Sometimes, I look at the amount of wrong in a page of these texts, and despair of ever getting through it. But we can, and maybe we’ll even be done before the Sun expands into a red giant. And hey, along the way, we get to wear lots of hats. Today, we don our Astronomy caps and learn how much the creationists of BJU Press get wrong about the solar system.
First, the Earth Science 4th Edition authors present us with the old-earth people’s ideas. As I’ve mentioned before, it’s a very distorted view of them. And they don’t waste time trying to get it right. I’m wanting to tell them to either educate themselves on what secular scientists actually think, or get an actual secular scientist to write these bits in the future, but I know that won’t happen. They can only defeat straw scientists. So straw scientists they shall create.
Therefore, we’re treated to the creationist idea of the nebular hypothesis. They’re right that scientists in the 1700s began to think the Sun and its solar system may have formed from a cloud of gas and dust, but they’re kind of sneaky about implying the hypothesis hasn’t been updated since. It has, and research is ongoing. Way to try to deceive the kiddies, though.
They’re also careless with the facts. Yes, looking at planetary nebulae may have inspired our initial ideas about solar system formation. But our theory is far more developed now, and we know that many of those first clouds we saw are supernova remnants. That’s what real science does, creationists. It comes up with hypotheses, tests them, discards them as necessary, and uses the successful ones to build robust theories. Which, by the way, aren’t guesses. And science updates theories as needed when new information comes in.
The ES4 authors have a vague idea that gravity has something to do with it, but you quickly get the sense they don’t understand how gravity works. They think that gravity pulling the solar nebula’s dust grains together and thus making the cloud denser caused the initial rotation. But the spin was already there – solar nebulae already have some angular momentum. To use the famous ice skater example, the skater already has to be rotating for them to increase their spin by pulling in their arms. Just standing on the ice and drawing their arms in won’t do it.
The famous ice skater analogy, by the way, is never mentioned. Maybe it’s because lady figure skaters aren’t modest and the boys are too sparkly. Can’t have kiddos getting any ideas outside their restricted gender boxes, now.)
We’re told we secular science types believe all this condensing forms a solar disk. They don’t actually know what a solar disk is. It’s just the face of the sun.
What they seem to be confusing it for is the protoplanetary disk.
Anyway. They continue ‘splaining what they think we think. In their telling, mysteriously, “dust and gas” at the center of the disk “become very dense. The immense pressure there formed a star, and it began to shine.”
These people have too much pressure on the brain. They’re always on about pressure. Geez. The pressures within the center of the disk aren’t compressing things, they’re trying to expand them. If it were up to pressure, we wouldn’t have anything more than a diffuse gas cloud. ‘Tis gravity forms the star. Gravity causes the initial heating: gas falling into the core of the embryonic star releases kinetic energy. And yes, pressure will become a factor, as the wee protostar (only a fraction of the mass it will be when it’s all growed up) continues to grow. Once it achieves a certain density, infrared radiation can’t escape (a sort of greenhouse effect) and it gets hotter, and yes, pressure in the core increases. But that pressure actually stops more stuff from becoming the core. Meanwhile, in the outer envelope where pressure’s not so high, gravity continues pulling matter in. And because angular momentum is conserved, the rest of the cloud is spinning faster than when it was all spread out and diffuse, and the gas and dust forms a disk (not a solar disk! A solar nebular disk, aka accretion disk. They mean different things!). That disk continues to to feed matter to the protostar due to the protostar’s gravitational attraction, until there’s enough heat and pressure in the core for nuclear fusion to begin. What happens after is a bit messy, with accretion and stellar winds and hot jets of matter and maybe even planetary formation and things but in the end, you’ve achieved a bright young star, and possibly a solar system in the bargain.
As we can see from this brief foray into stellar formation, the ES4 folk really haven’t got any idea how secular astronomy actually works or what non-creationist scientists know about it. And it’s only going to get worse when we see how they butcher planet formation.