I think most people realize this is true on a gut level. It’s one of the few times gut feeling is right.

Gary 7

Jupiter, to take a random example, is certainly not in hydrostatic equilibrium – an
observation which can be made with a small backyard telescope.

“The law that entropy always increases – the Second Law of Thermodynamics – holds, I think, the supreme position among the laws of physics. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations – then so much the worse for Maxwell’s equations. If it is found to be contradicted by observation – well, these experimentalists do bungle things from time to time. But if your theory is found to be against the Second Law of Thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.” — Sir Arthur Eddington

My dad, who does some skeptic writing on the side, was forwarded this URL by a friend:

http://observer.guardian.co.uk/uk_news/story/0,,1854305,00.html

Now obviously, this guy is either deluding himself, or out to make illegitimate money.

The problem is that we can’t find a reputable source from JREF, CSICOP or CFI who takes this guy on. It’s hard trying to convince people that this guy is just another crank without good sources.

Is there any chance that you know someone who’s done a thorough debunking? If so, we would love to hear about it.

Thanks.

-Rob

For example, what exactly is meant by “nearly round?” The committee defines it as an object in “hydrostatic equilibrium” (i.e. its mass is sufficient for gravitational compression to overcome its material strength and force it into a nearly round shape). But where does one draw the line between an object that is in hydrostatic equilibrium and one that is just slightly out of hydrostatic equilibrium? If they haven’t done so already, astronomers will find borderline cases, so the decision whether or not to include certain objects as planets will be arbitrary.

Will they? Seems like the line drawn is hydrostatic equilibrium. Perhaps the question “how do we really tell if an object is in hydrostatic equilibrium or not?” Seems like there is a solid definition of a line, just the means to measure to that definition aren’t available.

The simplest way to define “planet” is to use Pluto as the minimum size of a planet, and state that any body found orbiting a star (or brown dwarf!) the size of Pluto or larger is a planet…. I freely admit that my definition is arbitrary, but I challenge anyone to come up with a less-arbitrary scheme.

But I think they have found a less arbitrary scheme! Either one proposed by the IAU now uses physical characteristics to make the determination, rather than an arbitrary size limit chosen around a previously made choice (i.e. Pluto).

What seems to be bothering people is that “planet” is such a simple word, somehow the Solar System fails to provide a simple classification system to go with it. Well, that’s reality. Reality is what it is. Science is in describing reality as it is, not making up a description and then telling reality to conform or be ignored. So what if there are now likely a multitude, perhaps uncountable and never certain anymore, number of Planets? Why do we need a nice countable number? Does that make you feel better, to “know” there are 8 or 10 or 12 planets and that’s it, the rest are something else, but clearly not “planets”?

We can talk about “Major Planets” and make kids memorize the Big 8. Or 9, and throw in Pluto for historical purposes. We can then later talk about the lesser known planets and the ongoing cataloging of the Solar System bodies, and breakdown the classifications to Terrestrial, Gas Giant, Icy; mooned and non-mooned; etc.

Thanks!