From: Wayne Hayes (wayne@cs.toronto.edu)
Date: Sat Dec 13 1997 - 11:25:10 MST
I wrote:
>>It is almost certain that the quantum state of a normal, everyday object
>>(like a brick, or a human) is completely irrelevant when it comes to
>>true teleportation.
Erik Reid responded, via "Kathryn Aegis" <aegis@igc.apc.org>:
>Almost, but no cigar for the gentleman. The state of the particle is the
>most crucial part of physical properties.
OK, we need to be far more careful about the use of the term "state".
It's being thrown around haphazardly without being defined sufficiently
carefully. Obviously, if by "state" you mean everything there is to
know about the particle --- it's energy, momentum, position,
temperature, the chemical bonds it's participating in, vibrational
frequency, spin, etc, then obviously the state is crucial. However,
there are classical (Newtonian) elements of the state, and Quantum
elements of the state. Things like the spin are describable *only* by
Quantum Mechanics, and have no meaning in classical physics. It is
these kinds of states, describable *only* by QM, that Quantum
Teleportation is capable of duplicating. *None* of the other kinds of
states are. Quantum teleportation does not duplicate momentum. It
doesn't duplicate energy. It doesn't duplicate temperature. And most
importantly, it does not, and *is not capable of*, creating chemical
bonds amongst previously unattached atoms at the receiving end in order
to duplicate a molecule at the transmitting end. A chemical reaction
requires *energy* (among other things), and quantum teleportation does
not transmit energy (as Erik correctly points out), it only transmits
information.
>Yes, the raw materials must
>exist on the other end in order to do the recreation. If you are going to
>transport the state of a gold atom from point A to point B, you must have
>a gold atom at point B in order to have the state transferred.
Correct. Even more important, if you want to transport the state of an
NH4 molecule from point A to point B, then you must have an NH4 molecule at
point B in order to have the state transfered. It is NOT suficient to
have one unattached N and four unattached H molecules at point B.
>The state of the particles creates the larger object.
Only, as I said, if "state" includes the classical components of state,
which are *not* duplicated by quantum teleportation.
>They believe that they'll be able to
>transport molecules within 10 years with this method; in that case, you
>won't need the molecule at point B, all you'll need is the raw materials of
>the molecule to have it recreated.
Incorrect. They believe that in 10 years they will be able to transport
the quantum state of molecules from point A to point B, but the molecules
must already exist, as identical molecules, in all their spledour of
chemical bonds, at point B. Again, you need *energy* to create a molecule
from constituent atoms, and quantum teleportation does not provide that
energy.
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