nick c wrote:...a star system composed of 20 or 30 stars all contained in the volume of a sphere with a radius comparable to Pluto's distance would be easily detected. Visual/telescopic identification is only one of several techniques used to detect multiple star systems, in fact most known multiple star systems were discovered through non visual methods.
Let's have a look at that -- if it bears out, it definitely spells trouble for the "stellar cluster" concept, but I'm not sure that the data can definitively rule out stellar clusters with 20~30 members.
In optical binaries, the stars are far enough apart that they can be resolved by telescopes, but they have to be very far apart, with orbital periods of decades or centuries. Jupiter's orbital period is 12 years, making it relatively close to its companion (i.e., the Sun) and difficult to resolve optically from a distance. So consider Betelgeuse, whose radius is greater than the orbit of Jupiter -- are we really sure that all of its light is coming from "one star" and not a cluster? Another method of detecting binaries is with Doppler shifts, where one component of the spectrum gets blue-shifted when a companion is coming toward us, and red-shifted when it is moving away. Detecting such binaries requires that they be extremely close to each other and extremely massive, such that the orbital period is extremely small, producing the extreme velocities necessary for detectable Doppler shifts. None of the planets in our solar system have the required velocities. Another method is observing gravitational wobbles, by which the presence of a dead companion can be inferred. But that requires that the extinct star be massive enough to cause a wobble big enough to be detected in the period of time since we've been making high-precision measurements. And it's an odd configuration, in which the more massive companion has already burned out. In the case of the Sun versus Jupiter, the primary star is still burning, and the companion
does generate a gravitational wobble on the primary, where the Sun moves a distance greater than its own diameter through the cycle, but that's a small wobble when viewed from Betelgeuse.
My take is that such methods can, in some cases, reveal that something that was previously considered to be a point source is actually a binary (or trinary, etc.), but if none of these methods can resolve companions, it doesn't prove that there is just one star.
Also, we have to test Stellar Metamorphosis with its own definitions, not with somebody else's. If you acknowledge that half of the stars in the Universe have been shown to have more than one point source, and that some trinary systems have been detected, but very few systems with more than three stars have been detected, while far more systems have been shown to host exoplanets, whose definition of "planet" are you using? You might be assuming the conclusion. If the definition of a planet is that it is something that inexplicably produces more heat than it receives from its nearby star, StelMeta calls it a dark brown dwarf star, and we already have plenty of evidence in hand for stellar clusters with more than 3 components.
And we should also acknowledge that IF the planets in our solar system were once more active, they didn't last long. Jupiter, with less than 1% of the Sun's mass, perhaps burned out 100 times faster. So if we're looking for similar systems elsewhere, we need to look for systems that are very early in their development -- after the star-forming implosion, and before the smaller components burned out, where the components were far enough apart to be resolved optically, or rotating fast enough to be identified with Doppler shifts, or massive enough to be detected by gravitational wobbles, and close enough to us for high-precision measurements.
My conclusion is that it isn't time to start ruling out possibilities.
nick c wrote:Anyway, if Jupiter and it's moons, Saturn and it's moons, Uranus and it's moons, Neptune and it's moons, Venus, Mercury, Earth, Moon, Mars, and maybe a few asteroids were all stars they would have shined as stars at different periods with perhaps millions of years separating their reigns (as suns). How did they get to orbit the youngest (the Sun) member of the group? Which probably had not even formed when any of the planets were stars.
I "think" that Jeffrey & I disagree on this -- I'm saying that everything in our solar system formed at the same time, from the same imploding dusty plasma, and that the smaller companions burned out faster. I "think" that Jeffrey has different components forming at different times, so stars might have more-or-less the same lifespan, and young ones are still burning, while old ones have already burned out, and are now dark brown dwarfs. But this begs questions concerning the forces necessary for star formation. In my model, it takes a lot of extra energy, stored in the momentum of the imploding dusty plasma, to fuse the matter into a star. So stars don't slowly accrete matter until they reach the critical threshold for ignition -- the matter has to be slammed together with a lot of force, and that would have happened only once for any given system.
nick c wrote:Maybe you better go with Jeffrey's explanation....capture. But that seems slightly ad hoc. Sure capture is a real phenomenon but using it to explain the present order of the solar system seems to require an unrealistic length of time.
I agree, and that, along with your comment about the ecliptic plane, are problematic for the Saturnian Theory as well. So while I allow the possibility of capture, I favor the single implosion concept.
Aardwolf wrote:CharlesChandler wrote:Maybe there's a limit to the number of stars that could be packed into something the size of our solar system.
There certainly is, and I would say it's roughly 1.
More than half of the known stars have binary companions. Nobody told them that we prefer fairly ordered stellar systems.
Anyway, my calculations with dusty plasmas showed that charged particles with atmospheres actually repel each other, since the bodies are negatively charged, and the atmospheres are positively charged, and this means that the nearest aspects of two bodies will be the positively charged atmospheres, which repel each other. (The atmospheres have to be stripped off to get a net attraction.) So perhaps the planets repel each other, meaning that you'll get a finite number of them in any given space. So how does that account for Bode's Law? Well, in the inner solar system, the Sun's gravity is a bigger factor, so the electrostatic repulsion has less of an effect relative to gravity, and there can be more planets packed into a tighter space. Further away from the Sun, gravity is less of a factor, so electrostatics becomes more influential, and you'll get fewer planets per volume. And at what rate does the Sun's gravity fall off? That would be the inverse of the square of the radius. And at what rate do the orbits increase in Bode's Law? That's a doubling function, so it's a logarithmic increase, just as you get a logarithmic decrease in gravity. I haven't run the numbers, but there is at least a possibility that the balance between gravity and electrostatics defines the number of planets allowed in any given volume. (Does that make sense?)