(Tier 1) Adventures in Christianist Earth Science Education XXVIII: Wherein We Experience Astronomical Buffoonery

Last time, we watched the Earth Science Fourth Edition authors butcher the birth of the solar system. They’re so very bad at telling the secular story, but bless them, they’re trying. We left them just as our Sun began to shine, and planetary potential swirled around it. Let’s watch as they continue to mangle the secular science story.

Gravitational attraction starts clumping matter into wee little proto-planets in what’s left of the protoplanetary disk. Of course, the disk is still turning. That original spin (ha) has translated into rotation and orbits and such. We know that a star’s going to suck up most of the gas in the inner solar system, leaving the planets closest to it rockier than the ones further out. These are the basics, and ES4 gets those basics basically right.

But then they claim that we claim that “other planetesimals were captured by planets as moons.” LOLWUT? They sound like we think that’s the only way for moons to happen. But in the case of our lovely gas giants, we know some of their moons couldn’t have been captured, but had to have formed from amterial orbiting the giants in rings. Other moons, like ours, formed from collisions. What’s the difference? The material thrown up by a collision contains a lot of rocky debris, but not a lot of gas, while the stuff orbiting the giants contains plenty of gas. Therefore, we see moons around the giants that are far more gassy than ours.

The ES4 folk do okay explaining the early eons of the earth, with planetesimals colliding to form a big molten ball, and then getting hit by yet another planetesimal 30-50 million years later, which impact left a lot of debris that later became the Moon. Oh, so they do know we know there are many ways for moons to form and get captured!

They manage to understand that the oldest rocks are around four billion years old, and comets delivered water to our young planet and added gasses to its protoatmosphere. Having managed to keep hold of a few fragments of reality, they now lose their grip. There are problems with this model, they wail! It doesn’t explain everything 100% perfectly! Look at all these problems!

  • The sun rotates too slowly for the amount of matter it has if it were formed from a nebular disk.

Oh, look, they stopped calling it a solar disk, good for them. That’s about the only thing they get right. Remember those jets of material that stream out from the protostar? They take angular momentum with ’em. And then there’s magnetic braking and stellar wind to remove more. Not a problem.

  • Mercury is too dense to have formed by a gradual collection of matter. It also has a magnetic field, which secular geologists believe comes from a liquid core. But because of the planet’s small size, Mercury’s core should have solidified long ago.
Image shows a false-color photograph of Mercury in lovely shades of blue and gray and orange and white. Its floating on a black background. Caption says, I'm dense. But not as dense as creationists.
Meme by moi, Mercury courtesy NASA. Click here for a really neat explanation of the photo.

So, Mercury is very dense, yeah, but form by a gradual collection of matter it very likely did. It’s very close to the sun, and we’ve found rocky exoplanets that are like it: iron-rich and close to their star. That implies something natural’s going on, and it is, and it’s neat. Y’see, the Sun’s illuminating one side of a particle rotating around it. If that particle conducts heat well, one side won’t be cooler than the other. If it doesn’t conduct as well (like silicates), there’s a small difference between one side and the other. Now, you’ve got excited molecules in the nebular disk whapping into the particles. There’s some temperature equilibriation before the molecule is ejected. If one side of a particle is hotter than the other, the molecule will sort of push the particle away. That means that low-conductivity materials like silicates will be “pushed” further and faster, while metals like iron take longer for that “pushing” to happen. That difference is enough to leave an overabundance of metals close to a star. Since that’s what was available, that’s what Mercury formed from. Simple!

As for that core… dudes, it’s not pure iron. It has got sulfur. Sulfur lowers the melting point of iron. We also know from the Messenger mission that it has positively definitely got a liquid outer core (with a weird solid bit on top). I’m afraid that’s reality, and you shall just have to deal with it. Not that creationists are particularly good at that.

  • Venus rotates backwards compared to the direction it should rotate according to the model.

Just because things start in one direction doesn’t mean they’ll keep going that way. We don’t have all the answers yet, but plenty of things could get Venus spinning backwards. There’s collisions, and that fabulously thick atmosphere leads to some very interesting tidal effects. It’s not like spin is set in stone for a planet. Chill.

  • The planet Uranus is tipped over on its side.

Okay. So? The early solar system was a crowded place. Lots of planets got hit hard. Uranus probably got walloped a good couple-few times. Simulations show a few good whacks is all it takes to get it and its moons moving the way they do.

  • Uranus and Neptune shouldn’t exist. They are too large and too far away from the Sun to form within the model’s timeframe.

Sigh. You seem to think the planets are and always were restricted to their present orbits. They weren’t. Uranus and Neptune formed closer in before moving out to their present spots. There’s been plenty of time and material available for ’em.

  • The probability of a collision forming our moon with its unusually ideal size and orbital properties is so low as to be non-existent (see Chapter 4).

Awwww, the puddle’s amazed the hole it’s in is exactly its shape! How adorable.

Image shows a picture of a puddle of water in a pothole eroded into a gray schist creek bed. Beside it is a quote from Douglas Adams: “This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!'"
How adorable. Also: your probabilities are wrong. And even if the probabilities are low, even if it’s one-in-a-billion rather than 1 in 45, there’s a ginormous old universe out there. Bound to have happened more than once. Besides, moons like ours may not be necessary for life to arise and thrive. And if a Moon is a boon to life, well, no surprise that life evolved on a planet with such a moon, now, is it?

  • Almost any imaginable collision of another planet with the earth would have left it wobbling.

Oh, hey, good thing that collision formed a moon that stabilized it, then!

This section ends with the writers fretting about how we secular science folk modify our models and live with contradictions because we’re clinging to our worldview. Projection much? Yep, it’s true. We’re always tinkering and adjusting and sometimes coming up with entirely new models. That’s how our knowledge advances. We don’t know everything yet. We’re discovering new stuff every day. And sometimes we have to change our models because of that! It’s what makes science so exciting.

Now, the young earth creationist writers of ES4 would have you think their model’s better, and doesn’t require all that nasty modification. We’ll investigate whether that’s true next time. (Spoiler alert: it’s totally not true.)

(Tier 1) Adventures in Christianist Earth Science Education XXVIII: Wherein We Experience Astronomical Buffoonery