The people are usually lit as well, with glowing phosphorescent rings or their own personal El-wire sets. Wearing every odd costume or no costume. The lights from the cars and people and the art installations provide the only illumination, except for the moon and the stars.

The night air is warm, the ground is now soft and flat. You can wander off or bike in any direction you feel - towards some giant Rubic's Cube or a perhaps a huge music camp which is alive with a throbbing beat and lights and lasers. The music is is never-ending, without cues to signal the start or stop of songs, just an ever changing pattern of rythmic tonalities.

There is really nothing like night in the center at Burning Man, it is a unique experience, scary, strange, an endless visual and aural feast.

The following is my experience at Burning Man.

Imagine if you would, the biggest campground on the surface of the Earth. The average campground in the U.S. has space for 50 to 250 camp sites. Burning Man has some 50,000 people attending, resulting in about 10,000 camps. So its big. So big you can't see it all without spending days traveling about the site on bike. The camps as modest as one man in the back of his pick-up truck to camps of 30 Indian wigwams holding more than 100 people along with associated geodesic domes, trucks, power-generators, and very odd vehicles.

Unlike the normal campground, located in a scenic spot, near running water or a lake, Burning Man is located in one of the harshest places you can visit in the United States. The terrain is dead flat and utterly dry. The ground is completely covered in a fine dry white clay which instantly turns to sticky gray mud with a small application of water.

Let me repeat again: there is no water. None. There is no vegetation. There is essentially nothing living in the Burning Man camp zone. This is so strange that it is very hard to wrap your head around it. Every place that humans have ever settled has water, without exception. A place without water is only a place humans traveled across, never a place that they stopped at, unless bitter necessity forced such a stop. To voluntarily live in a place without water is profoundly unsettling. It feels unnatural, as indeed it is. At times, in the middle of the day, as the sun beat down on the cloth tarp spread over my mattress I felt desperate to escape - to leave Burning Man as fast as I could and find a lake to throw myself in. But I stayed. Just like nearly everyone stays.

At the outer edges of the Burning Man camp, the tents are usually quite normal and - except for the crowding - you would not think twice about what you saw. People sitting on camp chairs, in the shade they created with their own plastic cloths stretched over tent poles. Eating, talking, snoozing in the heat of the day. Occasionally you would see a bigger tent, or one built on the location in the shape of a geodesic half-dome made out of metal tubes and covered with a parachute, flapping in the wind.

Go further in, towards the center, and you see more unusual structures. Some tents in the middle zone are huge, the size of circus tents, sheltering 10 or 20 smaller tents underneath. Some camps are very odd indeed, decorated with a design motif, accessorized by the addition of statues, flags, or random bits of junk. Some camps offer things to passers-by such as: a chance to jump on their trampoline, a phone call to the outside world, a quick shower of water from their huge drum, a pancake, a melted cheese sandwich, a hug, a complement, a home-made drink, and so forth.

All of this is free as one of the few rules of Burning Man is that nothing can be sold or bought (there are two exceptions, you can buy ice and coffee at the center of the campground). If you offer something, you can not ask for money in return.

The inner ring of the camp is where the most unusual things are to be found. This is where you find groups (collectives? tribes? guilds? associations?) of people who have joined together to create places/things/art just because they feel like it. There is really nothing like these organizations outside Burning Man. The short description might be "a group of people that want to impress the other people at Burning Man with their created space".

One group collects costumes (discarded cloths as well as items they buy) and then encourages people to come and pick a costume and wear it. Another group built a giant video screen and invited people to come to a central booth to play Tetris against other random people. Another group gave away free watermelon pieces, still another group gave out free ice-cream. (I suppose if you really wanted to spend all your time mooching you could bring no food at all to Burning Man and still survive, though your diet would hardly be balanced).

By far the most common inner core structures are bars such as The Golden Cafe) or the Ashram Galactica. The groups that run these bars spend thousands of dollars to set up and run super-tents where people can come in, sit down and be served alcoholic drinks and food. They build structures that are decorated around a theme and they are typically open 24 hours a day for the duration of the event. Some 125 people set up and run the Ashram Galactica, an operation that requires major logistical and planning effort. Why anyone would do this is - at this time - unfathomable to me. I must suppose that it starts small, and just snowballs year after year.

The other major type of camp are the music camps, such as Opulent Temple, Root Society, and The Hookahdome. These camps a the biggest structures/places in the whole of Burning Man and they are filled with huge speakers, powered by fleets of generators, and blasting out very odd music from nightfall till dawn. Opulent Temple had lasers, two huge projection screens, and even a flame thrower all to add to the musical effect. Going to the Opulent Temple at night was better than going to the best dance clubs in San Francisco and, again, there was no charge. As for me, musically I don't particularly enjoy the music they played but I was truly impressed by the shows. How these huge music camps collect enough money to operate at Burning Man is beyond my understanding.

Driving around streets of the Burning Man camp are tanker trucks filled with water that spray the streets, temporarily turning the dusty roads to mud paths that are best not stepped on. Also there are sewage tankers that pump out the human waste from the many Port-A-Potties that are located around the grounds.

By far the most interesting vehicles are the Art Cars, the bizarrely decorated cars (and more rarely, bikes) that show off the creativity of the builders. Some of the art cars I saw were giant snails, an "eel" at least 75 feet long, a huge double-decker bus covered on one side with loudspeakers with a DJ on the top, and a huge glowing heart shape above him. There were so many art cars that I could not count them all, I lost track at 150. Cat cars, fish cars, sailboat cars, a car shaped like a sandworm from Dune, a dragon that could breath fire and more, and more again.

Nearly all the art cars are designed to be viewed at night and so they are decorated with lights. Formerly this was done with neon lights but now EL-wire is the new thing and few cars did not make use of the amazing properties of this new light source.

...(more later)...

This is from part of an essay by Ms. Gallagher which hits on some key points

But being American liberals, they increasingly look across the pond for moral leadership. And what we are finding in our sister democracies (which admittedly do not have First Amendments) is not very reassuring.

Consider what is happening right now in Great Britain, our closest sister democracy and the one with the strongest free-speech tradition. How does the British government treat religious liberty when it clashes with “gay equality”?

Can the British government force a Catholic school to retain a principal who enters a civil union? Yes, it already has. How can that be, given British religious liberty? Well, the government says that if a religion teacher at a Catholic school enters a gay union publicly, he or she could be fired. But nobody else.

Can the government fine an Anglican bishop who refuses to hire an actively and proudly gay youth minister? Yes, it already has. (How is this justified by the above principle? I don’t know. I just know the government can do it, because it has.)

In Great Britain, the use of “gay equality” to oppress Christianity is not down the road; it’s already here.

Check out this story from the Telegraph. Note how the “equalities minister” reacts to the suggestion that there should be exemptions from anti-discrimination hiring provisions for religious groups, so that they do not have to hire people who dispute their core moral teachings on marriage and sex:

Religious groups are to be forced to accept homosexual youth workers, secretaries and other staff, even if their faith holds same-sex relationships to be sinful. . . . Religious leaders had hoped to lobby for exemptions to the Equality Bill but Maria Eagle, the deputy equalities minister, has now indicated that it will cover almost all church employees.

Gay-marriage advocates complain that marriage itself is not the core of these emerging church-state conflicts. They are correct; gay marriage is not the core, but it is the ultimate manifestation of the core. The core is this strange use of an equality argument to transform an action — in this case, marrying persons of the same sex — into an equality right.

This is totally new in American legal and cultural discourse. Actions are typically protected by liberty interests, not equality interests. Sexual liberty means I have the right to do what I want, not the right to be free from the knowledge that others disagree, or from their choosing to build institutions that teach that my sexual actions are wrong and exclude those who engage in them.

Equality is typically predicated on characteristics that do not imply actions, because actions are always choices. Skin color is irrelevant. And unchosen. Sexual orientation is almost certainly unchosen, but the decision to incorporate a sexual desire into one’s identity, and then to act on it, is a decision. Maybe most people think it’s the right decision, the healthiest decision, but the point is that it’s a choice, and subject to moral reflection. A sexual desire is not its own justification.

And a further step in moral reasoning is needed to elevate the right to do what one wishes in private into a right to enter a gay marriage. Gay marriage as an equality right thus represents a strange new hybrid — it’s the right to act in a certain way, to have the state and other institutions bless one’s actions, and to punish people (the way we punish bigots) for expressing disagreement with those actions. It is a totally novel equality right, an equality right on steroids.

What is driving this is the race analogy for understanding gay rights. Unless gay-rights advocates find another metaphor (say religious liberty?), the rights taking hold in Great Britain will soon be incorporated (via Supreme Court Justice Sotomayor?) into the Bill of Rights.

Too many libertarians do not understand the essentially Marxist project they are now promoting. Watch out. Individuals may be left free, but institutions that stand against the state’s values will be repressed in the name of equality. Individuals who are not free to form institutions (associate) are impotent against the state’s power to impose its values.

Full essay here.

1) Learn your time limit and calculate your word count. The average person speaks at somewhere between 125 and 150 words per minute. It's always better to speak more slowly than quickly. Thus, if you're speaking for 20 minutes, you want a total word count of about 2,500 words. Be careful! I once got the math wrong and saddled a good friend with a 48-minute speech when he was trying for 30!

2) If you have to speak for more than 30 minutes, be certain to work in some sort of interactive component. Invite questions or give the audience tasks to do. The TV and the Internet have ruined our ability to sit quietly and listen to a talking head for very long.

3) Divide the speech into five parts: an introduction, point 1, point 2, point 3 and a conclusion. Or, in other words, tell people what you're going to tell them, tell them your points and then wrap up by telling them what you just said. This format is adaptable to a speech of just about any length but I'd divide a 20-minute speech as follows:

Introduction: 2 minutes (250 words)
Point 1: 5 minutes (625 words)
Point 2: 5 minutes (625 words)
Point 3: 5 minutes (625 words)
Conclusion: 3 minutes (375 words)

If you're thin on ideas for the three points, consider using a mindmap to help you. (Anyone who subscribes to my free newsletter receives an ebook on mindmapping at no charge.)

4) Tell stories or give examples. If you have a story to illustrate each of your three points, so much the better. Stories are "sticky" — that is, people remember them. Unless you're a scientist, always prefer sticky stories to statistics.

5) Employ humor — but use it carefully and build it into the subject of your speech. I hate opening jokes that are unrelated to the actual speech topic — they feel so fake and tacked on. You want humor to be organic — that is, related to the topic you're covering. Also be sure to avoid any comments that could be considered even remotely vulgar, or sexist, racist, ageist, etc. But if you're one of those people who can't quite pull off a joke, don't try. No humor is better than lame humor or bad delivery.

6) Read the speech aloud. Make sure the language is easy to say — even if you're writing the speech for someone else. Say it out loud many times, so you can check to ensure there are no stumbling blocks. For example, the line "a lower-cost alternative to traditional plans" is harder to say than it looks (try it!). Change that kind of language, fast.

7) Be yourself. While you can gain pointers from observing great speakers, you need to be true to yourself. Don't try to be someone you're not!

See complete text here.

Link here from the web site U.S. Food Policy

A new standard in data storage. A team at Stanford says they encoded essentially 35 bits of data into the interference patterns of electrons from essentially a single atom. The idea that you could store more than one bit of data per atom had been floating around. 1 bit per electron seemed really - really - hard. But this has been done in a lab.

Link here.

Retired senior NASA atmospheric scientist, Dr. John S. Theon has publicly joined the large (and growing) group of experts who are not convinced that humans are largely responsible for the warming trends seen in global climate.

My own belief concerning anthropogenic climate change is that the models do not realistically simulate the climate system because there are many very important sub-grid scale processes that the models either replicate poorly or completely omit. Furthermore, some scientists have manipulated the observed data to justify their model results. In doing so, they neither explain what they have modified in the observations, nor explain how they did it. They have resisted making their work transparent so that it can be replicated independently by other scientists. This is clearly contrary to how science should be done. Thus there is no rational justification for using climate model forecasts to determine public policy...

Link here.

When it was clear in May of 2004 that Bush was going to push this social security reform in the face of massive opposition I told my spouse "I think it likely that Bush will accomplish nothing in domestic policy during his second term". I was nearly correct. Sad.

The biggest problem with the Bush presidency was his lack of engagement with the people who were attacking his administration and policies. Powerline has a very good assessment of the Bush presidency and its failures here. This is a quote from them:

Bush's great failing was that his focus was almost exclusively on policy, and he was unwilling to pay adequate attention to politics. This failing manifested itself repeatedly throughout his term in office. With hindsight, the beginning of the end for Bush was his unwillingness to defend himself when he was attacked for the "sixteen words" in his State of the Union address--words that were indisputably true. The same thing happened after Hurricane Katrina, the event that got his second term off on the wrong foot. In truth, the federal response to Katrina was both the largest and the fastest response to any natural disaster in world history. Yet Bush was never willing to stand up to his critics and make the case in his own defense.

That tendency to turn the other cheek was, in the end, fatal. Bush never cared much about politics. He was almost contemptuous of political leadership, willing to engage in politics on a sustained basis only in his two successful election campaigns. But he was a politician, and the job of a politician, as President, is to use political skills to lead the American people. Bush's unwillingness or inability to do what it would take to be an effective political leader, in the end undid his administration.

It always amazed me how bloggers were capable of punching 10 foot holes in the arguments of the Bush haters - yet President Bush refused to actually use his Bully Pulpit to do the same. This really was a huge failure of political will on the President's part. The Vice President was out trying to convince people but Dick Cheney never had much traction with the public.

There are lots of problems with the Bush administration, he is hardly our worst president but there were many things he could have done better.

Bush was right.

Bush will be vindicated in history.

We had to respond to the 9/11 terror attacks. We had to strike at the very core of the Islamic world and convince them that attacks against the U.S. were the worst mistake they could ever make. For a myriad of reasons, Iraq was the best available target for a U.S. attack.

We won that war with just 2 and 1/2 divisions against an army that was five time larger. We destroyed Saddam's government and captured him and then set about the arduous task of rebuilding Iraq on totally new ground. We set about proving to the Islamic world that democracy was not incompatible for people just because they were Arabs, or because they were Moslem. We challenged Al Qaeda, not in some minor country like Afghanistan, but in the very heart of the Islamic world. They had to come and fight us there, Afghanistan they could flee from, Somalia they could leave any time but Iraq, no Iraq was a country that had to be fought for.

And they lost.

The effort of rebuilding Iraq is far from over but I believe we have won. Iraq may very well become what the Bush administration dreamed of: a stable, peaceful, prosperous and democratic country sitting right in the middle of the Islamic world. A constant, daily affront to the dictators in the Islamic world who always tell their people "you aren't ready to choose your government" or "Democracy is Unislamic". Bush tried to change the world and I think he has wrenched machinery of history from a terrible direction to a new and better pathway, better for them, better for all of us.

Things can still go badly. The future is unwritten and not always for the best. But as former President Bush flies home to Texas, I salute him for daring to do the hard, difficult, dangerous thing. And for standing up to the whole weight of opinion from the rest of the country and the rest of world who just wanted to let things stew in the Islamic world.

He was right. The Bush administration did the right thing. Iraq is a better country, and the world is better place thanks to the U.S. invasion and occupation in 2003.

To all the brave men and women who served in the U.S. Army and Marines and Air Force, I salute you. You fought under nearly impossible conditions and you won. Counter-insurgency is hard but our enemies were fools and our goals - peace and freedom for the Iraqi people - were noble.

Let me close with the immortal words of President Kennedy, spoken 48 years ago, and still true

Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and the success of liberty.

To President George W. Bush, champion of liberty!

America is said to always be reinventing itself. We Americans believe in the real possibility of change, of improvement. Obama, growing up in Indonesia, then Hawaii, and later California, was clearly not willing to see himself defined by his racial background.

I didn't vote for Mr. Obama though I fully expected him to win my state and (by mid-September) the election. That said, I wish him the best of luck in his coming term of office. I hope that he can accomplish at least some of his goals and I hope that he can make some progress on fixing the very real problems this country faces.

I'm proud to be an American, and I'm happy and guardedly confident in the future under the Obama administration.

President-elect Obama was not a strong candidate and McCain was a strong candidate on the Republican side so the race actually looked close for a while. But the hammer blows of the credit market freeze in September and the massive stock drops were nails in the coffin of the McCain effort. McCain's real weak spot in his resume was economics. He neither showed much interest in it over the last 20 years, nor did he have an "A Team" of advisers who could command confidence on the topic.

There was no chance for McCain to win following the collapse of Meryll Lynch and Lehman Brothers in mid-September of 2008. When icons of American investment go under, the American people will say "its time for a change of government".

To me the surprise was that Virgina and New Mexico were solid wins for Obama and Colorado wasn't that close. Most of the other results were extremely likely from a year ago. California was so out-of-reach for McCain that no effort was made here by the Republican party nor was any money spent on presidential advertising.

So far (mid-December 2008) I've been impressed with Obama's choices for his cabinet and White House staff. However, he has a world of troubles to deal with and I very much doubt he will manage to make much progress on any (?) of them during the next four years.

Here is the blog entry.

Some exerpts:

I have mentioned before that one of the possible great strengths of games is that they can present complex problems as being amenable to analysis.

…games are by definition tractable. They teach you to chunk up, to chop apart, to disentangle. Perhaps this is where games can most change society: a way to look at the problems so that we no longer throw up our hands…

— Games for Change, closing address

But when we look at that list from the top, about Millenial workplace attitudes, it’s hard not to draw the analogy to a generation raised in a system where there are always rules, always correct answers, where you geta pat on the head every time you do something right, and curves are always easily projected.

It was pointed out that all this sounds like I am slamming Millenials; in fact, I did write a whole book about how good games are as teaching tools, so let me point out the clear benefits of gamist thinking as reflected in Millenials: team-oriented practices, clear goal orientations, high self-confidence, a firm belief that things are solvable, a lack of the cynicism and skepticism common to GenX... it's not all bad!

And this:

games are, because of their inherently mathematical nature, limited in conveying certain types of information. But I think it is also worth asking whether the scope of their models is effectively misleading, or even actively lying, about how the world works.

In Taleb’s books, the bogeyman is the extremely rare event with a high impact, which he calls a black swan. These are historically visible, but exist on timeframes long enough that we consider them arbitrarily rare: essentially, a non-event in our planning. Yet they also have a highly disproportionate effect on the environment in which they occur.

Interesting ideas.

Full text from Slate in extended entry...

Full text of article in the extended entry.

(Hat tip to Marginal Revolution)

Where you vote...

More details here

See the graph for yourself

A new scientific understanding of perception has emerged in the past few decades, and it has overturned classical, centuries-long beliefs about how our brains work—though it has apparently not penetrated the medical world yet. The old understanding of perception is what neuroscientists call “the naïve view,” and it is the view that most people, in or out of medicine, still have. We’re inclined to think that people normally perceive things in the world directly. We believe that the hardness of a rock, the coldness of an ice cube, the itchiness of a sweater are picked up by our nerve endings, transmitted through the spinal cord like a message through a wire, and decoded by the brain.

In a 1710 “Treatise Concerning the Principles of Human Knowledge,” the Irish philosopher George Berkeley objected to this view. We do not know the world of objects, he argued; we know only our mental ideas of objects. “Light and colours, heat and cold, extension and figures—in a word, the things we see and feel—what are they but so many sensations, notions, ideas?” Indeed, he concluded, the objects of the world are likely just inventions of the mind, put in there by God. To which Samuel Johnson famously responded by kicking a large stone and declaring, “I refute it thus!”

Still, Berkeley had recognized some serious flaws in the direct-perception theory—in the notion that when we see, hear, or feel we are just taking in the sights, sounds, and textures of the world. For one thing, it cannot explain how we experience things that seem physically real but aren’t: sensations of itching that arise from nothing more than itchy thoughts; dreams that can seem indistinguishable from reality; phantom sensations that amputees have in their missing limbs. And, the more we examine the actual nerve transmissions we receive from the world outside, the more inadequate they seem.

Our assumption had been that the sensory data we receive from our eyes, ears, nose, fingers, and so on contain all the information that we need for perception, and that perception must work something like a radio. It’s hard to conceive that a Boston Symphony Orchestra concert is in a radio wave. But it is. So you might think that it’s the same with the signals we receive—that if you hooked up someone’s nerves to a monitor you could watch what the person is experiencing as if it were a television show.

Yet, as scientists set about analyzing the signals, they found them to be radically impoverished. Suppose someone is viewing a tree in a clearing. Given simply the transmissions along the optic nerve from the light entering the eye, one would not be able to reconstruct the three-dimensionality, or the distance, or the detail of the bark—attributes that we perceive instantly.

Or consider what neuroscientists call “the binding problem.” Tracking a dog as it runs behind a picket fence, all that your eyes receive is separated vertical images of the dog, with large slices missing. Yet somehow you perceive the mutt to be whole, an intact entity travelling through space. Put two dogs together behind the fence and you don’t think they’ve morphed into one. Your mind now configures the slices as two independent creatures.

The images in our mind are extraordinarily rich. We can tell if something is liquid or solid, heavy or light, dead or alive. But the information we work from is poor—a distorted, two-dimensional transmission with entire spots missing. So the mind fills in most of the picture. You can get a sense of this from brain-anatomy studies. If visual sensations were primarily received rather than constructed by the brain, you’d expect that most of the fibres going to the brain’s primary visual cortex would come from the retina. Instead, scientists have found that only twenty per cent do; eighty per cent come downward from regions of the brain governing functions like memory. Richard Gregory, a prominent British neuropsychologist, estimates that visual perception is more than ninety per cent memory and less than ten per cent sensory nerve signals. When Oaklander theorized that M.’s itch was endogenous, rather than generated by peripheral nerve signals, she was onto something important.

The fallacy of reducing perception to reception is especially clear when it comes to phantom limbs. Doctors have often explained such sensations as a matter of inflamed or frayed nerve endings in the stump sending aberrant signals to the brain. But this explanation should long ago have been suspect. Efforts by surgeons to cut back on the nerve typically produce the same results that M. had when they cut the sensory nerve to her forehead: a brief period of relief followed by a return of the sensation.

Moreover, the feelings people experience in their phantom limbs are far too varied and rich to be explained by the random firings of a bruised nerve. People report not just pain but also sensations of sweatiness, heat, texture, and movement in a missing limb. There is no experience people have with real limbs that they do not experience with phantom limbs. They feel their phantom leg swinging, water trickling down a phantom arm, a phantom ring becoming too tight for a phantom digit. Children have used phantom fingers to count and solve arithmetic problems. V. S. Ramachandran, an eminent neuroscientist at the University of California, San Diego, has written up the case of a woman who was born with only stumps at her shoulders, and yet, as far back as she could remember, felt herself to have arms and hands; she even feels herself gesticulating when she speaks. And phantoms do not occur just in limbs. Around half of women who have undergone a mastectomy experience a phantom breast, with the nipple being the most vivid part. You’ve likely had an experience of phantom sensation yourself. When the dentist gives you a local anesthetic, and your lip goes numb, the nerves go dead. Yet you don’t feel your lip disappear. Quite the opposite: it feels larger and plumper than normal, even though you can see in a mirror that the size hasn’t changed.

The account of perception that’s starting to emerge is what we might call the “brain’s best guess” theory of perception: perception is the brain’s best guess about what is happening in the outside world. The mind integrates scattered, weak, rudimentary signals from a variety of sensory channels, information from past experiences, and hard-wired processes, and produces a sensory experience full of brain-provided color, sound, texture, and meaning. We see a friendly yellow Labrador bounding behind a picket fence not because that is the transmission we receive but because this is the perception our weaver-brain assembles as its best hypothesis of what is out there from the slivers of information we get. Perception is inference.

The theory—and a theory is all it is right now—has begun to make sense of some bewildering phenomena. Among them is an experiment that Ramachandran performed with volunteers who had phantom pain in an amputated arm. They put their surviving arm through a hole in the side of a box with a mirror inside, so that, peering through the open top, they would see their arm and its mirror image, as if they had two arms. Ramachandran then asked them to move both their intact arm and, in their mind, their phantom arm—to pretend that they were conducting an orchestra, say. The patients had the sense that they had two arms again. Even though they knew it was an illusion, it provided immediate relief. People who for years had been unable to unclench their phantom fist suddenly felt their hand open; phantom arms in painfully contorted positions could relax. With daily use of the mirror box over weeks, patients sensed their phantom limbs actually shrink into their stumps and, in several instances, completely vanish. Researchers at Walter Reed Army Medical Center recently published the results of a randomized trial of mirror therapy for soldiers with phantom-limb pain, showing dramatic success.

A lot about this phenomenon remains murky, but here’s what the new theory suggests is going on: when your arm is amputated, nerve transmissions are shut off, and the brain’s best guess often seems to be that the arm is still there, but paralyzed, or clenched, or beginning to cramp up. Things can stay like this for years. The mirror box, however, provides the brain with new visual input—however illusory—suggesting motion in the absent arm. The brain has to incorporate the new information into its sensory map of what’s happening. Therefore, it guesses again, and the pain goes away.

The rest of the article is about itching...