seb wrote:Some are estimates, such as the strength of the magnetic field, but the others are taken from the textbooks.
The idea was to find out what size current you need to create the centripetal force, and that current is quite moderate in the scheme of things.
Minor nitpick: your calculation aimed at estimating the magnitude of a current for which the (maximum) Lorentz would have a magnitude {insert number of N here} if the magnitude of the magnetic field strength were ~nT.
Some conclusions can be drawn because observations set certain constraints that need to be met. For example, if the Sun is orbiting the galactic centre at a given speed then it must be subjected to a certain centripetal acceleration. If the solar system remains held together and it remains at the centre of the heliosphere then that centripetal acceleration is acting on the heliosphere as a whole; the heliosphere behaves rather like an elastic solid in that respect.
(highlight added).
As far as I know, the heliosphere is more like the point at which a pair of (closing) scissors meet; the matter of which it's composed is constantly changing. In this respect you need to be extremely cautious in how you apply the analogy. In any case, it's not spherical in shape is it? and the solar system isn't at its centre (however defined), is it?
In any case, the heliosphere appears to be pretty much self-contained - its external influence is in the form of gravity and (as reckoned here) electrical currents.
In situ observations of the heliosphere as a whole are rather limited, and those of the heliosheath and heliopause extremely few; however, as I understand it, the external influence on it is basically the pressure of the surrounding interstellar medium (ISM).
We can consider the orbit of the heliosphere as being that due to the alignment of the interstellar current and interstellar magnetic field, and the heliosphere properties. The heliosphere does not, AFAIK, appear to have an accelerating spin or non-orbital acceleration. Thus any forces on the bodies within the heliosphere, such as the Sun, can only be felt outside the heliosphere if there is an external force to react against it. Now, a torque applied to the Sun would need to be immense to rotate the Sun with any appreciable acceleration; the reaction force at the edge of the heliosphere would be tiny. And that is assuming that the reaction force does not appear on some other entity nearer the Sun such as a counteracting magnetic field. Therefore we can have quite powerful fields, forces, and complex motion in and around the Sun without the interstellar current or the path of the heliosphere being particularly bothered by it. The size of the Sun is so small compared to the size of the interstellar current feeding it that the fluctuations near the Sun are probably less significant (in terms of its galactic orbit) than the tortuous path followed by lightning to get from the cloud to the ground.
Here's an example of where your model (if I can call your analogy that) may not work; also, aren't there many more factors to consider, with respect to the behaviour of the heliosphere, than just any currents in the surrounding ISM?
In any case, for your model to work, in terms of a Lorentz force, don't you need to assume the heliosphere is a point charge? After all, whatever it is, the heliosphere isn't a current, is it?
Yes, as would any theory. Gravitational theories seem to expect ellipses as a natural consequence of orbits. Electricity is quite happy producing circular orbits.
Huh? I don't understand this at all; can you explain please? For example, what does "
gravitational theories seem to expect ellipses as a natural consequence of orbits" mean, as applied to disk galaxies?
Regardless of whether the orbit is due to gravity or electricity, I don't see any physics argument (either qualitative or quantitative) which justifies ruling out electricity as the main cause.
If by "electricity" you mean something like "a current in the ISM", and by "the main cause" you mean something like "of the inferred motions of stars in disk galaxies", then it can certainly be ruled out quantitatively! Why? Because there is no quantitative physics argument ... all you've done so far (caveat: as I understand it) is calculate magnitude of the Lorentz on a current of 10^16 A (did I get the number right?) in a magnetic field of strength ~nT, right?
Sometimes you seem to be arguing that if a theory is not quantified then the theory can not be quantified.
If I have given that impression, then let me lay it to rest right now: if something - to which we might want to attach the label "physics" - is to be called a theory, then it must be quantitative; conversely, if something isn't quantitative, then it isn't a theory (in physics).
The founding principles of plasma (or electrical) cosmology are from about the mid-60s, as I understand, so it has been going for only about 50 years. Only a small number of people have worked on it, and it has never had much funding. When you put this into the context that the entire global scientific establishment took over 200 years to get from Newton's principle of gravity to explaining the orbit of Mercury, is it reasonable to expect the PC/EU theories to be extensively documented, quantified, tested, and have all of the answers already?
Peratt's model, and simulations, were first published in 1986. Since then, as far as I can tell, there's been no new work done on it/them (Peratt's subsequent publications contain nothing new, in terms of model development, new lab-based experiments, or new simulations, for example). Yet the model is relatively simple, and the computer code likewise (and it's freely available). As far as I can tell, from my research into EU/PC, this model (and simulations) is the only quantitative piece of EU/PC work/model/theory/whatever, at least for stars, galaxies, etc. Don't you think it kinda strange?
Aristarchus , Dave, shame on you! Who cares what Thompson thinks of IEEE publications!
Whatever happened to examining, and discussing, Peratt's model (and simulations) on their own, scientific, merits? Don't you have anything to say about the fact that the values of the parameters he used rely upon the Hubble redshift-distance relationship? Or is your entire point one of
argumentum ad verecundiam (appeal to authority)?