I'm now going to demonstrate for you the miracles
of quantum mechanics
using just four coins and four cards.
We start by covering up the four coins like
so.
Now we give the system a quantum spin just
like this.
That quantizes it.
And this way, if we make an observation,
there's no telling if the system is still
in its initial state, which it appears to be,
or if it has changed spontaneously to a different
state.
If we make another observation,
the coins have jumped.
Let's do it again.
That coin has jumped from there over to there.
And the last one.
We say the magic word,
"Heisenberg's uncertainty principle,"
and that coin has vanished from there
over to there.
I don't normally repeat effects again,
but since this is more of a science experiment
than a magic trick,
I'll do that one more time for you.
Four cards, four coins.
We're going to place the cards down as before,
and we're going to give the system a quantum
spin.
Now, this system is now quantized.
So, if we make an observation, there's no
telling what might happen.
It looks as if everything is the way it's
supposed to be,
but if we make another observation,
it could be that that system suddenly changes.
We make another observation.
That coin jumps, goes over to there.
And the last coin,
we say the magic words,
"Heisenberg's uncertainty principle,"
it disappears and reappears right under—
Oh.
That's strange.
That's another property of quantum systems
I forgot to mention.
They can spontaneously reset themselves the
their initial state.
Thank you very much.
