View Single Post
  #125 (permalink)  
Old 10-March-2008, 10:43 AM
VanderL VanderL is offline
Senior Member
 
Join Date: Sep 2003
Posts: 2,590
Default

Quote:
Originally Posted by tusenfem View Post
But we have already flown through a comet with lots of instruments, and I even gave the link to the abstract by Harri Laakso and offered to send the pdf.
Thanks for the offer, I'll PM you for the actual paper.

Quote:
Originally Posted by tusenfem View Post
1. if there are to be bright arc, then why have they, up until now, not been seen by other spacecraft?
They probably have been seen (bright spots on all close-up images of Tempel 1 and Wild 2), we only lack dynamic, spectroscopic and plasma data from these sructures themselves.

Quote:
Originally Posted by tusenfem View Post
Secondly, the vocanoes of Io are NOT electrically driven, but tidally. You will probably refer to the XXX & Dessler paper (forgot the other author at the moment) where they saw that the plumes of the volcanoes were filamented when the were getting to the ionosphere if I am correctly remembering. This would be what one would like to see, as the ionosphere is the closure region of the currents flowing in Io's Alfven wings (what used to be called the unipolar inductor).
They might turn out to be electric phenomena after all, maybe both models are partly correct. The tidal mechanism rests on a number of assumptions that cannot be proven (like for example the internal composition of Io), so nothing is certain. Btw, you mean one of the most outspoken advocates of a Plasma Universe, Anthony Peratt.

Quote:
Originally Posted by tusenfem View Post
2. Well there has not been a lander, only an impactor, which did not create any EC signature.
I beg to differ, there certainly was a double flash, I'll look up the peer-reviewed published details today and see how this matches the predictions.

Quote:
Originally Posted by tusenfem View Post
3. Why not read up on Harri Laakso's paper, you will get more detail about the plasma environment of Comet Halley than you will like. But I guess that is typical EC behaviour, claiming stuff without even trying to find out if something already has been found.
You guess wrong (I know for a fact that some EU proponents do try to find relevant papers), and of course some thing have not been found yet.

Quote:
Originally Posted by tusenfem View Post
4. In any case the surface will be changing, either it gets machined (and I think you need a loooooooot of power to get to the emissions you need, but hey, no EC proponent is willing to do the calculations) or through the venting of gasses.
You're right that the surface changes will be harder to interpret, but I think EDM as a mechanism would favor the higher elevations, while outgassing probably wouldn't.

Quote:
Originally Posted by tusenfem View Post
So, how about coming up with a model? How much machining needs to be done? How do you get the charge of the comet? How do you get the necessary discharges? Do you believe that solar wind protons and cometary O or OH combine to make water in the tail, if yes, what is the reaction rate at the energies of the solar wind protons? etc. etc. etc.
To answer these questions you need to get measurements, either from experiments designed to mimic the processes, or in situ. I am convinced that all theoretical models must bow to the experimental data.

Quote:
Originally Posted by tusenfem View Post
Well, read Harri's paper and come back to us.
Will do.

Cheers.