After all ES4’s introductory nonsense about operational vs. historical geology, it’s nearly a relief to get into a discussion of the earth’s structure. However, seeing all seismic waves defined as sound waves rather curbs any enthusiasm: they’re their own things, people, even if p waves share sound wave characteristics.
It’s also not pleasant when we discover they think seismic waves slow down at the Moho. They, in actual fact, speed up, from about 6 kilometers per second to about 8 kilometers per second. These aren’t negative numbers, BJU people. Larger is faster, just like on your speedometer. Sheesh. I’m beginning to think you know nothing of seismic waves. (Also, you’ve made the average crustal thickness too thick by about 20 kilometers, FYI.)
They do a ho-hum job explaining matters from the asthenosphere to the core, skimming details or omitting them altogether in a way that makes me suspect they have little idea what they’re talking about. Then, when we reach the core, it just gets weird. Despite the fairly firm grasp we’ve got on the properties of it, they act as if geologists just throw up their hands and exclaim, “Can’t nobody know what that’s like!” Sure, it’s hard to imagine the immense temperatures and pressures down there, but that’s what science is for. Do a search on Google Scholar, and you’ll find plenty of papers talking about it. There are lots of lines of evidence that have led to our current knowledge of what the core is like, and although there are many blanks to fill in, the outline is pretty solid. So all this “Many geologists don’t even try to guess what the core material is like” and “We cannot imagine” and “geologists believe” the outer core is liquid and the inner is solid – all that’s just the creationist way of throwing out massive chaff in hopes of confusing their students. What the students will find, if they look beyond their appalling education, is that we do try and can imagine and are, actually, pretty damned sure we know a thing or two about the earth’s core.
Wondering why creationists are so desperate to deny what we know? Me, too! The clue is in the following paragraph: Continue reading “Adventures in Christianist Earth Science Education XXI: Wherein Seismology is Annoyed, and Extinction is In”