Is the Sun a binary?

"Theory and observations now agree closely. At least 99% of the effect is a necessary motion of Earth's spin axis imposed by the
gravity of Sun and Moon applying a torque to Earth's bulging equator." - TVF

Just curious, but how are such precise calculations done? This implies that if nothing were known from observation, an annual precession rate of about 50" would be calculated from the Earth's slight oblateness, the Moon and Sun. I know very little about gravitational theory, other than that when the interactions of more than two idealized bodies are involved, the calculations become extremely complex and even the most powerful modern computers can give only approximations.

"No known kind of force can rotate the whole solar system as if it were a rigid body." - TVF

No, not a rigid body like a phonograph record. But as a unit, I'd think. The satellite systems of the gas giant planets, mini solar systems in their own right, revolve as units around the Sun and have been evidently stable for billions of years.

I have surmised from this discussion that you feel there can be no large undiscovered object bound to the Sun beyond Neptune. How does this square with your theory of the original solar system? From articles elsewhere on this site you say the outermost planetary (fission) pair was bodies T and X. Body "T" supposedly exploded to form the Kupier belt. This would leave the outermost, "X", still to be discovered, wouldn't it?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by nemesis</i>
<br />how are such precise calculations done? This implies that if nothing were known from observation, an annual precession rate of about 50" would be calculated from the Earth's slight oblateness, the Moon and Sun.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That is correct. The Earth's "slight" oblateness of 0.3% is enough to rotate artificial satellite orbits at rates that can be several degrees per day, depending on how close the satellite is. And it is just what is needed to drive Earth's spin axis at the calculated rate of 50"/year.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">I know very little about gravitational theory, other than that when the interactions of more than two idealized bodies are involved, the calculations become extremely complex and even the most powerful modern computers can give only approximations.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">You are probably referring to higher-order harmonics in the gravity field, which satellites can now detect. At that level of precision, every major mountain or valley, and even the density difference between oceans and land, causes a small gravitational perturbation on satellites that can be detected. It takes fast computers to calculate these effects because there are so many.

But let's not fail to see the forest because of the trees. Basic calculations show that an oblateness of 0.3%, if torqued by massive bodies inclined to Earth's equator (such as the Sun and Moon), will precess the spin axis 50"/year. And the essence of that result can be computed by any student on the back of an envelope using the standard formulas for toquues on an oblate planet, such as those on p. 170 of the Explanatory Supplement to the Astronomical Ephemeris (1960).

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">[tvf]: No known kind of force can rotate the whole solar system as if it were a rigid body.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">No, not a rigid body like a phonograph record. But as a unit, I'd think. The satellite systems of the gas giant planets, mini solar systems in their own right, revolve as units around the Sun and have been evidently stable for billions of years.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Yes, and that is what "planetary precession" of Earth's orbital plane is all about. But our discussion here is about lunisolar precession, not planetary precession. Lunisolar precession affects each body differently depending on that body's shape, so there can be no commonality of motion for any group of bodies such as Jupiter's moons. And there isn't.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">I have surmised from this discussion that you feel there can be no large undiscovered object bound to the Sun beyond Neptune.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Correct. The keyword here is "large". One can always hypothesize a mass small enough to hide from any detector.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">How does this square with your theory of the original solar system? From articles elsewhere on this site you say the outermost planetary (fission) pair was bodies T and X. Body "T" supposedly exploded to form the Kuiper belt. This would leave the outermost, "X", still to be discovered, wouldn't it?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Two asteroids have already been discovered at the distance of "X", indicating that "X" is also exploded, as expected. In any case, these are planets with terrestrial-planet masses of 1-3 Earth masses, easy to hide. I have no problem with hypothesizing that lots of bodies that size remain to be discovered, although these is presently no evidence to support such a hypothesis.

But you want your dark companion to be the size of a dwarf star or gas giant planet. That is what is impossible to hide because it would be bright in infrared surveys, because its gravitational perturbations on planet orbits should be seen, and because pulsar timings would show the Sun accelerating toward it. Yet none of these is true. -|Tom|-

I'll have to try to find a copy of the Astronomical Ephemeris you refer to. The students are using formulas from that source, and I'd like to see how they were derived.

You mention a gas giant should be bright in the infrared. It seems I have read that Uranus does not radiate heat like the other three. Is that correct? (No real relevance to the binary question - just curious).

What does the pulsar data show about the solar system's actual movement through space? It will supposedly circumnavigate the galaxy in about a quarter of a billion years.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by nemesis</i>
<br />You mention a gas giant should be bright in the infrared. It seems I have read that Uranus does not radiate heat like the other three. Is that correct?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Uranus is tipped over on its side. And when its pole is pointed toward us, we see little or no excess heat. This suggests (unsuprisingly) that most of the excess heat escapes from lower latitudes, because that is where the internal friction caused by differential rotation arises.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">What does the pulsar data show about the solar system's actual movement through space? It will supposedly circumnavigate the galaxy in about a quarter of a billion years.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The strength of the Galactic force on the Sun is just a few parts per 100 million of the Sun's pull on Earth, which would probably make it undetectable in pulsar timing data. But I'll look this up to be sure when I have more time. -|Tom|-

I thought you postulated that excess planetary heat came from nuclear fission or, especially, graviton absorption - not differential rotation.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by nemesis</i>
<br />I thought you postulated that excess planetary heat came from nuclear fission or, especially, graviton absorption - not differential rotation.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">If you read my chapter in "Pushing Gravity", you will see a table of excess heat sources and a discussion indicating that two heat sources are apparently required. The graviton one is proportional to mass, whereas the other component is proportional to surface area. I originally suspected meteors as the cause of the latter. But heating from differential rotation on gaseous bodies is another good candidate still being investigated, which does a better job of explaining Uranus. -|Tom|-