String Theory - Is it science? Is it a theory?

As of yet string theory has made no predictions that can be tested. It also cannot explain certain observations of the universe such as dark energy.

Is string theory just a faith in mathmatical elegance pretending to be science? If it cannot be tested, how is it science? If it has not made any prediction that have should up to falsification, how it a theory?

If a scientist says that they “believe” string theory, then I think that would qualify as “faith,” as you suggest, since there is no evidence for string theory. But the scientists that I know personally who are working on string theory aren’t taking it on faith. They don’t “believe” in it per se; they are working on it because they think it might turn out to be physically relevant and they are trying to squeeze physical predictions out of it.

My personal suspicion is if string theory continues to be intensively worked on in the next few decades and no experimental tests of the theory are forthcoming, then theorists will gradually abandon it (assuming more promising models come along).

In the meantime, I don’t think it qualifies as a “theory” in the same sense that general relativity is a theory. Maybe the word “model” would be more appropriate.

Aspects of String Theory are falsifiable. In particular String Theory demands the existance of multiple other spatial dimensions through which gravity would permeate. It is not so far beyond current technologies to measure gravity precisely enough to test whether or not it behaves in accordance with the predictions of a 4 dimensional spacetime (one of time) or one of some number more. Consistency of those measurements with 4D spacetime would falsify String Theory albeit not “prove” it.

Many dimensional spacetime also allows for other speculations. For example, it has long been assumed that there is an excess amount of matter compared to antimatter in this universe and that for unclear reasons antimatter and matter are not exact mirror images of each other. Such has been a reasonable assumption as it is consistent with what we of matter observe so far. But if antimatter and matter actually are each n-dimensional objects that are actually mirror images of each other in substance and amount that each orient and can move about differently in many dimensional space, then that assumption may be invalid. This is also a falsifiable speculation and consistent with much of what has already been observed. It “predicts” for example, the existence of significantly more gravity than observable matter would explain.

Now many dimensional spacetime could be shown to exist and still not require String Theory, but if String Theory suggests other ways of understanding the universe, and those understandings suggest experiements that lead to new data consistent with that understanding, then it is a useful model to play with.

In addition to what was said above, those working on string “theory” are trying to define ways in which it can be falsified. From my reading the proponents of it are well aware of the weaknesses of the current theory. I trust that if an experiment was done that did falsify it, most would drop it like a hot potato.

I don’t know much about string theory, but a recent lecture I heard said the string theory predicts a breakdown of the equivalence principle at some ridiculously small level (10[sup]-18[/sup], IIRC). They think this is testable with current technology, and have proposed a satellite experiment to do so.

Is that the experiment that uses some form of gyroscope experiment?

That off that last “exiperment.”

Here is their web site.

I was wih them until they started talking about using squids to detect current changes in magnetic pickup coils. Seems very last century to me.