Exposing PseudoAstronomy

October 26, 2008

Asteroid Belts – Proximity of Rocks and Why Navigation Is Not Dangerous (Sorry, Han Solo)

Even though a majority of my posts-to-date have been post against religious astronomy arguments to “prove” the Judeo-Christian creation myths, the intent of my blog really is not to “bash” religion, but to explore and explain examples of bad astronomy (or, pseudo-astronomy … sorry Phil).

To that end, I’m going to take a break from AiG and ICR propaganda and talk about a sci-fi ploy that’s often used and yet is very unrealistic:  Asteroid Belts.

I’m certain that 90%+ of people aged 25-50 remember Han Solo zig-zagging around asteroids while the Emperor’s ships tried to follow in pursuit during one of the original three Star Wars movies.  Or, for the Star Trek fans, there are at least two examples of that series using this ploy — one was an episode of The Next Generation and another from Enterprise, the latter showing a highly chaotic belt system with large chunks of rock careening around and changing direction while their shuttle pod tried to maneuver around.

What do these have in common?  They’re not realistic, at least not based on what we know of our own asteroid belt.

A Brief History of the Asteroid Belt

The asteroid belt was first “discovered” in 1801.  I put “discovered” in quotes because it was actually the largest asteroid that was discovered then – 1 Ceres – by Giuseppe Piazzi.  Ceres’ orbit showed it to be between Mars and Jupiter, and it was hailed as a new planet.  But, rather quickly, more objects were discovered in nearly the same region of space as Ceres.  William Herschel, based on this, suggested they be termed “asteroids” as opposed to planets, and that’s what they are called today (though in 2006 the International Astronomical Union re-classified Ceres as a “dwarf planet”).

More and more asteroids were discovered over the years, most of them between Mars and Jupiter, from about 1.8 A.U. to just under 3.3 A.U. where 1 A.U. is the average distance between Earth and the Sun, 149,600,000 km or 93,000,000 miles.  To-date, over 429,000 asteroids have been identified, the majority of them lying in the main belt (data source: ftp://ftp.lowell.edu/pub/elgb/astorb.html ).

How Many Asteroids of What Size?

Now that you know a tiny bit about the history of what we know about the asteroid belt, the next information relevant for this discussion is how many asteroids there are of what sizes.  The first asteroids to be discovered were big, mainly because they’re bright.  “Big” in this case is a few hundred kilometers across, something like the size of the state of Ohio.

Most of the asteroids, however, are much much smaller than that.  In general, the distribution of sizes follows what’s known as a “power law” distribution, where the number of small asteroids grows much more quickly than the reduction in size.  The slope of this power law is generally estimated to be -3.  What that means is that every time you halve the size of an asteroid, you have 8 times as many.  So say there are 100 10-km asteroids.  With a -3 power-law slope, that would mean there are 800 5-km asteroids.  And 6400 2.5-km asteroids.  But only ~13 20-km asteroids.

In terms of what is known, there are about 20,000 asteroids between 2-3 km, which is about the smallest that we likely have a complete sampling of.  What that statement means is that, while we have identified asteroids that are smaller, our detection technology is not good enough to have found all of the asteroids that are smaller.

If we extrapolate, assuming a -3 power low, down to, say, 100-meter asteroids, there are probably ~82 million asteroids that are ~100-200-meters across.  If we extrapolate further, down to 1-meter asteroids, then we really have a gargantuan number of objects – about 1014 (100 quadrillion) objects of that size.  That’s quite a lot.

What Does this Mean for Navigation?

If we add up all of those objects, we have about 1.2×1014 asteroids larger than 1 meter.  Now, let’s look at the asteroid belt.  It stretches from 1.8 to 3.3 A.U., which is a distance of 1.5 A.U., or about 225,000,000 km.  That’s a fairly large distance (that’s actually about the distance between the Sun and Mars).

The area of a disk that size, however, is gargantuan:  A = π · r2 = π · ((3.3 A.U.)2 – (1.8 A.U.)2) = π · (1.7·1017 km2) = 5.4·1017 km2.  That is a huge area.  Simple division shows that each asteroid, regardless of its own size, could have 4,500 km2 all to itself – a little bit more than the entire U.S. state of Rhode Island.

And that’s if they were all just in one plane.  In reality, they occupy a volume of space, some orbiting “above” or “below” others (where those terms are relative to the plane that the Earth’s orbit makes).

Even if we cut the size of asteroids in half again, and were interested in all asteroids larger than half a meter (1.5 ft) in size, then we have 8 times as many asteroids, but each one still has over 500 km2 all to itself, and even more space if we consider the vertical component.

What does this mean for navigation?  It’s easy!  In fact, you really have to try to hit an asteroid, at least in our own belt.  And so, the next time you see a tiny ship careening through an asteroid field in a TV show or movie, remember that in real life, asteroid belts really aren’t that dangerous for navigation.

October 23, 2008

NASA’s “Follow the Water,” Ice Detected by Phoenix on Mars, and Noah’s Flood

Since this is my first post in regards to an Answers in Genesis (AiG) article, I want to give a few brief comments on creationist articles that I pick to critique on this blog. In general, I plan to use materials from two main sources – the Institute for Creation Research (ICR) and the Answers in Genesis (AiG). Both try to use astronomy to promote creationism, but they are different in the way they do it. From my observations, ICR radio is fairly preachy, giving quick snippets of just enough astronomy to raise questions and then saying that it supports creation. ICR articles, however, seem much more intent on putting forth half-truths and incomplete stories (like the solar neutrino problem) and then having the reader question the scientific standards on their own.

AiG, on the other hand, is the most extreme. They present the astronomy information, then quickly turn it around saying it either fits or does not fit with a literal interpretation of the Bible, and if it does fit they say it’s real, and if it doesn’t then they say there are problems with it and it must be false because it does not fit with a literal reading of the Bible.

Since I am attempting to keep this blog fairly neutral when it comes to religion, deities, and other related matters, I will not be talking about “God’s plan on Earth,” or whether the biblical worldview is supported by astronomy or not. Only when specific falsehoods, half-truths, misleading statements, or false assumptions are made will I address them in relation to astronomy.

This entry is in specific response to the “More Ice on Mars?” article from Answers in Genesis, written by Peter Galling on June 23, 2008.

This article discusses the recent findings of NASA’s Mars Phoenix lander, a mission to Mars that has been operating since May 2008, analyzing the Mars surface and shallow subsurface (within a meter of the surface). One of the major science goals was to find evidence of water-ice (as opposed to carbon dioxide ice (“dry ice”)). It successfully did that, digging trenches and finding white material that disappeared (sublimated – turning from a solid directly into a gas) within a few days of exposure. For more information on the Phoenix mission, visit the Phoenix Mars Mission Homepage.

What I want to address with this post is the middle of the article, as the first part mainly outlines my previous paragraph:

“If Nasa has indeed found … ice on Mars, it would not be a major surprise for young-earth creationists. … In fact, this particular icy discovery should cause a cold feeling for evolutionists, who would much prefer to find liquid water but instead have found only this scant evidence of subsurface ice.”

Alright, let’s pause here. That first sentence, I have no real comment on – I mainly quoted it for context. The second quoted sentence is very close to a straw man argument, the logical fallacy where you create a claim to argue against, though the claim isn’t actually made by the other side. I say it’s “almost” a straw man because it’s true that it would be an amazing discovery that planetary scientists and astrobiologists would delight over if liquid water were found on Mars. BUT, almost no one actually thinks that liquid water on Mars exists today.

In fact, it is not possible for liquid water to exist on Mars’ surface, as any professional planetary scientist knows. That’s because water requires two things to exist in a liquid form – the right temperature and the right pressure. First, the temperature is too cold, so any water would almost instantly freeze at Mars’ surface temperature. Second, the atmospheric pressure of Mars is very small, and any water that was exposed to the surface would almost instantly sublimate (turn directly into a gas).

What is possible is for liquid water to exist in some form beneath the Mars crust. There, the temperature would be higher and the pressure greater such that liquid water could exist. It could also be mixed with salts which would lower the freezing point, as well.

So yes, while we would “prefer” to find liquid water, no one thought that Mars Phoenix would find it.

Next, I will address this:

“[T]he very idea that liquid or frozen water on Mars is a ‘big thing’ comes straight from the evolutionary faith that where there’s water, life will follow. In fact, that’s the entire premise of today’s Martian landers.”

This is confusing correlation with causation, another logical fallacy (assuming that it’s an honest mistake). NASA – and astronomers – do not think that where there’s water there’s life. That’s a fairly ridiculous assumption that everywhere there’s water you’ll find life. What they do think is that water is a requirement for life. Every single form of life that we know of requires water to live. That is why NASA’s mantra these days is “Follow the Water.” If we want to try to find extraterrestrial life, then we should be looking where there are things that we think life requires … an energy source, water, and physical conditions that can sustain it (such as protection from high levels of radiation).

That is why we are trying to find where water ice is today, where liquid water may be today, and especially where liquid water may have once existed on the surface of Mars (when it was warmer and its atmosphere was heavier). It would be those places that would be most likely to have once harbored life as we know it and we have the greatest chance of finding it. It’s not because we think that wherever there’s water life will magically spring up.

Finally, that’s not the “entire premise” of all of the Mars landers today. Yes, it is the guiding premise, and it may even be the main mission statement. But, missions are generally only selected if they can serve multiple tasks and yield information to answer multiple questions.

For example, the science mission of Phoenix has three stated questions to answer: (1) Can the martian arctic support life? (2) What is the history of water at the landing site? and (3) How is the martian climate affected by polar dynamics. You’ll notice that only one of those deals with life, two of them with water, and the third one is completely different. Phoenix doesn’t even have instruments that could detect life (such as derivatives of the Viking lander experiments).

The last third of the AiG article discusses Noah’s Flood extending to Mars, making statements about biblical worldviews as a framework for understanding astronomy, and other religious statements that really don’t address much astronomy, hence I will not address them.

Venus and the Battle of Uniformitarianism (A Creationist Argument)

This entry is in specific response to the “Venus vs. Uniformitarianism” article from the Institute for Creation Research, written by David Coppedge.

This is meant to be a short post on the heels of my crater discussion from yesterday, and it actually fits in fairly nicely even though it’s about something completely different:  The planet Venus.

Venus is an interesting planet and has held peoples’ imaginations ever since it was realized that it was shrouded in clouds, hiding its surface from view.  At almost the same size as Earth, it was long thought of as Earth’s twin and it may hide a paradise beneath the atmosphere.  That view vanished in the 1960s when spacecraft showed it to be a planet with a surface temperature far above the boiling point of water, the clouds full of sulfuric acid, and the atmosphere so heavy that the surface pressure is the equivalent of being under 1 km of ocean on Earth.

But another highly unexpected observation was that Venus’ entire surface seemed to be the same age based off of the crater population (see, there is a link to my post yesterday!).  There are just under 1000 craters on Venus, and statistically they are distributed randomly over the planet, no region being older nor younger than another (to the accuracy of crater age dating).  And then, based off of the crater density, the surface age of Venus was estimated to be 500 million to 1 billion years old (the agreed-upon number today is about 700 million).

(Note that a pretty good, definitive paper on this is found in the Journal of Geophysical Research, vol. 97, No. E10, from 1992 in an article by Roger Phillips et al. entitled “Impact Craters and Venus Resurfacing History.”)

The question is:  What would make the entire surface a single age, between 11-22% the estimated age of the solar system?  That brings us to the Institute for Creation Research article I cite at the beginning of this post.  David Coppedge uses Venus to say that it “poses a serious challenge to uniformitarian views,” (views that say geologic history has resulted from the action of continuous and uniform processes throughout time; in other words, the opposite of catastrophism).

This is actually true.  It’s very difficult to think of a uniformitarian process that would produce what we see on Venus today.  That’s actually why no one really does (hence, it is a straw man argument, an argument against something that the other side doesn’t actually say).  The prevailing view today is that Venus’ current surface is the result of a catastrophic release of magma from within the planet that broke through the crust and covered the planet in a geologically short period of time - hundreds or thousands of years.

The proposed mechanism is that without plate tectonics to release heat and energy, the build-up in the planet’s mantle eventually overpowered the strength of the crust, resulting in the catastrophic release.  It is possible that this is cyclical, occurring once every few hundred million or few billion years – we just don’t know because we (a) haven’t seen it and (b) we can only see the evidence from the last time.

Why this becomes important to creationists, and why it’s on the ICR website, is two-fold.  First, creationism relies upon catastrophic events to explain geologic features like the Grand Canyon (general appeal is to Noah’s Flood).

Second, which is the point of the last two paragraphs of the ICR article, is, “One idea never considered is that the missing 90% never occurred.”  So he is arguing for a young solar system based on the data showing that Venus’ surface is ~700 million years old.  There are many, many things wrong with this argument, but for the sake of my promised brevity, I will only address two.

The first should be obvious:  For creationist arguments, the goal is to get the age of the solar system down to 6000 years or so.  However, it shouldn’t take a math major to figure out that 700,000,000 is much greater than 6000 … by a factor of over 100,000.  The point of the article is more likely to try to make the reader second-guess the “millions of years” arguments rather than have the reader actually think of the timescales that are being suggested.

Second, and this is more subtle, he is still relying upon an argument from crater age dating.  This has been calibrated from the Moon.  So let’s say that the lunar timescale were off by, oh, a factor of 1,000,000 (what’s needed to get it to 6000 years).  Remember from my post yesterday that crater age dating is relative, and so that would mean that Venus’ age (since the article is suggesting that its surface age is the same age as the planet) is also younger by a factor of a million.

That would place Venus’ age at between 500 and 1000 years old.  Not even creationists think that Venus is that young – they can’t, because there are historic records dating back over 4000 years showing observations of Venus.  As you can see, if you actually think about these arguments logically, and carry them through to their conclusion, they become unrealistic unless there is some sort of “other” special happenstance.  You can’t pick and choose how far you want to take the evidence, as they do in this article.

Finally, I want to end with two comments on the last paragraph of the article.  First, “If it were not that Darwinian evolution requires vast ages …, many of the features observed by the space program would be considered young.”  This is not true.  Geologists had already figured out Earth was at least on the order of millions of years old before Darwin ever presented his theories on evolution.  Geology in terms of figuring out how old things are has absolutely nothing to do with biological evolution.  It has much more to do with basic physics, such as heat transfer, collision rates, gravitational perturbations, etc.  Nothing in space is dated based on an idea that evolution says something has to be old … this is an absolutely ridiculous claim showing naïveté, especially coming from someone who “works in the Cassini program at the Jet Propulsion Laboratory.”

Now that I have that out of my system … second, a more philosophical point:  “Should scientists be allowed to infer histories that are indistinguishable from myth?”  Speaking as a scientist, the idea that I can or can not formulate a history from on my observations based on the whim of whether someone else thinks I should or shouldn’t be allowed is very … irritating.  Who is he to say whether someone can or cannot think something?

Science works by lots of people coming up with lots of different possible explanations based on the observations.  They can then test those explanations by making predictions for further observations, and those observations should be able to rule out some of the explanations and still allow others.  Then the process repeats until (hopefully) one is left that explains all the observations.  If none do, then a new hypothesis must be built that can explain all the observations, and then be further tested.

The “catastrophism” idea for Venus is not presently testable due to financial and technological constraints.  However, there are ways that it can be.  One would be sending ground-penetrating radar to Venus to peer within its crust and determine heat flows.  Another would be to find fissures across the planet that could be outlets for the resurfacing material.  A third would be to actually date material on the surface and to dig down within the crust and date that material, as well.  The argument from the article – that the first 90% of Venus’ history never actually existed – is not testable at all, nor does it make sense in the context of the rest of the solar system (as discussed in my demonstration that Venus would need to be 500-1000 years old based on this article).

October 21, 2008

Dating Planetary Surfaces with Craters – Why There Is No “Crisis in Crater Count Dating”

This entry is in specific response to the “Crisis in Crater Count Dating” article from the Institute for Creation Research, written by David Coppedge.

How can astronomers say that Mars had recent volcanism?  Or that the surface of the moon Io is younger than 50 years?  Or that the youngest stretches of terrain on our moon’s surface dates back to about 3 billion years ago?  The answer is one of the basic tools of comparative planetology:  Impact craters.

Impact craters are ubiquitous throughout the solar system – every single solid body has craters on its surface except for the moon Io (because its surface is so young due to the incredible amounts of vulcanism).  Impact craters form when an impactor – like an asteroid or comet – hits the target surface of a planet or moon.  The impact occurs at high speed, and the final crater depth, diameter, and shape are effectively determined by the surface gravity, the mass of the impactor, and the velocity of the impactor.  Almost all impact craters are circles; only impacts at very low angles (less than 10°) will form elliptical craters.

Note:  There are craters of other origins, such as pit craters or caldera craters at the top of volcanoes.  Only impact craters are used to date surfaces, and for brevity I will only be referring to them from this point on as “craters” instead of “impact craters.”

The basic idea behind using craters as an indicator of a surface’s age is that the longer the surface is around, the more craters will form.  If an impactor were to hit a target at a rate of 1 per year, then a surface that’s 1,000,000 years old should have 1,000,000 craters.  But if that surface were to have something happen to it, like it got covered by lava, then that would erase the craters and the crater age would be set back to 0.

That’s effectively what people do in order to date the surfaces of planets or moons that are not Earth:  We count the number of craters of different sizes for a part of the surface and then compare that with the rate of impacts of that size.  This is called “crater age dating,” and it is a form of “relative age dating.”  The reason that it’s relative is that it cannot give an absolute age in years, it can only say if a surface is statistically older or younger than another surface.

To actually calibrate the number of impactors of a given size to an absolute age requires us to date the rocks within that surface.  This was one of the science results from the Apollo lunar missions – samples brought back from the moon were dated in the lab and hence an absolute age could be assigned to surfaces with a certain density of craters (number of craters per area).  This can then be extrapolated to other locations in the solar system.

Craters form in all sizes – from microcraters on airless bodies like the moon to giant basins literally 1000s of kilometers across.  In general, researchers use craters that are on the 10s of meters scale to about 1 kilometer, or a few kilometers to a few 10s of kilometers for age dating (at present, there is a general mismatch gap in what is used; this is generally because the meter-scale craters are used to date smaller, isolated surface areas whereas kilometer-scale craters are used to date much larger geologic units that cover a significant percentage of the planet or moon).

One more piece of background information is that when craters form, they send up clouds of debris, from dust-sized particles to objects up to a few percent the size of the original impactor.  These larger chunks of material are ejected outwards from the forming crater, and they may end up forming their own craters.  These are called secondary craters since they were formed as a result of the original, or primary crater.

Secondary craters are different from primary craters in the way they look because of their formation history — mainly they are much smaller and they are also shallower.  This is both because the ejected material that formed them was much smaller than the original impactor and because the velocity of the debris is much less than the original impactor, so there is significantly less energy to form the secondary crater.  Observations and computer models have shown that the largest secondary craters can only be up to ~5% the diameter of the primary crater (observations made on Earth, Moon, Mars, Mercury, and Europa), although the vast majority are much smaller than 1% of the primary.  In addition, secondary craters that form closest to the primary (within about 10 crater radii) are usually very easy to identify as secondary due to the way they look and the surrounding surface.

The point of this background it that crater age dating has been used for over 50 years, and it rests on very solid theoretical, experimental, and observational grounds.  However, you wouldn’t think that given the ICR article, “Crisis in Crater Count Dating:”  “New thinking about ‘secondary craters’ has thrown this whole foundation of comparative planetary dating into disarray.”

The article continues with misleading statements:  “One writer in Nature estimated that a single large impact on Mars could generate 10,000,000 secondaries, and that 95% of the small craters on Europa could be from fallback debris.”  You are clearly expected to infer from this that almost all craters (95%) on surfaces are secondaries by simply connecting those two phrases together.  That may actually be true.  But there is no size range stated.

Those same authors, Alfred McEwen and Edward Bierhaus, who are not mentioned in that quote wrote a paper in 2006, “The Importance of Secondary Cratering to Age Constraints on Planetary Surfaces,” in the Annual Review of Earth and Planetary Science.  I highly recommend reading it if you are interested in this subject, and it is written at a non-technical level.

In their paper, they show that yes, secondary craters do dominate planetary surfaces, but for Mars (the object of interest at the moment), the critical diameter at which secondary craters dominate is about 1 km.  Craters smaller than 1 km are likely >50% secondaries, but craters larger are >50% primaries.  And because a significant amount of age dating is done with craters larger than 1 km, there is no way that “this whole foundation of … planetary dating [is in] disarray.”

The ICR article goes on from there, and either shows the author’s ignorance of the issues or that they are simply lying:  “Without a way to reliably identify secondary craters …”  As I stated above, the majority of secondary craters that are close to the primary can be identified because of their distinct shapes and characteristics – they are shallower, they are often elongated with the long axis pointing towards the primary, they appear in clusters, and there are generally trails of them that lead back to the primary.  One could also ask the question, “If there were no ‘way to reliably identify secondary craters,’ then how could we know that there even are secondary craters?”  Granted, it does become more difficult the farther from the primary crater and the smaller the secondary, but this becomes a non-issue when using large craters.

But, you can still use small craters to date planetary surfaces.  One of the arguments used is that reference crater densities that indicate a certain age for a surface were created  without taking secondary craters into account – in other words, they have both primary and secondary craters in them.  So when using them to date a surface, it doesn’t matter if there are plenty of secondary craters there because they are in your reference, too.

Besides this, this topic is still in active debate at planetary astronomy conferences today (William Hartmann and Gerhard Neukum are two of the strongest proponents that secondary craters aren’t even an issue for sub-kilometer age dating).  In fact, I was just at a conference – the Division of Planetary Science for the American Astronomical Society held at Cornell University in Ithaca, NY (October 2008) – where Dr. Hartmann presented results which indicated that secondary cratering is not a problem at sub-kilometer diameters for age dating.

In the last crater-related point I want to address from the article, it implies that astronomers applied crater age dating from the moon to other objects “believing they knew how old the earth-moon system was.”  This is true, but it’s not true the way they imply it.  From this statement (the next-to-last paragraph of the article), you are clearly meant to think that we used crater ages from the moon to go to other bodies, but if we don’t even know how many craters equals 1 year or 100 years or 1000 years on the moon, how could we possibly know what it means on other objects?

The answer should be apparent given the background I discussed above:  Craters give relative ages, while radioactive decay dating methods give absolute ages.  We applied the relative ages from the crater densities on the moon to other bodies, so it doesn’t really matter if we don’t know how old that surface is on the moon for that exercise.  But then we can calibrate the relative scale with the absolute scale from the moon because we have independently dated its surface with a completely different method.  Therefore, the ICR article is yet again trying to mislead the reader.

The final point that I would like to address is the article’s last sentence:  “There is an important lesson here, though, for all science lovers:  question assumptions.”  (emphasis mine)

I whole-heartedly agree.  You should question assumptions.  You should try to understand why someone says what they do.  You should do your own research, your own experiments, and make your own observations.  You shouldn’t take my word for it, you shouldn’t take ICR’s word for it, you should go out and look for yourself.

Finally, you should always question someone’s assumptions, especially if they are based in an ideology:  If they start from the premise that the Bible is Truth, the literal word of an omnipotent and infallible deity, and then try to make all observations fit within that view, you should be questioning that assumption.

October 20, 2008

The Apollo Moon Hoax: “No Stars” Claim and an Explanation of Dynamic Range

All posts in this series:

Continuing my sporadic series on claims made by people who believe that the US never landed humans on the moon, I am going to address one of the simplest and yet most prolific claims:  There are no stars in the pictures of the moon.  After all, the sky is black and without an atmosphere we should be able to see stars … right?  WRONG

I am going to address this in three ways, first by proposing questions which demonstrate the lunacy (pun intended) of this claim when you actually think about it.  Second, I will address the reason why we don’t see stars in a qualitative way, and third I will explain dynamic range and why stars aren’t visible in a quantitative way.

Method 1 – Why This Doesn’t Make Sense

The claim effectively goes:  On the moon without an atmosphere in the way, the sky should be filled with stars.  Since there aren’t stars, it must be fake.  In fact, it must be a really bad fake because NASA knew that they wouldn’t be able to figure out where every star goes on their black backdrops for their sets because other people would realize they are in the wrong place, so they just eliminated the stars all together and made the backdrops completely black.

This shows one of the major problems with conspiracy theories of this scale – you have to grant the conspirators a huge amount of power, intelligence, and influence, yet they have to be so unbelievably dumb as to make simple mistakes that the conspiracy theorists can then point out.

When I do my planetarium show on the Apollo Moon Hoax (“Why We Did NOT Not Land on the Moon”), I have the operator bring up the star projector along with a 360° lunar panorama to “simulate” what the conspiracy theorists say it should be like if we’re on the moon.  And it’s a good simulation.  Why?  Because the stars should be in the same place as they are on Earth!  Even though the moon is 384,400 km from Earth, that’s pretty much nothing in relation to where we would see stars from the Apollo cameras.  Only if the astronauts were to do very precise astrometry with very long-focal length lenses (as in telescopes) would they be able to discern any deviation from where the stars would appear from Earth, and even then, it would only be for the very closest stars to our solar system.

So, the fact that we have great planetarium star projectors that simulate the positions of thousands of stars means that NASA should have easily been able to figure out where to put the stars.  And not just that, but if NASA couldn’t figure out where to put the stars – when they had 1 out of every 360 Americans working on the Apollo program in some manner – how would someone else be able to figure out that they were in the wrong place when the exact orientation and location of every single Apollo photograph is simply not available to them?

It simply doesn’t make sense for NASA to have purposely left the stars out.

Method 2 – A Qualitative Explanation of Dynamic Range

Dynamic range (discussed with numbers below in Method 3) is the ability to observe/record/detect a range of values.  For example, if you look at an oven thermometer, it probably has numbers for 100° to maybe 500°.  That’s the dynamic range of it, it can’t record anything below 100° nor about 500°.  Same thing with a car’s speedometer – its dynamic range is probably 0 mph to around 150 mph.  Any speed above 150 and it’s useless.

With cameras, it’s a little more complicated because you can control the “window” of dynamic range with things like shutter speed and aperture.  So let’s go back to the thermometer example – the one above has a range of 400°.  Let’s say I re-calibrated it such that it can now record between -100° and +300°.  Its dynamic range is still the same, but I’ve changed what temperatures it’s sensitive to in the same way changing the shutter speed of a camera will change what light levels can be captured before they’re too dim to be recorded or too bright to be completely washed out.

This is what happened with the stars:  The dynamic range of the camera film was too small to both properly expose the lunar surface and to record stars.  And since, for the most part, the astronauts went to the moon to explore the lunar surface and not do stellar astronomy, they didn’t take pictures of the stars …

… except they actually did (example photo on the right).  Conspiracy theorists never actually bring this up because it’s one of those incontrovertible pieces of evidence that we actually did go to the moon.  Ultraviolet light is blocked by our atmosphere and so it doesn’t reach the ground (for the most part), which is a good thing for life such as us.  To do UV astronomy, you have to go above Earth’s atmosphere, and so the Apollo 16 astronauts actually brought UV cameras to the moon.  They took photographs that were made available, and they were the first of their kind showing features in the far-UV spectrum.  Many years later, when space-based UV telescopes became operational, they confirmed that the Apollo 16 photographs were real because they showed the same things.

Method 3 – A Quantitative Explanation of Dynamic Range

This is a discussion of dynamic range with more numbers.  For ease of argument, let’s say that the dynamic range of the camera film used by Apollo is between 1 and 100.  If only 1 piece of light or less hits the film, the film records it as black.  If 100 pieces or more hit the film, it’s recorded as white.

Now let’s say that the moon reflects between 6000 and 20,000 pieces of light per second, while any one reasonably bright-looking star hits the moon with more like 1 piece of light per second.  (This is actually the approximate scaling between the two.)  This is not because of any atmospheric effects (Earth’s atmosphere transmits over 90% of visible light through it, and it wouldn’t selectively screen out star light from moon light, anyway), but simply because the stars are much fainter because they’re much farther away.

As you can see right away, we have a problem:  Our film can only record between 1 and 100 counts, but the moon reflects over 100 times that amount of light per second.  That’s why we have a variable shutter speed.  We can expose the film for less than 1 second.  In this case, if we expose the film for 1/250th of a second, then the film should only pick up between (6000/250 = ) 24 and (20,000/250 = ) 80 pieces of light in that picture.  Since 24 and 80 are both between 1 and 100, then we have properly exposed the moon, getting its brightness within the dynamic range of the camera.

Now let’s look at the stars.  In that 1/250th second photograph, there’s only a 1 in 250 chance that a piece of light will enter the camera and be recorded by the film.  It’s very unlikely.  And so, to the film, that star wouldn’t even be there – it wouldn’t be detected – because it’s below the dynamic range of the film.

Now let’s say you actually did want to photograph the stars.  With 1 piece of light per second, you would probably want to take a picture for around 50 seconds (to get it in the middle of your dynamic range).  But, if you take a picture for 50 seconds, the amount of reflected light off the moon would be over 300,000 counts, and this is way above our dynamic range limit of 100 counts.  So while that star may be properly exposed in 50 seconds, the moon itself would be over-exposed and appear all white.

That is why the dynamic range of the film is not good enough to see both stars and the moon’s surface in the same length of exposure

To summarize, the basic reason there are no stars in the Apollo photographs of the lunar surface and sky is because the cameras were set to expose the lunar surface properly, and those exposures are too short to record stars.

In fact, you can easily do this experiment yourself:  On a night when there’s a fairly full moon out, or even a half-full moon out, go outside and try to photograph it.  If you use an aperture somewhere around 4.5 to 6.3, you will likely need a shutter speed between 1/200 and 1/100 of a second to properly expose the moon.  Now look at your photos.  Do you see any stars?  The answer will be “no.”

Now try to photograph the stars.  You will likely need to expose for at least several seconds in order to see any stars in your picture.  Now go back to the moon and use the same exposure settings, aperture and shutter speed.  You may get stars in the field this time, but the moon will be a pure white ball, over-exposed.

This simple experiment, along with all the arguments above, should clearly show why the claim that there are no stars in the Apollo lunar photographs does not mean that the lunar landings were faked.

October 19, 2008

The Solar Neutrino Problem – Why Something that Was Solved Years Ago Is NOT Evidence for Recent Creation

This post is in regards to the Institute for Creation Research’s February 9, 2002 program entitled, “The Young Sun.” You can listen to the audio here.

This particular episode of ICR radio is, to be quite blunt, fairly ignorant.  Its purpose is in discussing what was known as the “solar neutrino problem,” which was solved in 2001, the year before this episode came out.  In other words, it banks on an argument that was already resolved.

The broadcast starts out with a biblical reading and then gets to one of the regular members of their astronomy panel, Dr. Donald DeYoung.  He spends about 90 seconds giving a brief overview of our closest star, discussing how large it is, how quickly it produces energy, and hints a little at the “Goldilocks” situation where Earth is at the “just right” distance from the Sun to not be too hot (like Venus) nor too cold (like Mars).

About 4 minutes in, Dr. Danny Falkner comes on to discuss some of the specifics of the nuclear fusion processes that occur in the Sun’s core that produce its energy.  A discussion of this process can be found on my own website for it is not the purpose of this blog entry.

Finally, 5 minutes in, they introduce their argument:  The Solar Neutrino Problem.  In sum and substance, the theories of nuclear fusion that occur in the Sun’s core really haven’t changed much in over 50 years since it’s fairly straight-forward nuclear physics.  We thought we knew exactly what goes in and what comes out of the nuclear proceses in the Sun’s core, and some of what comes out are elementary particles known as “neutrinos.”  Neutrinos come in three different types, sometimes referred to as “flavors:”  The electron neutrino, muon neutrino, and tau neutrino (also, each of these has an antimatter partner, and antineutrino).  Part of the difference between these three flavors is their energy level (or, because matter and energy are interchangeable via E = m · c2, we refer to them as having different “masses”).

One of the properties of neutrinos is that they are very difficult to detect because they very rarely interact with what detectors can be made of (protons, neutrons, and electrons).  In fact, over 50,000,000,000,000 (50 trillion) neutrinos are passing through you every second.  Because of this difficulty, it was only in the 1960s that the first solar neutrino detector came online that would detect the electron neutrino rate from the Sun, and they found a deficit from what was predicted.  Subsequent experiments verified this deficit … either the Sun was not creating the right number of neutrinos, or something was happening to them on their way to the detectors.

Various solutions were proposed to this problem, such as the Sun doesn’t produce energy quite at the rate that was thought.  However, every observation that was made of different solar properties only confirmed previous solar models, and so there was still a problem.  The problem was resolved, however, by 2002, when this broadcast was made.

The solution involves tweaking the Standard Model of particle physics, which assumed that neutrinos were massless.  This meant that they couldn’t oscillate, or change flavors from one type to another.  However, if they actually did have a mass, then they could change from one type to another; hence the solution was that they have a miniscule amount of mass, and that a certain percentage of the electron neutrinos just changed flavor en route to the detectors here on Earth.  In 1998, a Japanese experiment showed that muon neutrinos could change into tau neutrinos, confirming the flavor change.

Direct evidence came in 2001 from a Canadian experiment which was built to detect all three types of neutrinos, and it found that about 35% of the arriving solar neutrinos were still electron neutrinos, the rest having either changed to tau or muon neutrinos.  BUT, the total number of neutrinos detected was what was expected to be produced from the Sun.  Pretty much every reputable astronomer agrees that this is the solution to the Solar Neutrino “Problem,” that neutrinos can change from one type to another.

Now that you have a background to neutrinos, on with the broadcast …

So starting just after 5 minutes into the broadcast, they start to discuss neutrinos, detectors, and the solar neutrinos.  About 7 minutes into the program, they begin to discuss their alternative idea:  Rather than accept every other independent indication of the Sun’s age, they propose that it’s really very young … you guessed it, about 6,000 years old.  This “solution” would work because, as they state, the rate of neutrino production would change depending upon the age of the star due to various factors like its temperature or composition.

The problem with this is two-fold.  First, as I stated, there are many other independent observations that indicate the Sun is 4.5 billion years old, and I’m not referring to radiometric dating of rocks in the solar system.  Second, they use the predictions from the Standard Model as it was in the 1960s and 70s as if it were gospel, ignoring its revision in the mid-2000s to now easily account for what’s observed.  It’s like using an astronomy textbook from 1800 and asking your teacher why you got the question wrong on the test when you said there were only 6 planets in the solar system (Mercury, Venus, Earth, Mars, Jupiter, Saturn, since the rest hadn’t been discovered yet).

However, they continue this line of reasoning and at about 8 min 15 sec into the program they discuss that, under our “evolutionary” model of the 4.5-billion-year-old Sun, it would have been about 30% fainter 4 billion years ago than it is today (which IS what solar models show).  They then say that Earth, as a result, would have been 15-20 °C cooler than it is today.  What makes this comment so … disingenuous (to be kind) … is that in the sentence just before it he states that “we’re wringing our hands over global warming and so-forth …”

And that’s the solution:  Earth’s atmosphere is not a constant composition through time, nor Earth’s reflectivity (the amount of light it absorbs vs. reflects back to space) is not a constant through time due in part to changing ice caps.  Earth’s original atmosphere was likely mostly hydrogen and helium, just like the gas giants of the solar system.  It was mostly removed by a stronger solar wind and a very hot crust, and likely nearly completely stripped away by the impact that formed the moon.  Earth’s second atmosphere was mostly volcanic in origin, made of water vapor, carbon dioxide, and ammonia — the first two being very efficient greenhouse gases, and estimates are that it was up to 100 times more massive than our current atmosphere.  These gases along with methane-producing bacteria that formed early on could easily have raised Earth’s temperature enough to keep the surface water from freezing.  (To complete the story, bacteria spent about 1 billion years converting a large amount of carbon dioxide into oxygen, bringing our atmosphere closer to what we would recognize today.)

So yet again, the apparent problems that are raised by the guests on this show are easily explained by us “evolutionary” scientists.  They are NOT problems that we cannot work out, and, as the guest even states, “[no one] suggests the Earth was ever that cold.”  But, he simply states, “You can argue about greenhouse gasses being greater in the past … that’s an issue I don’t want to address right now.”  Fair enough, it’s a short radio broadcast, but one must ask the question of why he wouldn’t address that when it’s the entire explanation for the problem he’s proposing!

The rest of the broadcast re-states what I mentioned 3 paragraphs ago – their young-Sun model, and then does the sign-off, reassuring listeners that the Bible can be taken literally.

However, as I hope to have demonstrated with this post, this is yet another line of evidence that does NOT lead to the conclusion that the Sun was created 6000 years ago.

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.

October 14, 2008

The Dangers of Believing that Our Technology is Reverse-Engineered from Aliens

Sorry that I haven’t posted in awhile, I’ve been bouncing around between two conferences and one consulting job in the last few weeks.

Anyway, this post is going to be a quickie, and, as the title suggests, I want to address why it’s “dangerous” to believe that all/some/parts of our “advanced” technologies are either given to us by aliens or reverse-engineered from alien technology, such as from crashed ships.

First, I want to very briefly address the logic behind aliens crash-landing on Earth with this simple scenario:  You have an incredibly advanced and intelligent race of creatures.  They have mastered space travel and either by getting around Relativity they can travel faster than light to other stars or they have built crafts that can travel and sustain generations of them for the thousands or tens or hundreds of thousands of years required to travel between stars.  So they’re really advanced (did I already mention that?).

They’ve managed to get to our pale blue dot of a planet, and then suddenly, they just crash.  They can navigate interstellar space, they can get off their own planet, yet for some reason they just crash land on Earth.  And not just once.  Many many times if you believe all the reports of crashed “saucers.”  It simply doesn’t make sense from a logical standpoint.

Anyway, I was just listening to the Sept. 23 2008 episode of Coast-to-Coast AM (a 4-hr radio show that I sometimes listen to to get ideas for this blog), and the guest, Dr. Shelley Kaehr, who is a person who advocates the apparent power of gem healing (that’s for another blog, I’m not going to address the pseudoscience of gem healing), was talking during the third hour of the show about extraterrestrials and her own views of cosmology and earth changes and frequencies around our planet changing (which is the whole mechanism for her energy/gem healing).

But what really stuck out above all this was when she was discussing how her 92-year-old grandmother had grown up on a farm and now she was able to send e-mails and text messages.  In this context, she stated, “The rapid changes that we’ve had are just — it’s unbelieveable.  You have to know there’s reverse-engineering from alien intelligence going on and you have to think that the planet must be speeding up or … the frequency of the planet getting higher and different and time speeding up …”

From there it really just deteriorates into such a lack of understanding of physics that I really don’t want to get into it.  What I want to address is, as I stated above, the idea of reverse-engineering alien technology.

As I stated earlier in this post, first off, the idea that we actually have technology from an extra-terrestrial civilization is very highly unlikely.  I will not say that it’s impossible, it is simply improbable (see my post on CERN about scientific certainty).

But there is a real danger to believing this:  If you believe that many or all of our technological advances are not actually the result of human ingenuity, but rather they are simply handed to us, then your expectations of humanity and of yourself diminish greatly.  Put more simply, you lose faith in your own ability to solve problems.

Think of this from the standpoint of a math homework:  A teacher only assigns even problems for a math assignment.  It just so happens that all the answers to the even problems are in the back of the book.  The student then, rather than actually figuring out how to solve the problems themselves, simply looks in the back of the book for the answers.  They have the answers, but they have no idea how to actually get them.  They may then go through life simply doubting their own ability to discover the answers to things and just wait for someone to show them the back of the book.

Admittedly, this is a small stretch to connect this situation to reverse-engineering alien technology.  Perhaps an example from psychology will help illustrate it better:  It’s been said by someone in the Vatican that Hitler and all of the Nazis were possessed by either Satan or multiple demons (I can’t actually find the quote at the moment).  They say that is the only explanation for the great evils of the German Holocaust.  The harm in believing that is you have now taken the human component out of it.  You now have a reason NOT to think that humans are actually capable of genocide, and rather than realize that about the human condition, you are relegated to a happy land where all people are good, and anything bad that happens is the result of some demonic influence.  This removes any personal responsibility (can you imagine if courts accepted that as a defense against murder?).

It’s the same idea here:  If you no longer think that humans can come up with this technology on their own, then you will be constantly waiting for some alien to hand you the next technological advance instead of going out there and doing the research and testing to find it yourself.  As someone in a basic science field, this idea is both dangers and disappointing to know that people hold.

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