String theory, despite its grand appeal and loads of researchers working on developing what was supposed to be "The Theory of Everything," is past the point of being considered actual science. I don't really want to go into what string theory is, but a quick little Google search will inform you on the basics (strings make up the universe). We'll also discuss the particular string theory that is supersymmetry, but we will also talk about all of string theory as a whole as pseudoscience. To show how string theory fails in the pseudoscience realm, I'll use a not as widely-known but still somewhat popular demarcation boundary proposed by Paul R. Thagard in 1978 in his "Why Astrology is a Pseudoscience." I'll explain his approach, which encompasses Karl Popper's idea of falsifiability among other criteria. While there are many papers on why string theory is a pseudoscience, I haven't yet seen one that approaches that claim from Thagard's perspective.
Basically, Thagard sees a theory as pseudoscience as a "matrix" of three things to examine:
Theory: This is what is examined as science vs. pseudoscience typically. The theory should have structure, predictions, reasoning, and problem-solving. Popper's falsification (being able to test and prove a theory false) is also part of this.
Community: Is the theory's community in agreement with the principles of the theory and on dealing with issues in the theory? Does the community care about anomalies in the theory and comparison to other rival theories? Are there active attempts to prove and disprove the theory?
Historical Context: Have the theories had anomalies for a while? Is it challenged by another theory?
Now, Thagard was able to apply these principles very successfully to prove why astrology was a pseudoscience. You can read his paper to learn more about how he came up with these key principles to draw the line between real and fake science. We will go one by one to show how Thagard's tests show that string theory is pseudoscience.
Theory: Okay, string theory meets a lot of this, but not falsification. There are predictions, like in supersymmetry, the higher mass particles that we are still waiting to detect. String theory isn't really falsifiable. It appears that string theorists can always say that there are still possibilities of detection, our technology and particle accelerators aren't advanced enough. That excuse has gone on for a while, though. And could we ever find a piece of definitive evidence that completely disproves string theory? So, far that doesn't seem so. Let's look at Thagard's other criteria.
Community: It also appears that string theory does not have a ton of agreement within the string theory community. Are there 10 or 11 dimensions in string theory? Is M-theory a part of string theory? Is supersymmetry part of string theory? The community of string theory seems to regard anomalies as "it will be answered later" in a sweep-it-under the table manner. Also, there appears to be no present effort to try and reconcile string theory with other leading theories of quantum gravity, such as loop quantum gravity, triangular quantum gravity, and entropic gravity. There are attempts to prove this, but as we said, when the particle accelerators aren't finding the particles predicted by supersymmetry, string theorists stick to the "the particles are still heavier" motto.
Historical Context: String theory has had its anomalies for decades now. There are other, more promising young theories that challenge string theory, such as loop quantum gravity, triangular quantum gravity, and entropic gravity, just to name a few. These theories are so young and less researched in the physics community to the point where they can still be classified under science.
What was once considered prominent science has now seen time progress and its theory demise into pseudoscience. After all, Thagard's interpretation of science vs. pseudoscience is not static for any particular theory. Hopefully, the above arguments resonated somewhat, and hopefully the physics community begins to shift away from string theory research and more into other pressing matters of physics and other theories of quantum gravity.
NOTE (please read): I know I may have sounded a little too attacking in this writing. I apologize and I do not have anything against string theorists. In fact, they are very brilliant. String theory may indeed be a failure, but it is an opportunity for us to learn as we move on. Also, the advanced mathematics required in string theory is quite impressive, and it could be useful in a future theory of everything. Thank you, string theorists, and I am sorry for being so attacking.