Podcast Episode 89: Remaining Issues with Lunar Formation, Interview with Robin Canup

What are the problems
With current models of the
Earth’s Moon’s formation?

Another slightly late one, this is the long-anticipated “what’s left in lunar formation?” episode, a follow-on to Episode 53: Lunar Formation and Origins, put up almost exactly one year ago. The episode is an interview with a leading researcher in the field, Dr. Robin Canup, and it’s about a half hour long.

The next episode is still slated to be about the claim that alleged UFO-contactee Billy Meier knew about Jupiter’s rings before scientists did. I expect the comments on that post might fill up, but I’ll note now that no comments to THIS blog post will be allowed on IF they are about Billy Meier material UNLESS they are a suggestion for a puzzler. Generic Meier conversations will be allowed on the next post about Episode 90.

Also, I’m starting to roughly plan out Episode 100. If you have Skype and are good at making stuff up for a few minutes that’s related to anything discussed so far on the podcast, please let me know and you might get on the first three-digit episode.

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Talks at Science Conferences Doesn’t Mean They’re Science

Introduction

My work load is starting to diminish from the 80 hrs/week as I prepare to head off to, um, “lovely” Houston next week for a conference on Early Solar System Bombardment (as in big chunks of rocks hitting other, bigger chunks of rocks).

The small conference – such that it’s called a “workshop” officially – has all the abstracts posted online, and I was browsing and downloading them today. I then came across abstract #4008, entitled, “Questions About Lunar Origin.” It’s by Fred S. Singer, and he’ll be talking about it on Wednesday evening during the poster session.

Innocuous Title

The title itself is fairly innocuous, and scientists know that there are questions about how the moon formed the way it did. Of course, if this were like “Intelligent Design” and their “teach the controversy,” then Singer would likely advocate teaching students that there is just as much evidence that the moon was (1) captured, (2) formed in Earth orbit originally, (3) was flung off Earth, (4) was formed when a Mars-sized object hit Earth, or (5) was put here by space aliens.

But I get ahead of myself.

Reading the Abstract

First off, the abstract is not in standard format. Almost all the rest of us put our abstracts in the same, required format by the conference, but there are always some people who think they’re special and don’t have to do what the rest of us do. But I’m not bitter or anything.

The abstract, I think, can be classified as a rant. The first three paragraphs read like a “Woe to the people who accept the impact hypothesis of lunar formation, but if you do …”

The remainder is a list of “12” questions that actually have many questions within them where he basically shows that he does not know how science operates. They read like “… well how do you explain THIS?! Huh!?”

I’m not going to bore you with reiterating everything from his two-page abstract, but I want to point out a few examples just to give you an idea of how pseudoscience works. This is really one of the first very clear-cut examples I’ve seen where someone is arguing about astronomy who is not a creationist in a very creationist way – by pointing out examples of apparent contradiction or lack of consensus in the literature as a way to argue that it’s all wrong, no one knows what they’re talking about, therefore he’s correct.

Example 1

3. At what stage of terrestrial accretion does the hypothetical impact occur? Early or late? Different papers give different answers.

4. What is the mass of the impactor? Twice lunar or more like that of Mars? Different papers give different answers.

These “two” questions are clear examples of, first, not citing your sources (he refers to “different papers give different answers” but he does not give those different answers nor does he list those different papers). Second, it’s pointing out what could sound like major issues to someone who does not know about the subject, but to those that do, it just seems silly.

For #3, the answer is “we don’t know” but we do have constraints. Dating of lunar rocks puts the moon’s formation at no later than 4.527 billion years ago (source). The age I’ve seen for Earth is about 4.54 billion years old (source). Quibbling over whether this was early or late-stage terrestrial accretion (when the planets formed) to me does not seem to actually be an issue in the literature. Hence why it’d be nice to see his “different papers.”

For #4, the canonical mass I’ve always heard is “Mars-sized.” Mars is about 45% the diameter of Earth, while the moon is around 25%. If they were the same density (they’re not), then the mass difference would be the ratio of their diameters cubed (0.45/0.25)^3 ≈ 5.8x different). Mars is actually 10.7% the mass of Earth while the moon is 1.2% Earth’s mass … meaning that Mars is 8.7x the mass of the moon.

Fred is arguing that the factor of 4.4x in range (2x Moon to 1x Mars) is apparently a major issue here. It’s not. There is absolutely no way to know the mass of the original impactor. The range comes about because of different potential impact models (I assume … if I had his “different papers” then I could look). If you have a different velocity or impact angle, you need a different initial mass. If you have a different initial mass for Earth, you’ll need a different mass for the impactor. A difference of a factor of 5x does not seem to me to be a deal killer.

Example 2

6. What happens to the splashed-out material from the impact; how many particles escape and how many return on ballistic orbits? Whence comes the angular momentum for a bound lunar orbit? How and where does “captured” material assemble and what exactly is the initial lunar orbit?

Asking “this” question is missing the point. Dr. Singer has had a varied career in science over the years, but from reading this question I doubt he’s ever done any N-body modeling (the kind of code where you have many particles and you simulate how they interact). If he had, then the question about “how many particles escape” is nonsensical. For example, if you had a simulation with 1 million particles and 10,000 escaped and 50,000 returned on ballistic orbits and the rest did something else, then I just gave you the numbers there. But then if you ran a simulation with 10 million particles you’ll get a completely different answer. Maybe he means “how many” in terms of a fraction?

The “how and where” of the moon’s formation in the impact hypothesis is a head-scratcher. The answer has pretty much always been that it “assembles” in orbit of Earth, actually fairly close to the planet, and the “how” is through normal processes of agglomeration (stuff hits other stuff and sticks).

The exact initial lunar orbit is kinda like a creationist asking, “What was the exact functionality and makeup of the very first cell?” We don’t know, but we can make educated guesses based on modeling and observations of what we see now. He’s asking unanswerable questions in their specificity, but ones that have been answered to most peoples’ general satisfaction.

Final Thoughts

The point of this post is to teach a little astronomy while also pointing out, as the title suggests, that presence at a science conference does not mean what you’re doing is science. Creationists actually have a habit these days of going to geology conferences, presenting something, and then coming back and saying, “See! We presented at a scientific conference even!”

Similarly, this is not to imply that there are no questions about the moon’s origin (as I mentioned above), nor observations that do not fit with the “Big Splash” model that is currently in favor. If you want to bring those points up, that’s fine. But going back and asking questions that are already answered, or cannot possibly be answered to your desired specificity, is not the way to argue your case.

And look, I got through that entire thing without mentioning that Dr. Singer is also a climate change denier.

Update: Singer was the only person to present today who was a no-show. No him, no poster.

Should the Public Be Able to Choose What Science to Believe?

Introduction

This blog post is about a statement made by Dr. Caroline Crocker on the ID The Future podcast episode from July 12, 2010, entitled, “Setting the Record Straight with Caroline Crocker.”

Got that straight? This is NOT about the Intelligent Design movement, it is NOT about evolution versus creationism versus ID, it is NOT about the movie Expelled, nor is it about Caroline Crocker.

Setting Up the Question

In the podcast episode, Dr. Crocker made an off-hand remark (starting about 7 min 15 sec into the episode):

“I also believe that freedom, which is foundational in our society, requires people to have choices. And if people are not given options – that is they’re not told the whole scientific truth in as much as they can understand it and most people I find can understand if you just explain – then they don’t have any choice! And I think it’s very important that people are given complete explanations, and that’s actually one reason I set up the American Institute for Technology and Science Education, so that people would have an opportunity to hear scientific options and to have a choice.”

That’s a long paragraph, about 30 seconds of speech, but what it really boils down to is this: Dr. Crocker thinks (based upon my understanding of what she stated) that people should be told the entire body of science behind something (i.e., she obviously is talking about evolution, but it would extend to any science). Once they are told this, which she believes they can understand, then they should be allowed to make their own choice about what they want to believe.

Hence the title of this blog post: Should the public be able to choose what science to believe?

An Example

I have perhaps written the title in a confrontational manner, more-so than need-be. I’m not trying to set up a post where I say that scientists from on high should pass down edicts of what is Truth and those must be followed without question. What I am asking, rather, is if the lay, non-scientifically trained public are in a position where they can make an educated opinion on a technical subject after being explained the basics for a few minutes.

Let’s have an example, and since this is an astronomy blog, we’ll take an example from astronomy. Let’s take Earth’s moon and how it may have formed.

Decades ago, the original theory (yes, I’m using that word correctly) was Earth’s moon formed the same way Earth did, in Earth’s orbit, from the solar nebula. But that had problems with it (like it couldn’t explain the composition differences). The second theory was it got captured, as we think Mars’ moons were captured and many of the giant planets’ moons were captured asteroids. But that has problems because there’s no good way to get rid of the extra velocity. The third one, this time I’d classify as a hypothesis, was the “fission” idea where Earth was spinning really quickly and it basically spun off the moon out of the Pacific ocean. This, however, required a ridiculously high spin rate and didn’t take into account plate tectonics.

Finally now we have the fourth theory that is pretty well established and has been nick-named, “The Big Splash.” This is where a Mars-sized impactor hit Earth early on, nearly destroying Earth, but throwing up a debris cloud that formed the moon in Earth orbit. This explains almost all the characteristics we observe of the moon.

But last year another hypothesis was proposed, one that some people have termed, “The Big Burp” (yeah, astronomers are real creative … everything is the “Big” something). The idea here is that, deep inside Earth’s mantle, a buildup of radioactive material suddenly went critical and there was a spontaneous nuclear reaction, blowing out a chunk of Earth that formed the moon. Kinda similar to the fission idea, but a different mechanism for the moon’s ejection.

As anyone who reads my blog semi-regularly knows, I just finished teaching an introductory astronomy class for non-majors. This was a solar system class, and we discussed the formation of Earth’s moon in about a third of a class period. I briefly went through the historic ideas and the problems with them in order to show why we think the “Big Splash” is the best model. I didn’t go into the “Big Burp” at all because (a) it is a very new proposal, and (b) it was published in a low-review journal after being rejected from mainstream ones.

When discussing all these different formation models, I didn’t go very deep into them. I explained them in about as much detail as I did above, with basically a one-sentence description. Then I went over some of the pros and cons for each. And when we got to the Big Splash, I said that this is the one that happened, this is THE way the moon formed, and they all scribbled it down, stared blankly, were dozing on their desks, or trying to hide that they were txting on their cell phones.

If Dr. Crocker’s position is to be carried to this, and I believe whole-heartedly this is what she is arguing, then I did my students a disservice. I should have gone into equal detail for each proposal. I should have explained thoroughly the pros and cons for each. I should definitely have included the Big Burp. And when all was said and done, after spending 45 minutes going through these, I should have said, “Now you have the information, it is up to you to make up your own minds as to what happened and how the moon formed.”

That’s right. Without any of the theoretical backing, without an understanding for three-body dynamical systems (problem with Theory #2), without an understanding of chemistry and mineralogy (problem with #1, #3), without an understanding of basic Newtonian mechanics and material strength (problem with #3), or nuclear forces and the structure of Earth (problem with #5), after explaining to the students the basics of each I am supposed to let them make up their own minds.

My Thoughts

I think if you have much perceptive ability you can tell what I think the answer should be to my rhetorical question based upon my last two paragraphs. Scientists in any given field of study will reach conclusions about their field based upon an thorough understanding of the data, an understanding that pretty much can ONLY come with studying it for years and years. No research field exists in a vacuum (despite what some “amateur scientists” will claim), and you have to have a lot of background information from a broad base before you can actually understand a problem.

As a planetary scientist, I have a broad, 10-year background in physics, geology, and astronomy, and that background allows me to make an informed conclusion about the state of the science and which lunar formation proposal is the most likely to represent what really happened. If it were almost any other field, I wouldn’t even go into the historical ideas, I would just jump in and say, “The ‘Big Splash’ is how the moon formed” and then explain what that means (teaching astronomy is rather unique in the sciences because we do A LOT of history of the field). But, if we were to extend Dr. Crocker’s thoughts to a field other than evolution (which is obviously what she is talking about), then I would be infringing upon my students’ right to make up their own mind without my influencing their decision.

Okay, a Teensy Bit of Ridicule

I was trying to be fairly objective and ignore evolution etc. in this, but I think I really should at least mention the whole larger context for this and the obvious case to what Dr. Crocker wants this to apply. Dr. Crocker appears to be an avid advocate for the whole “Teach the Controversy” when it comes to teaching evolution. She thinks that students should be presented with evolutionary theory at the basic level that they already are, but then also taught the problems with it that are normally not talked about until you get to a graduate level of study. The reason for the normal delay in teaching the problems is that they are minor problems on the more fine layers of evolutionary theory. For example, we know that the large cake of evolution is perfectly fine and holds its own, it’s a question then of if there are ripples in the icing on top that can’t be smoothed away yet. Anyway … besides teaching evolution and its problems, the whole other side to “Teach the Controversy” is that there should also be an equivalent amount of time devoted to intelligent design and creationism since they also have something to say about how different species came about. And then the students should be able to decide themselves what to believe.

It would be the same as with my moon example: I explain each hypothesis and also throw in that on the third day God created the moon by magic (Genesis 1:16). And then let them decide, and on the test when I ask them, not count any response wrong.

I gotta say, I think that’s silly. And it’s irresponsible. And it does the students a disservice because it makes them think that all ideas are equal, when in fact they’re not. The reason the majority of scientists who study this think that the moon formed in the “Big Splash” is because it best explains the observational evidence without resorting to something supernatural/alien/whatever.

Final Thoughts

So, does it make sense that the public should have all sides explained to them equally, assumed they understand them and all the background, and then allowed to make up their own mind and have it be just as valid a conclusion as anyone else’s? I think when you actually look at the issue in this way, fully exploring the consequences of the proposal, then the answer is reasonably obvious, and it is a resounding, “No.”

But when simply phrased in a, “let’s give people options because that’s what a free society does,” it seems so deceptively simple. Until you follow through with what it actually would mean.

I think I’ll close with a statement my former officemate made that I have repeated several times on this blog: Science is not a democracy, it is a meritocracy. Only the best ideas survive because they become the most widely accepted because they convince people who know how to understand the idea through their ability to explain the observational evidence.