moon receding from earth receding from sun?

[thalion]

The general rule for tidal orbital migration is this: for an object orbiting a primary in less time than the primary rotates, it will migrate inwards, while for an body orbiting more slowly than the primary rotates, it will migrate outward. This is in addition to the migration caused by the aforementioned "loss" of mass due to fusion. Thus, the Earth is probably migrating outward, but so slowly as to be statistically insignificant, IMO. The Earth certainly didn't start out much closer to the Sun. More important over the long term are probably tidal interactions with the planets and choatic oscillations.

 

[Saiph]

The sun and moon dominate the tidal interactions of earth (by a factor of several thousand IIRC), but even with the sun having an important role to play, the tidal forces won't cause earth to shift in orbit much, simply becuase the tides it creates on the sun are small, and so distant.<br /><br /><br />So you're right, tidal migration of the earth is definetely negligible. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[newtonian]

Thalion - Hi, and thank you.<br /><br />OK, how much faster does the sun rotate than the earth revolves - the latter is, of course, one year.<br /><br />And how long would it take for these to equalize?<br /><br />I assume there is a tendency to equalize these two rates - correct?<br /><br />Also, if earth's orbital speed equalizes the sun's rotation speed, ignoring other very important factors [like tidal effects of planets; precession, loss of solar mass, etc.] (for the sake of a simple math calculation), how far out would that orbital speed put earth from the sun?

 

[newtonian]

Thallion - I've got the 1991 solar rotation estimate:<br /><br />25 days at solar equator.<br /><br />35 days near the solar poles (rotational).<br /><br />What would the average rotation be for the mass of the sun - I know that gets more complex because it would involve internal rotation variations which cause the floating magnetic fields from the interior to the corona?<br />Those wanted details aside, it is obvious that you are correct that the sun is rotating faster and that tidal interaction will increase earth's orbit.<br /><br />Is there some ballpark estimate as to the rate of change, say per billion years, from this cause alone?<br />

 

[newtonian]

Calli- Thank you.<br /><br />Yes, it is clear the mass of a single comet would have negligible effect on the mass of the sun. However, the question as to whether it could cause perterbations to near the core could be very important.<br /><br />It seems likely that the heat would dissipate the mass of the comet long before it approached the solar core.<br /><br />However, note that other collisions modeled by scientists (and reported in a recent Scientific American) would pass clear through our sun!<br /><br />Logically, there must be some mass and speed that would penetrate enough to cause some mixing between core and outer layers without actually penetrating all the way to the core.<br /><br />I have in mind primarily shock waves. Or seismic activity- the sun is already active seismically anyway.

 

[newtonian]

crazyeddie- see my post of 10/08/04 07:49 PM. Clearly you want me to post more evidence, and I will do so.<br /><br />Meanwhile, you would do well to review the line of reasoning I already posted. <br /><br />For example, how far do the internal solar magnetic fields penetrate the sun? Do they extend through and beyond the solar core?<br /><br />Solar seismic activity also penetrates the core.<br /><br />Would you like me to post links and references as to the evidence, or would you prefer researching independently first?<br /><br />Hint: compare the stirring time of earth's ocean: 1,000 years.<br /><br />Then compare the mass of the solar gaseous 'ocean' layers. <br /><br />Also compare the speed of transmission of energy from core to surface - if I remember correctly it is about one million years.<br /><br />While there is much more energy available in the sun's layers than in earth's oceans, there is also a much larger mass. <br /><br />The temperature difference between core and outer layers is also similarly involved.<br /><br />I was simply giving a ballpark estimate on solar stirring time.<br /><br />To me it seems likely it is at least 1,000 times slower than the time it takes energy to travel from core to surface.<br /><br />Hence, the mixing time may be at least one billion years, likely 10 billion years, perhaps one trillion years.<br /><br />The standard model cannot be easily checked at this very slow mixing rate.<br /><br />By way of comparison, consider how difficult it was for astronomers to detect variations in the CMBR- so much so it was assumed by some to be smooth.<br />Astronomers are noting more and more how different stellar radiation and other properties can be.<br /><br />Therefore, it would be difficult to extrapolate a life span for our sun from an average from the so many different types of main sequence stars out there.

 

[newtonian]

Saiph - Sorry, but I tend to question everthing.<br /><br />Are you sure our little planet's mass is constant?<br /><br />Surely in the past we have accreted mass - where did we get our water?<br /><br />On the other hand, we may have lost mass - e.g. solar photolysis (=photodissociation) of water (H2O) into H2 and O2, some of the hydrogen may have escaped in the past.<br /><br />Is hydrogen still escaping?<br /><br />I assume increase in earth's mass from dust, etc., would have an effect - more so in the past - when extrapolated over billions of years.<br /><br />Is there a bias in direction of impact with earth that would favor a certain direction of resulting motion?

 

[newtonian]

stevehw33 - Hi!<br /><br />There are advantages and disadvantages to compartmentalizing. <br /><br />Science can benefit from specialization, but there are drawbacks.<br /><br />For example, if astronomers ignore geologic evidence of an early hot earth, they might conclude early earth was colder from models indicating the sun's radiation was lower.<br /><br />Chemical evolutionists have assumed early earth had an atmosphere mostly of methane (CH4) and ammonia (NH3) while the geological evidence indicates otherwise, notably more CO2. Likewise vocanologists studying volcanic outgassing conclude a high proportion of CO2 (carbon dioxide). And chemists note the photolysis of H2O producing a small portion of oxygen (O2 molecule) contrary to chemical evolutionist's models.<br /><br />The same can be said for many other subjects of research papers - often the published results concentrate on one field of science and ignore findings in other relevant fields which may contradict the published model.<br /><br />I have found including Biblical models is also important for scientific advancement. Certainly, failure to note the earth is round (Isaiah 40:22) and hung upon nothing Job 26:7) caused centuries of wrong popular scientific models between Bible times and the present.<br /><br />I have found this quote of Einstein to be accurate:<br /><br />"Science without religion is lame, religion without science is blind."<br /><br />

 

[newtonian]

crazyeddie- Woo- woo!<br /><br />Interesting link, do I perceive a sense of humor?<br /><br />I must say this tangent may send this thread into orbit!<br /><br />What I really would like to know, to be serious and back to thread theme:<br /><br />Have we been able to measure any actual change in earth's orbit around the sun?<br /><br />And what are some of the variant models for the earth's future orbit?<br /><br />I know there are good links on this - especially models for when our sun is considered to enter red giant phase.<br /><br />Alas, this was on the old SDC, which crashed.<br /><br />However, I remember studying links that indicated our earth would be well beyond the sun's red giant edge; while other links had our earth actually engulfed by the sun.<br /><br />The models were quite extremely variant, and I would like to understand why.