Planetary Torque

General physics and astronomy discussions not directly related to Celestia
GlobeMaker
Posts: 216
Joined: 30.10.2005
With us: 19 years 1 month

Post #21by GlobeMaker » 19.01.2006, 08:11

Hey Chuft-Captain,

if(you<satified)switch(forums)
{
case astronomy.physic:serious->factual;
case purgatory:comedy(this);
case bugs:rectilinear(gaps);
case users:users++;
case textures:user(visual.D--);
case addons:overlay.sound.start(data)->integrate.Celestia(1.4.5);
case scripting:educational(!C++);
}
if(yours>mine)editProfile;
if(mine>yours)status::quo;
interstellar.gases=0;
while(++time<infinity) iodine(Fe);

purple iodine(int Fe(-) int Fe(+) float cosmicRay)
{
for (Fe=26; FeFe<53; cosmic.ray++)
{
fusion(iron.plentiful + cosmicRay) -> iodine.isotope(53)!yet;
if (iodine==abundant)
break;
else interstellar.gases++;}}
Last edited by GlobeMaker on 19.01.2006, 14:10, edited 6 times in total.
Your wish is my command line.

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Chuft-Captain
Posts: 1779
Joined: 18.12.2005
With us: 19 years

Post #22by Chuft-Captain » 19.01.2006, 11:03

Oh dear,
I will say this, and no more (else Selden will purgatorise this thread):

GlobeMaker wrote:while(everythingYouSay==TRUE)
{
....return(0);
}
if (++time<demise) return(*argv[++facts]);
Chuft-Captain wrote:while (++time<demise)
{
....while (everythingYouSay==TRUE)
....{
........return(*argv[++facts]);
....}
}
return(0);


:wink: :D :lol:
"Is a planetary surface the right place for an expanding technological civilization?"
-- Gerard K. O'Neill (1969)

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wcomer
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Location: New York City

Post #23by wcomer » 19.01.2006, 16:07

What a bizarre topic. OK my two cents is that even if there were some force of appropriate magnitude. The planet wouldn't remain axially locked. Rather, the axis would necessarily precess. This whole problem could be solved precisely: for a given tidal force, what is the maximum rate of rotation for which the configuration is dynamically stable. Although highly contrived, this is the sort of problem that most advanced physics undergrads ought to be able to solve.

With this relationship in hand one can work backward, to determine an appropriate spin rate for the planet given realistic tidal forces.

Topic author
MKruer
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With us: 22 years 3 months

Post #24by MKruer » 20.01.2006, 02:22

First off I would rather this thread be closed then become a pissing contest between people who have no other intention other then to flame each other.

Second; on the note of a high precession rate, I would welcome a real discussion on what forces would be involved, even if I did not use the final outcome, it would be interesting just to know what truly would be involved. On that note I found a possible useful link that discuss about rotation, torque and precession.

http://hyperphysics.phy-astr.gsu.edu/hbase/rotv2.html

Finally on the color of the atmosphere Again any real discussion would be interesting and informative. The texture of the planet as well, would it have a bunch or bands or would the boiling process be so wide spread and of such a magnitude that planet would be spotted?

I hope everyone will keep this discussion civil.

Malenfant
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Post #25by Malenfant » 20.01.2006, 06:21

Ideally I'd recommend you look at papers on orbital dynamics, or an orbital dynamics textbook for the whole story, like Murray and Dermott's "Solar System Dynamics".

Tidal forces ultimately act to align equatorial bulges, reduce inclination and eccentricity and synchronise rotation and orbital periods. A planet tipped on its side so its rotational axis points toward the sun is not a stable scenario - it should act like Uranus, with its axis pointing in a fixed direction in space as it orbits the sun so that each pole is illuminated as it goes round the star. The only reason Uranus' tilt hasn't been reduced to lower values is that it's too far from the sun to be effectively affected by the tides - if it was a LOT closer then its tilt would have been more 'rectified' over the few billion years it's been around.

If you're mathematically inclined you might want to look at these:
http://scienceworld.wolfram.com/physics ... noxes.html
http://www.daviddarling.info/encycloped ... ssion.html
http://star-www.st-and.ac.uk/~fv/webnotes/chapt16.htm

They're a better reference than articles about spinning tops - after all these are planets we're dealing with here, not spinning metal discs :). But generally planetary precession is caused by perturbation from other nearby massive planets.

As for the appearance, I've told you pretty much what I know... I'm guessing that the planet's atmosphere would appear (structurally) to be more like Jupiter (ie strongly banded, belts blowing in different directions, lots of spots etc) than Saturn. The colours are anyone's guess though, they depend on the chemistry.

And let me just say that I know a fair bit about orbital dynamics (and brown dwarfs for that matter), so I know what I'm talking about here. I'm trying to point you in the right direction here, not see you getting distracted by poorly-considered, badly thought out ideas like 'magnetic locking' proposed by people who at best don't know much about the subject - if you want to perceive that as a 'pissing contest' then that's up to you.
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