**Trick of Mind Reader
**ericlin@ms1.hinet.net

Check the web site:

http://www.cyberglass.co.uk/assets/6845681/psy2003.swf

If we believe that to be "Mind Reading", then we must have seen too many Harry Potter movies.

Lets heck the underlying "Trick" of this "Magic".

Here is my version.

1. Do as the instruction on the SWF once, and feel what happens. OK, it guesses right.

2. What if we don't do calculation. We just pick one in the chart and "staring" at it for real 3 sec like an idiot ? Ok, it does not always guess the answer correctly. So, "staring" is not really important. Do correct calculation is important.

Most "mind-reading" trick wont allow you to pick number directly. The number it needs to guess is always created by a complex steps. In fact, the number is a pick of SWF not ours. Always remember this.

3. What if I am a "double-minded" person ?

My right mind picks a number "34" and my left mind picks a number "89". Lets see how it reads "double-mind". The result of right mind is (34-7)=27, and the result of left mind is (89-17)=72. Lets check the chart. Wow, both numbers point to the same symbol. Before clicking the crystal ball, lets test one more number: 61. The result is (61-7)=54. Wow, it happens again, the number 54 also points to the same symbol.

It is fishy. I guess, the swf calculates out all the possible numbers and make all possible results point to the same symbol which will be the answer in the crystal.

4. What are all the possible results ?

Lets reasonably do it by Math.

Pick two digit a and b. The instruction is (a*10+b)-(a+b); And the result is a*9; Since a is a number of 1 to 9, so the results is:

9,18,27,36,45,54,63,72,81

OK, we create a chart. Pick a symbol as the answer and then make all 9 numbers point to the symbol of answer. This is how we create the Mind-Reading Magic.

Lets do a similar game.

Pick two different digits. Square the first digit and subtract it by the result of multiplication of those two digits. Do the same calculation to the second digits again. Then sum them up to get a result number. Stare at the symbol 3 sec before click the crystal ball.

For example. We pick two digits: 7 and 4. Fist do (7*7)-(7*4)=21; Then do (4*4)-(7*4)=-12; Sum them up, 21+(-12)=9; Stare at the number 9.

Well, lets see the Math.

We pick two digit: a and b. The result of (a*a-a*b)+(b*b-a*b) will be (a-b)*(a-b); The range of (a-b) is from 1 to 9. So, all the possible results are: 1,4,9,16,25,36,49,64,81.

We make those 9 numbers point to the same symbol, that is the answer we need to put to the crystal.

However, the more complex the Math job, the easier users get wrong calculation. When user is staring a wrong result number, the SWF fails. We can not blame the user, and the user will know we were not really reading his mind.

**Conclusion:**

Those symbols in the chart are not arranged randomly. They are arranged with some trick.