Poincaré’s contributions to the field of special relativity were undoubtedly invaluable, but nonetheless those contributions do not constitute an independent discovery of the theory. ... he cannot be credited with an overall conceptual grasp of the theory.Here is her first argument:
One element which links the work of both Poincaré and Einstein is a preoccupation with the principle of relativity. But it is important to be aware that Einstein and Poincaré were not working with precisely the same principle. Compare their two fomulations:This is typical of the bizarre and strained arguments used to support Einstein. First, the whole point is contradicted by the footnote. Second, if you accept a difference in the principles, then Poincare's version is superior and closer to the modern understanding. Third, Einstein's version is contradicted by the cosmic microwave background radiation, which defines a privileged frame for observing motion.
Poincaré: ‘the laws of physical phenomena must be the same for a motionless observer and for an observer experiencing uniform motion along a straight line.’ (1904) 1
Einstein: ‘The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or the other of two systems of co-ordinates in uniform translatory motion.’ (1905)
The crucial difference between these formulations is that Poincaré finds it necessary to refer to an observer, while Einstein does not. The difference has been noted by Katzir: ‘In contrast to Einstein, who denied the existence of absolute motion, Poincaré denied the possibility to detect it.’ (2005) As a result Einstein’s principle leads to stronger constraints: for Einstein, there can be no difference at all between the forms of the laws of nature in different inertial frames, whereas Poincaré can accept that the laws of nature take one form relative to a privileged frame and a more complicated form relative to all other frames, provided they work together in such away that this difference between frames does not have any observable consequences.
[Footnote 1] In his 1902 essay ’Relative and Absolute Motion’, Poincaré gave a different formulation of the principle of relativity, omitting the reference to an observer: ‘the movement of any system whatever ought to obey the same laws, whether it is referred to fixed axes or to the movable axes with are implied in uniform motion in a straight line.’ (1902, p.111) But this version appears in a philosophical paper rather than a scientific one, and as we shall see, Poincaré’s scientific views must be kept separate from his philosophical ones.
Adlam's argument is essentially this: Poincare and Einstein said essentially the same thing about relativity; Poincare said it first; Einstein's version has some slight philosophical advantages if you ignore what Poincare wrote in philosophical papers; therefore Einstein gets the credit for the discovery of relativity.
I wrote the book, How Einstein Ruined Physics, because the Einstein literature is dominated by otherwise-intelligent scholars making completely ridiculous arguments in a desperate attempt to credit Einstein for relativity. I will comment on the rest of Adlam's paper when I read it.