ASTROnomy in MICHIGAN

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You may have heard rumors of disaster in 2012. The word disaster comes from some ancient language. The prefix dis means bad, and the word aster means star. So, we have bad star. And in the days of superstition, astronomy and astrology were the same thing.

We have superstition yet. And we have the Internet. The Internet allows the dissemination of unchecked disinformation faster than was ever possible in the past. Even faster than Hollywood. Pretty much as fast as anyone can think of it. Or at least type. Yes, it's more than a little ironic that this anti-superstition essay is posted on the Internet. But as fast as as the Internet is for dissemination of unchecked disinformation, it's also pretty quick for fact checking. I'll award no-prize to the first person to find a mistake in this essay. And, unlike the conspiracy theorists, i promise to correct it. If it exists. In the mean time, and to steal a line from a movie advertisement, let's find out the truth.

So, the latest disinformation (that's bad information) says that the world will end on December 21, 2012. Let's explore some of the claims, and how well they hold up.

First, the date. A calendar used by native peoples of Mexico, the Mayans, is said to end on that date. (By the way, it is widely stated that the Mayans are all dead. While the great Mayan civilization collapsed, there are Mayan descendants still.) What the Mayan calendar actually does is roll over then. That's pretty much what the Gregorian calendar did at the end of 1999. And at the end of 2000. At the end of 1999, the calendar flipped 9's into 0's. The year 2000 was the last year of the 2nd millennium. 2001 started the third millennium, more or less. Arthur's book got it right. Except that the date for the birth of Jesus isn't known for sure. For exmample, some evidence points to Labor Day, 3 BC.

But what was the big deal? The world didn't end in 2000 or 2001, despite claims to the contrary. None of the predicted floods, famine, pollution, or shift of the Earth's magnetic poles happened. The May 5th, 2000 planetary alignment did not bring solar flares, significant earthquakes, "land changes" or "seismic explosions". Even the famous Y2K bug didn't seem to cause much disruption. I know something of this, as i personally tracked down and exterminated many of the little buggers in my career as a computer professional. We have a history of mispredictions for the end of the world.

The Mayan calendar rolls over, but it's not much of a threat. December 21, 2012 ends the cycle called Baktun 13. A baktun is 144,000 days: a little more than 394 years. However, the evidence suggests that the Mayans did not attribute much significance to this event. Certainly not a disaster. Some surviving Mayan texts refer to dates well past Baktun 13. For more detail on the Mayan calendar, look up the November 2009 Sky & Telescope magazine article, The Great 2012 Scare.

There are numerous claims for 2012. One might be worried if any of them look as if they might be right. But one should also be extra skeptical if any of them should prove to be trivially wrong. I mean, if someone tells you five things, and one of them is wrong, or a lie, then perhaps the others are wrong, or outright lies. And we already have one that is wrong - the Mayan calendar. The Bible warns of wolves in sheep's clothing. That is, beware of people who lie to you. It's not a new problem.

Another prediction is, once again, a shift in the magnetic poles. Oddly enough, there is evidence that the magnetic poles of the Earth flip North and South from time to time. There is evidence of drift in the position of the magnetic pole over time. We are even, in some sense, overdue for a magnetic pole reversal. However, there do not appear to be any mass extinctions that coincide with these events. Life seems to be able to cope. One thought is that they happen so slowly, that life appears able to adapt. There doesn't appear to be any significant problem with cosmic rays (which are deflected by the Earth's magnetic field), the ozone layer, and so on. So, the evidence is that even if such a shift happened in 2012, it wouldn't be a big deal.

A related pole shift prediction is that the Earth's axis of rotation would somehow flip. This is unlikely in the extreme. The Earth's Moon keeps the Earth's axis of rotation locked into a pretty stable tilt, over the lifetime of the solar system. It's not likely to change much in a couple years.

But, the claim is that a large planet, the size of Jupiter and named Nibiru, will come into the inner solar system, and sweep from the outer solar system, and either strike the Earth or come very close. The name comes from Egyptian texts, apparently. And the similarity it has to the size of Jupiter is not just a coincidence. It appears that Nibiru was a name used by the Egyptians for the planet Jupiter. Jupiter is not heading our way any time soon. Certainly not in 2012.

Let's say that there was a Jupiter sized planet coming our way in 2012. Where would it be now? Well, it would have to be well inside the orbit of Neptune. And even if it was black as tar, it would be incredibly bright. The Moon is as black as tar. And it's much smaller than Jupiter. The millions of amateur astronomers would have seen it by now. And if, as has been suggested, that it's only visible from the southern hemisphere, then thousands of amateur astronomers who happen to live far enough south would have seen it. If an object happens to be overhead south of the equator, that doesn't mean that no one in the Northern Hemisphere can see it. From 42 degrees North, (Detroit), one can see 48 degrees South of the equator. That's more than half of the Southern skies. And It should be pointed out that thousands of people would not be able to keep a such a secret. After all, a hundred people weren't able to keep the Watergate scandle quiet. And, of course, amateur astronomers routinely post their latest finds on the internet, often minutes after discovery. Most of the conspiracy theories i've heard have this problem. Huge numbers of people can't keep secrets. The obvious conclusion is that this object, Nibiru, does not exist.

Another claim was that 2012 was to be the year of the most recent solar maximum. However, the Sun isn't cooperating. The current solar cycle has taken longer than usual, and it isn't expected to reach maximum until some time in 2013. And, we have such a maximum every eleven years, more or less. We've survived them so far. So much for that idea.

So, what is known for certain about the end of the world? Well, we know that nothing is permanent. The world will end. Eventually. Just not in 2012. For one thing, at about 4,500,000,000 years old, the Sun is middle aged. As it ages, it gets a bit hotter. Some estimates are that the Earth will be too hot in just another 150 million years. And in five billion years, give or take, the Sun will expand into it's Red Giant phase. The surface of the Sun will expand out to approximately the diameter of the Earth's orbit. The Earth will pull a tidal bulge out from the Sun, which will cause gravitational drag, causing the Earth to spiral in, and be consumed - vaporized. And such an event would be the end of the world, to be sure. Even if it is billions of years after the oceans boil away.

On the face of it, this fate seems certain. However, the Earth currently enjoys a peculiar chemical reaction which we call life. That includes us. And we're already clever enough to know how to save the Earth(!). We'd be stupid indeed, if we don't. It's a big project, but calculations suggest that we have plenty of time. The physics are already well understood. There are some fairly minor technical (engineering) details to attend to. But the general idea is to put a large asteroid on a figure eight orbit between the Earth and Jupiter. We steal some orbital energy from Jupiter (which will hardly notice), and give it to the Earth - expanding it's orbit. As the Sun heats up and expands, we move the Earth out in it's orbit, keeping it at a nice temperature. One can get a big asteroid moving by using smaller asteroids moving by it. One must be careful. An accident could cause the end of the world - which is what we were trying to avoid. It's a bit of irony that the technology to save the Earth can also end it.

While we're saving the Earth, we might as well save Venus. It has similar gravity to Earth. We'd need to cool it down, spin it faster, and fill it back up with water. Without it's runaway greenhouse effect, it would freeze where it is. It isn't as difficult as it sounds. A few thousand years at most to bring down the temperatures. These orbit moving projects take millions of years. Terraforming Venus would be finished before we knew what was happening. And, as the temperatures on Venus have been hot enough to melt lead, it's almost certainly currently lifeless. Unlike Mars, which still seems quite likely to have some sort of life on it. We could infect Venus at our leisure without any pesky ethical questions.

And after the Sun's Red Giant phase, it stops any nuclear fusion, and collapses into a White Dwarf phase. So, we reverse the outward spiral of the Earth, and keep the Earth at that just right toasty warm distance. At that point, the Sun slowly cools, but estimates are that we have trillions of years left. Plenty of time to colonize the rest of the Milk-dromedae galaxy. No, i didn't see the 2012 movie. I'd like to be able to enjoy such a spectacle, but there are limits to my abilities in the area of suspension of disbelief.

Some say the world will end in fire, Some say in ice. From what I've tasted of desire I hold with those who favor fire. But if it had to perish twice, I think I know enough of hate To know that for destruction ice Is also great And would suffice. - Robert Frost

Knowing Right From Wrong

On October 21, 2004, I gave a talk at the Warren Astronomical Society. It was based on a book written in 1909 called Curiosities of the Sky, written by Garrett Putman Serviss. Since it is out of copyright, it is available for free at Project Gutenberg. Download it and read it. That's what I did.

The book consists of a series of descriptions of the current problems in 1909 astronomy. For each issue, Serviss presents a brief overview of the available evidence, and then a series of current ideas that had been proposed to explain it. Finally, he picks his favorite idea. It struck me that he was wrong a large fraction of the time.

Would I have been wrong that often? I doubt it. Maybe it's my century-later perspective. But to me, evidence is evidence. Maybe I have higher confidence in spectroscopy than was common a hundred years ago. In any case, many of these concepts were cutting edge at the time, so it shouldn't be a big surprise if a mistake was made here and there.

My talk wasn't a book review. Nor was the talk about 1909 cutting edge science. My angle was to attempt to engage the club to use the past to try to see the future. My big idea was that with hindsight, we can see which (if any) of the explanations of 100 years ago was most correct. So, could this be a guide, of sorts, to learn how to tell if a modern idea is likely correct or not? Is there a way to learn thought processes that can teach us how to interpret modern discoveries? With that in mind, let's go over just a couple examples.

The Andromeda Nebula

I should point out that the nomenclature of the time had The Milky Way, and The Universe as basically synonymous. The Milky Way was thought to be a flat disk of stars. But it was not known if there was anything else. In particular, the Andromeda Galaxy was called the Great Andromeda Nebula. Measuring distances to even nearby stars is extraordinarily difficult. It was first achieved for a handful of stars around 1800. These were stars that were at most a few tens of light years away. We now estimate the distance to the Andromeda Galaxy as 2.5 million light years away. As galaxies go, it's nearby. And that could be inferred by it's being the biggest and brightest of these "spiral nebulae".

In 1885, astronomers were surprised to see a sixth-magnitude star glimmering in the midst of the hazy cloud of the great Andromeda Nebula. It soon absolutely disappeared. Its spectrum was remarkable for being continuous, like that of the nebula itself. A continuous spectrum is supposed to represent a body, or a mass, which is either solid or liquid, or composed of gas under great pressure. That is, both the "nebula" and the "new star" or nova, had a stellar spectrum, not a gaseous spectrum like the Orion nebula.

In other words, they thought that M31 was a nebula, despite spectrographic evidence to the contrary. Then, a faint supernova appears there, at least 9 magnitudes fainter than usual, indicating a factor of 4,000 reduced brightness, suggesting that the object is at least 60 times further away than usual. Perhaps, since they have really no idea how far away the bright ones are, this has no significance for them. If the bright supernova are at least 10,000 light years away (in the band of the Milky Way), then M31 ought to be at least 600,000 light years away, quite outside of the Milky Way. But this deduction didn't seem to happen. Note that they thought that nova are stellar explosions. Further, they were known to brighten by 7 magnitudes or more. This should indicate that these nova are pretty far away. Perhaps this is what Hubble was thinking some 15 years later, but wanted better proof.

An ancient Greek did better. One guy drilled a series of various sized tiny holes in a plate. He viewed the Sun through them. Then, at night, he attempted to remember which hole was closest to the brightness of the brighter stars. With the hypothesis that the Sun was a star, only closer, he wanted to figure out how far away the stars must be. And the estimate wasn't terrible, despite the inaccurate assumptions (like stars are the same brightness, and so on). For that matter, what was the state of arithmetic 2000 years ago. No zero. I'd hate to do the math with Roman Numerals. Given evidence that Andromeda is star-like, then the apparent brightness gives you a distance. This distance is well outside the Milky Way. I want to tell them, "get over it". But this is assuming that they could resolve any stars at all. We may have needed to wait for the 100 inch Hooker telescope for that.

Anyway, Serviss thought that Andromeda, whatever it turns out to be, must be smaller, closer, and inside the Milky Way.

There's another problem. It had been only a hundred years since the distance to the nearest stars had been measured. 20 trillion miles or more. People couldn't wrap their heads around such huge distances. They sort of gave up, calling such huge numbers Astronomical Distance. They didn't seem to be prepared for numbers a million or more times that far.

Nova

In 1901, a pre-maximum sighting of a nova was reported. Pictures days before showed that no star down to 12th magnitude existed. Then, the nova appears, and for two days brightens to maximum. Then, in jerks, it fades over time. Finally, pictures were taken and the nova was surrounded by a nebula - which they did not see before. The spectrum transforms from stellar to nebular over 6 months. The speculation is that two stars collided.

During the collision: the photospheric envelope of the star is destroyed, the internal incandescent mass gushes out.

The theories of what causes nova include collision of two stars, collision of a star and a nebula, chemical change in a star (including oxygen/hydrogen), and atomic explosion.

One theory is that most or all stars nova, but the ones we see are short lived stars. Most stars take "millions of years" to get to this point.

OK, so a stellar collision is fairly reasonable. I was amazed that there was any idea of an atomic explosion. I don't think anything was known about fusion. At the time, it was a total mystery how geologists could claim that evolution must have taken hundreds of millions or even billions of years, and the Sun must have been shining all that time. So the idea that only large stars with short lives explode was not known. These days, the idea is that stars generally don't collide, except in crowded globular clusters, or maybe the crowded center of the galaxy. Stars are just too far apart to have much chance at collision. And this might have been known at the time.

A Modern Example

The Hubble Space Telescope was launched, in part, to determine the age of the Universe. The idea was to get a better calibration for the Cephied Variable Star brightness to pulsation rate phenomenon. It would do this by measuring the distances to nearby examples and get better values for their brightness. Then, distances to nearby galaxies would be measured. Type Ia supernova in nearby galaxies would be calibrated, and finally distances to more distant galaxies would be obtained, along with their cosmological red shift values. All very good. It was called the Hubble Key Project.

But the team released an early report that the Universe must be a bit over 11 billion years old. I immediately thought that this value was not old enough. There are stars thought to be older than that. There are clusters thought to be older. And a correction was issued a few years later. And now, we have multiple lines of evidence, including a totally independant measurement that comes from the study of the cosmic microwave background. But i've no idea why i came to my conclusion so quickly. I turned out to be right. And, in all modesty, i usually am right. But if this is something that i learned, is it something that could be taught?

Conclusion

A longer version of this article is up on my before-blogs-were-invented web site. In my opinion, the original book, Curiosities of the Sky, is more entertaining. Really, go read it.

Science is an endeavor that attempts to discover truth. And, it's been extraordinarily successful. It is tempting to many to use it as a religion. After all, religions essentially all claim to either have the truth, or be in the process of seeking it. Further, just as most religions have a creation myth story, so does science. It's not our first creation myth based on evidence. So the question is, why do we feel that it's so much more correct than other attempts? The lay person doesn't have the time to personally investigate the current cutting edge claims coming out of science. So, it's easy to fall into pseudoscience, like the 2012 end-of-the-world predictions. How does one weed out the nonsense?

...the educated person is not the person who can answer the questions, but the person who can question the answers. -Theodore Schick Jr.

And yet, the show has an "Ask the Astronomer" segment, not "Answer the Astronomer".

Stephen Uitti, suitti@uitti.net