IS Forum
Forum Index Register Members List Events Search Today's Posts Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Reply
Old 21st November 2022, 01:25 AM   #1601
Sol88
Philosopher
 
Sol88's Avatar
 
Join Date: Mar 2009
Posts: 6,897
The Plasma Environment of Comet 67P/Churyumov-Gerasimenko

Quote:
From wake effects it can also be deduced that the bulk plasma flow is radial and supersonic. An ion velocity higher than the neutral velocity is in direct contradiction with the assumption that ions and neutrals are collisionally coupled
and thus in direct contradiction with the model suggested by Cravens (1987).

Vigren and
Eriksson (2017) showed that such a discrepancy can be explained by low collision rates due to low neutral gas densities and propose that an ambipolar electric field (see also Sect. 4.1) can accelerate ions to the observed velocities.

Fuselier et al. (2016) also pointed out that the unexpected H2O+ /H3O+ ratio can be explained by an ambipolar field inside the diamagnetic cavity. It should also be noted that the definition of the collisionopause as a sharp boundary that separates a region where neutrals and ions are coupled from a region where they are not coupled is inappropriate, since collisions are a process that occurs on length scales comparable with the diamagnetic cavity size (Vigren and Eriksson 2019).

As of now, it is unclear which process is responsible for deterring the magnetic field from diffusing into the diamagnetic cavity.
JD116, would you like to have a rethink on your position of a diamagnetic cavity caused by expanding gas?

Double layer....
Quote:
The same ambipolar field that accelerates the ions retards the electrons and couples them more efficiently to the neutral gas via collisions
Quote:
Whereas solar wind electrons are typically warm (around 10 eV),at large heliocentric distances (low outgassing) they are accelerated by an ambipolar electric field in the vicinity of the nucleus and reach energies of a few tens of eV responsible for ionisation and excitation of the cometary neutrals.
__________________
“No rock. Any charge separation is limited. The electric field is pointing in the wrong direction. Currents are doing nothing.” Jonesdave116.

“The 'electric comet' is physically IMPOSSIBLE to model using mainstream science! PERIOD! True story! End of story!” Indagator

Last edited by Sol88; 21st November 2022 at 01:33 AM.
Sol88 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 01:34 AM   #1602
Sol88
Philosopher
 
Sol88's Avatar
 
Join Date: Mar 2009
Posts: 6,897
Quote:
Unfortunately, no model can adequately treat both large and small scales alike.
pity 'cos
Quote:
Large-scale electric fields include the convective, ambipolar and polarization electric field. They affect both the ions and electrons, and are important for instabilities and wave
generation
.
Sounds like a problem with the mainstream model!
__________________
“No rock. Any charge separation is limited. The electric field is pointing in the wrong direction. Currents are doing nothing.” Jonesdave116.

“The 'electric comet' is physically IMPOSSIBLE to model using mainstream science! PERIOD! True story! End of story!” Indagator
Sol88 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 07:01 AM   #1603
tusenfem
Illuminator
 
tusenfem's Avatar
 
Join Date: May 2008
Posts: 3,091
Originally Posted by Sol88 View Post
Mmmmmm....local process.
mmmmmmmmmm doughnuts
__________________
Scientific progress goes *BOINK* -- Calvin & Hobbes
twitter: @tusenfem -- Super Duper Space Plasma Physicist
tusenfem is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 07:11 AM   #1604
tusenfem
Illuminator
 
tusenfem's Avatar
 
Join Date: May 2008
Posts: 3,091
Originally Posted by Sol88 View Post
Sounds like a problem with the mainstream model!
Nope, not at all, but if you happen to have a few billion dollars/euros/pounds to build an super-super-super computer, then the problem would be solved.

I will set up a kickstarter for you.
__________________
Scientific progress goes *BOINK* -- Calvin & Hobbes
twitter: @tusenfem -- Super Duper Space Plasma Physicist
tusenfem is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 01:36 PM   #1605
Sol88
Philosopher
 
Sol88's Avatar
 
Join Date: Mar 2009
Posts: 6,897
Originally Posted by tusenfem View Post
mmmmmmmmmm doughnuts
Quote:
Conclusions. The ambipolar and polarisation electric fields both have a significant influence on the motion of cometary ions. This demonstrates the importance of space charge effects in comet plasma physics.
https://www.researchgate.net/publica...ov-Gerasimenko



Local process... did the team consider the nucleus to be at a different potential to the local space charge?

Where are all these cold electrons comming from...

Are we settled on the electric fields doing the works after that?

Paper pretty well confirms the importance of the plasma environment in comets.

Asteroid and moons too strangely enough.

Plasma,ay.

Maybe you could run the nOobs thru what “space charge effects” are? In relation to charged particles in a particular.
__________________
“No rock. Any charge separation is limited. The electric field is pointing in the wrong direction. Currents are doing nothing.” Jonesdave116.

“The 'electric comet' is physically IMPOSSIBLE to model using mainstream science! PERIOD! True story! End of story!” Indagator

Last edited by Sol88; 21st November 2022 at 01:40 PM.
Sol88 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 01:52 PM   #1606
tusenfem
Illuminator
 
tusenfem's Avatar
 
Join Date: May 2008
Posts: 3,091
Originally Posted by Sol88 View Post
Maybe you could run the nOobs thru what “space charge effects” are? In relation to charged particles in a particular.
Nope, you will have to figure it out for yourself with some books and such.
__________________
Scientific progress goes *BOINK* -- Calvin & Hobbes
twitter: @tusenfem -- Super Duper Space Plasma Physicist
tusenfem is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 05:05 PM   #1607
Sol88
Philosopher
 
Sol88's Avatar
 
Join Date: Mar 2009
Posts: 6,897
Too scary, space charge effects?

Space charge effects have significant influence on the motion of cometary ions and electrons.

Plasma stuff. Electric currents, electric fields, instabilities inc DOUBLE LAYERS (Ambipolar electric fields).

Wow space charge stuff, very electric comet.

Quote:
Large-scale electric fields include the convective, ambipolar and polarization electric field. They affect both the ions and electrons, and are important for instabilities and wave generation.
Quote:
Comets therefore cover an extensive part of parameter space and present an excellent laboratory to study large scale structures as well as small scale interactions.
The Plasma Environment of Comet 67P/Churyumov-Gerasimenko

__________________
“No rock. Any charge separation is limited. The electric field is pointing in the wrong direction. Currents are doing nothing.” Jonesdave116.

“The 'electric comet' is physically IMPOSSIBLE to model using mainstream science! PERIOD! True story! End of story!” Indagator

Last edited by Sol88; 21st November 2022 at 05:08 PM.
Sol88 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 21st November 2022, 05:09 PM   #1608
Sol88
Philosopher
 
Sol88's Avatar
 
Join Date: Mar 2009
Posts: 6,897
We could just skip to my favorite:


Quote:
5.2 Open Questions
1. What is the impact of electric field acceleration and dust charging on the plasma balance and vice versa?

2. What is the combined effect of the polarisation and ambipolar electric fields?
Is the dust charged, tusenfem?

What is the combined effect of the polarisation and ambipolar electric fields on the motion of the charged dust?

You up for it again?

Quote:
For example, could there be strong nanodust releases at outbursts from the nucleus, or some high energy electron events causing so much charging of dust grains that electrostatic fragmentation near the nucleus becomes very strong, yielding lots of sub-micron grains and corresponding dust-plasma interactions effects? There may still be surprises awaiting us even in the existing datasets.
__________________
“No rock. Any charge separation is limited. The electric field is pointing in the wrong direction. Currents are doing nothing.” Jonesdave116.

“The 'electric comet' is physically IMPOSSIBLE to model using mainstream science! PERIOD! True story! End of story!” Indagator

Last edited by Sol88; 21st November 2022 at 07:06 PM.
Sol88 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 06:08 AM.
Powered by vBulletin. Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.