One way to visualise this kind of stuff is to understand why Quantum Field Theory (QFT) is seen as weird. Imagine a 2D field (a sheet) that you excite with some energy – you get waves in the sheet of course. What QFT says is that if you reduce the excitation energy to some very small value, you don’t get small waves, you get no waves at all. Then, as you increase the energy past some threshold, you get a localised wave-like excitation, a standing wave if you will. In the 2D analogy, you can imagine it as a small vibrating bump in the sheet.
This bump has some important properties. It has to be capable of persisting in the field for some time after the excitation energy has been removed. Depending on the nature of the bump it can last for nanoseconds or for millennia, before it eventually decays back into the sheet (creating other excitation bumps as its energy is dispersed). It can move around the sheet without losing its localised integrity. It can interact with other bumps, attracting or repelling them as it wanders about.
So QFT describes a series of local wave excitations in a field, which because they remain locally small appear as particles. Because there are several fields, and because the particles interact with (exist in) more than one of them, the resultant dynamic system is rich and complex. The fields remain subject to the laws of relativity, and it is the fields that are the fundamental structure of the universe, not the particles.
So for example, in the search for evidence of the Higgs Field, the idea was to use the LHC to make a sufficiently large ripple in the Higgs field that a localised wave-group (particle) would be formed. This was the Higgs Boson, and much was said about it. But the boson was just evidence of the field. It is the field that is the fundamental structure, the thing that by its interaction with other particles gives them mass.
This is a much, much more important topic than most people realize, and many of the reasons have not even been mentioned yet in this discussion. Firstly, there is a limited number of top quantum/relativity scientists in the world. This fact is extremely important, because a big portion of those work on M-theory. People argue that M-theory is so complex that you need many of the top minds working on it (which they are), BUT that actually limits the brain resources for the rest of the fields. And I do not only mean science, but also ideas that could one day lead to science. One of their main argument is, quantum physics has hit a roadblock last 30 years, only discovered things that was more or less already expected, and only real progress come from astronomy. Well if old experts keep saying that to young students, they are going to choose something like M-theory, they don't want to devote their career on something that has no promise of big breakthroughs. But younger generations have often in science history come up with radical new ideas that can make a stale field move forward. Well, that might take a long time now, that many of the brightest works on M-theory.
And another thing. Even if M-theory can be applied to our universe(s), it looks to be a long way from science. People often say M-theory is like next centuries science, by accident discovered in the last. Well, it sure looks that way, also in terms of when it will become science. Likely not next 10 years or 50. As far as I understand it does not even have the string equivalent of fields yet. And, with the 10^500 permutations of possible universe configurations, it’s not even sure it will ever be useful, even if does fit the world we live in.
I am not saying it should be thrown away, it just vacuums too many bright minds away from other fields. One step at a time. Not all the steps at once, is what I vote for. Cannot force it on people of-cause, people should research what they feel like. Like doing more research into Grand Unified Theory (GUT), instead of trying to skip directly to Theory of everything (TOE), like M-theory. I just think it’s a problem, and a big one.
Many scientist working in quantum theories, often also believe in M-theory, even though it is not the field they work in. That could also be a problem, as they might for example think, "hmm, I would not spend my time on GUT, as M-theory will be the theory on that". Which would also limit competing theories on aspects M will cover.
First place to start; top M-theory experts should stop trying to paint opponents of M-theory as crackpots. It's not done directly, but can often be read between the lines. And stop calling it science, until it is. I hope this gets better, so science can move forward faster. I see only one reason to stop progress, that is if the scientists suspect new insight can lead to unwanted weaponization. Like antimatter bombs or something similar that is too powerful for us to handle. Then of-cause scientist should find ways to prevent progress in that field. But this does not seem to be the case, so please let’s get more research diverted from M-theory into improving our current framework of nature, so we can understand dark matter/energy, and other weird empirical data from the universe.
Were high-energy and fundamental physicists found to have abandoned the scientific method and to have resorted to 'metaphysics' or just plain juju, that would have serious repercussions for science, but little immediate effect on anything else. On the other hand, misrepresentation of science in popular works is definitely something we should avoid on grounds of general policy and good governance, but is rarely perpetrated by working scientists, and has itself zero effect on science.
It is true that one has the impression that science at the present cutting edge is rather theory rich and data poor. However I suspect that this is always the case, because at the frontier of science it is usually easier to theorize than to gather and interpret data. As the frontier moves on, unsuccessful theories fall by the wayside and are forgotten. We thus suffer from a sort of historical tunnel hindsight in which we see the path that science has traversed as an obvious high road, and forget that it was usually far from obvious at the time.
At the end of the day there is no problem with spinning all kinds of theories, because ultimately the facts will decide the issue. Scientists know that. There's no downside. Nobody is about to take string theory or whatever as fact and base their actions on that.
