http://news.bbc.co.uk/hi/english/sci/tech/newsid_1310000/1310771.stm
'Tractor beam' technology advances
The beam consists of a helix of twisting laser light
By BBC News Online science editor Dr David Whitehouse
A "tractor beam" that can reach out, trap and move objects has been developed
by British scientists.
But while fictional tractor beams of the kind depicted in Star Trek can
ensnare a giant spaceship, this real version works only at the microscopic
level.
The beam consists of a helix of twisting laser light, which is able to seize
hold of objects as small as a protein molecule.
Scientists believe it will be an invaluable tool for manipulating parts of
living cells or components of micro-machines.
Glass beads
Dr Kishan Dholakia, of St Andrews University, said: "Our technique could be
used to drive motors, mixers, centrifuges and other rotating parts in cheap,
tiny, automated technologies of the future."
The beam can rotate tiny objects
The researchers speculate that components like these might one day appear on
microchip laboratories capable of performing a range of chemical and
biological tests.
So far, the scientists have tried out the system with glass beads 100 times
thinner than a human hair, and a tiny glass rod which could be used for
stirring minute amounts of liquid.
They also used the beam to rotate a hamster chromosome to demonstrate its
potential for studying structures inside the cell. Optical tweezers, which
allow particles trapped in a tightly focused laser beam to be moved from one
spot to another, already exist.
But the devices are severely limited because they cannot change an object's
orientation. A proper tractor beam, say scientists, must be able to rotate
objects as well as move them.
Just a beginning
The researchers describe in the journal Science how they extended the
principles of optical tweezers technology. In both systems, a particle gets
trapped in the laser beam because some of the light refracts when it hits the
object.
This changes the momentum of the object, which is forced towards the spot in
the beam where the light is most intense.
"The beauty of our technique is that we can dictate how far we want the
spiral pattern to go around and at what speed," Dr Dholakia said. "That means
we can fully control the rotation of that one particle."
He added: "We've only just begun to realise the possibilities for what we
might do with this technology."
attached mail follows:
Cynical postulate: He made a decision to rely upon the advice of
someone(s) older and wiser, who remained in the background.
Alternatively, could be he was freakishly advanced (in a good way)
from a very young age and so began gathering relevant experience and
accumulating wisdom while others his age were still sucking their
thumbs--in which case, the wisdom *still* took time to develop, and
he simply began earlier. Not knowing him, I can only speculate.
jm
On 2 May 2001, at 23:03, Ben Goertzel wrote:
>
> > #There is something to be said for *relevant* experience. Age is
> > immaterial except in regard to two things: relevant experience, and
> > wisdom. The former can sometimes be gathered quickly; the latter,
> > never.
>
> This is an interesting statement, but I know some counterexamples to it.
>
> The guy who ran our Brazilian office and later our whole international AI
> Development Division, Cassio Pennachin, demonstrated an *amazing* amount of
> maturity wisdom at age 21 when we hired him, and continued to do so over the
> next 2 years. (I know Cassio doesn't read this list, so I don't mind
> flattering him...)
>
> It always baffled me how he came by such a reserve of wisdom about
> everything from system design to people management to business... his life
> history, which is perfectly ordinary, doesn't explain it at all.
>
> The diversity of human nature is well worth keeping in mind when thinking
> about the future personalities of AI's. AI systems will have vastly more
> diversity than humans, one can expect, since there have got to be many very
> different ways to create real AI (and many different pathways along which
> eventual self-modification will lead real AIs). Glib generalizations will
> be even harder to make!!
>
> ben
>
>
>
>
John Marlow
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