From: Forrest Bishop (forrestb@ix.netcom.com)
Date: Tue Jul 15 1997 - 09:42:26 MDT
Interview of Forrest Bishop by Bill Spence
December 10, 1996
The "Optical Assembler," fka the "Food Replicator"
[[Note: This is a partial description of an idea I originally had several years ago.
It has not
proceeded past the conceptual stage, and is offered only for your entertainment.
Forrest Bishop ]]
Bill (B): Forrest Bishop on a different kind of replicator, one that does not
involve robot arms.
Forrest (F): Right.
B: What does it use to manipulate?
F: This is very similar to what was on the original Star Trek episodes. They
called it the "Food
Replicator". It was depicted as a box in which things would simply appear when you
wanted them, and so I
use that name because it has some of the same properties.
B: Is the food replicator...Earl Grey tea or ...general country doctor?
F: Yes, this is very speculative technology; it's not a for-sure thing; it's more
out on the fringe. The
central idea is ...
B: Well, first, let me ask you, what is a replicator? It manipulates atoms in
foods and puts them in
specific places where you want them to be?
F: Yes, to build an object, you want to create an object that's atomically
precise. So, some kind of
device to do this.
B: And one kind of system is basically robot arms that physically
move things.
F: Yes, that's the most popular version.
B: And this is completely different?
F: Yes, it uses electromagnetic energy in a structured
electromagnetic field to do the same thing.
B: To move individual atom, more than one atom:?
F: Individual atoms, molecules, small structures.
B: Small structures?
F: Yes, possibly.
B: What does this device look like? How does it function? How does
it work?
F: The central idea is to create a structured electromagnetic field
that is variable in real time. The
atoms are moved around by the electromagnetic field.
B: Atoms can be moved around by electromagnetic field?
F: Yes.
B: What frequency are we talking about?
F: Roughly, light, visible spectrum, about [600 nanometers]
depending on the particular atom,
depending on whether you're trying to ionize it or not.
B: So you're pushing atoms with light?
F: Yes. This is already being done now. It's partially based on
..
B: Trapping an atom with lasers, right?
F: Yes. This has already been accomplished. In this environment,
imagine a flat plate of emitters
that are--each emitter is addressable; each emitter is very tiny. By
changing the timing--you have a row of
them--by changing the timing on them, you can create a wave front
that's steerable, just as in a phased array
radar.
B: OK. Light frequency.
F: Yes. So, a planar array of these --
B: A whole plane.
F: A whole plane consisting of a grid of emitters can construct a
beam of the frequency of your
choice. The frequency can be varied over [time, space, and phase]
also, and that way, you're creating a
beam that is coherent or different frequencies in different parts of
it, that's steerable over the half-sphere.
Ideally, you want to use emitters as small as possible--quantum well
lasers are one possibility.
B: Are they attainable?
F: They are.
B: In frequency?
F: There's already existing devices that are wholly suitable. These
are also called artificial atoms for
the reason that you have -- in them, you have an electron that is
trapped in some kind of a potential well,
which then [radiates] as the voltage varies the size of that potential
well.
B: Oh, it's [an] orbiting electron. Instant frequency of what it's
going to throw off in radiation?
F: That's right.
B: Pretty clever.
F: Yes. These are existing devices. Currently, researchers are
trying to make arrays of these which is
going to be difficult, from the one emitter ________one its neighbor.
B: Why?
F: Because these are tiny [quantum] mechanical properties that
you're playing with.
B: So the radiation field of one would affect the other?
F: Yes, you could put it that way. The electric field of the
voltage that's being used to adjust the
potential well in one is affecting its neighbor as well.
B: How would you overcome that?
F: In this idea, the way to overcome it, if you will, is simply
through computation [of] the wave
function [of the entire planar array].
B: Would it take into consideration how one field affects the
other? And changing whatever
parameters necessary?
F: That's right. It would take a massive amount of computer power.
B: OK, so you have a plate.
F: Yes, behind this plate, you have -- the equivalent of millions of
supercomputers are needed to run
this.
B: Oh, that much power?
F: That's right. You're running in real time, and in this case,
real time means you're obtaining a type
of _________ range, so it's a huge computational problem that require
nanocomputers in order to realize it.
B: I see. So you've got one plate with a hemisphere that's
completely controllable where the wave is,
and even what frequency it is. Then what?
F: Then what? Now, imagine two of these plates facing each other.
A quantum well emitter is also a
receiver. A wave that comes in will cause a electron or quantum well
emitter to transition to a level, if it is
the correct frequency, which it will be, because it is part of the same
system to design that in. Therefore,
you can create a standing between two plates. You can steer that wave;
you can, by phase shifting between
the two plates, you can cause the nodes, the standing of the nodes...
B: Where there's energy and where there's no energy.
F: Yes, it vibrates something down, kind of like a violin string,
and there are certain points on it that
where the field strengths don't change, called the nodes, and at those
points is where you place an atom and
have it stay. It's kind of similar to, if you take a board and want to
saw on it, sawdust will bounce up and
down on the boards and collect in the nodes, which is the places on
that board that aren't moving up and
down. Some parts of the board move and some stand still, and that's
where the sawdust collects. It's a
little bit like that.
B: So you could have atoms that would stay in the low-energy spots.
F: Yes, which is the nodes.
B: But you could move those nodes, is that correct?
F: Right, by phase shifting between the two plates, you could move
the nodes back and forth, and the
atoms, theoretically, will move with the nodes.
B: Aha! So, you can move atoms in one axis.
F: Yes, one axis.
B: So far.
F: So far. Now, make it six plates. Now you can construct a
three-dimensional, fully specified,
electromagnetic standing-wave field. You can move it, and the atoms
that are in it can be moved, shifted,
in space.
B: Relative to each other?
F: Relative to each other, and relative to the box.
B: A lot closer together, if need be, or want?
F: You'd want it to be.
B: Yes, I guess you would want it to be.
F: Yes, the idea is to inject an atom and have a wave front set up
at that point that catches that atom,
or small molecule, or what have you, perhaps you want to hit it with
high energy to ionize it, to create a
radical group, and then you use the standing waves to move it, in three
dimensions, over to where you want
it, and theoretically, cause a reaction.
B: Oh, in other words, bring it closer to another atom or molecule
and cause a reaction.
F: Yes, [close to the structure] you're building. Cause a reaction.
B: And because you have so much resolution, you could inject lots of
atoms at one time in lots of
places.
F: Because you have lots of computational power, you should be able
to do that. Every time you
place an atom in this electromagnetic field, its field interacts with
that field and, in principle, you can
deduce the location of that atom by...
B: By its shadow?
F: By its effect on the overall field.
B: OK, so you constantly know where the position of all the atoms are, in real
time?
F: Yes, like I say, this is getting kind of far out there. Another problem is
the wavelength is, say, 500
nanometers, which is much greater than the positional accuracy required for
reactions. However, by time-
averaging the position of that atom, you should be able to deduce its position to a
small fraction of a
wavelength, in other words, to the resolution required for positional chemistry.
B: All right. So, what we've got here is a box that you can inject atoms into
and grab them with
standing, very complex lightwaves, and literally move them around independently and
get them into
position to go into place. As opposed to robot arms, you're using lightwaves,
energy. It sounds very
exciting.
F: And the higher frequency lightwave can be used [to knock] an electron off an
atom to create a
radical group, and at the desired time.
B: Oh, so, it's more reactive; can jump into...
F: Remember, I was saying the plane consists of tuneable quantum well lasers that
have a spatial
frequency distribution so that you can address that atom with the UV ray you want.
B: Sounds pretty utilitarian to me. It's very useful.
F: Yes, it's a lot of speculation. It may or may not happen. There's some
research and ideas that are
similar to this already being done, so...
B: Briefly, what is that research?
F: Well, I just learned of a fellow--I think he's simply conceived it--with what
he calls an "optical
crystal"--I think that's what he calls it--and it is kind of the same idea, of
having a three-dimensional
standing wave and placing atoms in the nodes, but not shifting it, but placing atoms
in the nodes such that
they form a lattice structure that's like a crystal, except the atoms are actually
separated quite a distance, at
least one wavelength of light apart, but they're in a lattice. Now, as I've said
before, the presence of those
atoms alters the field, alters the electromagnetic field in spots, and therefore,
gives it a new optical property
that it didn't have before those atoms were there.
B: And it's detectable.
F: Yes. For instance, the index of refraction would be different than if it was
a box of [just]
electromagnetic [energy]. And so by, for instance, changing the frequency, you're
changing the lattice
spacing, you're altering .. the [optical] properties of this volume ....
B: With this Optical Assembler...
F: That's a good name for it.
B: What do you feel like you could build? Anything? A cup of Earl Grey?
F: No, it's so speculative that I'm already out on a limb, and I don't know how
much further I want to
go. Conceivably, anything; practically, there's a lot of unanswered questions.
Somewhere between there.
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