Problem Management — principles
Magic

Many things are not what they appear to be, and many things appear different to different people. What we perceive as reality is actually a construct within our minds. How closely that construct corresponds with whatever may or may not exist outside of our minds is not easy to test. Most of us choose to accept that illusion as reality, and probably couldn't reject it even if we wanted to.

A more specific example would be that despite what most people believe, we don't see with our eyes. Yes, we do use our eyes to see, but vision itself is a function of the brain.

This can easily be demonstrated by taping a newspaper that you haven't seen before to the wall at the end of a hallway, then starting at the opposite end, slowly walking towards it until you can read one of the article headlines. Mark your distance away from the paper. Then, starting very close to the paper and staring at that same headline, walk slowly away from it until the final moment when the headline loses focus. You'll almost certainly find that you are much farther away than in the first case. But despite appearances, it really isn't true that your eyes could see that much better than before. What you thought was in focus was actually caused by your brain's mapping the fuzzy input into its internal construct of what you were seeing. Your eyes really couldn't see that well, but your brain could (using previously stored information).

An even simpler demonstration is to move your hand sideways in front of your face while keeping your eyes fixed ahead. (Don't do this in front of your computer monitor, that might invoke different effects (e.g. strobing).) The hand will appear as a blur as it moves. Again, without moving your eyes within your head, keep your hand still and move your head from one side to the other. The hand will not appear to blur (nor will the background). In both cases, the eyes would see exactly the same thing, eyes not moving within the head, and a hand moving across their field of vision. But in the two cases the brain interpreted that input differently, and what you saw was significantly different.

Our other senses behave the same way. For instance, listen to Led Zepplin's recording of Stairway To Heaven played backward and you'll hear someone talking in something that sounds like English. You'll likely even be able to pick out a few words. Then listen again while looking at printed lyrics for the backward version and you'll recognize many more words. Repeat this a few times and you'll be able to hear all of the lyrics and will wonder why you had trouble hearing them the first time.

Similarly, despite what most people believe, that part of our mind that we perceive as an internal voice (most of us hear only one), isn't what we actually think with. Typically that internal monologue spends its time rationalizing decisions that the rest of the brain (and body) has already made. And occasionally it gets to override those decisions; that is perhaps what makes us human.

And in the larger world, we tend to see what we expect to see, not necessarily what is actually there. The traditional lion tamer defends himself against dangerous lions armed with nothing more than a whip and a chair. At least that's what we see. In reality, the lions are doped with drugs and almost asleep. The crack of the whip keeps them awake, and the chair legs annoy the lions enough that they'll roar and swipe at them.

Magicians and con-artists constantly use this principle of vision to deceive their audiences.

Visit Times Square, or any major US downtown, and join in a 3-card monte game, in which the dealer shows you which of three playing cards is the queen, and then shuffles them around on the table while you try to follow the queen. Bet $20, pick which of 3 cards is the queen, and get $60. That's fair odds, so in the long run you can't win or lose much even by blind guessing, and if you can keep track of the queen, you should win. To make it even better, every once in a while after you pick the wrong one, they'll give you another chance: bet another $20 and pick which of the remaining 2 cards is the queen, and they'll still give you $60 back. They're paying 2 to 1 on an event with even chances, so in the long run even with blind guessing you'll make a profit.

The only trick (other than having amazing skill) is in how the queen is revealed. To ensure that no one can accuse the dealer of cheating, once you have picked a card he doesn't touch it again. Instead he takes one of the other cards and uses it to flip the chosen card over. He then reveals the other two cards, one of which is the queen.

This move that flips the card over is called the Mexican turnover. When done well, and these guys do it very well, it's impressive. Add in a crowd-gathering patter and secret assistants to occasionally argue with him, to bend a corner of the queen when he isn't looking and wink to encourage you to bet on a sure thing, and these people can rake in a lot of money from the tourists.

As in the quantum world, the card you chose is never really anything until you look at it. There are two cards to consider, the one you have chosen, and one of the other two cards that the dealer picks up. The dealer takes the card in his hand, slips it under the edge of the chosen card and flips it over. No matter which of the two cards was the queen, after the flip the queen is the card in his hand, and the flipped over card isn't. When done well, it's effectively impossible to detect the sleight of hand even when you know how they do it. Your mind will always see him flipping over the downturned card no matter which one he actually flips over.