One more nail in the proverbial death coffin of String Theories - the M version in particular. The Inflationary Theory always was considered a hack at best and now its foundational assumptions are shaken to the core.
Undergraduate engineering students are drilled extensively on units and unit conversion exercise for a good reason; ie their designs must work in the real world. Confusing mass, energy, length and time, no matter how fancy of a mathematical theory prescribes it, is a disaster waiting to happen.
I can't really see how you go from what the paper said to your conclusion about String Theory. A lot can be said about the latter, but I don't see how that paper changes anything about that in particular.
As for the paper itself.. I wasn't particularly impressed. A lot of it was about discussing nuances on how to interpret "Bedeutung" in English, and honestly, it's not that important. Or should I say "significant", which is what the paper claims is an incorrect translation in this case. Well, I know what "Bedeutung" means, and though I can agree that in this case "meaning" would be a more correct translation than "significant" (or "significance"), but really - that by itself doesn't change anything about how "planck units" should or would be used, and what for.
How is this related to the failure of String Theories and what's the connection to Inflationary Theory?
As I understand it, the choice of which units/scales are simply a matter of convenience and whilst measuring length in terms of Planck lengths may be appealing scientifically, it's unlikely to gain much usage outside of scientific circles due to the non-human scale numbers used. Of course we could adapt to using e.g. 1.0e35 Planck lengths instead of approx 1.62m but why bother.
The point of article is not just to debate English translation of Planck's original paper, but to also point out that there is nothing "fundamental" about Planck's scales in any known experimental physics - ie Planck's length isn't the dimension of one pixel of universal reality, or movement.
In all String Theories "the characteristic length scale of strings is assumed to be on the order of the Planck length, or 10−35 meters, the scale at which the effects of quantum gravity are believed to become significant."
In Inflationary cosmology, the unit of expansion is Planck's time scale, and is needed to justify existence of negative gravitational pull (repulsive force).
If as the author argues, Planck scales are merely "defining" renormalization constants and don't represent anything physically "fundamental" in experimental physics, then both of these theories lose their foundational connection to reality, even theoretically speaking, let alone any experimental evidence.
>"the characteristic length scale of strings is assumed to be on the order of the Planck length, or 10−35 meters, the scale at which the effects of quantum gravity are believed to become significant."
Does it matter for the theory that it has to be exactly at (the currently defined) Planck length, and that if it's anything else the theory breaks down? What about simply "that order of magnitude"?
Undergraduate engineering students are drilled extensively on units and unit conversion exercise for a good reason; ie their designs must work in the real world. Confusing mass, energy, length and time, no matter how fancy of a mathematical theory prescribes it, is a disaster waiting to happen.