I sometimes watch the American TV show "Penn and Teller: Fool Us"
which the ABC has been showing on their second channel for years. I
actually preferred it when they has Jonathan Ross hosting because
he added a bit more comedy to the mix, but anyway it's good light
entertainment for when I'm looking for that sort of thing.
The idea is that magicians go on to try and "fool" the famous
magical duo of the show's title by performing a trick and seeing
whether either Penn or Teller can work out how it was done. Much
like the robot combat TV shows, this naturally makes me think about
what magic tricks I could design if I were into that sort of thing.
One blind spot that P&T seem to have is for the more electronically
based tricks. They're very clued into physical tricks, which I
usually have no idea about, but sometimes tricks involving
electronics that seem fairly obvious to me actually fool them. So
I've been thinking about these sorts of tricks and here are a
couple of acts that I've come up with:
THE TIME MACHINE
My theme as a magician is a mad inventor who'se been trying to sell
his magical machines but for one reason or another it never quite
works out and he has to keep on using them in magic shows instead.
In this case I'd start the act by presenting an extravigantly built
'time machine' complete with various dated-looking gizmos and a
printer-like device. After explaining the background, present this
as an example of how things don't work out: "People always say if I
had discovered the secret to time, then why do I not find
tomorrow's winning lottery ticket. So I built a machine to do this.
It looks into the future to see the winning ticket when someone
presents it at the store. But it has a limited range so I had to
drive to all the stores in the country, and the cost of fuel sent
me broke before I found one. So now I demonstrate it here for your
amusement..."
Now select a couple of people from the audience, sitting well
apart, to come up (or have an assistant go to them). Give one a
card envelope with a piece of coloured paper inside, as well as a
permanent marker, and tell them to go back to their seat and draw a
picture. Tell them to keep on drawing whatever they like, one thing
or many, until you ask them to stop.
While they do that, take the other audience member over to the
machine and set it going. Explain that it will look forward in time
and copy the drawing before the other audience member has even
finished it. But of course if the other audience member saw it
before they'd finished, the paradox would cause some great
calamity, so they have to keep it in its envelope until you ask
them to take it out. Meanwhile the printer-like part of the machine
has spat out a sealed envelope the same as the other one. Give this
to the second audience member and ask them to return to their seat,
then ask the first audience member (is there some shorter magician
slang for audience member?) to finish up their drawing then put the
paper into the envelope and seal it.
Then after superfulous tension-building talk, ask the second
audience member to open their envelope and hold up the (differently
coloured) piece of paper inside, showing it to everyone including
the first audience member. Ask the first audience member to confirm
that it matches what they drew, which it will, then ask them to
pull out their drawing from the envelope to show the audience.
But oh shock! The piece of paper has disappeared from inside the
first audience member's envelope. Fake concern for a brief moment,
then sigh. roll your eyes, and explain that it must have got jammed
inside the machine again. Open up the printer-like part of the
machine and pull out a piece of paper the same colour as the one
given to the first audience member, and hold it up with their
drawing also clearly visible on it and matching the drawing on the
paper held by the second audience member. Applause, whoo, you're
amazing.
But how's it done? Well I've worked out the rough method, although
some details would naturally take quite a bit of work to pin down:
Here are some secrets about the stuff given to the first audience
member:
The permanent marker has been filled with conductive ink (there's
some research paper I can't be bothered finding alink for which
explains how this can be made at home thinly enough to work in ink
jet printers, or there are commercial conductive pens if you can
get them to look convincing as regular markers), and has a wide,
flat, enough tip that the poor audience member won't be able to
draw fine details easily.
The envelope is made of stiff card, folded over at the edges. Along
the sides are tiny wires (or possibly flexible PCB material with
exposed tracks, but this would be harder to disguise), in a tight
grid. These join with a thin circuit board running along one of the
stiff folded-over edges of the envelope, which at the corners has a
tiny microcontroller and radio circuit as well as a little flat
Li-Ion battery like are used on things like smart watches. The
paper of the envelope is also the same colour as the permanent
marker ink (eg. black).
The paper is coated with a substance that will turn it the same
colour as the inside the envelope (eg. black), and an adheasive
that will bond it to one of the envelope's sides. This might be
activated by the wire grid heating up (if using thermal paper), or
by chemical reaction with a coating inside the envelope.
Now for the second audience member's envelope and paper:
This envelope has a flexible PCB, possibly similar to the other
one, sandwiched between the outer envelope card and an inner
lining. It also has electronics similar to the other envelope, but
these heat up small parts/pixels of the grid to reproduce the
pattern of tracks shorted in the other envelope by the conductive
ink. The other envelope images the drawing by determining which
conductive tracks/wires are shorted by the ink, then sends the
pattern to this envelope via radio.
And finally for the machine itself:
This is simply (a) a dispensor for the second envelope, and (b)
contains duplicate circuitry of the second envelope which also
reproduces the drawing inside it, on a piece of paper coloured the
same as the first audience member's before it turned black.
So if it's not already obvious, the trick works as follows:
First audience member draws picture on their paper with conductive
ink.
Machine dispenses sealed envelope containg a blank piece of paper
to the second audience member.
First audience member seals their piece of paper in their envelope
which images the drawing they've done on it according to where
sensors are shorted out by the conductive ink.
Paper in second audience member's envelope and inside the machine
is both printed thermally with the image sent wirelessly from a
hidden transmitter in the first audience member's envelope.
This is really only my latest variation of this trick. The printing
part alone is good enough to do a typical mentalism trick where you
'guessed', eg. which card someone will pick, before the show. The
'time machine' aspect adds an extra diversion, and the drawing is a
little more interesting, although it will probably only look
convincingly like the original from a distance (hiding the original
from the audience also helps with this, the first audience member
only really confirms that it looks something like what they drew,
even if it's a bit of a dodgy copy).
I ran out of energy for writing up trick no. 2,
"Electro-Telekinesis", which is a less clever one anyway.