How to Perform the Unknown Law of Physics Card Trick

In this card trick, the "unknown law of physics" causes both the magician and an audience member to choose the same card from two different decks of cards. The magician may introduce the trick by talking about the principle of entanglement from quantum physics.

Difficulty: Moderately Easy

Instructions

1. Take two decks of cards and hand one to a spectator. Ask the spectator to shuffle and cut the cards until the cards are thoroughly mixed. You do the same, and sneak a peek at the bottom card of your deck.

2. Trade decks with the spectator and cut the deck, placing the top half to the right of the bottom half. Hold up the top card of the bottom half so the spectator can see it but you can't. Tell the spectator to memorize this card.

3. Place the card on the top of the top half of the deck (the one on the right). Place the bottom of the deck on top. The bottom card of the deck, which you have memorized, is now on top of the card the spectator memorized.

4. Cut your deck. Ask the spectator to look through his or her deck for the card he or she memorized from your deck. Ask the spectator to place this card face-down on the table.

5. Look through your deck for the card you memorized. The card to the right of it is the spectator's card. (If your card is on the bottom of the deck, the spectator's card is on the top of the deck.) Place the spectator's card face-down on the table.

6. Turn your card over at the same time that the spectator turns over his or her card to reveal that the cards are the same.

Tips & Warnings

• This trick is also known as "Do As I Do." It works best when the two decks are obviously different, such as a deck with blue backs and a deck with red backs.

Resources

• Learn about entanglement at California Literary Review.