In a slightly delayed offering, episode 41 has been posted. Sorry to say that episodes over the next month may be delayed by a few days, as well, for I have several trips coming up and won’t have my equipment with me.
As the title suggests, this episodes details a few claims by creationists to try to argue that craters really show the solar system is only 6000 years old instead of the solar system being around 4.5 billion. It may get a bit technical at times — sorry.
This is a bit of a longer episode. ‘Cause, this is what I do.
I give you a pretty detailed overview of how crater age dating works, the difference between absolute and relative age dating, how we can assign absolute ages to the relative ages of craters, how geologic mapping works and why it’s important for crater age dating, and then many of the known problems and caveats with the method.
Finally, there’s an open question about the puzzler: Is it worth doing? I wanted to do it initially to get interaction between me and the listeners. But participation has been around 1 for each. So if you have any opinion regarding the Puzzler, please let me know in the Comments to this post.
A slightly delayed episode is finally up. Part 2 of the series of 2 on radiometric dating, part 2 of the series of 4 (this month’s theme) on dating techniques. I talk about four of the main categories of claims that young-Earth creationist arguments fall into in their attempts to refute radiometric dating.
It’s also the first regularly formatted episode since #35, including the main segment, new news, Q&A, feedback, puzzler, and announcements.
This is Part 1 of two parts, the next to be in the next episode, conveniently, and will discuss what young-Earth creationists say about the topic.
But in this one, I give you a 50-minute interview with geologist Rachael Acks who explains some of the history of radiometric dating, the very basic physics of it, how it works in practice, and some cases of when and why you can’t use the method.
This month begins a four-part series (though it’ll be labeled as two Parts 1 and 2) on age-dating techniques and then the young-Earth response. The first set is radiometric, second set will be craters. It’s a bit of a different thing, so we’ll see how it works out.
Note that because this interview ran longer than I like to make normal episodes, I’m pushing the not-main segments to Episode 39.
I ended up giving my talk anon how YECs arrive at their conclusion of a young Earth versus how “secular scientists” do it. This episode has been posted in both audio and video. Hopefully they both work, and hopefully not too many will yell at me for posting a 90 MB video without warning to the RSS feed. The video is MP4 format … that is the general universal format these days, right?
One of the best and most reliable ways to determine the absolute ages of a material is through radiometric dating. Because of this, and because they show the age of things to be older than 6000 years, young-Earth creationists (YECs) have spent decades trying to show that it doesn’t work or just claiming that assumptions that scientists make are not true.
Their attempts at this include bringing samples of newly formed lava to a lab where they find an age of a few million years and then laugh saying that it only formed a decade ago. (Two issues there are that (1) the type of dating employed isn’t accurate for a sample younger than 500,000 years, and (2) they dated small minerals in the lava that did not melt in the original lava so actually were many millions of years old.)
Or they will claim that radiocarbon dating isn’t even used for dating dinosaur fossils … leaving out that radiocarbon dating can’t be applied to things that are more than ~50,000 years old.
Anyway, all that’s for another post. The purpose of this post is to point out that the point of science is to develop a model that can be applied to everything it attempts to describe. Gravity works the same on Earth as on the moon as in the center of a galaxy cluster. For the issue at-hand, YECs need to decide whether they believe in radiometric dating and its usable, or whether they don’t and so don’t use it.
In the news over the past week, yet another group of YECs have claimed to discover Noah’s Ark on top of Mt. Ararat in Turkey. There are many outlets for this story, but out of fun, I’ll link to the one over at FOX News. The relevance to radiometric dating? I’ll quote (emphasis mine):
“The group claims that carbon dating proves the relics are 4,800 years old, meaning they date to around the same time the ark was said to be afloat. Mt. Ararat has long been suspected as the final resting place of the craft by evangelicals and literalists hoping to validate biblical stories.”
Didja see that? Meanwhile, over at Answers in Genesis:
“All radiometric dating methods are based on assumptions about events that happened in the past. If the assumptions are accepted as true (as is typically done in the evolutionary dating processes), results can be biased toward a desired age. In the reported ages given in textbooks and other journals, these evolutionary assumptions have not been questioned, while results inconsistent with long ages have been censored.”
Or from an older Institute for Creation Research article:
“Creationists are not so much interested in debunking radiocarbon as we are in developing a proper understanding of it to answer many of our own questions regarding the past. At the present time it appears that the conventional radiocarbon dating technique is on relatively firm ground for dates which fall within the past 3,000 years. For periods of time prior to this, there are legitimate reasons to question the validity of the conventional results and seek for alternative interpretations.”
Or, a case of very special pleading from another ICR article:
“A ‘Back to Genesis’ way of thinking insists that the Flood of Noah’s day would have removed a great deal of the world’s carbon from the atmosphere and oceans, particularly as limestone (calcium carbonate) was precipitated. Once the Flood processes ceased, C-14 began a slow build-up to equilibrium with C-12—a build-up not yet complete. Thus carbon dating says nothing at all about millions of years, and often lacks accuracy even with historical specimens, denying as it does the truth of the great Flood. In reality, its measured disequilibrium points to just such a world-altering event, not many years ago.”
You can’t have it both ways. Or all four ways (I kinda lost count). Either (1) radiometric dating doesn’t work, (2) radiometric dating does work once you account for things that YECs have yet to really define, (3) it does work for the recent past to 3,000 years ago but not for anything before that, or (4) it works for everything made after the flood (as in the ark was built before the flood so can’t be dated with it).
What this all boils down to is the Inconsistency Fallacy, one I didn’t address in my series the last two months of 2009 on Logical Fallacies (but I do intend to return to that series later this year). The Inconsistency Fallacy is basically summarized as, “Multiple statements that contradict one another.” For example: “Statement A is true and B is true. Use one of these statements to prove the other is false.” Or, “Bill is younger than Jill, and Jill is younger than Charles. Charles is the oldest of the three.”
And that’s the case here. Either it’s valid, or it isn’t. You can’t use radiometric dating to claim the Bible is literally true to claim that radiometric dating doesn’t work.
A few weeks ago, I wrote a post about Saturn’s rings, in a preemptive attempt to address some recent research that I thought some young-Earth creationists (YECs) may use to assert their views. I am somewhat surprised that the three main sources I read for creationist stuff have been silent on it. Swing and a miss on my part.
Let’s see if my fledgeling psychic powers are better-tuned for this one. This past week, several news outlets were running the story that the planet Venus may have active volcanism, revealed by the ESA spacecraft Venus Express (ESA press release, NASA press release, and Science journal article (the last one requires a paid subscription)). Seems like a possible story that a YEC may latch onto, so here’s another preemptive post explaining the science so if there is a YEC response, I can dive right into it without the background info needing to be repeated.
There is some basic information about Venus that’s relevant to this discussion. First, as most people know, Venus is the second known planet from the sun, residing about 71% as far from the sun as Earth does. Conveniently, and importantly for this post, Venus has a diameter that is 94.9% Earth’s diameter. However, since its overall density is less, its mass is 81.5% that of Earth’s.
The surface of Venus is shrouded from Earth in visible light, hidden by clouds so thick that the temperature is around 465 °C, and hence you often hear that the surface is hot enough to melt lead. The atmosphere is nearly 100 times as massive as Earth’s exerting 92 bars of pressure on the surface that is the equivalent of being under about 1 km of water. Now you may have an idea why it’s hard to build a spacecraft to land on it and survive long enough to do anything useful.
The other thing about its surface is that it has been imaged, just not in visible light. The spacecraft Magellan mapped nearly 100% of Venus’s surface and determined its topography when it orbited in 1990 through 1994. Among other things, the data showed that Venus has many volcanoes, and it only has about 1000 craters.
Now you may be wondering, “Why is he talking about craters? Is it because he studies them and just thought it would be fun to mention?” Well, yeah, I do study them, but they are also the ONLY way to tell relative geologic ages in the solar system since we lack any way to absolutely determine the ages (such as through biological means on Earth and radiometric dating on Earth and the Moon). In contrast to Venus having only 1000 craters, and nearly all of them larger than 5 km in diameter, means that Venus’ surface is very young. In contrast, the planet Mars has about 45,000 craters that are larger than 5 km in diameter.
Based on a lot of modeling, current estimates of Venus’ surface cratering age shows it to be about 700 million years old. Yes, that may seem old, but compared to the moon, Mars, and Mercury – the other large, non-Earth bodies in the inner solar system – Venus has the youngest overall surface. And the last paper to really study the distribution of craters on Venus shows that they are completely random, so it’s not just that half the planet’s surface is 1 billion years old and the other half is 500 million, but the whole surface is about 700 million years old.
The next question one may logically ask is how an entire planet with a surface area 90% that of Earth’s (95%^2) can be resurfaced? From the geologic evidence of massive volcanoes across the planet, the general consensus is that it was volcanic eruptions.
Let’s look at Venus, Earth, and Mars. Mars is only 45% the diameter of Earth, and its mass is only 10%. The analogy I like to give is that if you take a little cupcake and a big cake out of the oven at the same time, which is going to cool faster? This is why Mars has long been termed “geologically dead,” though it does show some pittance of active geology today — but none from internal heat sources.
In contrast, Earth has a lot of internal heat, and we see that every day in the form of volcanoes and undersea vents. Our heat drives plate tectonics, making earthquakes that have also been in the news a lot lately with Haiti, Chili, and Mexico. So while Earth is internally molten, our lithosphere (the region below the crust and above the mantle) is thin enough and fractured enough to let some of that heat out.
The thinking is that Venus has a lot of internal heat like Earth, but, it has a thicker lithosphere. That lithosphere under normal circumstances is simply too thick to let heat escape, so the heat stays trapped inside.
Now here’s another analogy: Let’s say you’re going to spend another lonely night in your 1-bedroom apartment, and even the cat doesn’t want to have anything to do with you. You’re going to watch a cheesy movie and don’t want to cook, so you go to the freezer and look through your few dozen frozen microwaveable dinners that you bought in bulk at Costco. You choose one and read the directions for lack of anything better to do. The directions state quite clearly: “PUNCTURE WRAPPING BEFORE MICROWAVING.” From past experience, you know that if you don’t, the heat will build up and explode in what means 10 minutes of messy clean up. But if you do puncture the wrapping, the steam can escape and it’s all good.
This is the same – albeit simplified – thing that happens with planets. Since Earth can release its heat, it doesn’t “explode.” With Venus, the thought is that since the lithosphere is thicker, the heat builds up until the molten rock finally forces its way out. When it does, the lithosphere cracks and planet-wide, catastrophic volcanism ensues. And the last time this happened – based on the craters – was around 700 million years ago.
Good question, I’m glad you asked. Let’s get back on-topic. With a last massive planetary resurfacing 700 million years ago, one question has been, “Is this going to happen again?” Another is, “How often does this happen?” And the most relevant to this discussion, “Is there still some dribble of volcanism today?”
It’s that last question that Venus Express may have found evidence to answer in the affirmative. From the NASA press release: “For the first time, scientists have detected clear signs of recent lava flows on the surface of Venus. The observations reveal that volcanoes on Venus appeared to erupt between a few hundred years to 2.5 million years ago. This suggests the planet may still be geologically active, making Venus one of the few worlds in our solar system that has been volcanically active within the last 3 million years.”
I’m guessing they had to add “one of the few” because of Earth and Io.
Anyway, going off of the press release (I don’t have access to the Science article right now — I’ll update this later if needed when I get ahold of it), the researchers were able to study the mineralogy on three of Venus’ volcanoes. The mineralogy matches that on recent volcanic eruptions from some volcanoes on Earth, like Hawai’i. On Earth, the rock’s reaction with oxygen quickly changes the mineralogy, and hence the research strongly suggests that the flows are young enough to not have been modified. They suggest anywhere from a few hundred to 2.5 million years old.
This may change the picture that I outlined above of the catastrophic volcanism. In perhaps the more controversial part of the press release to me, they suggest that this could indicate the volcanism on Venus has been gradual throughout time – in a kind of steady state situation where localized events happen to resurface the area and cover a few craters, die down, and then happen elsewhere, but not covering enough to maintain the 700-million-year-old crater surface age. It’s a possibility, but at least to me they will need to show more evidence before I find it more convincing than the catastrophic scenario.
Venus has come up in the YEC literature before. I wrote one of my first blog posts on, “ Venus and the Battle of Uniformitarianism (A Creationist Argument).”
In this case, I am guessing that if some YEC person or institute chooses to use this to try to add evidence for their claims it will be along the lines of, “Since Venus has active volcanism today, it must have been created in the very recent past – 6000 years ago. Evolutionists/Darwinists/Evilutionists will have to completely change their thinking in order to reconcile an active Venus with an old-Earth.” Or something like that.
We’ll see if my budding psychic powers have been led astray again. I hope not, but we’ll see. Even if they have, hopefully I’ve given you enough information to find this press release interesting and have newfound interest in the field of planetary geology and geophysics.
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!
Today I had a happy occurrence – Phil Plait mentioned me in his “Bad Astronomy” blog in the context of my previous post on this subject. As a consequence, my blog received over a 5-fold increase in hits. Thanks, Phil, and thanks to all of you who came here from the BA blog.
The purpose of this particular post is a follow-up on that first one. In the first one, I wrote that the video sample on the CreationAstronomy.com blog is approximately 13 minutes long. However, I was only able to view about 4 minutes of it for free from the website. Well, one of the readers of my post sent me a link to download the full section of the video.
So, without further ado, let’s examine the claims in the next 9 minutes of the video.
1. “The more we study Jupiter, the more evolutionists have realized it doesn’t fit into their models.” He then shows another quote from Richard Kerr (the same author he quoted from out of context in my first post on the subject) stating, “… no one has a satisfying explanation of how they were made.” Psarris then states that, no, that’s not true, “the Bible has a very satisfying explanation of how they were made.” (3 min 50 sec)
2. “Jupiter has over 60 moons; they pose problems for evolution, too.”
2.a. “Ganymede has one of the most bizarre surfaces in the entire solar system. … Evolutionary models predicted that Ganymede couldn’t have a magnetic field. But when our space probes arrived and started taking measurements, we found that it does have a magnetic field.” (4 min 30 sec)
2.b. “Then there’s Callisto. This moon is the most heavily cratered object in the solar system. Evolutionists believe that it has one of the oldest surfaces of any object, about 4 billion years old. It was a real surprise, then, when our space probes took some close-up pictures.” It was expected that there would be many small craters, but there was a lack of them. Also, “some of the pictures show what appears to be fresh ice on Callisto’s surface, … [but] evolutionary models say Callisto is old, cold, and dead.” (5 min 30 sec)
2.c. “Next, there is Europa. … Europa is the smoothest [object in the solar system]. … [The ice on Europa] is several miles thick, but some scientists think there might be liquid water beneath it. And where there’s water, there has to be life, right?” Apparently in a previous video section he addressed “how ridiculous that idea is,” but Psarris goes on to say, “you still hear it in the news a lot: Somebody finds a new crack on Europa, and thinks, ‘Ooo! Look! Water might ooze into the crack, and there could be life evolving in the water!’ Then some reporter runs a story about it saying we’re on the verge of finding life elsewhere in the solar system even though all we found was a crack in a moon.” (6 min 30 sec)
2.d. This claim deals with craters on Europa, about which he makes a claim straight from the Institute for Creation Research (I know this because I already debunked this claim before): “Because Europa has only a few craters, we’ve been able to study them closely. One recent study has shown the evolutionary model for cratering is all wrong.” He goes on to explain that it’s apparently wrong because a single crater forming can create up to a million or so smaller, secondary craters (formed by debris from the primary crater event). Because of this, he makes the claim that you need fewer impactors to make all the craters we see, which then implies a younger age than “all these billions of years.” Psarris then extrapolates this to Venus and the moon. (I’m not going into significant detail here since I’ve addressed it extensively before, and I’ll talk about it in my next section where I address these claims.) (7 min 10 sec)
2.e. For the last of Jupiter’s large moons, Io, Psarris makes light of the massive volcanism on Io’s surface. Psarris’ main claim is simply that Jupiter’s tidal heating of Io is not enough to account for all the heat, so some of it must be left-over from its formation which means it formed recently. (9 min 15 sec)
2.f. The second of the Io claims is that, given the amount of lava that is erupting, Io must have completely recycled itself 30 times in the ~4.5-billion year history of the solar system. (10 min 30 sec)
2.g. We get a third claim out of Io: Apparently, astronomers were “flabbergasted” to learn that the temperatures of the lava on Io reaches 3000°, when it only reaches 2000° on Earth. Also, the lava is dense when it should be formed of low-density material by this point due to simple differentiation (heavy stuff sinks). (11 min 20 sec)
The rest of the video (post-12 min 15 sec) is a review of all the points that Psarris makes. But, there are some typical statements at the end:
1. No Models Explain How Jupiter Formed
This is simply not true, and at its nicest level is taking statements out of context and sorely downplaying the status of solar system formation modeling. I address this quite a bit in my first post in this 2-part series.
The other aspect of this claim that deserves to be addressed is the very common “god of the gaps” logical fallacy: “We don’t know how this happened, therefore God did it.” Among the skeptical community, this often is compressed into the single word, “goddidit,” because we hear it so often from Creationists. The basic fallacy here is that you confuse something that we don’t currently know with something that we can’t possibly know, and therefore it is only explainable through the miracles that a divine creator can make.
2.a. Ganymede
Ganymede’s magnetic field is interesting. But, as I stated in my first post about this CreationAstronomy.com site, that’s what makes astronomers happy! We like it when we find something that we can’t immediately explain. If nothing else, that means Job Security! But on a more explanatory level, the theory for the formation of a magnetic field on a planetary scale is that it requires a molten interior, but Ganymede shouldn’t have one by this point in its life because it should have cooled. On that point, Psarris is correct. But, what does this mean, then, for an explanation?
It means that we need to explain how Ganymede’s core could have either remained warm until at least 1 billion years ago or was heated up until about 1 billion years ago (since a remnant field can still exist for ~1 billion years even without something actively driving it). What modelers have come up with is that the main jovian satellites were not always in their current orbits, but that they slowly migrated into them. This migration passed through resonances until it got to its current resonance of 1:2:4 (Io, Europa, Ganymede … Callisto isn’t really in a resonance (yet)). Getting into this resonance caused enough tidal heating to create a dynamo in Ganymede’s core. In other words, there’s a perfectly reasonable dynamical model that explains this without resorting to goddidit.
2.b. Callisto’s Lack of Small Craters
This is another (almost) true observation about Callisto: It does lack as many small craters as were predicted from simple cratering models. Note here that “small” is ~1 km sized craters and smaller. Before I get into possible explanations, though, I have to pose the likely rhetorical question: How does a lack of small craters prove the solar system is young? I honestly don’t see how it has any relevance to it, other than under the quite childish false dichotomy notion that, “if I can show you’re wrong, then I must be right!”
What this implies, however, are a few different things. One idea is that the main impactor population of Callisto – possibly comets – simply lacks a small size population (impactors a few 10s to 100s of meters). Personally, I don’t find that explanation incredibly convincing from my own research in craters, however. Another possible explanation (Bierhaus et al. (2000) “Small Crater Populations on Callisto”) is that it is simply a resolution issue, and that when viewed under higher resolution, previously indiscernible small craters become evident.
There are also other possible explanations here, but my main point is one that I’ve been stressing when dealing with this CreationAstronomy.com website: A lack of conforming to known, simpler models is something that astronomers – and scientists in general – like, because it means that they then get to go and figure out a new model to explain the new results.
2.c. Europa -> Liquid Water -> Life?
This claim is one that I’ve addressed before, namely in my post, NASA’s “Follow the Water,” Ice Detected by Phoenix on Mars, and Noah’s Flood. It’s one of my older posts so not as well organized, but the basic idea is that all life that we know of needs liquid water to live. Therefore, the first step in attempting to find life is to find places where liquid water is. It’s that simple.
2.d. Europa and Secondary Cratering
This is another claim that I have addressed, in-depth, before. The post is, Dating Planetary Surfaces with Craters – Why There Is No “Crisis in Crater Count Dating”. Psarris’ claim really is identical to this ICR article. The basic response boils down to: Astronomers know of the issue. And we take it into account. It’s another of the classic creationist tactics where they will give you a problem with “evolutionary” science and then say it invalidates everything about science, but they don’t tell you that we already know about the issue and take it into account.
2.e. Io Is Too Hot
Says who? I have not heard nor seen this claim before, and I took a graduate class from the guy who literally wrote the book on Jupiter’s moons. If Psarris would like to show his calculations, I will gladly look over them and get back to this claim.
2.f. Io Is Erupting Too Much
While the basic idea behind this claim is not new, I have never seen it before raised as an issue. Planetary crust is recycled. Stuff coming out of volcanoes on Earth now used to be buried miles beneath the surface which used to be on the surface. I’m sorry, but I honestly don’t see the issue here with this claim.
2.g. Io’s Lava is Too Hot and Too Dense
First, I just love it when articles say that scientists are “flabbergasted,” “surprised,” “shocked,” “astounded,” “puzzled,” “clueless,” “can’t understand,” “unbelieving,” “amazed,” “bewildered,” “baffled,” and other such phrases. (Okay, more honestly, I really don’t like it.) Seriously, we’re apparently the people who are supposed to know everything and so it’s like a “gotcha” game when there’s a discovery that “surprises” us. Need I repeat it? THAT’S THE POINT OF SCIENCE — TO FIND OUT NEW THINGS!
Alright, deep breath … now, what about the temperatures of Io’s volcanoes. Again, I do not know of why this is particularly an issue. If Psarris would like to show his math – or show someone else’s as to why magma cannot be heated to 3000° on Io, I will take a look at it. But this is another case where I do not particularly want to do his work for him to then add more work to my own plate.
I’ll start off by saying that I threw this post together rather quickly (if “quickly” can mean an hour of writing and looking things up and watching the video segment), so I apologize if I seem a little flippant at the end, brushing off his claims.
However, my point really is the same: If he is going to make the claim, he needs to back it up. You can’t just state something and leave it at that and expect people to bend over backwards to flesh out your own claim and then go to the trouble of pointing out why it’s wrong (if it actually is). And at least with the few physics things that Psarris addresses (basic thermodynamics), he needs to show the math. Otherwise, it holds as much weight as me saying that my oven can’t possibly heat up past 500° by itself therefore it contains heat left over from its formation which means it’s young.
Otherwise, I hope that at the very least this post will lead you to question the validity of Psarris’ claims. And if you’re already a firm critic of young-Earth creationism, then I hope that I have armed you with more information to stop the spread of bad pseudo astronomy.
In the last few days, I’ve seen a few blog posts about Saturn being a young system on the usual creationist sites or those responding to the creationist sites, and being a bit behind in my blog, I thought I’d check out the usual suspects. Predictably, I found the article posted yesterday, May 7, 2009, on the Institute for Creation Research by my own favorite, Brian Thomas (who I picked apart in this blog post.
The article in question now is entitled, “Planetary Quandaries Solved: Saturn Is Young.” Okay, I admit I needed to take a deep breath with this one before reading it. After all, you’d think that if scientists had really discovered that Saturn had been created/formed recently, it would be all over the news, right? So right off the bat, the title is misleading, but understandable for a creationist website.
Then I picked through some of the references. Why? Because I actually do research on Saturn’s rings. I will be submitting revisions to a 50-page manuscript to the journal Icarus in the next 3 days that should be published in a special edition of the journal at some point this summer, and the conclusions from my simulations are that the ring system is at least 2 times as massive as before, likely more, and the implications are that the system can then easily be a corresponding amount older (e.g., at least 2 times older).
And, lo!, one of the references in the article directly cites my work — a ScienceNews article from September 2008. (Check out paragraph 4 of the article.) So now, it’s personal — Brian Thomas is using MY research (in part) to advance his creationist agenda, and I will not be silent about it. Hence this blog post. 
Let’s ignore all of the outside evidence that it’s old. Let’s ignore solar system formation models. Let’s ignore standard conventional wisdom. Let’s ignore the scientific problems about biblical creation. What is the evidence that the system is old, or at least not young.
Well, being a crater counter when I’m not running simulations of Saturn’s rings, I point to craters. Craters are used throughout the solar system as the only cross-planetary method of relative dating methods. In other words, how many craters a solid object has is the only thing that we can measure, at present, that gives us the relative ages of two solid surfaces.
Crater ages have been calibrated via Apollo lunar sample returns, and so – at least for our moon – we know that a certain number of craters per unit area corresponds with one age, and a different number corresponds with a different age — and we know what those ages are to reasonable accuracy for the moon.
Much work has been done and is being done to try to extrapolate what we know from our moon to other solid bodies, including Mercury, Venus, Mars, and the giant planets’ satellites. While the work isn’t perfect and uncertainties remain, the state of the research is that we can tell the difference between an object that is 6000 years old or 4 billion years old.
The surface of Titan? The last number I saw is that there are around 150 impact structures that have been observed, so the present-day surface age of Titan is reasonably young. Yes, I admit that — I’m not hiding it.
What about the surface of the other moons, such as, say, Iapetus? Well, take a look at the image to the right. There are A LOT of craters there, and the surface age of Iapetus is likely on the order of a few billion years (I say “likely” because I haven’t actually done the crater counts there). Now, unless you’re going to engage in some very special pleading, this is pretty good independent evidence that at least some parts of the Saturnian system is old.
I grew up reading that Saturn’s rings were young – probably formed only 100 million years ago after the breakup of a medium-sized moon, about the size of Saturn’s moon Mimas (shown on the right). That was based on a few things, including estimates of its mass from Voyager data as well as spectroscopic observations showing that the rings are fairly “fresh,” showing relatively little contamination by, basically, space dust.
This was still the predominant idea in 2002, when Jeff Cuzzi made his quite that Brian Thomas uses in the second paragraph of this article:
A history of mystery surrounds the youthful features of Saturn’s rings. Jeff Cuzzi, a planetary scientist at the NASA Ames Research Center, said in 2002, “After all this time we’re still not sure about the origin of Saturn’s rings….There’s a growing awareness that Saturn’s rings can’t be so old.” Cuzzi said, “There are two reasons to believe the rings are young: First, they are bright and shiny like something new. It’s no joke.” Indeed, after millions of years, the icy rings should have collected so much space dust that they should be charcoal-colored by now. Second, after only a few million years, the little moons embedded among the rings should have “flung away. This is a young dynamical system.”
And, this was still an issue in 2006, when I was just starting my simulations. The third paragraph of this article cites Josh Colwell in a presentation he gave. He was listing some of the current problems in a few-billion-year-old rings system, but the problems were still based on old data estimates for both the mass of the ring system and the viscosity of the particles (viscosity can be thought of as how well particles can transfer energy from one to another or how well they flow — water is not very viscous but molasses is).
Enter the simulations. I use Mark Lewis’ code for these simulations, and I make a point of that because Mark is quoted in the fourth paragraph of the ICR article:
Mark Lewis of Trinity University in San Antonio cautioned that it is still not known how they really clump. “It isn’t as straightforward as saying that high-density particles would lead to more clumping.”
This is true. There are many different parameters that go into these simulations to model the physics involved. Even though I explored a huge range of parameter space in my simulations, performing over 150 different N-body simulations that took over 27,000 CPU hours to run, I still did not explore the whole range of space, and a few of those parameters do affect how ring particles clump together.
Clumping is important because it directly affects how we estimate the mass of the rings. If the rings do not clump at all, then for every particle it will block an equal amount of light. Kinda like if you spread a lot of sand on a sheet of paper and you spread that sand evenly around, you will only see a little of the paper through the sand. But, if you use the same amount of sand and start to make little sand piles, you will see more and more of the paper.
That’s how we estimate the mass of the rings – by how much paper (how much light) can be seen through the rings. And, if the ring particles are clumped together, then you need many more ring particles to get the same amount of light blocked. What my simulations show is that clumping plays a much larger role than previously thought, and so we need more material in the rings to match the observed light-blockage.
Why do more massive rings mean that the ring system is older – or can be older? Because more massive rings means the viscosity is higher and so they spread out more slowly (one of the arguments they were young is that they would spread out too quickly). Also, it means they can be older because the same amount of pollution will get spread out over a larger area, and hence they won’t be as “dirty.” So, arguments that they are young because they don’t show a large amount of pollution can be answered that the pollution is just better hidden than we thought because there is more material within the rings to get polluted.
What was the connection to me here? Well, they’re my simulations. And that fourth paragraph has a quote from an article that talked about my results. Hence why I take this a little personally.
In paragraph 5 of his article, Brian Thomas says that Saturn’s moon Enceladus “shows no hint of being 4.5 billion years old, but instead appears remarkably young.” I’m not going to harp on Brian’s grammar mistake here because I’m sure I have made my fair share of mistakes in this article grammar-wise, but I will say that it’s a poor journalist who doesn’t know what a sentence fragment is.
Anyway … this statement is simply wrong. It is true that the geysers that were discovered coming from Enceladus’ south polar region were a surprise, and they have made many people in the planetary community excited to find out why they are there. (Note – yes, new discoveries that challenge old models make scientists happy, not upset, as creationists would have you believe.) And a lot of Enceladus’ surface does appear to be young. However, a fair portion of the surface also appears to be very old, as shown in the picture on the right. Yes — I’m talking about all those craters.
That’s really the point of this article. So, no, the planetary quandary has not been “solved” to say that Saturn is young. Rather, the ring system can still easily be old based on the latest (and if I do say so myself, the greatest) simulations, and even though some features of Enceladus appear young and active, there are other parts of the moon that tell the tale of being ancient.
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