[Gordian Knot (OP)]

This has been buggin' me for some time. As I understand it a scientific theory is a query that is analyzed through experimentation to achieve an answer. Results must be capable of being duplicated independently to be considered valid.

That is a loose definition, but it will do for my purposes.

Although mathematically, strings seem to answer some basic questions about quantum mechanics, equations are not proof.

Strings, if they exist, are infinitesimally smaller than anything we can perceive by any devices currently in existence. As such, there is no way to test for the existence of strings.

Ergo, ipso, facto, Columbo, Oreo the existence of strings cannot be considered a "theory". Can it?  Wouldn't a more appropriate terminology be the String proposal?

[Geezer]

I think it's correct to say it's not strictly "scientific theory" until the math leads to the prediction of some phenomenon that could (in theory) be observed. AFAIK they have not managed to come up with anything yet.

[imatfaal]

There are a few very early predictions that have been born out - half the problem is finding a test that we can actually carry out.  Strings are meant to operate at the level beyond what we can currently probe - and they are meant to be completely consistent with all current theory at accessible energy/length levels; so that anything we CAN DO won't show strings as anything different from current models

[graham.d]

I don't see a problem with referring to String Theory as a "Theory". The basis is in the mathematics but it does allow some conceptualisation of the structure of matter with which the human brain can cope. That reality at a quantum level should be so is, by no means, a necessity of the real world. It is more than likely it is wrong in some way, as is likely to be the case with all our theories, but it does provide a basis in which to think about a subject. It could be argued that its flexibility to adapt to observation is a strength as well as a weakness of the theory but until there are better theories it has to be worth persisting in what we have.

[Gordian Knot (OP)]

Graham, I'm not suggesting the proposal should be ditched. It IS a way to explain some things in the world of the very small. As such further study is certainly worth while.

My objection is calling it a theory. Maybe we are just playing with words here, but I do not think so. In science above all else we need to be very careful how we identify things. Scientific theory, as part of its definition, requires testing. We cannot test in any direct way for strings.

Mathematics is not a basis to depend on. Mathematics is a tool invented by humans. As such I am not convinced it is dependable, unless results can be verified.

My concern is that science loses a lot of people because of its internal terminology. For example to say that the theory of evolution has been proven to be fact. To a lot of ordinary people that statement is a contradiction in terms. If evolution is a fact how can it still be a theory? See what I mean?

[Geezer]

Yes - I think we do need to be a bit careful about the definition. There are enough people running around claiming that evolution "is just a theory".

[graham.d]

Hang on here; as far as I am concerned evolution IS a theory. It has been thoroughly verified and not disproved, but that does not constitute proof of validity in a proper scientific sense. One may like to simplify such an explanation to non-scientists who do not understand this, but this would be strictly bending the definitions to suit one's particular beliefs, as sound as they may be. There are no "proofs" of a theory, only disproofs. This is the basis of the scientific method. Similarly, string theory HAS passed many tests that are consistant with real world behaviour but remains a theory. The whole point of the scientific method is that we produce theories to explain observations. These theories are continually tested and must be discarded or improved should any inconsistancy with such measurements arise.

I would also disagree that mathematics is a tool invented by humans. Being based on logic, mathematics should be one of the few areas that can be relied on to be correct. A particular application of mathematics in forming models of the real world may be wrong, but it is not the mathematics itself here but the validity of its application. It is in this sense that the mathematics is being used as a tool and may be being applied incorrectly.

[Geezer]

Hang on here; as far as I am concerned evolution IS a theory. It has been thoroughly verified and not disproved, but that does not constitute proof of validity in a proper scientific sense.

Thoroughly verified and not disproved is as good as it ever gets for any scientific theory, so why is evolution different?

[JP]

I'm not sure how string theory came by its name, but I suspect they're using theory in the sense of theoretical physics.  Theoretical physics is a branch of physics involving a lot of mathematics and abstract models. Even though its called theoretical physics, the ideas coming out of it aren't proper theories until they're tested against reality.

[Gordian Knot (OP)]

Which dovetails, JP, quite nicely into my second issue related to this subject. The word "theory" itself is used in too many ways, as part of too many definitions. No wonder the non-scientist is completely bewildered.

I understand, Graham, what you are saying about evolution being a theory in the strictest sense as all scientific understandings are always open to possible revisions or complete rewrites.

However consider this. Both evolution and the existence of strings are called theories. Yet the evidence for the former is substantial while the evidence for the latter is practically zero. There should be a better word for a process we believe to be factually verified enough that we are confident of its truth.

[graham.d]

However consider this. Both evolution and the existence of strings are called theories. Yet the evidence for the former is substantial while the evidence for the latter is practically zero. There should be a better word for a process we believe to be factually verified enough that we are confident of its truth.

Yes, I agree with this. Perhaps we need a "strength" scale attached to a theory.

JP, I suppose you could call String Theory a "String Model". I am not sure where the boundaries between the two lie at the quantum level. A proper description of the reality maybe beyond the human mind to comprehend so some models that are at least a good analog may be the nearest we ever get.

You could say, as a definition, that a theory should be able to make testable predictions. However, I don't believe that the general definition would exclude the possibility of calling something a theory just because nobody has yet thought of a way to test it.

[JP]

It's not about making testable predictions, its about whether its passed any tests yet.  A theory should be supported by a sizable number of experimental or observational tests based on predictions.  Until it passes those tests its not truly a theory.

It's still a promising area of research and leads to a lot of interesting math and ways of thinking about the universe, however.