisms that cause evolution to occur.
Wrong. The fact that laws are falsifiable (like theories) does not mean that laws are the same as theories. They are two completely different things, and one is not “better” than the other.
In fact, your very phrasing (i.e. “nothing more than Theories”) belies the rest of your excellent opening paragraph emphasizing that a theory (no capitalization needed) is in actuality an “extremely rigorous elucidation of the field it was created to explain.”
It may be semantics, but as this whole discussion has noted, it has led to misunderstandings among lay people.
In any event, to reiterate, laws are summaries of observed behavior, and theories attempt to explain observed behavior. The only real similarity is that both laws and theories can be disproven, and may need to be modified or scrapped altogether when additional, more precise data is obtained. Theories don’t turn into laws, and laws don’t turn into theories.
As others have said, theories and laws are fundamentally different things scientifically. A lot of people seem to believe that they’re two rungs on the same ladder, and law is a rung above theory, but they’re on two completely different ladders.
This sort of thing comes up a lot, not just in evolution, but in other things too. Why can’t we go faster than the speed of light? Because of General Relativity. But that’s “just a theory”. As much as I think the common usage of theory to mean guess has a lot to it, I blame education as well. I specifically remember through much of my education up until college being taught that a theory was an experimentally validated hypothesis, and that when a theory got enough evidence it became a law. I can’t imagine I was the only one who was taught this, especially since it was in multiple school districts and one of those was a magnet school specifically for science.
The problem I’ve often run into more recently, when I’ve had discussions about this and explained the difference, instead of getting “well, it’s just a theory”, I get a counter-argument like “well, they haven’t tested EVERYTHING, so it’s still possible that it’s wrong.”