Exposing PseudoAstronomy

October 18, 2008

Solar System Characteristics that Do Not Point Towards Creationism (Though Claimed To)


This post is in regards to the Institute for Creation Research’s January 13, 2001 program entitled, “Sun, Moon, & Stars.” You can listen to the audio here.

The basic premise behind this episode of ICR radio is to talk about the sun, moon, and stars, and to raise enough questions as to lead a listener to think that these “three” celestial items prove the Universe was created.

The first train of thought has to do with one of the first real scientific ideas of how the solar system formed:  The “Nebular Collapse” theory that was thought of by a fairly famous mathematician named Laplace.  The Nebular Collapse theory’s basic premise is that a large cloud of dust and gas would collapse, the main center of collapse being where the star would form, and other points that started out as higher density eventually forming planets.  The ICR episode goes on to say that this is still the basis for how we think solar systems form today, which is true – it is the basis for it.

However, the program then goes on to discuss the debate that came to a head in the 1920:  Were “spiral nebulae” actually nebulae in our own galaxy that were in the process of collapsing into solar systems, or were they actually outside of our galaxy, being their own “island universes.”  The answer turned out to be the latter, when Edwin Hubble (you may recognize that name, there’s a fairly famous space telescope named after him) discovered individual stars in the “Andromeda Nebula,” thus proving that it was not a collapsing solar system.

As far as I can tell, the only purpose of bringing this up is an ad hominem attack on Laplace’s Nebular Collapse theory:  Because Laplace was wrong about these galaxies being nebulae, his whole theory of solar system formation must be wrong, which means that since it forms the basis of our current theories, they must also be wrong and so we have no idea how solar systems form.

If you listen just a little further (starting at 3 min 50 sec), you’ll find that my supposition (which I made before listening to the rest of the episode) is correct:  They use it to cast doubt upon our current theories.

They have Tom Henderson who used to work at NASA’s Johnson center (getting a former NASA employee to say this for them really helps their Argument from Authority fallacy) to talk about how the “Evolutionary Theory that the solar system formed by some solar nebula …”  can’t explain what we see today.  (Yet again, as seems to be the theme for these Creationism posts, I have NEVER introduced myself – nor thought of myself – as an “evolutionary” astronomer.)

For example, he points to Venus’ spin.  He correctly states that Venus revolves “backwards” on its axis, which “shouldn’t” happen according to the Nebular Collapse theory.  Well yes, that’s true, everything should be orbiting and spinning the same way.  But we can fairly easily explain it by a giant asteroid impact early on in the solar system’s history.  In addition, there are other possible mechanisms for flipping Venus over, none of which involve God.  The alternative that they imply but don’t explicitly state, of course, is that they want the listener to think that God must have created Venus just as it is.  But there’s no way to test that, no way to model it in a computer, and no way to make predictions based upon it.  In other words, it’s not science.

Next up, around 5 minutes into the program, they have Wayne Spencer talking about Saturn’s “Dancing Moons,” Janus and Epimetheus.  What’s intriguing about these two moons is that they are separated by only about 50 km from each other in their orbital distance from Saturn, which is smaller than many large cities.  And, every 4 years, they swap orbits.  Wikipedia actually has a decent section on this.  Wayne says the fact that they don’t collide must be evidence that God Did It.  However, computer modeling of the break-up of a large object and then what would happen to the fragments show that this kind of thing really can happen under the normal laws of physics and can remain fairly stable, again, not needing the Hand of God.

He then makes a side-note about how there are lots of surprises out there that we wouldn’t predict based upon a naturalistic worldview. This is correct. And that’s what makes science interesting: We’re always finding things that we can’t explain at that time, and then we work to try to understand why it is the way it is.

The broadcast then introduces Donald DeYoung (about 6.5 min. in) to discuss that ocean circulation is largely due to the moon creating tides, this being essential for the ocean’s health and that we require the ocean to be healthy for life, and without the circulation there would be no oxygen which he then equates with air for us to breathe. This goes from true to possibly to wrong. Yes, the oceans get stirred up quite a bit through the tidal effects the moon has on Earth. Maybe this is a requirement for life, but it’s unlikely because there are other mechanisms for circulating the water, such as winds as well as the simple rotation of the planet. There could still be plenty of biota in the oceans without the moon, it just may not flourish as much. And as to oxygen for us to breathe, this is not correct, for land-based plants also make free oxygen, not just ocean plants, and if there weren’t oxygen in the atmosphere for us to breathe, we may just as well have evolved to take advantage of some other gas that was plentiful in the atmosphere.

They then go on to discuss the moon’s stabilizing effect on our axial tilt, also known as obliquity (presently at the oft-quoted number of 23.5°). This is true – Earth’s tilt changes only by about ±1° because we have the moon helping to stabilize us. Mars, without a large moon, wobbles chaotically ±5-10° on the “short” timescales of millions of years, and between 0° to nearly 90° on much longer timescales. This ensures that our seasons are fairly steady and we don’t have the kinds of temperature extremes over various sections of the planet that we may otherwise have. It is entirely possible that life at our complexity could not have evolved on a planet with the kind of obliquity that Mars has. But this does not mean the moon was created — in fact, one could just as legitimately ask why (a) g/God didn’t create us on a planet WITHOUT a large moon for stabilization, just to show that s/he could?

The broadcast then (about 8.5 min.) starts to talk about Earth being unique and designed for life. This is actually a fairly straight-forward logical fallacy, the Argument from Final Consequences. In other words, they argue God must have created Earth because Earth is suited for life. This is not how science operates: They should be saying, “Earth seems to be suited for life as we know it, let’s try to find out why.”

After this, the program reverts to standard creationist arguments that don’t really have to do with astronomy, so I will end this post here.

Why Few Supernova Remnants Do NOT Indicate a Young Universe


This entry is in specific response to the “Where Have All the Remnants Gone?” article from Creation Science Evangelism, though it is espoused in other creation literature.

There is a young-Earth creationism argument that goes as follows:  Stars that are much more massive than the Sun end their lives by exploding their outer layers into space in a process called a “supernova.”  These outer layers of stellar debris are heated and lit up by the energy from the supernova event.  The claim then goes that there is a certain expected rate of these (this particular article claims 1 every 25 years in our Milky Way galaxy).  Then, if you take the number of observed remnants (around 200) and multiply by the rate of occurrence, you get an age of our galaxy of around 5000 years.

Seems pretty bad for a 13.7-billion-year-old Universe, right?  Well sure it does when you’re fed half-truths.

The real story is a little more complicated, though I’m going to work a little backwards through this problem.  First, almost no astronomer says that a supernova should occur in our galaxy once every 25 years.  Rather, the canonical number is about 1 every 100 years (in fact, this was featured in an episode of Star Trek Voyager, “The Q and the Gray”).  Revisions over the past few years have pinned it down more at once every 50 years.

So now, if we do straight multiplication, we have about 50 * 200 = 10,000 years.  Isn’t that exactly what creationists say (more or less) the age of the Universe should be?  Yep, but there’s more.

We cannot observe supernova remnants across our entire galaxy – basically nebulae.  Supernova events we can see across the visible universe, but the actual gaseous remnants are much fainter because they are more diffuse.  Because of dust and gas in the way, we cannot see all the objects in our own Galaxy.  Probably the farthest we can see into the galaxy is maybe to a distance of 10,000 light-years.  The galaxy is about 100,000 light-years across.  Doing a simple calculation of the area of a disk 10,000 light-years vs. 100,000 light-years (but 50,000 light-years in radius) yields an area of our galaxy about 25 times larger that we can NOT survey for supernova remnants vs. what we can.

So now, we need to multiply our 10,000 years by 25, giving us 250,000 years for the age of the galaxy.

The next part is that supernova remnants don’t just form out of nothing, they form from the explosions of dying stars.  The stars that live and die the fastest still take about 10,000,000 years before they “go nova” and release a cloud of debris that will later become what we observe.  That’s pretty much the minimum time a star can “live” during the current epoch of the Universe.  Only after that will we see a supernova form.

So, add that to our estimate of the age by the number of stars and we have 10,250,000 years, or 10.25 million years for the age of the galaxy.  You should note at this point I’ve been saying “age of the galaxy.”  That’s because this would only be used to date our galaxy, not the Universe as a whole.  So you need to add in the time for galaxy formation … which is still a number that’s hotly debated, but no respected astronomer will say happens instantaneously.

BUT, there’s another complication to this situation which shows why this apparent “method” for dating our galaxy isn’t valid:  Supernova remnants fade! They only are visible for a few tens of thousands of years.  What does this mean for our estimate of 1,000,000 years for the age of our galaxy?  Well, by the time the “oldest” supernova is fading, we starting to observe supernova 200!  We should only expect to see in the neighborhood of a few hundred supernova remnants in our vicinity, regardless of how old our galaxy actually is.

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