Exposing PseudoAstronomy

May 23, 2009

Jupiter: Confounding Evolutionary Models of the Solar System


Introduction

Making the rounds on the blogs and skeptical websites – including PZ Myers’ Pharyngula blog – is an up-and-coming young-Earth creationist, Spike Psarris and his CreationAstronomy.com website. Now, when I was made aware of this site, I tried to go to it but kept getting 505 errors meaning that they had exceeded the bandwidth they paid for.

I’m guessing this was due to PZ’s blog post about it. Well, a few hours later, it was back up and I got to see what the hooplah is about. It’s a guy selling a YEC DVD. He has a free preview on his site – at least at the time of writing this blog – that shows the intro to the DVD and the “chapter” on Jupiter.

The title of this blog post is what he claims within the first minute of the Jupiter video segment. The rest of this post will be correcting the errors, half-truths, and misstatements throughout the rest of the 13-minute video.

Update: I have posted a follow-up analysis of the Jupiter segment claims that are not addressed in this post here: “Jupiter: Further Confounding Those Darn Evolutionists.”

Psarris’ Claims

There are many claims made in this segment. The main points are the following:

1. “Evolution says Jupiter can’t be spinning as fast as it is … [because] evolutionary model make certain predictions about how fast a planet should spin.” He then quotes a “recent” article to back this up, where “recent” is 1992. He then makes the argument that evolutionary models cannot supply the energy to spin up Jupiter such that its day is only 10 Earth hours long. (1 min)

2. “Evolutionary models predicted that Jupiter would lack certain elements, Ar, Kr, Xe, N, and others. But it turns out that Jupiter has lots of these elements. … [An overview of the article of the results said] ‘Jupiter is the largest of all the planets, but results in Nature now reveal the embarrassing fact that we know next to nothing about how – or where – it formed.'” (2 min)

3. “The evolutionary model requires Jupiter to have a large core inside of it [at least 10 times the mass of Earth]. This would have been necessary for Jupiter to form from the solar nebula billions of years ago. Unfortunately for evolution, a recent space probe measured the mass of Jupiter’s core. … We now know that, at most, the core can only be 3 times the mass of Earth. … Jupiter does not match evolution’s predictions.” (2 min 30 sec)

4. The next claim is that models require 10-100 million years for a planet like Jupiter to form, but that the solar nebula would have dissipated around the sun within 5 million years. “So, according to evolution, Jupiter shouldn’t exist at all.” (3 min 15 sec)

This is where the video stops for me. Even though my player lists the video as being 13 min 28 seconds long, it keeps stopping after 3 min 54 seconds. But, that’s really enough to get a flavor of the video, so let’s get to what’s really going on.

The First Big Clue

Okay, even if you’re a young-Earth creationist, please please PLEASE stop talking about astronomy in terms of “evolution,” “evolutionists,” and “darwinism.” The Theory of Evolution has ABSOLUTELY NOTHING to do with astronomy (unless you are talking about really far down the line things). Natural selection says nothing about how planets form. Punctuated equilibrium has nothing to do with the gases in Jupiter’s atmosphere.

Now that I’ve gotten that out … the first big clue as to an alternative agenda (as if that weren’t obvious from the get-go) is relating evolution to astronomy. As if somehow showing that Jupiter’s rotation rate cannot be explained by an outdated model has something to do with the validity of common descent of species. And this is quite telling in this clip because in practically every single sentence, Psarris claims that this has to do with evolution, evolutionary models, or evolutionists.

With that said, I will not address the non sequitur “evolution” references in each and every claim when I address them in the next section.

Addressing the Four Main Claims

1. Jupiter’s Rotation Rate

First off, I should note that we have known what Jupiter’s rotation rate was as far back as 1835 (since that’s the first paper that I can find on the subject) but I would guess that Galileo was able to estimate its rotation period, as well. For those interested, here is the article from 1835.

With that out of the way – we know how fast it’s spinning on its axis – how does it spin so quickly? The preliminary question would be, why does it spin in the first place? This webpage has a pretty good simplified explanation for why objects in the solar system spin, and why they mostly spin in the same counter-clockwise direction (when viewed from the North Pole). The basic one-liner is that the protoplanetary disk was orbiting the protosun in the same direction, and due to the differential rotation within the disk, a net spin was imparted onto any condensing objects.

And now we get to the part where the objects spin quickly. This is the classic ice skater analogy: If your spinning on the ice and you have your arms extended, you will spin slowly. If you bring your arms closer to your body, you will spin faster. That is because of the conservation of angular momentum. Now let’s say you put 20-lb lead weights in your hands. If you now bring your arms close to your body, you will spin even faster than before. In other words, the more mass you bring close to the center, the faster you will spin.

Jupiter has a lot of mass – the most mass of any object other than the sun in the solar system. It also has the fastest rotation rate. Saturn, the second-most massive planet, has the second-fastest rotation rate. Neptune, which has the third-largest mass, has the third-fastest rotation rate. See a pattern?

Now, I’m not sure what “evolutionary model” he’s talking about that predicts a slower rate. He doesn’t cite his source. Regardless, he has not presented any case that anyone should take seriously as to why Jupiter “can’t” spin quickly under an “evolutionary model,” so at best this is an unsupported claim where the burden of proof is solely upon him to at least present reasoning rather than a simple claim.

Update since original post: I have now obtained a copy of the paper that Psarris quotes from (Kerr, (1992), “Theoreticians are putting a new spin on the planets,” Science, 258: 5082, p. 548.). This is a very obvious example of a fairly common YEC tactic, quote-mining. This is where they search for a line or two in pretty much any scientific paper/book/press release and use it completely out of context.

In this case, the quote is, “The simulated bombardment leaves a growing planet spinning once a week at most, not once a day.” The main problem is that, just as I point out in the rest of my blog, this isn’t a “naked” announcement — the two teams that this paper cites have modified current models in order to explain how the planets spin faster than once a week. In fact, that quote comes from the fourth paragraph. The second paragraph states: “Neither group claims to know exactly what actually set the planets spinning so furiously. But both groups–Stony Brook’s Jack J. Lissauer and David Kary and Toronto’s Luke Dones and Scott Tremaine–are ready with alternative scenarios. Lissauer and Kary favor a modified version of the small-collisions scenario, but Tremaine and Dones lean toward a more catastrophic mechanism, in which planets acquired their spins from a few giant impacts, or even one, late in their evolution.”

I can’t go on to quote the paper verbatim because that is not the purpose of this blog post and it is not completely legal (and the paper requires a subscription to the journal in order to read it). But the upshot is that this paper simply describes, in short, two small modifications to the main planetary formation models that can better account for a preferred direction once you consider even more of the real, physical dynamics that occur in a protoplanetary disk.

2. Elemental Composition

This second claim is at best misleading, at worst just an outright lie. The main composition of Jupiter is H2 (molecular hydrogen) at 89.8% (±2.0%). The secondary element is He at 10.2% (±2.0%). Notice that those two add up to 100%. Now, there is a very little bit of other stuff, but it is what we call “trace,” meaning that there is very very little of it there.

The main trace constituents are methane (0.3±0.1%), ammonia (0.026±0.004%), hydrogen dueteride (.0028±0.001%), ethane (0.00058±0.00015%), and water (0.0004% (varies with pressure)). This is data from NASA’s Jupiter Factsheet.

Looking at a recent paper, the amount of argon in Jupiter is about 2.5x the sun’s or ~0.0009% of the total composition. Krypton is 2.7x the sun’s, or ~0.0004% the total composition. Xenon is 2.6x the sun’s, or ~0.0004% the total composition. And nitrogen is 3x that of the sun’s abundance, or ~0.0003%. It’s noted in the paper that the nitrogen amount is likely off, that the probe landed in a “hotspot.”

Now why are these tiny tiny numbers cause for mention? Well, they do show a relatively significant enhancement over the solar abundance, and Jupiter is supposed to be reasonably like the sun in its composition. But not totally. What I have noticed that creationists commonly fail to realize is that scientists want to make observations that disagree with their theories. But rather than throwing away their theories, they modify them in order to improve the theories so they can explain all of the evidence. That is what has happened since the determinations of the jovian atmospheric composition: It has placed constraints on models of Jupiter’s formation. Rather than make assumptions, we now have legitimate constraints upon parameters, like where in the solar nebula Jupiter may have formed, or where the smaller pieces that combined to form Jupiter may have formed themselves.

That is what real science is: Making a model from current observations and then making predictions from that model. If future observations do not match those predictions, then the model must be altered or replaced in order to be able to account for the new observations. We can still build Jupiters in planetary formation models (as opposed to evolution models). We just now have more constraints upon how, where, and from what they form.

3. The Core of Jupiter

This claim is fairly silly at this point in time. Before the Galileo probe reached Jupiter in the 1990s, estimates of the size of the core of Jupiter were around 5-15 Earth masses, though the actual value varied considerably based upon what model you used and what you assumed (think back to section 2 above on how science is done).

Once Galileo reached Jupiter, it was able to take various measurements and it being in orbit allowed various tracking stations on Earth to record its position — allowing us to create a model of Jupiter’s gravity field. This, along with Jupiter’s moments of inertia, are needed to really constrain models of how big Jupiter’s rocky, solid core may be — or if it even has one.

The current state of the science, however, is inconclusive. The measurements from a decade ago were not good enough to conclusively state whether or not Jupiter has a core, and how large it may be. The data generally indicate that the core can be no larger than ~12 Earth masses — a far cry from whatever source Psarris used that said the core can be a maximum of only 3 Earth masses. But, the results from Galileo provide few limits towards the size of the core, and so it is still not well-constrained. One example reference is: Guillot, Gautier, & Hubbard, (1997), “New constraints on the composition of Jupiter from Galileo measurements and interior models” Icarus.

Another recent paper (where I use “recent” as meaning 2008) models what Jupiter’s core will be from first principles of physics and comes up with 14-18 ±6 Earth masses, within the range of what Galileo results show.

4. Formation Timescale

The next claim is that the solar nebula would disappear within 5 million years, but Jupiter takes 10-100 million to form. Obviously a problem!

But that’s what happens when you take the extreme numbers on the one hand with the opposite extreme numbers on the other, along with outdated models.

Let’s look at the 2004 publication, “Formation of the giant planets,” from 2004. The author clearly states that the protoplanetary disk will dissipate within 1-10 million years. So, yes, the “5 million years” number Psarris quoted is reasonably accurate and jives with the latest science.

However, this isn’t a “gotcha” moment for the YECs. It’s not as though they caught us astronomers with our proverbial pants down, that we didn’t realize there’s a contradiction here. We do. And yet again, this simply serves to place further constraints on how planets can form. And new models have come out of it.

The main model of forming planets is referred to as the “core instability model,” and it takes 6-8 million years to form a nice-sized gas giant. A possible problem. Then there’s the “disk instability model,” which is at-present poorly modeled but promises to form planets somewhat faster. This is still a very active area of research, and the state-of-the-art can change over the course of a grad student’s tenure. (Case-in-point: There was a grad student in my program who was 4 years ahead of me who, when I took the “Planetary Formation” class my third semester, sat in on the class. I asked him why, and he said that it’s changed so much in the 4 years since he took the class that he wanted to see what people were discussing now.)

One example is this model which proposes a diffusive redistribution of water as one of the primary mechanisms for forming Jupiter, and they can form Jupiter’s core within 100,000-1,000,000 years. Or there’s this paper, which forms the gas giants by concurrently accreting both solids and gas (generally thought to accrete separately). It can form Jupiter and Saturn in 1-10 million years.

Of particular interest in planet formation, to be honest, is how Uranus and Neptune form. All models require significantly longer timescales for them because they are farther from the sun. The fastest I’ve seen still requires ~2x as much time to form. them as Jupiter and Saturn, but they have to form while there’s still enough of the solar nebula left.

The very first line of a 2002 paper by Thommes, Duncan, and Levison states, “The outer giant planets, Uranus and Neptune, pose a challenge to theories of planet formation.” Even though this was written over 8 years ago, it still holds true today. They do pose challenges. But astronomers welcome those challenges as opportunities to learn more about the universe around us rather than throw up our hands and turn to a young-Earth creationist model, which is ultimately what Psarris wants you to do.

Final Thoughts

In general, Psarris is not presenting new arguments. I’ve heard of the last two before, though not the first two. And I can almost guarantee that he uses some of the classic arguments that I’ve addressed before in other sections of his DVD.

What’s the bottom-line? He points out apparent observational evidence that seems to conflict with the “evolutionary” picture of Jupiter. The problem with that is astronomers know about these problems – if they are problems at all – and we actually use them rather than ignore them in order to refine models of how Jupiter formed and has changed through time. All because it has 3x more nitrogen than the sun does not mean that astronomers will suddenly throw up their hands in despair and change their views to reflect that of young-Earth creationism.

But, for $19, that’s what Psarris is going to try to convince you of.

Update: I have posted a follow-up analysis of the Jupiter segment claims that are not addressed in this post here: “Jupiter: Further Confounding Those Darn Evolutionists.”

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5 Comments »

  1. nicely done.

    Comment by garth — May 29, 2009 @ 8:15 am | Reply

  2. The consensus of denialist science likes to laugh at alternative explanations of the creation. But science cannot explain everything, nor can it prove alternative explanations 100% wrong. Scientists should be more open minded that there could be rational alternative theories of cosmic evolution put forward by non scientists. Humility in the face of knowledge should be at the heart of science, not derision of alternative theories, no matter where they come from.

    Comment by Anthony North — May 31, 2009 @ 6:58 am | Reply

    • Anthony – First, I suggest you read my post about what a “theory” actually is in science. Following that, the Big Bang Theory is supported by many separate and very different observations that are all best explained by the current Big Bang Theory. If they weren’t, then we would be looking for a different theory. It’s generally really that simple.

      It amazes me how many people don’t understand this — scientists want to show that older theories are wrong. Everyone knows of names like Newton, Galileo, or Einstein. These were people that, through hard work and by gathering lots of observational evidence (and mathematical frameworks) overturned paradigms. But how many people know the names of the countless scientists who run experiments nearly every day and just confirm those theories?

      Comment by astrostu206265 — May 31, 2009 @ 9:51 pm | Reply

  3. [...] 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 [...]

    Pingback by Mercury’s Uniqueness Revealed by MESSENGER: Does It Mean a Recent Creation? « Exposing PseudoAstronomy — August 7, 2011 @ 11:20 pm | Reply

  4. If the big bang happened and science says that all things must equalize, then why is the universe speeding up? Science has some solid basis, but is mostly theory – thinks, but doesn’t know and this article elevates the problem. Science needs to keep their ideas quiet until there is proof. What about the second law of thermodynamics which science cannot allow for in their theories of the big bang and evolution – everything goes from order to disorder? This whole article and all references are mere speculation with no facts.

    Comment by Roger — November 30, 2012 @ 5:42 am | Reply


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