Magnetic field of
Mercury: Has it decreased
Or just stayed the same?
It’s a bit of a nuanced topic, since, to understand it, we have to get into magnetic fields and how you measure them around planets. Hopefully my squishy water balloon analogies make sense.
It’s a bit of a shorter episode, three days late, but I’ve been pretty busy catching up with work that I let slide while I was working on the Cydonia movie.
Oh, and the logical fallacies in the episode are: Cherry picking, and quote-mining.
An interesting thing that happens when you’re defending your thesis and consequently not blogging for a few months is that other blogs can crop up that tend to cover similar material. In this case, there is a blog entitled, “Eye on the ICR” run by a high school student from New Zealand. Ah, if only we had blogs back when I was in high school … though I probably wouldn’t have been writing against creationism as my topic of choice.
Anyway, this New Zealander seems to take great delight in ripping to shreds the news postings by the Institute for Creation Research (ICR) writers. Much as I do. Unfortunately, he’s posted his before me! (And I couldn’t find his name on the site, so throughout this post, he’s the “high school student.”)
Whatever … he’s still a high schooler, I’m a Ph.D. astronomer. Hopefully I can add something to the conversation he started. We’ll see.
This post is yet another about the “science” writer, Mr. Brian Thomas, and in this case his ICR article, “Messenger Spacecraft Confirms: Mercury Is Unique.” First off, the name “MESSENGER” is an acronym that stands for “MErcury Surface, Space ENvironment, GEochemistry and Ranging.” In other words, you need to capitalize it, unless you’re writing for the BBC which doesn’t seem to capitalize acronyms. Ah, we’re off to a good start.
After the title, Mr. Thomas does his normal routine of spending a paragraph or two (in this case one) giving some very brief background about the subject. It’s okay, something you’d get in a normal news article but which most third graders know.
Then we get to the line that those who are familiar with young-Earth creationist (YEC) writings know is the kicker: “Mercury possesses unique characteristics … clues point in the opposite direction to what astronomers expected.” Yes, that’s right, because something is not exactly as a model predicts, God did it. That’s basically what the remaining six paragraphs say.
The third paragraph presents Mr. Thomas’ first problem-of-choice: Mercury’s high density and large core. The issue is that Mercury does have a high overall density. In fact, it is the second highest of any planet at 5.43 grams per cubic centimeter (water = 1); only Earth is more dense, at 5.52. But, Mr. Thomas quotes Spike Psarris from 2004 claiming, “according to naturalistic origins models, ‘Mercury can’t be anywhere near as dense as it actually is.'”
For my very loyal readers (hi Joe, Susan, Karl), you might remember that I discussed Spike Psarris twice (here and here) in ripping apart a 12-minute video segment he produced on why Jupiter needs God to have created it 6000 years ago.
In skepticism, we often give YECs and Intelligent Design (ID) proponents the proud title of the best examples of quote miners. In this case, a creationist (Brian Thomas) is quote mining another creationist (Spike Psarris). Spike does indeed say that in his 2004 article. But he actually goes on to explain that we have a perfectly reasonable natural model for how Mercury got as dense as it did. Granted, Spike in his own special way then tries to rip it to shreds through an argument from personal incredulity, but that’s somewhat beside the point for this post.
For those wondering, the “evilutionist” way of explaining this is that Mercury was involved in a massive collision early in its history that stripped away all of its crust and a large portion of its outer mantle, leaving behind the core of an originally much larger planet along with some mantle material. We know that these kinds of large collisions happened in the early solar system, there is an enormous amount of evidence for that, so it is perfectly plausible that this is what happened on Mercury. Despite what Spike says.
Paragraph four of Mr. Thomas’ article states, “assuming that the planet formed naturally and close to the then-forming sun, lighter-weight elements like sulfur should have been ‘lost in space,’ … and yet Mercury has ‘high levels’ of sulfur.” Hmm. I guess that means evolution can’t be true and God created everything 6000 years ago.
As with pretty much the rest of this article – and I’ll just point it out here for the time-being – Mr. Thomas does not actually make an independent argument for a 6000-year-old universe created by God. He simply tries to cast doubt on his own – highly limited – understanding of planetary astronomy. Anyway, moving forward …
Yes, one of the interesting discoveries of MESSENGER is that it detected high levels of sulfur on Mercury. And yes, Mercury likely formed close to the sun, well inside the temperature line where we would expect lighter elements and molecules to be gaseous and not condense and be incorporated in large quantities into forming planets. Except, well, obviously they did. And there are numerous ways of getting them to these planets — remember I talked in the last section about lots of massive collisions? This is the way we think Earth got most of its water.
Paragraphs five and six talks about the magnetosphere of Mercury:
In the Space.com Q&A, Solomon commented, “I’m now fascinated by the magnetosphere.” And it is small wonder that he is, because for many years the “dynamo theory” (which has since been shown to be false) was the only explanation offered for magnetic fields on rocky planets that are supposed to be billions of years old. However, this theory requires a molten magma core. And Mercury is so small — only slightly larger than the moon — that its core should have cooled into a solid millions of years ago. Therefore, it should not have a magnetic field at all … . And yet it does.
Messenger’s new magnetic measurements fail to explain why Mercury has a magnetic field. Instead, they add ammunition against a naturalistic origin for the planet. Scientists did not expect to discover that Mercury’s magnetic field is lopsided, but the 2011 Messenger data showed that it is stronger in the north than it is in the south. What natural process would cause that?
I actually want to disassemble the second part first, in that the “magnetic measurements fail to explain why Mercury has a magnetic field.” As a science writer, Mr. Thomas should know that measurements (data) do not explain anything. Data are data (“data” is the plural form of “datum”). They have no explanatory power in and of themselves, the data simply are what they are. It is how the data fit into models that will then support or refute them.
Further, on the lopsidedness of the field. I know I’ve said this before, but for new readers and returning ones who like the reminder: That’s what science is!! We want to find something we can’t immediately explain because that means that we can then go try to figure out why it is the way it is! It’s only YECs that don’t want anything that doesn’t fit with their own Goddidit model because that would mean that, gasp!, maybe goddidn’tdoit. In fact, Mr. Thomas, in what is obviously meant to imply that goddidit, asks the exact question that I’m sure that mission scientists are trying to answer: What process causes a lopsided magnetic field?
Okay, back to the first paragraph quoted above. I’m not even sure I really need to go into this too much. Suffice to say, yes, the fact Mercury has a strong magnetic field was a surprise when it was discovered, and it is actually one of the main questions that drove the MESSENGER instrument suite choices that will try to gather the data that will be used to test and further develop models to explain why it has an active magnetic field. Obviously, ongoing scientific research is just too much for Mr. Thomas to handle, though, because he clearly wants these observations to force us evolutionary astronomers (I still don’t understand what evolution has to do with astronomy) to throw up our hands and admit that his God did it.
Oh yeah, and the whole “dynamo theory which has since been shown to be false” is him blowing out his you-know-what. That’s about the only outright lie I came across in this article.
I’m not sure what it takes to be a science writer with ICR. I actually looked over their site for a job description or any information related to jobs, and all I found were bible versus from the Book of Jobs. Go figure. Regardless, I don’t think the requirements can be much, especially any knowledge of science. In the next-to-last paragraph, Mr. Thomas clearly shows his ignorance: “If nature formed the planets from the same cloud of space debris, then why are they not uniform in constitution, orientation, and placement?”
I have explained to 6-year-olds why there are differences in objects in the solar system even though they formed from the same “cloud of space debris.” And they understood it. (One of the big reasons is that, as the sun heated up, it caused a temperature gradient in the cloud that resulted in significant compositional differences in the inner and outer solar system.)
Mr. Thomas, please, do your homework next time. And by that, I mean read something other than the bible or Spike Psarris. But, I suppose when you’re content with a god of the gaps outlook on everything in life, actually learning something new is not important.
Oh, and in all seriousness, check out the Eye on ICR blog if you like reading this kinda thing. A high school student willing to take on the ICR, even if it’s just in a blog, and point out their foolishness is pretty cool. When I was in high school, the only creationists I confronted were classmates (ah, I still remember 7th grade when I made a girl cry just by saying that we didn’t know why the Big Bang happened, but who created God?).
In the early days of 2010, specifically January 4, I read an article on Wired Science entitled, “Age of Solar System Needs to Be Recalculated.” After having written this blog for nearly a year and a half and having a fair number of posts about young-Earth creationism (YEC), I read the article knowing that it would just be a matter of time before someone at either the Institute for Creation Research (ICR) or Answers in Genesis (AiG) would use the article to effectively say, “Look! See!? Scientists don’t know what they’re doing, all of radiometric dating is wrong, creationism is right!” And they didn’t disappoint, though I have to admit it took longer than I thought it would (17 days).
The process of radiometric dating and all its corollaries and techniques could likely fill a decent-sized graduate textbook. That’s not the purpose here, rather it’s to give you the most basic information so you can understand the issues at-hand.
The principle behind radiometric dating is that every atom has many different isotopes. An atom is made of protons, neutrons, and electrons. The number of protons determines what atom it is (1 proton = hydrogen, 2 protons = helium, etc.). The number of neutrons determines the isotope (1 proton = hydrogen-1, 1 proton + 1 neutron = hydrogen-2 (deuterium), 1 proton + 2 neutron = hydrogen-3 (tritium)). The electron number determines the ionization state, which is unimportant for this discussion.
Atoms that get too heavy are inherently unstable. If you cram too many protons and neutrons into the center, the atom will decay. If you cram too many neutrons into an already stable isotope of an atom, it will decay. “Decay” is when it releases either one or more of its neutrons or protons by turning it into something else. That decay time is based purely on fundamental physical laws and constants, it is a quantum mechanical process, and it is different for all isotopes.
The time over which half of a sample of an isotope will decay into another is called the “half-life.” After two half-lives, 75% will have decayed; after 3, 87.5%, after 4, 93.75%, etc. (1-0.5# of half-lives). Half-lives can be measured over human timescales, and/or they can be correlated with other established dating mechanisms, such as ice-cores, tree rings or written records.
An assumption of radiometric dating and necessary corollary is that the sample is from a self-contained system. In other words, it has to be “original;” if the sample was contaminated some time after it formed, then the dating will be thrown off. Similarly, we need to know how much of the original “parent” isotope was present relative to the “daughter” isotope so that the amount of original daughter isotope can be removed from the equation.
The Wired Science was reporting on an article from Science News, which itself was reporting on an article published in the journal Science at the end of 2009. (Unfortunately, you have to pay for the article unless you are at an institution that has a subscription. The citation is, Brennecka et al. (2010). “238U/235U Variations in Meteorites: Extant 247Cm and Implications for Pb-Pb Dating.” doi: 10.1126/science.1180871. An earlier abstract of their findings can be found for free here.)
It had been assumed for years that the amount of original uranium-238 and uranium-235 in asteroids was even throughout all the asteroids. This had been measured independently many different times and the ratio had been the same. However, there is no theoretical reason why this should be true, and so people kept measuring it to continue to check the results. What these researchers found was that, actually, when measured more accurately and taking a few more things into account, that there actually are slight differences and the ratio isn’t quite what it was thought to be.
What does this do? It changes the age of the solar system by 1 million years. So it could be either 4.566 or 4.567 billion years old.
One of the co-authors explicitly states, “It’s not as if this age-dating process doesn’t work anymore,” says coauthor Ariel Anbar, also of Arizona State. “But if you want to push this isotope system to get ages that are really precise, suddenly we realize that there’s this variation you need to take into account.””
What they did not find is that radioactive decay rates are not the same within a given isotope. As I stated above, that is set by the fine-structure constant of the universe and purely quantum mechanical processes.
The very first sentence of ICR’s January 21, 2010 article, “It’s Official: Radioactive Isotope Dating Is Fallible,” states: “New data collected by secular researchers has confirmed what creation scientists discovered decades ago—geologists’ cornerstone assumption that the rate of radioactive decay is constant over time is not correct.”
Except … NO! That was NOT what the article nor paper nor abstracts nor researchers said.
Moving on … the third paragraph starts with, “Gregory Brennecka of Arizona State University and colleagues measured the relative amounts of Lead 238 to that of the stable Lead 235 from several samples taken from the large Allende meteorite, named for the village in Mexico near where it landed in 1969.”
Again … NO! They used uranium-238 and uranium-235 as a proxy for lead-206 and lead-207.
Next paragraph: “The differing amounts of material that were found in separate samplings of the same meteorite should not have been detected if isotopic decay of Uranium is indeed stable over time.”
NO! The parts of the same meteorite that the researchers analyzed are almost guaranteed to have formed at the same time because – in part – they are in the same meteorite. Therefore, if the rate were to change through time, then they all should still show the same ratio of parent to daughter isotope because they all would be changing at the same rate. Therefore, what it shows and what the researchers concluded is that the original ratios were slightly different.
Brian Thomas, the ICR article’s author, goes on a quote-mining expedition for the next two paragraphs to try to show that radiometric dating was never an established thing.
He then goes on the expected, “But creationists knew it wasn’t!” by stating, “For years, creation researchers have published ample data to refute the assumed stability of nuclear decay rates in general, as well as specifically for Lead.” (Again missing the actual point it was uranium that they were analyzing.) He continues with standard YEC arguments after that.
Thomas closes with: “Although Brennecka and his colleagues detected only a small difference in the same Lead isotope amounts in the same rock, this was quite enough to falsify any notion that this Lead 238 decays at a constant rate into Lead 235. And this dovetails with other valid research which found similarly falsifying data.”
This is a standard creationist tactic: (1) They find anything that is an iterative step in science (in this case refining an established dating mechanism and showing that at the 0.1% level there are additional issues to take into account). (2) Misrepresent it. (3) Find supporting quotes through quote-mining that shows that “even secular scientists” had doubted the technique. And (4) therefore God did it 6000 years ago.
Every quote presented above was copy-pasted from the original ICR article. The next day, I was notified in the comments section below that the article had been revised “for accuracy.” As it now reads, every quote that I took has been either slightly or wholly changed. The most obvious is that they have fixed the “lead 238/235” to make it uranium.
But perhaps more interestingly, the language is less scathing. For example, the opening paragraph is now, if one were to show the edits via strikethroughs and insertions:
“New data collected by secular researchers has confirmed what creation scientists discovered decades ago — geologists’
cornerstoneassumptionsthat the rate ofabout radioactive decayis constant over time isare not always correct.”
Is it just me, or does that actually seem to be a softening of the language? It actually seems to represent the research now.
Then there’s this one:
“The differing amounts of material that were found in separate samplings of the same meteorite
should not have been detected if isotopic decay of Uranium is indeed stable over timewere unexpected.”
Again … the language seems softer and actually seems to represent the research. The rest of the article is still effectively, “This calls all radiometric dating into question,” but at least it’s not based on quite an obvious straw man. Thank you KT_trebor for pointing out the revision!
I’m going to interrupt my purely logical fallacies series to do one on a related idea, fallacious arguing. The difference that I’m drawing here is that there are still ways of arguing that are “wrong” or misleading without actually being formal logical flaws. The case I’m addressing here is that of “Quote Mining.”
In yet another aptly named term, quote mining is when you search for a quote – any actual statement – that someone has said, and then use it out of the actual context in order to imply that it meant something else.
In a completely contrived example, I could state, “The United States of America is a wonderful country where its citizens enjoy many freedoms. We have freedom of and from religion, the right to freely assemble, freedom of the press and speech, and we have the freedom to petition (something that I used in 10th grade to get an unpopular program removed from my high school). However, in recent years, this has come under attack by many people who claim that we are a Christian nation and they interpret the First Amendment to mean that everyone has the freedom to practice and promote their religion in all places at all times.”
Someone could then quote-mine that statement and claim that I said: “The United States of America … [has a First Amendment] that everyone has the freedom to practice and promote their religion in all places at all times.”
Grammatically, that is a perfectly valid thing to do. However, it has completely changed what I was arguing, and hence quote mining is a fallacious way to argue a point.
There are a tremendous number of examples of quote mining across nearly all fields of, well, anything. One might think of lawyers, politicians, and news reporters as some of the most prolific quote miners around.
Because of this, I’m not going to look too hard to try to find one, but rather I will use one that very clearly illustrates the idea from a presentation I gave about young-Earth creationist claims about astronomy (and geology).
The particular claim was made by Kent Hovind in his “Creation Science Evangelism” series, Disk 6 part 1. Hovind was trying to claim that Earth’s magnetic field has never reversed polarity (the magnetic “pole flip” that has many people worried for 2012). In order to bolster this claim, he used an apparent Argument from Authority (another logical fallacy) from a Science paper from 1979. The quote was: “It is clear that the simple model of uniformly magnetized crustal blocks of alternating polarity does not represent reality.”
That statement seems pretty damning. We’ll ignore that it’s been 30 years since that statement was made and that science changes with new evidence, since this is a clear example of quote mining. Fortunately, Hovind provides the reference and I was able to look up the article (Hall, J.M., and P.T. Robinson. (1979). “Deep Crustal Drilling in the North Atlantic Ocean.” Science, 204, pp. 573-586.). The VERY NEXT SENTENCE of that article reads, “Clear reversals of polarity with depth are observed.”
In other words, Hovind used the first sentence to claim that these authors were arguing that the entire model of alternating magnetic polarity embedded in the ocean crust is false. Rather, when put into context, we can see that the authors were rather arguing that the simple slab model of alternating magnetic polarity is not accurate, that they do see alternating polarity, but you need a more complicated model than a simple brick-like approach.
Through quote mining, one can effectively make anyone say almost anything. It’s an unfortunate thing, but nearly everyone does it. By leaving out context or by using enough ellipses (the “…”), it’s very difficult to actually know if what someone is “supposed” to have said is what they meant. This is especially the case in print media (newspapers, magazines, etc.), but even with video, a good editor can make it appear as though someone has said something that they did not mean.
The fallacious method of quote mining is definitely something to watch for.
With that said, I would like to try to reassure my readers that when I have used quotes from sources that I argue against, I have tried to not fall into this fallacy. That is partly why I provide links back to the original sources, or I provide references, if possible, so that you can go back to the source to check it for yourself.
Exposing PseudoAstronomy 