I have a background in physics (but not astrophysics) and to me MOND seems much more ad hoc than dark matter does. Dark matter posits that there is some kind of particle we have not observed directly that has a large effect on cosmological scales. We already believe that the standard model of particle physics is incomplete, so this is at least plausible. These particles are not in anyway "unobservable" in an absolute sense, they must at least interact via gravity in order to do what we need them to. They may even interact via the nuclear forces. They just don't interact via the electromagnetic force. We can make hypotheses about these particles, put constraints on their properties from observational data, use particle physics theory to come up with candidates, and do experiments to find them. They are not "unobservable", the are simply hard to observe and require advances in experimental technology. MOND on the other hand was discounted in the early days exactly because it was a fudge factor in Newton's second law. We saw some anomaly in galaxy rotation curves, MOND fixed it by adding a fudge factor to Newton, a theory which we already knew at the time to be incomplete! That is why most physicists preferred dark matter to MOND. Since then, other observational data has increased the evidence for the existence of dark matter (most famously the Bullet Cluster mentioned by others), making MOND that much more unpopular. There has been some work, like this RelMOND theory, that work to integrate the original MOND theory with general relativity. Critically, however, the way in which RelMOND is doing this is by positing the existence of an additional field that can act in the "clumpy" way required by observation. Basically, they have just reinvented dark matter. So I do not doubt this new theory fits the observation, but it does so by adding a new degree of freedom which plays the part of dark matter. This talk (https://www.youtube.com/watch?v=iu7LDGhSi1A) is somewhat technical, but it goes in to some detail as to why we can't explain current observation by messing around with gravity.
I think this argument is quite facile. These people are scientists trying to understand superconductivity at a basic level, and this theoretical research (as well as the experimental results posted on this forum earlier this week) are a genuine advancement in that field. You are judging this research based on how it is directly applicable to making handheld devices with room temperature superconductors when that is not what these people are attempting to do at all. The fact that a superconducting state can be maintained at these temperatures at all is, indeed, "record shattering". We do not have the ability to simply engineer a material that can superconduct at ambient temperature and pressure at will. I don't mean to be to confrontational, but reading the comments on these articles it really pisses me off to see the hard work of actual scientists judged by the rubric of whatever science fiction garbage internet commenters think should be possible.
Since this is the second story about this kind of research that has been posted this week, I feel it should be made clear that the purpose of this kind of experiment is not to develop room temperature superconductors for use in devices, but to study the physics of BCS (normal, "low temperature" superconductivity seen in metals like mercury, as opposed to that seen in materials like YBCO) superconductivity in materials with much lighter nuclei, and to get an idea of what might occur in theoretical states of matter like metallic hydrogen. It is only "applied" in the sense that it allows one to understand the mechanisms behind superconductivity, no one doing this research thinks that this will be a useful mechanism for making superconducting transmission lines or whatever.
I have the feeling it will be more economical to just use a low-temperature superconductor and cool it down with a closed-cycle cryocooler, rather than try to get a large enough pressure vessel that can maintain such high pressures.
The limiting factor is the critical field of the superconductor. Superconductors tend to expel magnetic fields, but if the field is strong enough it will bring the material back to normal conduction. Since a current will generate a magnetic field, this is what sets the maximum current.
