Pretty soon, on March 9, we’ll all change our clocks one hour forward to change from standard to daylight-savings time. An absolutely pure misnomer, daylight savings time is nevertheless, to my mind, the greatest success story of mass psychological control there ever has been. Just imagine if the government put out some sort of strongly worded encouragement that everyone needs to get up an hour earlier, starting Monday, and should continue to do so for the next eight months, so as to save energy and have a little more time in the evening when it’s light out. I imagine not many people would comply.

But, what they do instead is to say, “okay, starting early Sunday morning, it will suddenly be an hour later on your clock for the next eight months!” And, magically, just about everyone complies…it’s breathtaking, actually.

But what time is it really? This week, on February 29 we have a Leap Day, a once-every-four-years event. Actually, it’s not once every four years; we skip it every hundred years, except we don’t skip it every four hundred years. That is, 2000 was a leap year, but 1900, 1800, 1700 etc. were not. We’ve been doing this since 1582 when Pope Gregory introduced the new calendar to keep Easter from drifting, slowly but surely, away from the spring equinox, that magical moment when the earth’s axis makes an angle of 90 degrees to the line connecting the center of the sun with the center of the earth. On the spring equinox, the length of day and night are equal everywhere on the earth (at the poles the sun remains on the horizon all day). In the Gregorian calendar, the average calendar year is 365.2425 days, because this is the average number of days from one spring equinox to the next.

If you ask the average person on the street, though, just what “one year” means, though, they’ll most likely say “it’s the amount of time it takes the earth to go around the sun”. What they are probably thinking is that the imaginary line mentioned above from the earth to the sun sweeps out a full circle in one year; this is called a sidereal year: the time it takes for the sun to appear in the same place against the backdrop of the fixed stars. They’d be close, but no cigar: the earth’s axis, which is tilted at about 23.5 degrees to the plane of the earth’s orbit, is actually not fixed in its direction in space. The earth rotates on an axis which precesses, similar to that of a spinning top with one point fixed. It takes 26,000 years to go al the way around and come back roughly where it was. And so, in fact, the calendar year (also called the “tropical year”) is about 20 minutes shorter than the sidereal year. (You can easily calculate this yourself: it’s 1/26000 of a year!)

Our Gregorian calendar will keep the spring equinox quite close to March 21 or so, but eventually our familiar winter constellations like Orion will eventually become summer ones, and the North Star will appear to move in ever-widening circles about the celestial north pole.

If you dig further into all this you quickly see that the day, which I am sure you’ll find people to tell you is “24 hours” has a similarly ambiguous definition. The sidereal day, the time it takes the earth to spin once on its axis, is 23 hours, 56 min, 4.1 sec., just less than the solar day of 24 hours. Not surprisingly, after you think about it, this difference is close to 1/365 of a day, since as the earth goes around the sun, one full orbit is in effect a day. (If the earth were not rotating, then there would be one solar day per year.)

But is a day even exactly 24 hours? It turns out that for various reasons, the earth’s rotation speeds up and slows down over long periods. The second was redefined in 1967 to be the time it takes for 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. This is the basis for our measurement of time in the SI system of units. As a result, we no longer define the second as 1/86400 of a solar day, and we need to add in a leap second every so often to account for the fact that the earth’s rotation is slowing by about 2.3 milliseconds per day per century, and we chose the year 1900 as the reference for the second. This means we are now accumulating one leap second every 430 days or so. We’ve added leap seconds at about that rate since the first one in 1972 (always at midnight on New Year’s Eve).

So now we have International Atomic Time (TAI) with no leap seconds, and Coordinated Universal Time (UTC) which have drifted apart by 33 seconds since 1972. We need both systems, since we want a simple way to calculate accurate time differences without having to take into account leap seconds, but we want noon to stay when the sun is high in the sky. The US Navy is on it, don’t worry.

Except for that one-hour daylight “savings” time…

Actual footage of U.S. Senator Arlen Specter questioning National Football League commissioner Roger Goodell as part of an inquiry into whether or not the New England Patriots sneakily videotaped their opponent’s sidelines. An issue, we can all agree, of world-historical importance.

Brad DeLong disentangles the messages that a (male) professor sends by wearing a tie. (Inspired by this sad little diatribe, properly mocked here.)

I have found that wearing a suit and tie is very effective if done occasionally with non-math-oriented students. It tells them that I care because it shows that I have taken sufficient time to prepare and teach the class even though I am a busy person whose schedule requires meetings with:

• some powerful political figure,
• some powerful economic figure,
• some powerful university administrative figure, or
• some TV interviewer

With math-oriented students, however, a tie tells them that I spend too little time thinking about isomorphisms

Cf. Focus. Professors were once students.

Rediscovering this ancient Sesame Street skit has been my one source of joy while I slog through the writing of an immense, tedious, but necessary data paper.

Given that no one seems to have told Seattle about the housing bubble or economic downturn, developers are throwing up Hip! New! Condos! all over the metropolitan area. The most heavily advertised are those just north of downtown, in the South Lake Union area, largely because this area is underdeveloped, awash in biotech firms, and the future site of the new Amazon headquarters. Given the neighborhood’s demographic, the new condos are naturally targeting high-tech urban professionals who can afford $500K for a one-bedroom loft.

Now, if you were marketing condos to someone working in “high-tech”, would you then name your condo development this?

Carbon-fifty-WHA!?!?! Carbon 12, or Carbon 13, now that I’d consider, but 56????? There’s no “56″ anywhere in the address, or even in the stupid phone number. It’s not at the intersection of 7th and 8th (it’s near 9th, but 56 isn’t even divisible by 9). A bit of web research finally reveals that there are 56 units in the building, but that’s hardly reason enough for forcing residents to sound like scientifically illiterate ignoramuses every time they give their address: “Where should you pick me up? Oh, just outside of Carbon-mumble-mumble-mumble….”

I just can’t wait till they sell all the darn things, because the ads make me flinch.

Craig Barrett, the chairman of Intel Corporation, doesn’t mince words. In a scathing op-ed piece in the SF Chronicle, he describes the high-tech industry view of the dreadful state of funding for basic science research in 2008, due to the last-minute earmarking by the congressional appropriations committees.

“At a time when the rest of the world is increasing its emphasis on math and science education (the most recent international tests - NAEP and PISA - show U.S. kids to be below average) and increasing their budgets for basic engineering and physical science research, Congress is telling the world these areas are not important to our future.”

Mr. Barrett, thank you!

I do so love the internet. Anyone who has gone to pick someone up at the airport knows that planes don’t always land at their scheduled times. So nowadays, of course, you can check the web page for the appropriate airline and find out whether the plane is delayed or on time.

But you know what would be even better? If you could call up a Google map that showed the flight plan and current location of the plane.

And now you can! At least, for Delta flights. Do any other airlines do this? And if not, why not?

Wait, I answered my own question, using — you guessed it — the internet. Just go to Flightstats.com (obviously), where they will apparently give you a map of whatever flight you want. And if you’re bored, you can just pick a random flight! And then you will be, if not less bored, at least somewhat bemused.

This year, the Edge World Question Center asks people what they have changed their minds about. Here are excerpts from some of the most interesting answers. (Not that I necessarily agree with them.)

Joseph LeDoux changed his mind about how memories are accessed in the brain.

Like many scientists in the field of memory, I used to think that a memory is something stored in the brain and then accessed when used. Then, in 2000, a researcher in my lab, Karim Nader, did an experiment that convinced me, and many others, that our usual way of thinking was wrong. In a nutshell, what Karim showed was that each time a memory is used, it has to be restored as a new memory in order to be accessible later. The old memory is either not there or is inaccessible. In short, your memory about something is only as good as your last memory about it. This is why people who witness crimes testify about what they read in the paper rather than what they witnessed. Research on this topic, called reconsolidation, has become the basis of a possible treatment for post-traumatic stress disorder, drug addiction, and any other disorder that is based on learning.

Tor Nørretranders now thinks that it’s more appropriate to think of your body as software, rather than hardware.

What is constant in you is not material. An average person takes in 1.5 ton of matter every year as food, drinks and oxygen. All this matter has to learn to be you. Every year. New atoms will have to learn to remember your childhood.

Helen Fischer now believes that human beings are serial monogamists.

Perhaps human parental bonds originally evolved to last only long enough to raise a single child through infancy, about four years, unless a second infant was conceived. By age five, a youngster could be reared by mother and a host of relatives. Equally important, both parents could choose a new partner and bear more varied young.

Paul Steinhardt is now skeptical about inflation.

Most cosmologists would say the answer is “inflation,” and, until recently, I would have been among them. But “facts have changed my mind” — and I now feel compelled to seek a new explanation that may or may not incorporate inflation.

John Baez is no longer enthusiastic about working on quantum gravity.

Jaron Lanier put it this way: “One gets the impression that some physicists have gone for so long without any experimental data that might resolve the quantum-gravity debates that they are going a little crazy.” But even more depressing was that as this debate raged on, cosmologists were making wonderful discoveries left and right, getting precise data about dark energy, dark matter and inflation. None of this data could resolve the string-loop war! Why? Because neither of the contending theories could make predictions about the numbers the cosmologists were measuring! Both theories were too flexible.

Xeni Jardin is depressed by the lack of spontaneous self-moderation in online communities…

But then, the audience grew. Fast. And with that, grew the number of antisocial actors, “drive-by trolls,” people for whom dialogue wasn’t the point. It doesn’t take many of them to ruin the experience for much larger numbers of participants acting in good faith.

…but Kevin Kelly is impressed by the success of Wikipedia.

How wrong I was. The success of the Wikipedia keeps surpassing my expectations. Despite the flaws of human nature, it keeps getting better. Both the weakness and virtues of individuals are transformed into common wealth, with a minimum of rules and elites. It turns out that with the right tools it is easier to restore damage text (the revert function on Wikipedia) than to create damage text (vandalism) in the first place, and so the good enough article prospers and continues. With the right tools, it turns out the collaborative community can outpace the same number of ambitious individuals competing.

Oliver Morton has changed his mind about human spaceflight.

I have, falteringly and with various intermediary about-faces and caveats, changed my mind about human spaceflight. I am of the generation to have had its childhood imagination stoked by the sight of Apollo missions on the television — I can’t put hand on heart and say I remember the Eagle landing, but I remember the sights of the moon relayed to our homes. I was fascinated by space and only through that, by way of the science fiction that a fascination with space inexorably led to, by science. And astronauts were what space was about.

Jonathan Haidt no longer believes that sports and fraternities are entirely bad. (This is my favorite.)

I was born without the neural cluster that makes boys find pleasure in moving balls and pucks around through space, and in talking endlessly about men who get paid to do such things. I always knew I could never join a fraternity or the military because I wouldn’t be able to fake the sports talk. By the time I became a professor I had developed the contempt that I think is widespread in academe for any institution that brings young men together to do groupish things. Primitive tribalism, I thought. Initiation rites, alcohol, sports, sexism, and baseball caps turn decent boys into knuckleheads. I’d have gladly voted to ban fraternities, ROTC, and most sports teams from my university.

I came to realize that being a successful scientific heretic is harder than it looks.

Growing up as a young proto-scientist, I was always strongly anti-establishmentarian, looking forward to overthrowing the System as our generation’s new Galileo. Now I spend a substantial fraction of my time explaining and defending the status quo to outsiders. It’s very depressing.

Stanislas Deheane now thinks there may be a unified theory of how the brain works.

Although a large extent of my work is dedicated to modelling the brain, I always thought that this enterprise would remain rather limited in scope. Unlike physics, neuroscience would never create a single, major, simple yet encompassing theory of how the brain works. There would be never be a single “Schrödinger’s equation for the brain”…

Well, I wouldn’t claim that anyone has achieved that yet… but I have changed my mind about the very possibility that such a law might exist.

Brian Eno’s disillusionment with Maoism changed his views on how politics can be transformative.

And then, bit by bit, I started to find out what had actually happened, what Maoism meant. I resisted for a while, but I had to admit it: I’d been willingly propagandised, just like Shaw and Mitford and d’Annunzio and countless others. I’d allowed my prejudices to dominate my reason. Those professors working in the countryside were being bludgeoned and humiliated. Those designers were put in the steel-foundries as ‘class enemies’ — for the workers to vent their frustrations upon. I started to realise what a monstrosity Maoism had been, and that it had failed in every sense.

Anton Zeilinger now believes that you should never describe your own research as “useless.” (Hmmm…)

When journalists asked me about 20 years ago what the use of my research is, I proudly told them that it has no use whatsoever. I saw an analog to the usefulness of astronomy or of a Beethoven symphony. We don’t do these things, I said, for their use, we do them because they are part of what it means to be human. In the same way, I said, we do basic science, in my case experiments on the foundations of quantum physics. it is part of being human to be curious, to want to know more about the world. There are always some of us who are just curious and they follow their nose and investigate with no idea in mind what it might be useful for.

Martin Rees thinks we need to take the “Posthuman Era” seriously.

Public discourse on very long-term planning is riddled with inconsistencies. Mostly we discount the future very heavily — investment decisions are expected to pay off within a decade or two. But when we do look further ahead — in discussions of energy policy, global warming and so forth — we underestimate the possible pace of transformational change. In particular, we need to keep our minds open — or at least ajar — to the possibility that humans themselves could change drastically within a few centuries.

It might sound a little crazy, but betting against Sir Martin is a bad idea.

A few internet tidbits to keep you going through the intra-holiday blogging lull.

• The World’s Smallest Website! Seriously, this website is not only extremely small, it probably has a lot more interesting stuff than yours does. You should be ashamed.
• How interesting is your IP address? Mine is prime, which is nice, but it makes a terrible poker hand.
• Cosmic Variance Calculator. Sometimes, you just want to calculate your cosmic variance. By Michele Trenti, based on this paper.

Two stories, superficially unrelated, neatly tied together by a deep lesson at the end.

The first is the case of Lucia de Berk, a Dutch nurse sentenced to life imprisonment in 2003 for multiple murders of patients under her care. However, there was very little direct evidence tying her specifically to the deaths of the individual cases. Much of the prosecution’s case against her was statistical: it was simply extremely unlikely, they argued, that so many patients would die under the care of a single nurse. Numbers like “one in 342 million chance” were bandied about.

But statistics can be tricky. Dutch mathematician Richard Gill has gone over the reasoning presented in the case, and found it utterly wrong-headed; he has organized a petition asking Dutch courts to re-open the case. Gill estimates that 1 in 9 nurses would experience a similar concentration of incidents during their shifts. And he notes that there were a total of six deaths in the ward where de Berk worked during the three years she was there, and seven deaths in the same ward during the three years before she arrived. Usually, the arrival of serial killers does not cause the mortality rate to decrease.

But patients had died, some of them young children, and someone had to be responsible. Incidents that had originally been classified as completely natural were re-examined and judged to be suspicious, after the investigation into de Berk’s activities started. The worst kinds of confirmation bias were in evidence. Here is a picture of what de Berk actually looks like, along with a courtroom caricature published in the newspapers.

Also, she read Tarot cards. Clearly, this is a woman who is witch-like and evil, and deserved to be punished.

The other story involves a brilliant piece of psychological insight from Peter Sagal’s The Book of Vice, previously lauded in these pages. It involves the reason why people play slot machines, or gamble more generally. There are many complicated factors that go into such a phenomenon, of course, but it nevertheless remains a deep puzzle why people would find it so compelling to roll the dice when everyone knows the odds are against you.

Peter asks us to consider the following joke:

An old man goes to the synagogue and prays, every day, thusly: “God, let me win the lottery. Please, just one big win. I’ll give money to the poor, and live a righteous life. . . . Please, let me win the lottery!”

For years, he comes to the synagogue, and the same prayer goes up: “Let me win the lottery! Please, Lord, won’t you show your grace, and let me win the lottery!”

Finally, one day, after fifteen years of this, as the man mutters, “The lottery, Lord, let me win the lottery. . . ,” a golden light suffuses the sanctuary, and a chorus of angels singing a major C chord is heard. The man looks up, tears in his blinded eyes, and says, “Lord . . . ?”

And a deep resonant voice rings out, “Please . . . would you please BUY A TICKET already?”

And that’s why we gamble: so God can answer our prayers. Fortune’s wheel, in other words, might occasionally want to favor us, but how can it if we don’t give it a chance? By playing the slots, we make it so much easier for Providence to bestow its bounty upon our deserving heads.

The common thread, of course, is the deep-seated aversion that human beings have to accepting randomness in the universe. We are great pattern-recognizers, even when patterns aren’t really there. Conversely, we are really bad at accepting that unlikely things will occasionally happen, if we wait long enough. When people are asked to write down a “random” sequence of coin flips, the mistake they inevitably make is not to include enough long sequences of the same result.

Human beings don’t want to accept radical contingency. They want things to have explanations, even the laws of physics. They want life to have a purpose, chance events to have meaning, and children’s deaths to have a person to blame. They want life to make sense, and they want to hit the triple jackpot because they’ve been through a lot of suffering and they damn well deserve it.

Of course, sometimes things do happen for a reason. And sometimes they don’t. That’s life here at the edge of chaos, and I for one enjoy the ride.