When will certain scientific theories become laws?

When we use ‘theory’ in commonspeak, we use it like scientist’s would say ‘hypothesis’- I’ve got a theory of why my car won’t start! Nope, that’s a hypothesis. In science, a theory is a principle that has been backed up by an enormous amount of test results- and never has there ever been a result conclusively proving it wrong in any circumstance, so it is accepted generally as fact and becomes a ‘theory’- theory of evolution, for example.

Let’s not get into a debate, but it’s because so many Americans don’t understand that ‘theory’ in science is not a hypothesis (like they have about their car above) but a damn proven hypothesis that has MOUNTAINS of evidence supporting it and has never, within a scientific experiment, EVER been proven wrong. Ever. But certain Americans will argue against the theory of evolution b/c they see it as equal to the theory they have about their friggin’ car, darn those guys :mad: :smack: :rolleyes: .

Some have pointed out that scientists should come up with a new term for these ‘theories’- like maybe ‘theorythatisalreadyprovenbymountainsofevidenceneveroncedisprovenandisnotlikethetheoryyouhaveaboutyourfriggin’caryoudumbass.’ Another term might be: ‘Damnnearfact’. Is there a Latin term for either that we could use? :smiley:

Anyways, it’s obvious that only a few theories ever make the final jump to the wonderful ‘law’-

There is no theory of gravity- that jank is a LAW. Law of conservation of mass, laws of thermodynamics, the rule of three (American Pie 2)- is there any estimate you can give (no) of when certain scientific theories (like evolution) will become laws? What’s the average amount of time it takes? Evolution hasn’t b/c of it’s offensiveness to certain people, possibly- but I know that’s not the only reason. Why?

Theories don’t become laws. Laws are statements of what happens, and theories are statements of how things happen.

Of course, it’s a well-proven fact that Canadians, Mexicans, Germans, and Lithuanians all understand this. It’s just those darned Americans that don’t get it. :rolleyes:

I apologize if I offended- I often just refer to Americans when I rant or make pleas on the internet, b/c they’re the yokels all around me claiming that evolution is guided by ‘god’ :smack: (do you understand the concept of ‘random change in nature’ and ‘chance biological mutation’?) Of course there are plenty of people from many countries on these boards, many of whom are also ignorant of evolution :smiley: (not b/c foreigners are ignorant, but b/c most people never make any attempt to understand it besides reading a friggin Time or other magazine that asks ‘is it true?’ on the cover. Those issues should be used as toilet paper, of any magazine that does that).

Theories don’t start out with mountains of evidence for them. Many just have a little bit of evidence in their favor in the beginning. It is also not true that theories must have no conflicting evidence against them. That is simply not true. The strength of theories builds over time and single experiments don’t usually invalidate them. It could be something with the experimental design or the theory may need to be modified. Look at Newtonian physics. It was a well established theory for a while before we found out it was an incomplete picture of the way things work.

People shouldn’t automatically translate “theory” into “proven fact” when they hear the term. Some theories are much stronger than others but there is always room for a breakthrough to displace a well established theory. You just chose some mature theories with lots of evidence supporting them as examples but they aren’t all that way.

Actually, not only is gravity a theory, but gravity is a theory that is wrong.

The theory of gravity states there exists an attractive force between two objects. The problem is that gravity affects massless objects such as photons. The Theory of General Relativity correctly explains such phenomena (objects are taking straight paths through curved space, not curved paths through straight space) where the Theory of Gravity fails.

I consider the law of gravity to be a subset of the Theory of Gravity: F = -GMm/r[sup]2[/sup]. There is no disputing the law of gravity – find two masses and the force will be exactly what’s described – but the law of gravity is incomplete.

There’s the rough rule of thumb in the history of science that “laws” stopped being invented sometime in the 19th century. What once upon a time would have been called laws had they been invented earlier tend to have been dubbed “principles” or “rules” or whatever in the 20th century. This isn’t an absolute pattern and you do get 20th century notions called “laws”, but there definitely isn’t quite the same cachet attached to these as there were to the earlier ones.
Why this has been the case is difficult to pin down exactly. Among the possible explanations:

[ul]The advent of relativity and quantum mechanics showed that existing “laws”, even in physics, weren’t quite so absolute as people had thought, producing a reluctance to give new ideas the same title.[/ul]
[ul]There were significant shifts in prevailing notions about the philosophy of science between the 19th and 20th centuries. The change in terminology may be related.[/ul]
[ul]In physics, there was an important shift towards explaining “laws” in terms of underlying - and hence more fundamental - symmetry principles. Then you have the notions of inexact and broken symmetries. Increasingly, the “laws” can be seen as consequencies of other ideas - and only approximate at that.[/ul]

Furthermore, the Wikipedia statement that “the elevation of some principle of that field to the status of “law” usually takes place after a very long time during which the principle is used and tested and verified” wasn’t terribly obvious in practice, even before the 20th century. By the 19th century, calling something a “law” in science had immense rhetorical advantages in debates and controversies, with the result that all sorts of suggested patterns got quickly called one. Many of these “laws” then never stood up over time nor were even accepted by many scientists in the first place.

Thus it’s wrong to expect that anything in contemporary science is likely to become a “law” in future, regardless of what evidence is gathered or how much time elapses. Science doesn’t work like that - particularly now.

As mentioned, the current theory of gravity is based relativity, the Newtonian “law” of gravity being what happens in a specific case, close enough for everyday matters. Ohm’s law does little to explain the nature of elecromagnetism: Just tells you what you need to do to light up the house. The Ideal Gas Law (PV=nRT) does not itself go into the nature of the attractive forces between atoms and molecules, and how/why particles bounce.

You use theories to explain the whys and hows of how come the “laws” work.
The “law” of evolution, in its broadest grade-school level, is that life-forms are adapted to their ecosystem to the point of structural and morphological optimization, that as you examine the history of ecosystems on Earth, you will see evidence of this happening to distinct life-forms changing over time, to the point of entire species and orders arising and becoming extinct, while sharing structural and morphological commonalities.

The theories are about how do we explain this without having to call upon “and then a miracle happened”.

A “Law” is not the end-all and be-all of science. Laws are actually very pedestrian statements of observed relationships. Hence, Ohm’s law (which describes the relationship between current, voltage and resistance); the gas laws of Boyle ,Charles and Raoult (describing the relationship between volume, temperature, pressure and quantity of gas) and many, many others. These relationships are called laws because they are always observed to be true (with the occasional fudge factor/weasel clause thrown in)- not because there is a complete understanding of their mechanism.

Then there’s the matter that many “Laws” are true by definition. Ohm’s Law, V = IR, for instance, can be taken as the definition of resistance, and the Ideal Gas Law can be taken as the definition of an ideal gas (any fluid which obeys that equation of state is an ideal gas). Is the Ideal Gas Law true? Well, yes and no. By definition, that equation is exactly correct for any ideal gas. The trouble is, no gas is truly perfectly ideal. So for any real gas, the Ideal Gas Law is only an approximation (though usually a very good approximation).

To further complicate things, the definition of the issue isn’t clear. When people say they don’t believe in evolution, most of them are talking specifically about human evolution.

Is there really any well-informed person on the planet who refutes that species evolve and change? Can anyone argue that Mendel’s fundamental research on genetics was wrong? Can anyone argue that new strains of bacteria don’t evolve that are resistant to specific antibiotics? I think all of this is proven by such an overwhelmingly huge body of evidence (with no contradictory evidence, as far as I know), that “evolution” can’t be argued.

What most of the creationists (oh, pardon me, “intelligent designists”) seem to really be saying is that (a) it doesn’t apply to humans, and (b) life didn’t spontaneously arise. They say that God created life and allowed it to evolve, and created Man as an independent action.

So, andrewdt85, which part of it do you wish to have declared as a law? Can we actually prove that the first life came into being because lightning struck a large pool of water with exactly the right mix of elements in it at 2:45 a.m. on October 13, 2,340,504 B.C.? Nope. Can we prove that random mutation sometimes creates a critter resistant to penicillin, which eventually creates a new strain of critter? Yep.

But remember, regardless of how you feel about a particular theory, the law is the law!


I know a college educated computer scientist who insists that species could not change into another species through a sequence of small changes. Rather, there’s a fixed number of things that can change (or change back) and that’s it. Also God does it. :rolleyes:

Just to clarify, in science, you can’t prove a hypothesis, nor can you prove a theory. You can only gather observations supporting them. However, conversely, if your observations do not support a given hypothesis or theory, you can certainly disprove them.

I agree with much of your larger point, however. Many people not well-versed in science seem to think that scientific theories are somehow invalid or not well-supported because they have not yet been proven, when in fact that is impossible and contrary to the whole concept of a theory.

This statement that us Americans don’t know anything about how to use the word “theory” is a hypothesis.

Simply, there is no scientific standard or consensus on the use of the nomenclature “Law” vs “Theory”. Most laws and theories are only popularly named as such after they enter the general public awareness. Theories never graduate to laws in any sort of ceremony or event, nor do they ever get their nomenclature demoted if a superceding law or theory gets accepted.

andrewdt85: “…In science, a theory is a principle that has been backed up by an enormous amount of test results- and never has there ever been a result conclusively proving it wrong in any circumstance…”

No, not even that. Science will recognize currently accepted theories as you described, but when a theory is discredited or supplanted (say, the Theory of Spontaneous Generation, or Ptolemaic Theory) nobody goes back and cleans up the titles and nomenclatures to say “The ex-Theory of Spontaneous Generation Henceforth to be Known as the Silly Rodents Generating from Nothingness Quackery Principle”.

This is the distinction in a nutshell. Laws are observations of a fundamental behavior or phenomena that is universally accepted and are unfailing reproducible or consistently observed, stated in formal terms. The Law of Gravitation, for instance, is an observation (to wit, that two bodies are attracted to each other by a force inversely propotional to their masses and inversely proportional to the square of their distance r) that holds true in all observed circumstances, albeit we may have to expand our definition of mass and treat r as a path across a Lorentzian manifold rather than just observed spacelike distance. Note that this doesn’t explain the mechanism behind gravity–a force that we still don’t fundimentally grasp–but it describes its effects in such a basic way that we can use it to predict other behavior and deduce derived properties. Kepler certainly didn’t understand gravity, or even have a good working theory as to why the planets follow orbits described by his eponymous Laws of Planetary Motion–heck, he didn’t even have the math to derive an explaination of the mechanism–but that doesn’t stop the laws from being just as valid today as they were when he first published them.

Laws speak to fundamental principles of nature, and as a distillation of a single influence or effect are necessarily simplified. The Ideal Gas Law, as Chronos mentioned, doesn’t describe the behavior of any real world gas; it instead illustrates the behavior of an ‘ideal’ gas, i.e. one that does not involve any electrostatic or Van der Waals forces. It gets damn close with a light noble gas like helium or neon, is a reasonable approximation when kinetic effects dominate over intermolecular forces, and serves as a basis for understanding the combination of effects that result in the real world behavior of a gas, but it isn’t really subject to challenge or disproof without overturning virtually every observed behavior in gases and numerous other fundamental processes as well.

Theories, from the aspect of natural science, are descriptions of the mechanisms to real world behavior; they involve the laws or principles in combination to explain complex observed phenomena, and while they are validated by repeated experiment or observation they are always subject to falsification. The study of thermofluidfluid mechanics and aeroelasticity, for instance, is rife with theories and models which describe behavior in one regime or set of conditions, all dependant upon the basic laws of motion, ideal gas behavior, and thermodynamics.

There’s a grey shading in some areas regarding what can and should properly be considered a law–I have a feeling that General Relativity will be recognized as a fundamental law in the reasonably near future–but others, like Natural Selection (which is a collection of mechanisms which explain what should be known as the Law of Evolution) will always be considered a theory, subject to test, falsification, and refinement.


No, it’s an observation. :wink:

Er, that should be “…one that involves only Van der Waals forces…”

Bloody good for nothing copyeditors. I’d fire mine, but then the other voices in my head would strike in protest. :wink: