mersenneforum.org (https://www.mersenneforum.org/index.php)
-   Astronomy (https://www.mersenneforum.org/forumdisplay.php?f=142)
-   -   10th Planet Discovered (https://www.mersenneforum.org/showthread.php?t=4429)

 jinydu 2005-07-30 04:23

10th Planet Discovered

[url]http://www.msnbc.msn.com/id/8760309/[/url]

If you visit Brown's website, you should find something not in the article...

 Numbers 2005-07-31 07:40

I guess that depends on how you define a planet. The guys trying to do just this have been hard at it for 5 years without arriving at any consensus, so it would seem that despite what we might intuitively feel is the definition we would almost certainly be wrong.

Two things about this interest me though. The article says the plane of its orbit is at about 45 degrees to the rest of our planets, which would seem to imply that it must at some point cross the orbit of our planets, though a long way out. Also, does its distance from the sun fit in with the pattern of the others. I read somewhere that our planets are spaced at distances from the sun that are Fibonacci numbers of AU. Is that correct and does this new object fit in with that?

 jinydu 2005-07-31 08:55

[QUOTE=Numbers]Two things about this interest me though. The article says the plane of its orbit is at about 45 degrees to the rest of our planets, which would seem to imply that it must at some point cross the orbit of our planets, though a long way out.[/QUOTE]

Actually, many scientists do not regard Pluto as a planet; and one reason is that the plane of Pluto's orbit is also inclined relative to the plane of the 8 "surefire" planets. However, this new "planet" is even more inclined.

[QUOTE=Numbers]Also, does its distance from the sun fit in with the pattern of the others. I read somewhere that our planets are spaced at distances from the sun that are Fibonacci numbers of AU. Is that correct and does this new object fit in with that?[/QUOTE]

I thnk I know what you're thinking of. Until the last few centuries, only 6 planets were known: Mercury, Venus, Earth, Mars, Jupiter and Saturn.

Today Kepler is mainly famous for his observation that planetary orbits are elliptical, rather than being made up of perfect circles. However, he also had other ideas about the solar system that are no longer taught today because they have turned out to be wrong. Being a strong believer in the "perfection of the heavens", Kepler developed a model of the solar system based on the five Platonic Solids. He imagined that the orbit of each planet contained inside the surface of spheres, which were nested inside Platonic solids.

Even with the limited (by modern standards) technology of his day, it was clear to the scientists of Kepler's day that this model of the universe was severely flawed, since it didn't fit observations particularly well. The correspondence between the ratios wasn't very precise. Although, Kepler attributed the "pattern" to divine intervention, we now know that it is due mainly to chance. In short, if you stare at a collection of data for long enough (especially a small collection of data), you can always "discover" a pattern.

 trilliwig 2005-07-31 11:12

Actually, it sounds like [URL=http://en.wikipedia.org/wiki/Bodes_law]Bode's Law[/URL], which "predicted" the existence of the asteroid belt. By that rule, Pluto should be the 8th planet (Neptune doesn't fit in at all), and the 9th planet should be around 77.2 AU from the sun, which doesn't fit especially well with 97 AU.

[quote=Numbers]The article says the plane of its orbit is at about 45 degrees to the rest of our planets, which would seem to imply that it must at some point cross the orbit of our planets, though a long way out.[/quote]It must at some point cross [i]the plane of[/i] the orbit of each other Sun-orbiting object, but that's true of all the planets, asteroids, comets, etc.

[quote]does its distance from the sun fit in with the pattern of the others. I read somewhere that our planets are spaced at distances from the sun that are Fibonacci numbers of AU. Is that correct and does this new object fit in with that?[/quote]Bode's Law, AKA Titius-Bode Law, is an example of the Strong Law of Small Numbers ([url="http://mathworld.wolfram.com/StrongLawofSmallNumbers.html"]http://mathworld.wolfram.com/StrongLawofSmallNumbers.html[/url]). As jinydu explained, Bode's (or Titius's or Christian Wolff's) formula has no real basis in physics.

 battlemaxx 2005-08-02 19:46

What should they name the new planet? How about "Bob"?

:banana:

 trilliwig 2005-08-02 20:55

I'm partial to Persephone. Doesn't quite roll off the tongue the way "Bob" does though.

 JuanTutors 2005-08-03 05:31

Did anyone hear that the minimum size of this rock is actually bigger than Pluto? If you call Pluto a planet, then you have a really hard time not calling this thing a planet. (Think size; orbit eccentricity, orientation; .....)

 jinydu 2005-08-03 12:02

Perhaps another possibility is to eliminate the term "planet" from science altogether:

[url]http://www.space.com/scienceastronomy/050802_planet_definition.html[/url]

And it looks like Brown's webpage has undergone a major update:

[url]http://www.gps.caltech.edu/~mbrown/planetlila/index.html[/url]

 Jwb52z 2005-08-03 13:33

[QUOTE=dominicanpapi82]Did anyone hear that the minimum size of this rock is actually bigger than Pluto? If you call Pluto a planet, then you have a really hard time not calling this thing a planet. (Think size; orbit eccentricity, orientation; .....)[/QUOTE]

Actually many scientists think it is almost impossible for this planet to be bigger than pluto due to other details about it.

 jinydu 2005-08-03 14:18

[QUOTE=Jwb52z]Actually many scientists think it is almost impossible for this planet to be bigger than pluto due to other details about it.[/QUOTE]

Do you have a link? Brown is sure that this object is bigger than Pluto.

All times are UTC. The time now is 00:39.