Tuesday, January 24, 2012


American values

It’s that time of year: a Tuesday near the end of January. It’s just past another anniversary of the president’s inauguration, and time for the annual tradition, the State of the Union address.

In this case, it’s President Obama’s third anniversary, and tonight he’ll give his third SotU speech. According to the Washington Post, this year’s talk will stress a return to American values.

All right, here it is: I’m sick to death of hearing about values. Values has turned into a codeword for reactionary politics, repression, and censorship. I don’t want to hear a speech about those kinds of values, especially from a president who has done little to fix the overstepping excesses of his predecessor, and, to the contrary, seems to embrace many of them.

American values used to be about freedom and opportunity, not control and rigidity. America was a country that didn’t abuse and arrest people for assembling peacefully. It didn’t arrest people for documenting how the police were handling situations. It didn’t keep political prisoners, detaining people indefinitely with no chance of formal accusation, trial, and defense. It didn’t limit the rights of people because of who they are, it didn’t restrict their access to medicines and medical procedures, it didn’t try to teach children mythology in science class, and it did not march a conservative Christian agenda down the streets everywhere.

You want to return to American values? Demilitarize the police, and get them back to engaging with the communities they serve and protect. Don’t send people off to secret prisons, close Guantánamo, and give everyone there a proper, open trial. Stop using terrorist the way dictatorships have used denunciation, as a way to whisk troublesome people away. When people get angry and want to protest, encourage them and give them a venue, don’t beat them down and throw tear gas at them as they sit non-aggressively. Allow yourself to be held accountable for your actions, and don’t threaten people who want to record what you’re doing. Don’t get involved in people’s private lives and personal decisions. And keep religion out of the government and public education. You can start that by not saying God bless in your speeches. Try it tonight.

Remember that American values came from our flight from having to live under someone else’s values. We can’t just replace the king’s values with those of your family, your church, or any other relatively small subset of Americans. Our values were set up to protect our rights and our freedom — everyone’s — and that is what we need to return to.

Oh, and fix the economy, yeah? Don’t just talk about it.

Tuesday, January 17, 2012


That argument again?

New Scientist, which seems to run hot and cold out of the sensible science tap, is chilling our tootsies off with an icy-cold flow: an unattributed editorial titled The Genesis problem. In it, they make one of the oldest, lamest arguments that attempt to support creation myths over the Big Bang theory:

The big bang is now part of the furniture of modern cosmology, but Hoyle’s unease has not gone away. Many physicists have been fighting a rearguard action against it for decades, largely because of its theological overtones. If you have an instant of creation, don’t you need a creator?

Cosmologists, the editorial goes on to say, thought they had a workaround.

Well, no... no workaround is needed. The argument is that my creation story (the big bang) involves an entity that itself needed to be created, but your creation story works because it involves the creator misses the point that your creator is also an entity that itself needed to be created. You don’t get to make a set of rules for the one and ignore them for the other, and if one creation entity can exist without creation, then so can another.

No, what’s needed isn’t a workaround, but an explanation, an understanding. You, perhaps, have your understanding because someone made up an answer and you believe it: God has always been, and always will be. Cosmologists — at least the majority, who aren’t trying to fit cosmology into a theistic system — still have a piece that they don’t understand, because they’re not willing to make up an answer that doesn’t follow from the data. If they were, of course, their explanation could be very similar to the theistic one: the primeval atom always existed, and created the universe through the big bang.

We come into a clash of aspects of human understanding when we discuss any genesis explanation. People understand things to have beginnings and ends, and have a hard time coping with things without beginnings. And people like to have questions answered, definitively. When each answer uncovers more questions, we tend to be unsettled. That it seems easier to accept a God with no beginning than a primeval atom with no beginning is perhaps odd, but there it is. God can then be used to explain anything, wrapping things up nicely... for those who are willing to believe those explanations.

I’d rather accept that we don’t yet understand, than to make up facile answers that have no basis in reality. I even accept that we might never really understand it, might never have the real answers. We’ll keep looking at what’s actually there, and we’ll find what we’re able to find.

Thursday, January 12, 2012


No mean feat

Physicist Stephen Hawking turned 70 last weekend, and has been living with ALS — amyotrophic lateral sclerosis — for nearly 50 years. Usually, the disease is diagnosed in patients over 50, and they die within a few years. I was reading an article in Scientific American about Dr Hawking’s longevity. The article contains an edited interview with Dr Leo McCluskey, an ALS expert at the University of Pennsylvania.

One answer, in particular, struck me:

Sci Am: What has Stephen Hawking’s case shown about the disease?

Dr McCluskey: One thing that is highlighted by this man’s course is that this is an incredibly variable disorder in many ways. On average people live two to three years after diagnosis. But that means that half the people live longer, and there are people who live for a long, long time.

The mathematician in me rose up at that: no, on average does not mean that half the samples are on each side of the average. Average refers to the arithmetic mean — take a bunch of numbers, add them, and divide by the count (how many numbers you added) — and it’s easy to show, by example, how that’s wrong.

Suppose we had five patients with ALS. Suppose four of those patients lived for one year following diagnosis, and one lived for eleven years. 1 + 1 + 1 + 1 + 11 = 15, and 15 / 5 = 3. So on average, people in this sample lived for three years... and only one of the five (20%) survived more than even one year. Given Dr Hawking’s experience of on the order of 50 years, he could offset about 25 patients who succumbed after one year, and still give us a three-year average.

The problem with the arithmetic mean is that it’s easily skewed by outliers. In the extreme example here, if 96% of the samples are 1 and 4% are 50, we get an average of 3 — three times the normal value. That means that with such a situation, the average is useless in giving us any reasonable prediction of what to expect. More generally, if the numbers are widely variable, the average doesn’t tell us anything useful. If we have nine patients who made it through 1, 2, 3, 4, 5, 6, 7, 8, and 9 years, respectively, what do we tell the tenth patient who shows up? 5 years, on average, sure, but, really, we might as well tell him to take a wild guess.

Averages are useful when the values tend to cluster around the arithmetic mean, particularly when the number of samples is large. They’re also helpful in analyzing trends, when we look at the change in the average over time... but, again, we have to be careful that a new outlier hasn’t skewed the average. Sometimes we adjust averages to try to compensate for the outliers — for example, we might eliminate the top and bottom 5% of the samples before taking the average.

Another common error is to confuse the mean with the median. The latter is often used in financial reporting: median income, median purchase price for houses, and so on. The median is a completely different animal from the mean. It’s, quite simply, the middle value. List all the sample values in increasing order, and pick the one in the middle (or one of the two in the middle, if the number of values is even).

In the first example above,[1] if we write the values as 1, 1, 1, 1, 11, the median is the value in bold: 1. In the second example, we have 1, 2, 3, 4, 5, 6, 7, 8, 9, for a median of 5. You can see that in the first case, the median is not related to the mean, while in the second case it’s the same as the mean. It’s also the case that the mean (or average) is an artificial value that might not appear in the samples, whereas the median is, by definition, one of the sample values.

Also by definition, at least half the sample values are greater than or equal to the median (and at least half are less than or equal to it). In other words, Dr McCluskey’s statement would have been true (at least close enough) had he been talking about the median survival period, rather than the average. Medians are also less susceptible to skewing by outliers, as you can see from the first example.

But as the second example shows, when the numbers are all over the place, neither is of much use in predicting anything.

[1] My examples use small numbers of values for convenience. In reality, both mean and median require a fairly large sample size to be useful at all.

Wednesday, January 11, 2012


What’s that rhyme?

Now that I have the file-count limit sorted out on the audio system in my car, it’s much better at playing songs in random order. Now I’m hearing Yes, Linda Ronstadt, Steely Dan, Toni Price, and Jackson Browne, and not just artists in the alphabetic A’s and B’s.

Thus, the other day I heard a song from Los Lobos’ great album The Neighborhood. The song that came on was the one that opens the album, Down on the Riverbed, and it struck me, as it has before, that there’s a slight oddness to the rhyme in the chorus. It goes like this (emphases mine):

Down on the riverbed,
Down on the riverbed,
Down on the riverbed,
I asked my lover for her h...

...for her h...

You want it to be head, don’t you? I certainly do. They set you up with bed thrice, and what rhymes with bed? Well, head, most assuredly.

Of course, it’s hand; Down on the riverbed, I asked my lover for her hand.

Trips my brain up every time I hear that song.