How does this card trick work?

★ wanayoo — archive 1999 http://www.howstuffworks.com/question187.htm

Question of the Day

Q&A Archive

HSW keeps a complete archive of previously answered questions to help you find answers quickly. Please Click Here for a complete list of previously answered questions.

Asking Questions

If you would like to ask a question, you can click here.

Each weekday Marshall Brain answers questions submitted by the readers of How Stuff Works in the Question of the Day section of HSW. You can also view previously answered questions in the HSW Question Archive. Here is today's question!

Question

"How does this work...have asked several no one can figure it out...so I will go to the master! The Cave of Magic"
"Please go to The Cave of Magic and tell me how this can possibly work! It has some of my friends convinced that we are being taken over by computers."
And so on...

Answer

This is a classic magic trick! And it demonstrates one of the most important aspects of many magic tricks. If you have not seen this page (or one of the many like it), go try it and see how it works. Unless you catch what is happening, it is amazing the first time you see it! Do not read the explanation until you have tried the trick yourself.

This trick, like many magic tricks, relies on the power of suggestion and the fact that the human brain does not tend to notice fine detail. You can start to get a sense of what is happening by repeating the trick but this time picking two or three cards instead of just one. Try it one more time and write down all of the cards that appear in the first deck, and then all of the cards that appear at the end, and you will see exactly what is happening. All of the cards have changed!

When most people try this trick, they look at the first deck and the brain registers a general fact like, "a collection of cards". The brain does not store the actual face of each card. So when the second deck is shown the brain again registers "a collection of cards". The fact that all of the cards are different escapes notice and it is assumed that they are the same because none of the detail was stored.

This same phenomenon allows a magician to saw a lady in half. When the lady is placed in the box, her head sticks out one end and her feet stick out the other. The magician then spins the box and when the feet are pointed away from the audience the lady retracts her real feet and replaces them with a pair of fake feet. The lady is a contortionist, so she folds her legs into the upper part of the box and the magician "saws her in half". Because we saw the lady stick her feet through the holes, we assume they must be her feet the entire time, and the illusion is completely baffling!

If you are interested in learning how a variety of magic tricks work, see Magic Secrets Revealed.

How Stuff Works Power Panel

	Table of Contents A complete list of all HSW articles		About Marshall Brain Information about the creator of HSW
	Search Search for any word or concept in HSW		Citing HSW Information about citing HSW in articles and papers
	Question of the Day Ask questions or browse hundreds in the archive		Books A variety of books for people interested in how stuff works
	HSW Newsletter Sign up to receive the monthly HSW newsletter		Contacting HSW Contact HSW directly with email
	What's New Review newsletters to chart HSW's development		Awards Check out HSW's awards and reviews!
	Disclaimer The disclaimer required by the lawyer		Author Information Learn how you can write for HSW
	HSW Fan Buttons Link to HSW with these snazzy fan buttons!		Suggestions Leave a suggestion in the suggestion box

How Stuff Works (http://www.howstuffworks.com) is a production of
Howstuffworks.com, Inc.
P.O. Box 40492 - Raleigh, NC 27629
See http://www.howstuffworks.com/contact.htm for contact information