My Nobody's Business co-blogger Rogier has a pretty good article up about divine delusions v.s. observable reality. It's a plea for rationality, even if faith and mysticism seem like more fun. As is often my way, I have a small quibble.

Rogier and his opponent are discussing a Facebook poster's insistence that a bit of lens flare in a photo of a pyramid is actually a sign that the "goddess era has arrived." Rogier's opponent is arguing that her subjective interpretation has meaning.

So here's perhaps how she making the connection between her beliefs and aspirations and this photo. This photo for her is a symbol of her convictions: To bring the masculine energy (which she perceives is out of whack) into balance with the feminine energy.

He goes on to conclude:

So this image is a visual confirmation and symbol of her beliefs, and makes perfect sense.

Rogier had a problem with that:

I don't see how he arrived there. At all. Unless he means that it makes perfect sense for some poor guy in an asylum to believe that he is Napoleon Bonaparte, or for the cat lady down the street to worship her scraggly charges as multiple reincarnations of Nefertiti. Yes, it makes sense to those two people, I'm sure. But almost everyone else easily recognizes the outsized fallacies involved.

There is no equivalence between the unprovable views of Cat Lady and Fake Bonaparte on the one hand, and the provable ones of Richard Feynman, Neil DeGrasse Tyson, and all the rest of science on the other.

This is where I feel the need to add a small clarification. I think "provable" is the wrong word. The key difference between the theories of scientists and the pronouncements of mystics is not that they can be proven, but rather that they can be disproven. In the terminology of Karl Popper, the theories of scientists are falsifiable.

What distinguishes a scientific theory from other kinds of ideas -- personal beliefs, religious faith -- is that scientific theories allow you to make predictions about the world that can be tested and that might be found false. (Note that I'm not saying that a theory has to be disproven to be scientific -- that would make it a false theory -- only that it has to be conceivable that it could be disproven.) Conversely, if there's no way that an idea can be disproven, then it's not really a scientific theory. If the theory can't be tested against the real world, that means it doesn't say anything useful about the real world.

Rogier's opponent implicitly agrees that the goddess theory is not falsifiable:

For her [the Facebook poster] it's a sign that the goddess era or whatever has arrived. Who's going to prove she's wrong?

If no one could ever prove her wrong, then she's not saying anything interesting about the world.

A few days ago, at the conservative Illinois Review, an unnamed author who I assume is editor Fran Eaton got excited about some basic science in a post titled "Biology Textbook Author Asserts Life Begins at Conception":

When does life begin?  At conception?  When the fertilized egg begins to multiply cells?  When the zygote embeds itself into its source of nutrition?

A growing number of scientists are beginning to assert that life can begin nowhere else but at conception, because at the moment when an egg is fertilized, it is either a human, a squirrel, an elephant or a dog. At that moment on, then, is when human life should be protected from planned destruction.

Actually, this is not some new trend that is getting support from "a growing number of scientists." I'm pretty sure that biologists have never disputed the fact that fertilized eggs are alive -- at least not since 1651, when William Harvey figured out that all animals, including humans, come from eggs -- nor is there any doubt that a fertilized egg is of the same species as its parents. Fertilized human eggs have been human life since as long as scientists have known where babies come from.

In referring to an article at LifeNews.com by biologist Gerard Nadal, Eaton describes it as reporting Professor Scott Gilbert's "findings." But the quote is from the 9th edition of Gilbert's Developmental Biology, which is one of the standard textbooks in the field. I doubt that Gilbert is reporting any novel findings.

Here is the quote:

Traditional ways of classifying catalog animals according to their adult structure. But, as J. T. Bonner (1965) pointed out, this is a very artificial method, because what we consider an individual is usually just a brief slice of its life cycle. When we consider a dog, for instance, we usually picture an adult. But the dog is a "dog" from the moment of fertilization of a dog egg by a dog sperm. It remains a dog even as a senescent dying hound. Therefore, the dog is actually the entire life cycle of the animal, from fertilization through death.

I don't have a copy of the book handy, but that doesn't sound like a scientific conclusion. Rather, it sounds like a scientific definition. It sounds like Gilbert is describing what his book is about, and why it is an important field of study. He's making the point that a thorough scientific study of life isn't only about what an organism is, it's also about the changes that organism underwent to become what it is.

Eaton finishes with this conclusion:

Gilbert says a dog's life begins at fertilization and ends at that dog's death. How soon can we expect him and other scientists to define a human's life cycle the same?

I think that's backwards. Dr. Nadal was't quoting Gilbert's book as evidence that scientists have changed their minds, he was using the quoted passage to show that his own pro-life position is based on science that is so widely accepted it's in a textbook. Here's part of Nadal's conclusion:

We are human for our entire life cycle. We are whole and complete in form and function at every stage of our development, for that given developmental stage. The prepubescent child is fully human, even though they lack the capacity to execute all human functions, such as abstract reasoning, or reproduction.

In the same way, the early embryo is alive and fully human, though it has not yet executed all human organismal functions.

Except for the overloaded use of the word "fully," that's certainly how I'd expect a biologist to see it, especially a developmental biologist who studies organisms' entire life cycles. I really don't think it's a controversial idea. Eaton is missing the point if she thinks this is some new breakthrough. No one seriously doubts that fertilized eggs are human life.

Or so I thought. You see, just to be sure, I decided to do a little Googling, which lead to the National Abortion Rights Action League's answer to the question:

DOESN'T LIFE BEGIN AT CONCEPTION?

That's a question each person must decide for him- or herself. These issues involve matters of personal, moral, religious, and scientific beliefs. This is an area where politicians should have no role.

Here NARAL is using the word "life" to mean something more than just biological life. That's not exactly unjustified -- there's plenty of etymological support -- but it seems to me they're evading the question.

The Pro-Choice Action Network also has an evasive answer to the same question:

There is no scientific consensus as to when human life begins. It is a matter of philosophic opinion or religious belief. Human life is a continuum---sperm and eggs are also alive, and represent potential human beings, but virtually all sperm and eggs are wasted.

This is technically true, and I think it's the same point Nadal was making in his article. Human life doesn't begin at birth. It doesn't even begin at conception. The unfertilized human egg was alive, and it came from a woman who was alive, and she grew from a living egg, which came from a living woman...and so on, going back maybe 100,000 generations until you reach the predecessor species from which humans evolved. Human life extends back continuously over millions of years.

But that's not what people mean when they ask, in the context of the abortion debate, "Does life begin at conception?" That's because they're not really asking the right question.

Professor Scott Gilbert has been out of the office, but he found the time to dash off a quick note when I asked him to comment:

Thanks for sending this on. One can't help people taking quotations out of context. Creationists do it all the time. We also call a human a human when that person is dead, even if they are not a person anymore. We don't eat humans, we bury them. But the dead can't vote or inherit. So calling a dog a dog even as a zygote is kind of obvious. Even a dog sperm is a dog sperm and not a human sperm. But (unless your a Monty Python fan), that don't make the sperm a person.

(Professor Gilbert also suggests reading an op-ed he wrote for the Philadelphia Inquirer.)

Nadal stumbles into this when he argues that we consider both prepubescent children and embryos to be human life, even if neither is capable of performing all human functions. He's right on the biology of course, fertilized human eggs are human life, but he's not properly addressing the moral issue, because when it comes to morality, function matters.

Here in the United States, the legal and clinical definitions of death are specified in terms of brain activity. A person's body can be kept alive by machines, and that's certainly human life -- blood is still flowing, the metabolism is still processing nutrients -- but if the brain has irreversibly ceased to function, we pronouce the person dead.

Or consider that having consensual sex with an adult is not generally considered an immoral act, but having consensual sex with child is a crime. The reason we make this moral distinction is because even though a child is fully human, we don't believe they have the mental function to make decisions about their sexuality.

Similarly, a person's rights depend on their behavior, which is another aspect of how they function. Obey the law, and you remain free. Rob a bank, and you go to jail. Try to kill someone, and you can be killed in self-defense, or executed after a trial.

The rights we grant people, and the respect we show to them, do not depend solely on the scientific fact that they are human life. We usually make the distinction by discussing not when a fertilized egg develops into human life, but when it becomes a person. That's a harder question, and one that science can inform but not fully answer. 

Immanuel Kant, who believed that Newton's laws of gravity are not merely true but necessarily true, argued that we humans lack the ability to comprehend the universe as a whole, and thus that we can never construct a valid argument for a designer. Our thinking can take us from one point to another along the chain of events. But it cannot take us to a point outside the chain, from which we can pose the question of an original cause.

If Mr. Hawking is right, the answer to the question "What created the universe?" is "The laws of physics." But what created the laws of physics? How is it that these strange and powerful laws, and these laws alone, apply to the world?

My son was quite impressed with an in-law who grew up in Mexico and ate habanero peppers whole, so my wife suggested a father-son gardening project. The first year only one plant survived the woodchucks and deer. But what a plant -- it produced a bumper crop of killer orange habaneros. Nothing ate them. In my mind I still see that plant dangling its little orange heat grenades in front of the deer and growling, "Bite me, Bambi."

The fact that capsaicin causes pain to mammals seems to be accidental. There's no evolutionary percentage in preventing animals from eating the peppers, which fall off the plant when ripe. Birds, which also eat fruits, don't have the same biochemical pain pathway, so they don't suffer at all from capsaicin. But in mammals it stimulates the very same pain receptors that respond to actual heat. Chili pungency is not technically a taste; it is the sensation of burning, mediated by the same mechanism that would let you know that someone had set your tongue on fire.

New computer simulations have shown how a glass slipper, as described in Grimm's Cinderella, could have been created using a unique combination of quartz-rich silicates found only in northern Germany. When heated to just the right temperature, as was available in primitive furnaces of 14th century middle Europe, the model demonstrated that glass could have annealed by chemicals from nearby dung fires forming a unique matrix. Early cobblers could have used this glass to construct a slipper durable enough to be worn by a young stepdaughter destined to become a princess.

It's a procedure. Like rebuilding a carburetor has a procedure. You know, when you rebuild a carburetor, the first thing you do is you take the carburetor off the manifold? Supposing you skip the first step, and while you're replacing one of the jets, you accidentally drop the jet, it goes down the carburetor, rolls along the manifold, and goes into the head. You're fucked. You just learned the hard way that you gotta remove the carburetor first, right? So that's all that happened to me today. I learned the hard way. Actually, it was a good learning experience for me.

My astronomy correspondent sent me this very cool image of the Earth and the Moon, as seen from near the sun:

I had a frustrating science discussion with a friend the other day. Somehow, our conversation had turned to the subject of cooking -- about which I know nearly nothing -- and my friend mentioned that someday he'd like to have an induction cooktop. He told me that when you place a pan on an induction cooker and turn it on, the food will begin to sizzle almost immediately.

To me that sounded like trouble. My intuition was that a fast-heating cooker would result in cooking temperatures that were way too high. I tried to explain why, but my grasp of physics and engineering is sketchy at best, and I wasn't able to get my point across.

Now that I've had time to think about it, and done some research, I think I know how to explain it. So I figured I'd post it here and maybe someone who understands the principles better will stumble on it and straighten me out.

The idea behind an induction cooktop is that the cooking pan is positioned right over an inductive electrical coil that's just under the surface of the cooktop. An oscillating current is passed through the coil, reversing direction a few thousand times a second. The current creates a magnetic field that oscillates at the same frequency. This field is just large enough to pass through the metal base of the pan, allowing the rising and collapsing magnetic fields to induce eddy currents. The metal of the pan has a natural electrical resistance, so the induced eddy currents cause the pan to heat up.

The advantage is that the cooking pan itself is the source of all the heat used to cook the food. There's no open flame or red-hot heating coil, and neither the cooktop nor the induction coil heats up. (The cooktop does come in contact with the heated pan, so it will warm up from conduction, but it's usually made of something that absorbs heat slowly.)

Imagine a pan sitting on a stove that hasn't been turned on. If the pan has been there a while, it should be at room temperature. This is not as simple a situation as it seems, because the pan isn't just at the same temperature as the room, it's also in thermal equilibrium with the room. That is, there is no net heat flow between the pan and the room, so the pan stays at a constant temperature.

This is not to say that the pan is thermally isolated from the room. The warm surface of the pan radiates heat out into the room, and the warm parts of the room radiate heat into the pan. Similarly, if any part of the pan is warmer than the air around it, heat will be conducted into the air, and vice versa. The point is that the pan and the room still exchange heat by the usual means -- radiation, conduction, convection -- it's just that the heat flowing into the pan is exactly matched by the heat flowing out of the pan.

This is a necessary condition for any object that is staying at a fixed temperature. If the heat flows in and out didn't match, the object would experience heating or cooling.

Now fire up the burner under the pan. The flame is a new source of heat that is transfered into the pan. However, simply turning on the burner does nothing to change the rate at which heat flows out of the pan. Since more heat is flowing in than out, the pan must heat up.

When the temperature of the pan rises, that affects the heat transfer between the pan and the surrounding room because a hotter pan will transfer more heat into the relatively cool room. Since the room stays at about the same temperature, the rate of heat transfer back into the pan stays about the same. (When you cook something, the kitchen probably does heat up a bit, but only by a few degrees, which is negligible compared to the cooking pan, which heats up hundreds of degrees.)

Eventually, the rate at which heat is shed to the surrounding room will be high enough to exactly offset the new heat flowing into the pan from the burners. At this point the pan will once again be in thermal equilibrium with its environment -- which now includes the burner -- and the temperature of the pan will stop changing.

The process is pretty much the same for an induction heated pan, except that instead of heat flowing in from the burner, the heat is generated within the material of the pan by induction. The pan's temperature still starts increasing, and stops only when the temperature of the pan increases to the point where heat transfer to the room is high enough to exactly offset the rate at which heat is being generated in the pan.

(I'm pretty much hand-waving away the effects of the food in the pan by assuming that there's just enough food to give us that sizzle we were talking about. Maybe it's just a few slices of bacon.)

Over a broad range of conditions, the amount by which an object changes temperature is proportional to the amount of heat energy transferred. So, for example, raising the temperature of an object by 5 degrees will require a transfer of 5 times as much heat energy as raising its temperature one degree.

Similarly, the rate at which the temperature changes is usually proportional to the rate at which energy is transfered. Any change in energy over time is called power, which is usually measured in watts. The higher the power, the more energy is transferred per second. So the less time it takes to heat an object to a given temperature, the greater the power of the heating mechanism.

For our purposes, let's assume that a typical gas stove can heat a pan to the sizzle temperature in one minute. Let's also say that when my friend says an induction cooker makes the food sizzle almost instantly, he means within 5 seconds. Since that's 1/12 the time it takes the gas burner, that means that the induction coil must produce heat in the pan at 12 times the rate at which the burner transfers heat.

Actually, since the shorter time span allows less time for the heat to flow out of the pan into the room, quicker heating is also a more efficient way to reach the same temperature. The magnitude of this effect is very dependent on the system under consideration. In the interest of keeping the math simple, I'll assume that the induction system has 10 times the power of the burner.

Now let's pull another number out of thin air and assume the burner is transfering heat at 1000 watts. Then the induction coil must transfer heat at the rate of 10,000 watts to achieve the desired heating speed.

That gets the pan to the sizzle point, but the heating process doesn't necessarily stop, since the heating only stops when the pan is in thermal equilibrium with its environment, which now includes a 10000 watt burner.

As near as I can tell from a little Googling, on a typical gas stove, a dry pan can heat to about 500°F. In other words, if the burner is transfering heat to the pan at 1000 watts, then when the pan reaches 500°F, it's transfering 1000 watts to it's environment. So how hot does the pan have to get to shed 10 times as much energy?

It's hard to say, because it depends on details of the heat transfer mechanism, which I'm not very sure of. However, since a gas burner heats a pan hot enough to cook food, I think the induction stove with 10 times the power is going to get way too hot for normal cooking.

I've since looked up a little bit of thermodynamics and learned that in the worst case, getting rid of 10 times the heat could require a full 10-fold increase in temperature difference between the pan and the room, meaning the pan wouldn't stop heating until it hit about 3000°F. That's more than enough to turn the pan into a pool of white-hot molten metal, melting its way down through the stove.

On the other hand, I think the best case would be if the process is dominated by radiative cooling, in which case the radiated energy increases as the fourth power of the the temperature, which my rough calculations show would require a temperature of only 860°F. That's still way above normal cooking temperature. If you turned the lights out, you'd see a faint red glow like a branding iron.

When I was trying to explain my concerns to my friend, I didn't present it nearly as clearly as I have here (and I realize this is still not a model of clarity). He didn't see the problem, and he kept pointing out the induction process heated the pan much more efficiently than an open flame, so not as much energy was needed.

But that misses the point. The amount of waste heat is irrelevant to the problem. In order to heat the pan 10 times faster, the induction cooker simply must pump energy into it 10 times as fast. This means that when the pan stabilizes at its equilibrium temperature, it's going to have to emit 10 times as much energy into the surrounding room. This far higher energy emission rate can only occur if the equilibrium temperature is also far higher.

My point was that something was missing from our mental model of how induction cooking worked, because our mental model predicted a top-end cooking temperature far too high for normal cooking. No engineer would design an induction cooktop to overheat food so much. There's no point to it.

We did manage to come up with a couple of theories. My friend pointed out that induction cookers only heat the bottom of the pan. This means the burners need less than 10 times the power to get to the sizzle point 10 times as fast, because they are bringing less of the pan to that temperature.

My theory was that the induced eddy currents would occur on the surface of the pan, the inside and the outside, without directly heating the interior thickness of the metal. Since the food sizzles when the surface touching it reaches the sizzle point, this again reduces the amount of mass required to be heated, thus reducing the required energy and requiring less power to reach the sizzle point quickly.

A bit of research on the web seems to indicate that both of these theories are true. Induction cookers don't heat the pan sides directly, and eddy currents do indeed hug the surface. However, it turns out that neither of those is the real solution to the overheating problem.

When heated by an induction cooker, each type of pan reacts differently, depending on its shape, size, and construction materials. To achieve optimum cooking and energy transfer, an induction cooktop has to be able to adapt its performance to each pan. Fortunately, the effectiveness of a particular frequency can be detected by measuring the rate of energy consumption of the induction coil, and the induction wave can be modulated until the energy transfer is at the desired level.

The point is that, contrary to what I had been imagining, an induction cooktop is not just a coil that blasts out a magnetic wave. The inductor's resonance circuit includes a switched power supply that is controlled by a microcontroller -- a small computer -- that continually monitors the coil current and adjusts the induction wave form from moment to moment according to a programmed formula.

Once you have a computer on board, lots of things become possible, like changing the wave if the pan is moved to a new position, or shutting off the power when the pan is removed.

Or detecting when pan overheats. In a modern induction cooktop, each induction coil has a temperature sensor that detects when the cooktop, and therefore the pan, gets too hot, at which point it cuts off the power until the pan cools.

People I trust have been saying good things about Jeff Gamso's blog, Gamso - For the Defense, and I've been meaning to check it out for months now. I finally got around to it, and I'm glad I did, because I discovered a fascinating post called "Hobgoblins of Little Minds."

It's about what experts mean when they say a piece of evidence is "consistent":

The criminalist who did the ballistics comparison wasn't sure he had a match...The most he could say is that the gun was "consistent with" the one that fired the bullet that killed the young woman. The murder weapon.

"Consistent with." What the hell does that mean?

It means "might be." It means "maybe or maybe not." It means "sure it's possible." It means "who knows." All of which is a way of saying that it means not much of anything at all.

I have no idea what the ballistics expert means by "consistent," but if he has any scientific integrity, the word "consistent" has a slightly more precise meaning than Gamso is allowing for.

Consider Gamso's next paragraph: 

"He's not desperately poor." That's consistent with the guy who got laid off from the plant and is struggling to get by on unemployment and food stamps and also with Bill Gates and his billions. It tells you nothing.

But it does tell me something. It rules out the possibility that he's desperately poor. Assuming we have a reasonable definition for "desperately poor," it tells me he's not living in the streets, sick and starving.

"Not desperately poor" is an awkward phrase, because it's the negation of "desperately poor" rather than a positive assertion the way "consistent" is. But that leads us to a clearer understanding of what "consistent" means in ordinary usage: It means not inconsistent. That is, when the expert testifies that the gun he tested is "consistent with" the murder weapon, it means he cannot rule it out.

It sounds pretty weak, doesn't it? Saying you can't rule something out is a long, long way from saying it's true. As a matter of philosophy of science, however, this is as good as it gets. Scientific tests never really prove anything is completely true. The only possible results of any test are that it is consistent or inconsistent with the idea being tested. Our technological civilization is built on scientific theories which have never been proven true, but which have survived countless attempts to prove them false.

"Consistent" means something, and when you have enough consistent results, it comes as close to certainty as science can get.

Gamso quotes from the Federal Rules of Evidence:

Rule 401. Definition of "Relevant Evidence"

"Relevant evidence" means evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.

That definition bothers me for a reason that is probably a bit pedantic. In particular, I'm botherd by the phrase "make the existence of any fact...more probable or less probable". I think I know what the rules are trying to say, but I believe it is an error in reasoning to say that a fact can be more probable or less probable.

The facts may be unclear, confusing, complex, uncertain, or unknown. But whatever the facts are, they happened. "Probable" has nothing to do with it. There's no way that evidence or testimony at a trial can somehow reach back in time and change what really happened, or change the probability that something happened. Evidence can't make reality more probable or less probable, because reality is fixed.

Evidence in science is no different when you examine it carefully. For example, a public health study might be reported in the nightly news as estimating that "10 million Americans have Greenfield's disease." A newspaper report might add that the study has an error of "plus or minus 2%." That sounds like a strict cutoff, but a scientist would explain that it's really a confidence interval. If you delve into the study, you'll probably find out that the newspaper reporter used the study's 95% confidence interval. The scientist would explain that this means there's a 95% chance that the true number of Americans with Greenfield's disease is within plus or minus 2% of 10 million.

The scientist would be wrong, however, for the same reason the rules of evidence are wrong. However many Americans have Greenfield's disease---let's say it's 9,982,458---that's how many have Greenfield's disease, and there's no chance or probability involved. What our 95% confidence interval of plus or minus 2% is really saying is that conducting this scientific study has a 95% chance of giving us a result that is within plus or minus 2% of the true number. Or, to put it another way, our result is consistent with the theory that Greenfield's disease affects about 10 million people.

Getting back to our ballistics expert, when he says the defendant's gun is consistent with the murder weapon, he's not---despite what the Rules of Evidence say---making it more likely that the gun is the murder weapon. Rather, he's saying that with some degree of scientific confidence, the prosecutor's theory that the gun us the murder weapon was not disproved by the ballistic examination.

Now let's look at a simpler example.

Suppose we suspect that a coin has been modified so that when flipped it always come up heads. We think this modification is subtle and undetectable to the naked eye (and we have no instruments available). How can we prove that the coin has been gimmicked if we can't detect the modification?

Simple: We flip the coin.

If we flip it once and it comes up heads, that proves almost nothing. The coin will do that half the time even if it's perfectly legitimate.

So we flip the coin again, and it comes up heads again. With two tests of the coin in our data set, the possibility that it's a gimmicked coin is slightly higher, because this result will happen by random chance only one time in four. Do a third test, and it's one time in eight. Four tests will come up all heads only one time in 16 with a fair coin, and so on.

If we keep flipping the coin and we keep getting heads, the possibility that this is a fair coin gets smaller and smaller. Ten heads in a row is only a 1-in-1024 possibility with a fair coin. By the time we get to 20 straight heads in a row, the odds of this being a fair coin are less than one in a million. It's safe to conclude there's something wrong with the coin.

(I've just made the same mistake the Rules of Evidence made. The coin is either gimmicked or it's not. The 1-in-a-million probability is really a statement about the accuracy of the testing method. That is, it's not really that the odds of this being a fair coin are less than 1 in a million. Rather the odds of a fair coin behaving this way are less than 1 in a million.)

The coin testing process I just described is good science for three basic reasons. First, it puts numbers to its results. Real science almost always involves some math, and real scientific studies usually state their results in form of probabilities and confidence intervals. Gamso does not report that the ballistics expert gave any probabilities with his conclusions.

Second, and more generally, our conculsion about the coin includes information about the error rate of our testing process: The chances of a coin that is not gimmicked behaving this way are less than 1 in a million. When the ballistics expert testified that the gun was consistent with the murder weapon, did he quantify or even characterize the possibility that it wasn't the murder weapon? For example, did he explain what percentage of all guns would be consistent with the murder weapon? If it's 1 in a million, that's a pretty good sign that you've got the right guy. If it's 1 in 10, the expert's conclusion is just barely relevant.

Third, our conclusion about the coin is based on a series of independent tests. Each flip of the coin is a test. The results of any single flip indicate very little, because even a fair coin will come up heads (produce a false positive) 50% of the time. However, when we conduct a series of 20 independent tests, we can reduce the false positive to one in a million. In general, the more tests we conduct, the more we can reduce the liklihood of a false positive.

This last point is crucial to reaching a conclusion because (in theory, anyway) that's logical rationale behind how the evidence in a trial builds up to a conclusion. Let me see if I can illustrate this with some data that I totally made up.

Let's pretend that the ballistic match is a very simple two-step process. First, we match the caliber of the gun, which must be one of 10 possible calibers which occur in equal numbers---i.e. for any given caliber, 10% of all guns are a match. Second, we match the land-and-groove pattern within the barrel, of which there are 10 possible patterns, all occuring in equal numbers. Since each matching step eliminates 90% of the guns, a ballistic match that passes both steps has eliminated 99% of the guns, meaning that only 1 in 100 guns will match.

In addition, we have a witness ID, which we'll assume is also 90% accurate. Combined with the gun match, this eliminates 90% of the remaining false positives, meaning that only 1 in 1000 gun owners match the criteria. We're getting somewhere.

It all goes wrong, however, if there are hidden connections between the criteria. For example, how did the police narrow down the suspect list that they presented to the witness? If they already had the ballistic report, perhaps they did a database search for people who owned guns of the same caliber as the murder weapon, and used the resulting list to build their suspect list.

If so, this means that the witness ID and part of the ballistic examination are correlated and not independent. And to the extent that they're correlated, we have to factor that out of the calculation. In this case, every suspect presented to the witness was known to have a gun that matched the caliber of the murder weapon, so the ballistic expert's discovery of this fact adds nothing new. This eliminates the 1-in-10 ratio for the caliber match, and we're back down to a 1 in 100 chance of a random person matching the known facts about the murderer.

One of the reasons DNA evidence is considered so good is that scientists have a pretty good understanding of the prevalence of various DNA markers in the human population and of the correlations between them. In fact, DNA testing is explicitly based on statistics, which is why DNA test results usually include an estimate of the chance of a false positive. With a good DNA sample, the chance of a random match is often less than 1 in a billion, and lawyers love to bring that number out in trial because it is so impressive.

By comparison, Gamso's account of fingerprint experts saying things like "There is no error rate. It's 100 percent accurate." is infuriating. Only abstractions are perfect. Everything in the real world has an error rate.

Sometimes that error rate is vanishingly small, which allows us to say that something is "error-free" when speaking informally. But if you press for a number, a real scientist should be able to find one.

I'll tell you, I didn't have much Love for the Pluto haters. But I've come to accept the truth of it. Pluto crosses the orbit of Neptune, it's tilted out of the ecliptic, there's other crap all around it, and it's small---almost as small as its moon, which doesn't even orbit a point inside Pluto.

It's a rock. Just like all the other outer-system dwarf planets: Haumea, Makemake, and Xena.

Yeah, you heard me. I said Xena. If the discoverers called it Xena, then that's what it should be.

The television show Xena: Warrior Princess had more fans for any given episode than Makemake has had worshippers throughout all time. Admit it, until I mentioned it, you never even heard of Makemake. You're still not sure I didn't just make it up. So how come Makemake gets a (dwarf) planet and Xena doesn't?

The International Astronomical Union wants to call it "Eris," but they're headquartered in France, so we don't have to listen to them. Besides, haven't we named enough shit after those fucking Greeks already?

Hmm. This sounds more like Bargaining. Maybe I'm only at the third stage.

In another post, I mentioned that I was worried that I might write something that was so bad it wasn't even wrong. I borrowed that phrase from Steven Pinker (who borrowed it from someone else), and since saying that, I've been concerned that people might not understand what I mean. I'm talking about a level of level of misunderstanding so profound that it's difficult to evaluate because it has no logical connection to the subject under discussion.

On a completely unrelated subject, Eric M. Wallace at Illinois Review has just posted this video of World Net Daily commentator Jason "Molotov" Mitchell talking about "Darwin vs. Liberals":

It's hard to know where to begin, but let me see if I can give it a shot.

I guess I'll start with the misconception about the purpose of the theory of evolution. It's not a normative theory. It doesn't say how things should work, it just describes how things do work. In a soundbyte: IS, not OUGHT.

So when Mitchell says "I thought that the struggle is supposed to build a better breed of human," he's way off the mark. The struggle for survival isn't supposed to build a better breed of human, it just does. But it's not a moral system. There's no reason we should bow down to evolution and let it rule our lives. We're smarter than it is. We can control our lives on our own terms.

While I'm at it, the reason for believing in evolution isn't "hiding behind evolution" to escape "moral responsibility." It's because evolution is a scientific theory that explains a lot of things about the world. People believe in evolution because it works.

Then there's the whole bit about England. Based on a few incidents with some Islamic protestors, Mitchell declares that the United Kingdom will be under Sharia law within 10 years. He then claims this proves the superiority of the god-believing Muslims, even though his "proof" is something he totally made up in his head.

Our cousins in the U.K. are definitely acting a little screwy these days, but they still have a far higher standard of living than in Muslim countries. With a population of 60 million, the U.K. has more than twice the GDP of any Islamic nation, and nearly 2/3 the GDP of Egypt, Iran, Iraq, Jordan, Kuwait, Libya, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, and all the -stans combined, despite their vast oil wealth and a combined population of over half a billion people. On a per-capita basis, only a few of the small oil kingdoms have a better standard of living.

And if economics doesn't convince you, how about the Brits' kickass special forces, blue-water Navy, and arsenal of nuclear weapons?

Getting back to the main point, although evolution and capitalism both feature competition and failure to survive as key concepts, they aren't quite the same thing. I'm sure someone has done a point-by-point comparison of the logical structure of evolution and capitalism, but basically, economic entities don't survive and grow like reproducing organisms, and reproducing organisms don't have intelligent managers guiding their development.

Besides, if evolution and capitalism go together, shouldn't believers in God be socialists?

Finally, there's the gay rights v.s. evolution issue. There's no need to re-hash my speculation about gayness in evolutionary theory to explain why Mitchell's argument is so stupid. For one thing, it's enough to point out that Larmarck's theories about inheriting acquired characteristics were discredited long ago. Discouraging gay behavior will not eliminate gayness from the human species because you can't change people's genetics by changing their behavior. It would be like getting yourself hair implants in the hope that it would keep your children from going bald.

Further, there's a real logical disconnect in saying that gays are harming the human species because they don't reproduce. People who don't reproduce can't possibly affect the genetic composition of future generations because they don't have future generations.

I know, I know, I've wasted a lot of time on this idiotic video. It would be easy to just call it "stupid" and move on. Sometimes, however, I just get the urge to point out that idiocy is not always about bad ideas or bad values. Often it's about factual, objective errors. Sometimes stupid stuff is stupid for a reason.

I think I've read about a dozen science fiction stories that start this way. It's usually not a good sign.

In a paper to appear in the Astrophysical Journal, astronomers working on the Supernova Cosmology Project report finding a new kind of something that they cannot make any sense of.

...

On February 21, 2006, in the direction of a far-away cluster in Bootes...Hubble began seeing something brighten. It continued brightening for about 100 days and peaked at 21st magnitude in two near-infrared colors. It then faded away over a similar timescale, until nothing was left in view down to 26th magnitude. The object brightened and faded by a factor of at least 120, maybe more.

The good news is, it's a minimum of 130 light years away..

Or it could be as far away as 11 billion light years. They really don't know what this is.

I just hope it wasn't some other civilization's test of their Large Hadron Collider.

There's been some excitement among criminal defense bloggers such as Mr. Greenfield, Mr. Katz, and the Dude over a fascinating Los Angeles Times article about some strange search results in some of the major DNA databases.

State crime lab analyst Kathryn Troyer was running tests on Arizona's DNA database when she stumbled across two felons with remarkably similar genetic profiles.

The men matched at nine of the 13 locations on chromosomes, or loci, commonly used to distinguish people.

The FBI estimated the odds of unrelated people sharing those genetic markers to be as remote as 1 in 113 billion. But the mug shots of the two felons suggested that they were not related: One was black, the other white.

Troyer went on to find 144 other 9-loci matches in the Arizona database, and other people have found comparable numbers of stray matches in other state databases.

The article summarizes the response to this from Steven Myers of the California Department of Justice:

Many of the Arizona matches were predictable, Myers said, given the type of search Troyer had conducted.

In a database search for a criminal case, a crime scene sample would have been compared to every profile in the database -- about 65,000 comparisons. But Troyer compared all 65,000 profiles in Arizona's database to each other, resulting in about 2 billion comparisons. Each comparison made it more likely she would find a match.

When this "database effect" was considered, about 100 of the 144 matches Troyer had found were to be expected statistically, Myers found.

Myers is talking about a famous non-intuitive statistical result called the birthday paradox. Suppose we're in a room with about 50 people, and I offer you a simple even money bet that at least two people in the room have the same birthday.  Should you take the bet?

The math seems simple: There are 365 possible birthdays, so 50 people cover 50/365 of the possible birthdays. It seems like I'm offering you even money on something with only about a 1 in 7 chance of happening, which sounds like a good deal for you.

Actually, it's a sucker bet. With 50 people in the room, there's about a 97% chance of two or more people having matching birthdays. I'd only lose this bet about 1 out of every 30 times I tried it.

It's easiest to understand why this works if you imagine admitting the people to the room one at a time, checking their birthdays as they enter, and stopping when you get a match. The first person gets in free, because there's no one to match. The second person is then checked against the first. The chance of a match stopping the process at the second person is therefore 1/365 (we're ignoring leap years). To put it another way, the chance of continuing is 364/365.

The third person to enter the room can match either of the two people already in it, so the chance of a match is 2/365 and the chance of a non-match is 363/365. But the third person is not allowed to enter unless the second one didn't match either, so the chance of no match with three people requires that both fail to match, the chance of which is calculated by multiplying (364/365) x (363/365) = 0.991796. That's the chance of failure to match, so the chance of success is given by 1 - 0.991796 = 0.008204, less than 1%.

For the fourth person, the chances of failure to match the other three is 362/365, bringing the total chance of failure to get a match for 4 people to (364/365) x (363/365) x(362/365) = 0.983644, meaning the chance of success is 1.6356%.

Note that each person who enters the room is checked against everybody in the room, so the first person is not checked at all, the second person is checked against the first, the 3rd person is checked against the 1st and 2nd, for a total 3 pairs checked. Person #4 is checked against the first 3, bringing the total to 6 pairs checked. By the time we get to the tenth person, we've checked 45 pairs of birthdates, and the chance of success has accumulated to 11.69%.

Here's the rundown of all 50:

# People	Chance of Success	# Pairs Checked
1	0.00%	0
2	0.27%	1
3	0.82%	3
4	1.64%	6
5	2.71%	10
6	4.05%	15
7	5.62%	21
8	7.43%	28
9	9.46%	36
10	11.69%	45
11	14.11%	55
12	16.70%	66
13	19.44%	78
14	22.31%	91
15	25.29%	105
16	28.36%	120
17	31.50%	136
18	34.69%	153
19	37.91%	171
20	41.14%	190
21	44.37%	210
22	47.57%	231
23	50.73%	253
24	53.83%	276
25	56.87%	300
26	59.82%	325
27	62.69%	351
28	65.45%	378
29	68.10%	406
30	70.63%	435
31	73.05%	465
32	75.33%	496
33	77.50%	528
34	79.53%	561
35	81.44%	595
36	83.22%	630
37	84.87%	666
38	86.41%	703
39	87.82%	741
40	89.12%	780
41	90.32%	820
42	91.40%	861
43	92.39%	903
44	93.29%	946
45	94.10%	990
46	94.83%	1035
47	95.48%	1081
48	96.06%	1128
49	96.58%	1176
50	97.04%	1225

Note that the actual break-even 50/50 chance of a match occurs when there are only 23 people in the room. Also note that by the time we've reached 50 people, we've checked 1225 pairs. Since each pair has a 1/365 chance of matching, we should actually have several matches by now.

A similar statistical effect should be at work in the DNA database. Troyer's database search was comparing everyone in the database against everyone else. Since each person is compared with every other person, the chances of a successful match are much higher than intuition suggests. With 65,000 entries in the database, Troyer checked 2 billion pairs of people for a match.

That still doesn't get us over the hump of the FBI's claimed 113 billlion-to-one odds, but there's another difference between Troyer's search and a typical cold DNA search.

The second part of Myers' explanation for the strange DNA results is here:

Troyer's search also looked for matches at any of 13 genetic locations, while in a real criminal case the analyst would look for a particular profile -- making a match far less likely.

To understand this, suppose you want to flip 3 coins and have three heads come up to win. What are the odds? If you flip the coins, there are 8 possible outcomes:

TTT

TTH

THT

THH

HTT

HTH

HHT

HHH !

Since only one of these has three heads (marked with an !) , the chance of three heads with three coins tossed is 1/8.

Now let's look at the chance of getting 3 heads by tossing 4 coins. Here are the possible results:

TTTT	HTTT
TTTH	HTTH
TTHT	HTHT
TTHH	HTHH !
THTT	HHTT
THTH	HHTH !
THHT	HHHT !
THHH !	HHHH !

Now there are 5 winners out of 16, which means we've more than doubled the chance of getting three heads just by allowing an extra flip. This is the unsurprising result of the fact that the more tries we get to win, the greater our chance of success.

Something similar happens in the DNA database, but to understand it, we have to look at how a database match is normally done.

When some DNA evidence is found at a crime scene, a forensic technician attempts to find samples of all 13 of the loci that are used for a standard test. If the sample is degraded, there may not be enough surviving loci. It's my understanding that unless the tech finds 9 or more usable loci, the sample is considered too poor for forensic purposes.

So, if the tech finds 9 loci, she plugs them into the database and looks for someone who matches on all 9. However, if the tech finds 10, she has to do a search for someone who matches on all 10. A match on 9 isn't good enough, because that would mean that the sample doesn't match on the 10th loci, and any mismatch excludes a person from the search.

That's the key: In a real search, you have to match on every loci in the evidence sample. 9 out of 9, 10 out of 10, 13 out of 13.

In the search that Troyer did, however, she compared each 13-loci database entry with every other 13-loci entry, but considered it a match if only 9 out of 13 were successful.

From the information I've found, I can make a rough estimate of what that does to the search. If a 9-out-of-9 match happens by chance one in 113 billion times as the FBI says, that works out to the chance of a random match at each loci of only about 5.9%. In other words, to get a 9-out-of-9 match by accident, the sample would have to beat that 5.9% probability 9 times in a row. (5.9% is about 1 chance in 17, so beating the odds at all 9 loci works out to about 1 in 17⁹, or 1 in 119 billion, which is a rounding error off the FBI's number.)

So, with a per-loci probability of 5.9%, we can use the binomial distribution to determine that the probability of 9 matches out of 13 is about 1 in 197 million, which is about 570 time more likely than the FBI's estimate for a 9-out-of-9 match. Further, since Troyer's query checked 2 billion pairs, we could expect about 10 matches at those odds.

Myers said the expected number of matches was 100, which is 10 times my figure. I assume he's working with better data than I am.

In particular, my way of calculating the per-loci probability of a match assumes that all loci have equal variance, and that all values found at each loci are equally likely. Both of those assumptions are almost certainly wrong for real DNA data, and any deviation would lead to clumping that would make some loci values more likely to match than others, which would increase the chance of a coincidental match.

I also setup an Excel spreadsheet to run the birthday paradox math based on a 1 in 197 million match per pair, and the chance of a match is even money when there are only 16500 samples in the database. So it's not surprising that these kinds of searchs find people who match on 9 loci.

So, what does it all mean? For one thing, my back-of the envelope calculations come close enough to Myers' caluculations that I don't think he's saying anything too outlandish when he says this is nothing to panic about.

On the other hand, I'm not accusing Troyer of doing anything wrong in her experiments, either. Her selection of 9 out of 13 loci and her all-against-all match in the database are an attempt to simulate a very large number of real-world searches. As long as she and everyone who uses her results understand the statistical issues, there's no problem.

The real questions require more detail than the blunt numbers that I'm using. Some of the results obtained by Troyer and others cannot be explained as statistical artifacts. Defenders fo the DNA databases have invoked some suspicious just-so explanations. For example, suggesting that a perfect 13-out-of-13 match is either a duplicate entry or a pair of twins.

While either explanation could be correct, simply asserting it doesn't make it so, at least not until the matter has been properly investigated by statisticians, DNA experts, and law enforcement.

Unless there is already a track record showing that all such matches inevitably have ordinary explanations, it's probably worth further investigation. It could be that DNA testing doesn't quite work the way we think it does, and the large law-enforcement database could be a fruitful source of scientific data worth studying.

And that's where we hit a bit of a snag. The FBI is resisting these kinds of queries in its CODIS database.

In California, Michael Chamberlain, a state Department of Justice official, persuaded judges that such a search could have "dire consequences" -- violating the privacy of convicted offenders, shutting down the database for days and risking the state's expulsion from the FBI's national DNA system. All this for a search whose results would be irrelevant and misleading to jurors, Chamberlain argued.

In Illinois,

Callaghan suggested they tell the judge that Illinois could be disconnected from the national database system, the summary shows. Callaghan then told the lab officials that "it would in fact be unlikely that IL would be disconnected," according to the summary.

In an interview, Callaghan disputed he said that.

"I didn't say it was unlikely to happen," he said. "I was asked specifically, what's the likelihood here? I said, I don't know, but it takes a lot for a state to be cut off from the national database."

And in Maryland,

After the defense filed a contempt-of-court motion, Michelle Groves, the state's DNA administrator, argued in court and in an affidavit that, based on conversations with Callaghan at the FBI, she believed the request was burdensome and possibly illegal.

According to Groves, Callaghan had told her that complying with the court order could lead Maryland to be disconnected from CODIS -- a result Groves' lawyer said would be "catastrophic."

...

After the judge, Steven Platt, rejected her arguments, Groves returned to court, saying the search was too risky. FBI officials had now warned her that it could corrupt the entire state database, something they would not help fix, she told the court.

...

The search went ahead in January 2007. The system did not go down, nor was Maryland expelled from the national database system.

Some of these excuses don't pass the smell test. The query "could corrupt the entire state database"? I wonder if the IT staff running CODIS are aware that someone in the FBI is badmouthing them this way.

I can understand that the folks running CODIS might not want it to be used in ways that slow down processing and waste valuable resources, and I can understand that only certain uses of the CODIS database are authorized by Congress, but there is something not quite right about the way the FBI is fighting these searchs.

For one thing, it just sounds funny when law enforcement agencies suddenly become concerned about the privacy rights of the people they've arrested.

Besides, the FBI keeps telling us that CODIS has extensive privacy protection. This is presumably why states have been able to find matches, but have not been able to investigate further and learn the reasons for the matches.

Also, each state has apparently only searched the DNA profiles that they themselves have submitted. Presumably the same data exists in non-database form in each state's crime labs.

Finally, the apparent fear of these kinds of database searches is inconsistent with the continued assertions that the science is sound. If the science is good, it will stand up to further investigation. That's the definition of good science.

To use the favorite formulation of every cop: If they're not doing anything wrong, they shouldn't have anything to worry about.

(Note: As is often the case in this blog, I'm trying to sing outside my range. While some of this is simple statistics, a lot of it is based on information in the original Los Angeles Times piece by Jason Felch and Maura Dolan. I also used Wikipedia for details about DNA testing and the CODIS DNA database. Wikipedia also has a more rigorous description of the Birthday Paradox.)

In an article about the legal defenses for a drug possession charge, Jon Katz mentions a case in which a suspect was caught with ten pills, all allegedly methadone. The state had a chemist test one of the pills to determine it was methadone, then the chemist testified that the other pills looked similar. This was enough to convict, and the decision quoted favorably an earlier ruling that

"Random sampling [of controlled dangerous substances] is generally accepted as a method of identifying the entire substance whose quantity has been measured." 

Katz argues:

The chemist had the alleged drugs available to test; it is not too much to insist that a possession with intent to distribute conviction for methadone be precluded without testing each pill, or at least over half the pills.

My prob-and-stats classes were long ago, but I'm going to try to figure out the math behind sampling a bunch of pills. I think I can get some useful results fiddling with the hypergeometric distribution function in Excel. (Although I could certainly be screwing this up.)

I believe the situation in the methadone case is similar to sampling the output of a production process and trying to set an upper limit on the defect rate, where a defect is equivalent to a pill that is not actually methadone.

For example, if our production process manufactures a batch of 1000 lightbulbs and we sample 5 random bulbs to test, and none of them are defective, can we conclude that the entire batch has no defects? What if we test 100 bulbs?  500?  999?

The short answer in all these cases is no. As long as we do not test every bulb, there is always a chance that one of the untested bulbs is defective. And there is always the chance that one of the defendant's pills is not methadone unless we test them all.

So, before we can answer questions about the scientist's methadone tests, we need to answer a policy question: How confident do we need to be in our results?

It would be easy to say we need 100% perfect confidence, but that would be hyperbole, not reality. 100% confidence implies an error rate of exactly zero, which is unrealistic. We routinely accept larger risks, such as the inherent error rate of the test for methadone or the risk of assigning a lab sample to the wrong case. We need to pick a more realistic number.

They say it's better for 10 guilty people to go free than to convict one innocent person, which kind of implies about a 90% confidence would be acceptable. Let's use that to keep the numbers simple.

So, if the scientist tests 1 pill out of a batch, and it's methadone, what percentage of the pills can he conclude are methadone with 90% confidence? Well, 1 sample is a degenerate case: He can only conclude that 10% of the pills are methadone. Since he has actually sampled 1 of the 10 pills, he already has empirical evidence that 10% of them are methadone. Statistical sampling is useless in this case.

How many samples would he need to be 90% confident that more than 90% of the pills---i.e. all of them---are methadone? He would need to sample more than 90% of them---i.e. all of them. Again, statistical sampling is useless.

The problem here is that a total population of only 10 pills is an absurd use of statistical sampling. A better use would be if you recovered a bag of 300 little glass bottles which you suspected to contain crack, and you wanted to know if your suspect had enough crack to reach the sentencing enhancement at 100 bottles.

How many straight successful tests for crack in a bottle would be necessary to ensure with 90% confidence that at least 100 of the bottles held crack? It only takes about 3. If you tested 13 straight bottles and all of them were positive for crack, you could assert with million-to-one confidence that at least 100 of the bottles in the batch were crack.

(It's important that the sampling be truly a random sample of the bottles. Merely taking the first 13 could lead to mistakes if the initial bottles differ from the others in some way.)

So what was really going on in the Williams case? Well, the court's opinion that the scientist was using random sampling is nonsense. As we've seen, random sampling of a single pill out of 10 tells him nearly nothing.

However, one of the crucial assumptions behind these statistical calculations is independence: The calculations assume that the contents of any pill (or bottle) is in no way related to the contents of any other pill (or bottle). This is often not the case in the real world. If you find an unlabled bottle of identically shaped and colored pills in your medicine cabinet, and you see that one of them has "aspirin" written on it, you can fearlessly conclude that you have a bottle of aspirin.

That works because you assume someone (the manufacturer, the pharmacist, you) put all the pills in the same bottle because they are the same kind of pills. The prosecutor in the drug case just asked the court to infer the same thing about the defendent's pills, which it did.

The court apparently made this inference based on common sense. However, the prosecution also used testimony from a police detective whom the court described as "an expert in the packaging, use, and distribution of narcotics." I'm sure he would have been willing to back up the claim that drug users and distributors don't usually mix pills.

(Lord knows, he testified to all kinds of other amazing things. It's a wonder these police drug experts aren't just allowed to testify that it would be very unusual for a young black or hispanic male to be standing on a street corner for reasons other than selling illegal drugs... Sheesh.)

In short, the scientist's sole contribution was identifying the one pill as containing methadone. The rest was inference by the fact finder, which did not involve statistics in any meaningful way.

We had a 5.4 magnitude earthquake in Illinois this morning. It hit around 4:36, so I was asleep and missed the whole thing. Bummer. Quakes are really rare in these parts and it would have been fun.

5.4 isn't much of a quake, but it's huge for Illinois. It also attracts a lot of attention because of the way our seismic region is structured. We're sitting on top of solid rock, which carries vibrations really well, so even a small quake like this one can be felt 450 miles away. That means that the quake was reported by people over an area of 600,000 square miles.

Our buildings aren't built to survive quakes as well as the ones in California, but solid rock doesn't bend and flex much, so there's not a lot of damage. The worst I've heard of is a collapsed porch roof.

Bill Beckman at Illinois Review is concerned about human embryos destroyed during in-vitro fertilization:

A January 2nd LifeSiteNews article covers findings following a UK Parliamentary question on IVF. Data from a government organization showed that over one million human embryonic children were killed in the UK in the past 14 years as 'waste' embryos from IVF processes.

The acquired data showed that 2,137,924 embryonic humans were created using IVF between 1991 and 2005, but about 1.2m were never used. Scientists killed the embryos who were not deemed strong enough for implantation, and froze those not considered 'waste' embryos. Those that survived the freezing process will die in ten years if not implanted.

'Surplus' embryos were created because women responded differently to fertility drugs, doctors told the Times Online. As many as 40 IVF-fertilized eggs can be used in some treatments. The embryos are then assessed for viability, with only about 20% usually considered strong enough to implant successfully in a woman.

Wait a minute! These numbers do not compute. If only 20% are deemed viable, then 80% are killed before ever reaching the point where the phrase "excess embryo" might get used. Does this mean in reality that the death toll was over 8 million non-viable embryos, killed to create over 2 million viable ones, of which 1.2 million were not used because deemed excess?

I'm having a little trouble researching the details, but I think human embryos produced by IVF are assessed for viability when they've divided into a total of 8 undifferentiated cells, and they are implanted by the time they reach 100 cells. You probably scrape off several times that many cells each time you scratch your nose.

This seems to have crossed the line from pro-life into some weird form of cell worship.

I'm fascinated by the conservative obession with evolution. On Illinois Review, Jill Stanek quotes with some approval this statement by Presidential candidate Mike Huckabee:

If anybody wants to believe they are the descendants of a primate, they are certainly welcome to do it. I don't know how far they will march that back. But I believe all of us in this room are the unique creations of a God who knows us and loves us and created us for His own purpose.

Well, I certainly believe I'm descendant from primates. I just saw them a few days ago. It was mom's birthday.

You see, Huck, it's worse than you think. No only are we descended from primates, we are primates.

If you examine us humans carefully, looking at our bone structures, our organ systems, our eyes, brains, blood chemistry, the proteins that we're made from, and the DNA that makes the proteins, we bear a close resemblance to all the other animals in the order of Primates.

In fact, we fit into the Hominidea family, along with orangutans, gorillas, and chimpanzees, also known as the great apes. So, we're already living on the Planet of the Apes, because we are apes too.

This has nothing to do with evolution. The morphological similarities between humans and the apes was obvious well before Darwin proposed his great theory. Some discoveries, such as the similarities of our DNA, came after the theory of evolution, but they are true independently of whether evolution is true.

Evidence that the effects of fertility are detectable by men:

A study shortly to be published in the journal Evolution and Human Behaviour found that lap dancers in their most fertile phase of the menstrual cycle earned much more than dancers in the least fertile phase.

Read the whole story.

Want to win $20 million from Google?

All you have to do is land a small spaceship on the moon and send back pictures.

No, not in a video game. I'm talking about a real spaceship on the real moon.

It's the Google Lunar X Prize.

(Hat tip: Philipp Lenssen)

I'm pretty comfortable with technology, complacent even, but every once in a while some commonplace thing about our modern world just amazes me.

One day about 120 years ago, French actress Sarah Bernhardt left the Broadway theater where she was performing and set out on a journey that took her over the Hudson River into New Jersey. She was the most famous actress in the world, known as "Divine Sarah," and she was going to Menlo Park to visit the most famous inventor in the world. She didn't reach his home until after midnight, but that was okay, because she was there to see Thomas Edison, and he had the lights on.

Electric light wasn't the only new invention in use. Edison had also invented the first audio recording device. Never before had anyone heard a human voice that didn't come directly out of a human mouth. For the first time, people could hear voices from the past. Or record them for the future.

That night, Edison used one of his machines to make a wax cylinder recording of Sarah Bernhardt as she did a dramatic reading from Jean Racine's opera Phèdre.

Reading about that moment, I found myself thinking about how far we've come. Two amazing things struck me:

The first one is that I have a Sony Digital Voice recorder that I use for taking notes and (if I ever attempt actual journalism) recording interviews. Its tiny little condenser microphone captures sounds far better than Edison's wax cylinder phonograph, it stores almost 24 hours of audio, and it operates on a pair of AAA batteries. When Thomas Edison recorded Bernhardt's performance, he was the world's expert on audio recording. Skip forward 120 years, and I can make a better recording using a device I keep in my pocket.

The second amazing thing is that when Edison recorded Sarah Bernhardt's reading from Phèdre there was no way to copy phonograph recordings. To hear her performance, you would have had to have that exact cylinder, recorded in her presence. 120 years later, sitting in the comfort of my own home, I was able to find a copy of it just minutes after finding out that it had been made. All you have to do is click here and dozens of computers spread all over the landscape will briefly cooperate to pull a digital copy from magnetic storage, transmit it to your location, and play it over your speakers. (Be warned, however, that because of the recording medium it's very quiet, and of course it's also not in English.)

(I found the Bernhardt-meets-Edison story while reading The Grid: A Journey Through the Heart of Our Electrified World by Phillip F. Schewe who cites Gotham: A History of New York City to 1898 by Edwin G. Burrows and Mike Wallace as his source. You can find Sarah Bernhardt's wax cylinder recordings at the Cylinder Preservation and Digitization project at the University of California in Santa Barbara.)

Why the world is going to be an exciting place in the new century:

Did You Know?

Thanks, Susan, for bringing this little presentation it to my attention.

A few days ago, Kip Esquire posted a fascinating thought experiment. Imagine that whatever biological mechanism it is that makes some people gay also produced a clear and unmistakable sign of its presence, such as a birthmark on the forehead. If you see a person with this mark, you know they're gay. Children with the mark are sure to grow up to be gay adults.

In other words, what if there could be no "closet"?

Kip thinks this would turn out pretty well:

One could imagine either of two cultural responses:

1. Kill the infants upon birth.

2. Or not.

I can't conceive a theory of anthropology or sociology where Option #1 would be the equilibrium outcome. If it were clear, from birth, that being gay is not a choice, if it were clear that a noticeable — even if small — minority of the population were gay, and if it were impossible to conceal one's true identity, then how, exactly, could bigotry arise in the first place?

My first thought was that a visible mark would be similar to a racial characteristic, and we all know how much bigotry there is about race. But as Kip points out, the birthmark's presence would track the prevalence of homosexuality, which is (mostly) not a hereditary characteristic, so there wouldn't be pre-existing family and social groups that have the mark.

Consider that about 14% of the U.S. population has very dark skin because they have African ancestry. Suppose that instead of being inherited, dark skin was a random occurrence at birth, meaning that regardless of the skin colors of the parents, every infant had a 14% chance of having dark skin. Would we still have bigotry over skin color?

Kip basically says no, and also no bigotry over the "gay mark" either. I say maybe a little.

There are real-world examples of the kinds of phenomena Kip is imagining. The first one that comes to mind is left-handedness. The U.S. has about as many southpaws as African Americans, but left-handed people don't face the same kinds of discrimination as African Americans. They do have problems because most tools are designed for right-handed use, as is our writing system, but they don't face active hatred for being left-handed.

However, that hasn't always been true here, and it's not true all over the world. The pattern is similar for other conditions that follow Kip's pattern, such as epilepsy, dwarfism, colorblindness, and deafness. I don't believe these people have faced the sort of organized hatred that characterises racism, but they have certainly faced some discrimination and prejudice.

There's a bigger problem. Kip says he "can't conceive a theory of anthropology or sociology" that would cause people to kill gay-marked infants at birth. I don't know enough about either discipline to tell if he's right, but I know one applicable theory that implies the death of gay-marked infants: Evolution.

Roughly speaking, the theory of evolution causes organisms to try to increase their genetic representation in future generations.

I'm no expert on evolution, so take what follows with a grain of salt, but it seems to me that a perfectly gay organism would have no future generations, so the forces of natural selection neither favor it nor disfavor it. A gay organism is no longer playing the game of evolution.

However, the gay organism's parents do have future generations, so they are still in the game. If the parents are involved in raising their children at all, as is certainly the case for humans, then from an evolutionary standpoint it is wasteful to spend time and energy raising the gay child. They would be better off lavishing more care on their other children, or having more children. One way to accomplish this is for organisms to evolve an instinct to kill their gay children.

Evolution is an unplanned process, so it would simultaneously follow other paths to try to eliminate the waste of resources. It's not hard to imagine that the species would evolve a way for parents to have fewer gay children, or a way to have children that are less than perfectly gay. Either of these might be accomplished by changing the biochemical conditions in the womb, but the latter could also be achieved by social pressure to reproduce despite the gay sexual preference.

Once that happens, gays are back in the game of evolution, and to the extent there is any genetic component to gayness, they will evolve. If their parents have evolved the instinct to kill gay offspring, then the gay offspring will evolve a way to to resist. One solution would be to evolve a way to hide their gayness, in which case the gay mark will go away.

A few notes are in order: I have taken the liberty of describing evolution as if it had a purpose. It doesn't. But its results often seem to have a purpose, which is good enough for my purposes. Also, as far as I know, how homosexuality fits into the theory of evolution is not well understood. We might figure it out when we learn more about how the sexual modules of the brain develop and function. Finally, don't assume this theory means it's natural or right for parents to hate their gay children. Human psychology and culture is a lot more complicated than the simple reasoning of this article. In any case, nature is a terrible guide to morality.

A couple months ago I mentioned that Richard Nixon's name would be long-remembered because it's engraved on the Apollo 11 plaque on the airless surface of the moon. I started wondering how long the plaque would actually last and did some research, but for some reason I didn't post what I found. I can't find the links to my sources, but here's what I wrote about it:

On Earth, a plaque like that on Apollo 11 would be subject to erosion by wind and rain. The wind and rain would also carry pollution and other corrosive chemicals which would be deposited on the plaque and eat it away. The moon, on the other hand, has no atmosphere, so there's no wind or rain or flowing water to damage the plaque. It could last a long time, except for a source of erosion we don't encounter on Earth: Micrometeorites.

The space between the planets is hard vacuum, a harder vacuum than we can create in earthbound laboratories, but it's still filled with with very, very small dust particles and even individual molecules floating free. Anything moving through interplanetary space collides with these dust particles at speeds of several miles per second.

The Earth itself collides with hundreds of tons of space dust every day. However, all this dust hits the atmosphere first and slows to a crawl, eventually settling to the surface. All but the largest rocks will lose their orbital speeds in the atmosphere and drop like, well, like rocks.

The Earth's moon, on the other hand, has no atmosphere at all to protect it, so even invisibly small dust particles will smack into the surface at several miles per second. These are called micrometeorites to differentiate them from meteorites large enough to survive the plunge through the Earth's atmosphere.

The continuous lunar micrometeorite storm is mostly insignificant. Astronauts walking around on the moon would have been pelted constantly, but even at a 50 miles per second, the impact of a few molecules would have been unnoticable. However, over time, these dust particles would pit whatever they strike, eventually wearing it down, much as wind can erode away a rock.

Except much slower. From a paper about the design of the Message From Earth plaque on the Pioneer spacecraft, I found an estimated wear rate of about 1 angstrom per year in our solar system. An angstrom is a ten-billionth of a meter. For comparison, Niagra Falls erodes away at the rate of about 1 meter per year. It would take cosmic dust more that twice the age of the Earth to erode that same distance.

This is just a rough estimate, of course. The estimate for Pioneer is for small objects like man-made satellites drifting through space. The moon is large enough to have meaningful gravity, and it will pull in dust from the space around it, increasing the erosion rate. On the other hand, if you look at this image from NASA, it's clear that the plaque isn't just set on the surface of the Moon, it's mounted on one of the landing legs of the Lunar Excursion Module.

That could shield the plaque from some of the dust, reducing erosion. For the sake of this article, let's just assume the one-angstrom-per-year estimate is good enough.

If the engraving on the Apollo 11 plaque is a reasonable 1/10th of a millimeter deep, it will take a million years to wear away Richard Nixon's name.

To put that in perspective, I think the oldest people whose names we know are the Egyptian Pharohs, a comparatively recent 6000 years ago.

I was driving home from dinner with the parents when suddenly it hit me: I don't know how many planets there are!

The IAU met to decide on it a few months ago, but the rule they settled on was not the rule everybody thought they'd settle on. I can't remember what they decided, so I have no clue how many planets there are.

I think that means I get to make up my own rules. I'm going to go with eleven: The eight non-controversial planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune). I'll add Pluto (you haters can kiss my ass), plus the slightly bigger new one that its discoverer calls Xena (the IAU wants to call it something else, but I say if they want to name a planet they should get off their asses and find one of their own), plus Ceres because it's big and round too. I'm not counting Charon no matter what they say. It's still just Pluto's moon.

Over at NewScientist.com, someone named Bob Holmes imagines all the wonderful things that would happen to the Earth if all the people disappeared:

By some estimates, we now commandeer 40 per cent of all its productivity. And we're leaving quite a mess behind: ploughed-up prairies, razed forests, drained aquifers, nuclear waste, chemical pollution, invasive species, mass extinctions and now the looming spectre of climate change. If they could, the other species we share Earth with would surely vote us off the planet.

Now just suppose they got their wish. Imagine that all the people on Earth - all 6.5 billion of us and counting - could be spirited away tomorrow, transported to a re-education camp in a far-off galaxy.

Re-education camp. There's a lovely idea for you. I suspect it says something about Holmes's view of humanity that his ecological fantasy doesn't begin with humans suddenly discovering cheap space flight and deciding to convert the Earth into a nature preserve.

On the one hand, it's a fascinating bit of speculative science, but on the other hand, the whole thing has an unpleasant "teaching humanity a lesson" vibe to it, in which Holmes imagines that humanity would be wiped away completely and the Earth would return to some mythical unmolested state.

He wishes away problems like still-running nuclear power plants melting down, and he sort of ignores the mass die-off that would occur when there's nobody to feed the billions of animals we keep as livestock. He seems to regard even our domesticated animals as some sort of pest that will eventually be wiped out.

Toward the end, he imagines aliens visiting the Earth and finding few clues that a civilisation once flourished:

The humbling - and perversely comforting - reality is that the Earth will forget us remarkably quickly.

Well, most of us will be forgotten. Except for Richard Nixon. As President during our brief flirtation with space exploration, his name is engraved in gold on a plaque on the airless surface of the moon.

(Hat tip: Instapundit.)

See also: The Voluntary Human Extinction Movement. No, I can't tell if they're serious either.

When Neil Armstrong stepped onto the surface of the moon in 1969, everyone heard him say,

"That's one small step for man, one giant leap for mankind."

But that doesn't really make much sense, does it? "Man" and "mankind" mean the same thing in this context, so he's saying that mankind took a small step and a giant leap at the same time.

That's not very profound, is it? It would have been much better if he'd thrown the indefinite article "a" in there right before "man" to contrast the easy step of a single human with a vast leap forward for all humankind. Like this:

"That's one small step for a man, one giant leap for mankind."

Well, for three and a half decades now, that's what Neil Armstrong has been claiming he did say. So now some accounts of the event have the "a", and some of them don't. A few of them try to hedge:

"That's one small step for [a] man, one giant leap for mankind."

Lately, even Armstrong himself is beginning to believe he didn't say it.

Until...

An Australian computer programmer says he found the missing "a" from Armstrong's famous first words from the moon in 1969, when the world heard the phrase, "That's one small step for man, one giant leap for mankind."

...

Ford said he downloaded the audio recording of Armstrong's words from a NASA Web site and analyzed the statement with software that allows disabled people to communicate through computers using their nerve impulses.

In a graphical representation of the famous phrase, Ford said he found evidence that the missing "a" was spoken and transmitted to NASA.

"I have reviewed the data and Peter Ford's analysis of it, and I find the technology interesting and useful," Armstrong said in a statement. "I also find his conclusion persuasive. Persuasive is the appropriate word."

Via Jesse Walker at Reason, the coolest thing you'll see today.

Astrophotographer Thierry Legault used a telescope and camera to catch a picture of the sun at the exact moment when the International Space Station passed between the sun and his position on the Earth. It was just after the Atlantis shuttle had undocked.

Awesome photo.

Note that the space station and shuttle were not just drifting lazily across the sun when this photo was taken. Stuff in space only appears to move slowly when the camera is either very far away or else is in orbit with the spacecraft.

This camera was on the ground and relatively stationary, whereas orbital velocity at that height, 400 kilometers, is about 7670 meters per second. (That's 250 miles, and about 4.8 miles per second.) At that speed, a trip from Chicago to Milwaukee takes twenty seconds.

The longest part of the space station, the long arm clearly visible in the photograph, is about 108 meters long (half a city block), so the space station travels (7670 / 108=) 71 times its own length every second.

At that height, the station subtends an arc of about 0.0155 degrees, whereas the sun subtends an arc of about 0.5 degrees. So if you look at the picture, the sun is (0.5 / 0.0155 = ) 32 times larger than the station, and since the station travels 71 times its length in a second, it was only in front of the sun for half a second.

Even though Legault took a series of pictures, he still showed a lot of skill to get this shot.

Update: I should point out that my calculation is only a ballpark figure. The camera is actually on a spinning planet and is therefore probably moving at a few hundred meters per second itself, but I have neglected this motion to make the calculations easy enough for me to do. Also, the station was not directly overhead for the photographer, and it was rotated slightly from his viewpoint. To figure all this out, I'd have to have the station's actual velocity vector at the time, which would have to be calculated from its current orbital parameters, and I don't know how to do that. Legault himself used the software at www.calsky.com and got slightly different (and more accurate) results.

Pluto is not a planet.

Despite earlier indications that the International Astronomical Union might adopt a broad definition of a planet that includes Pluto and additional objects in the list of planets, they've decided that Pluto isn't a planet after all, and neither are the other three objects they had been considering: Charon, Ceres, and 2003 UB313.

The good news, I guess, is that now that UB313 won't be a planet, it will probably be allowed to keep its way-cool nickname: Zena. (Yes, named after the television character.)

In addition to the earlier parts of the definition (round, orbits the sun) they've also added a provision that planets must have cleared their orbit of other debris. Pluto and its moon, Charon, are in an orbit that crosses Neptune's orbit, so obviously there's other stuff there.

Then again, mighty Neptune (eight thousand times more massive) hasn't yet hurled Pluto out of the solar system (or into the inner system) so how come it's still considered a planet? Sounds like fuzzy thinking by Pluto-haters.

The meeting was held in Prague, but somehow I suspect the French are behind this...

There's some interesting news news from the International Astronomical Union this morning. They may be about to settle on the definition of a planet...and there are more of them than you think. (For those of you who don't remember this stuff, you're supposed to think there are nine of them.)

The sticking point has been the most distant planet, Pluto. We've been calling it a planet for a long time, but with a diameter of only about 1400 miles, it's actually smaller than the Earth's moon and is closer in size to an asteroid. Some people don't think that's significant enough to call a planet.

The problem was exacerbated with the discovery of something cataloged as 2003 UB313 which is even further away, and ever so slightly larger than Pluto.

This isn't a vitally important issue—not even to astronomers—but they'd like to settle it to avoid the embarrassment of having children in different countries learning different lists of planets.

The IAU appears to be settling on a two-part definition. The first part, which settles the matter of Pluto, is that planets must be round. That is, for an object to be considered a planet, it must be large enough that its own gravity has shaped it into a sphere. (The IAU definition actually talks about "hydrostatic equilibrium" which accounts for some variation in shape, most significantly that spinning planets bulge at the equator.) In practice, this means it must be at least 500 miles in diameter with a mass of at least 1/12000 of Earth.

Pluto is round, therefore Pluto is a planet.

Unsurprisingly, UB313 is also a planet under this rule, but they'll probably give it a real name. Actually, its discoverer, Michael Brown, has nick-named it Xena, as in Xena: Warrior Princess, and naming rights usually go to the discoverer, but the IAU says it will probably be named something else later. (I hope not.)

Slightly more surprising is that the asteroid Ceres, orbiting between Mars and Jupiter, will become a planet under this rule. It's 900 miles in diameter and mostly round. It was considered a planet when it was discovered, but downgraded to an asteroid when all the other asteroids were discovered in roughly the same orbit (i.e. the asteroid belt).

"What about the moon?" you may be asking. (Or not.) It's round and it's bigger than Pluto, Ceres, and UB313. Shouldn't it be a planet? For that matter, Jupiter's four largest moons are all pretty big, shouldn't they be planets too?

That brings us to the second part of the definition: Planets orbit the Sun. Not other planets. Thus, the Moon remains a moon. And the planet-sized moons of Jupiter remain moons too.

Pluto is once again a troublemaker. Its moon, Charon, is about half the size of Pluto itself and is quite massive. That's a problem because a planet's moon doesn't technically have an orbit centered on its planet. Rather, the planet and the moon orbit a common center of gravity. When the moon is a small rock, like the moons of Mars, that common center of gravity is very nearly the center of the planet. But with a larger moon the center of gravity shifts away from the planet's center. The Earth's moon is so large that the center of gravity is 3000 miles from the center of the Earth, but that still puts it 1000 miles below the Earth's surface, so it's still accurate to say the Moon orbits the Earth. That's why it will remain a moon.

Not so with Pluto and Charon. The center of gravity of the Pluto-Charon system is a point between Pluto and Charon. This means that Charon doesn't technically orbit Pluto. So Charon is a planet too.

If you're counting, that's twelve planets: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon, Xena.

Let's see now...I learned the memory mnemonic for the order of the planets as "Mary's Violet Eyes Make John Sometimes Unusually Nervous Perhaps." I guess we'll have to change that to something like "Mary's Violet Eyes Can Make John Sometimes Unusually Nervous Perhaps Concerning Xylophones." No, that doesn't work...

Update: They decided it's not a planet after all.

I think I'm just a little creeped out at the thought of Google having a soul of its own.

http://news.yahoo.com/s/ap/20050809/ap_on_sc/space_shuttle