After citing The Electric Universe by Wallace Thornhill and David Talbott, and The Electric Sky by Donald Scott, he avers that these "ideas are supported by much computer modelling".
The computer modelling facade is due to Peratts use of supercomputers in the early 90's to model a new type of galaxy formation. We have not seen the coding, so no-one can really comment on this further.
I'm fairly confident that Peratt's work is okay. In fact, I've skimmed Peratt's long review of that work myself.
(ETA: I'm talking about Peratt's work on numerical modelling of plasmas in general. So far as I know, Peratt hasn't simulated any plasma universe theory of galaxy formation. So far as I know, the plasma universe theory of galaxy formation does not exist in a form that's sufficiently well defined to be modelled numerically.)
It was not okay for Dunning-Davies to suggest that Peratt's (or anyone else's) computer modelling supports the two books by Thornhill/Talbott and by Scott.
[*]He complains about routine use of "powerful mathematics".
Yes he does, well done. Crothers, unlike Thornhill, can actually do maths however. And Crothers provides a very specific context for this misuse of powerful mathematics in place of rigorous
experimental physics.
I'm sorry, but Crothers got the math wrong. I could walk you through some of his errors, but
Jason Sharples has already done that. Crothers responded to Sharples, but I could also walk you through the errors in Crothers's response.
Crothers gave a devastating proof of his mathematical incompetence in a
back-and-forth with Sharples in written comments at the "Dealing with Creationism in Astronomy" blog site. During that exchange, Crothers defended the claim made in one of his papers that there exists a homeomorphism (which all of the discussants referred to as a one-to-one correspondence, but they meant homeomorphism) between Euclidean 3-space and an arbitrary 3-dimensional metric manifold.
No such homeomorphism exists.
(ETA: Not in general, and Crothers was talking about the general case in his paper.) That's a variation of exercise 8 in
part 1 of the exercises I formulated for Farsight, and it's a fact that undergraduate math majors should learn (even if they may not learn how to prove it). Crothers contradicted that well-known theorem in one of his papers, and continued to deny that fact even after his wrongness was pointed out to him. He couldn't even handle the one-dimensional case, which Sharples asked him to address.
Had Crothers been competent at math, he wouldn't have given us that demonstration of basic incompetence.
[*]He says astrophysics should treat gravity as "secondary" because "the electric force is so much more powerful."
Do you know how many sig fig EM forces are stronger than gravity? 36 sig fig is not a small amount!
As I said, that comparison is not relevant to astrophysics, where the charge balance is nearly perfect.
[*]He repeats the canard about "the strength of a magnetic field produced by an electric current is inversely proportional to the distance from the current but the gravitational force between stars is inversely proportional to the square of the distance." (Both fields, gravity and electromagnetic, obey the same inverse-square law. He's comparing the force produced by an infinitely long generator of the field to the force produced by a point source.)
You seem to be confused between the inverse square law for magnetism and electrostatics (which is indeed 1/r
2) where as Amperes law (or its equivalent Biot Savart force law) does indeed obey a 1/r relationship when the filaments in question are an infinite line of charge, which for most intents and purposes they can be considered as.
I am not confused about this. I stated the situation correctly.
An infinitely long line of matter would generate a 1/r force just as an infinitely long line of current density produces a 1/r magnetic field. A small, compact source of matter generates an inverse-square field, as does a small, compact source of current density.
[*]He then says "this well-known difference between the two forces" (which doesn't even exist) "could lie at the heart of the problem of the galactic rotation curves".
It does exist, Im afraid, as explained above.
As explained above, you're wrong. I've done the math. You should try it sometime.
In the second paragraph of his section III, Scott constructs a caricature of magnetic reconnection and then attacks that strawman. As I proved in the "Electric Sun" thread,
magnetic reconnection is a simple consequence of Maxwell's equations. Scott discredits himself whenever he pretends otherwise.
If you are going to try to discredit him based on a few sentences you will never understand why he is saying what he is saying.
Scott denies magnetic reconnection in many of his articles and at his web site. The magnetic reconnection that Scott denies is a simple consequence of Maxwell's equations.
I've done the math.