HDTenEightyP/NetNews huggingface dataset:
From: clarke@acme.ucf.edu (Thomas Clarke)
Subject: Re: Help: Programs for Computer Generated Holograms
Organization: University of Central Florida
Date: Tue, 8 Sep 1992 15:22:28 GMT

In article <AAphceg4t6@ifftr.msk.su>  fisun@ifftr.msk.su (Oleg Fisun) writes:
> 
> Dear Colleagues,
> 
> Would someone please tell me where I can get the programs
> for designing of computer generated holograms (CGH) and,
> in particular, those that use the binary cell-oriented,
> pixel-oriented and fringe-oriented encodings.
> I use IBM-compatible mashine (IBM 386) working under DOS.
> 
> Thanks in advance,
> 
> Oleg Fisun
> Institute of Physics & Technology,
> Prechistenka str. 13/7,
> 119034 Moscow, Russia.
> Internet: fisun@ifftr.msk.su

Could you please post a summary of responses you get.
I am also interested in this topic.

--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
Newsgroups: sci.optics,sci.materials
From:  rr@randg.lt.su (Remigijus Rimkevicius)
Subject: Help! Absorbtion crossection of Nd3+ in YAG at 633 nm needed
Reply-To: rr@randg.lt.su
Organization: Rimkevicius and Gintautas Company
Date: Mon,  7 Sep 92 20:33:25 +0200 

Help!

Do anyone can tell me the absorbtion crossection of Nd3+ at HeNe laser
wawelength of 632,8 nm in YAl2O5 host (Nd3+:YAG)?
Or optical density of Nd3+:YAG with acurate known Nd3+ concentration at HeNe?

Thank You,

Remigijus
-- 
   R&G Co., Box 2487, 2051 Vilnius-51, Lithuania
   Ph +7-0122-620172, Fax 624872, Tlx 261250 POST SU
   Rimkevicius@Randg.Uab.Lt
From: swami@sauron.eece.unm.edu (Swami srinivasan)
Newsgroups: sci.optics
Subject: Re: Diode Laser Holograms ?
Date: 11 Sep 92 21:35:49 GMT
Followup-To: swami@chtm.eece.unm.edu
Organization: University of New Mexico, Albuquerque

In article <1992Sep10.233058.12840@leland.Stanford.EDU> joelfire@leland.Stanford.EDU ( Firehammer) writes:

>In article <BuCGMp.L0o@bunyip.cc.uq.oz.au> coates@newton.physics.uq.oz.au (Tony Coates) writes:

>>I think that you will find that diode lasers tend to have a
>>coherence length of around 30cm or 50cm or the like, which
>>means that all the path lengths for the holograms would have
>>to be kept rather short.  Whether this is impossibly short
>>

>A rule of thumb that I've always used in making holograms is to
>keep your path length difference between your obj. and ref. beams
>well within the coherence length.  What this usually meant was that
>your resolvable object depth was limited by the coherence length.
>The total path lengths were always much longer than the coherence length.
>
>-joel 
>


	One can also make deep holograms with limited coherence length.
A simple Michelson setup can be used to verify that visibility is
maximum at 0 path length difference for the object and reference beams.
The visibility then goes down, but COMES UP again at periodic intervals. 

For a HeNe laser we had, the visibility used to come back at every 50 cm,
which was the length of the laser. Hence it allowed us to record
holograms  over 1m deep! However, the depth of the object(s) at
each of these locations was limited to a few centimeters, as observed in
Joel's post. 

	It's real easy to verify this with a Michelson interferometer.


							   swami

=======================================================================
swaminathan srinivasan
center for high tech materials
eece, university of new mexico
albuquerque, nm 87131				swami@chtm.eece.unm.edu

=======================================================================
Newsgroups: sci.optics
From: chi@ecf.toronto.edu (Winston Chi)
Subject: test
Organization: University of Toronto, Engineering Computing Facility
Distribution: can
Date: Tue, 8 Sep 1992 19:09:16 GMT

This is only a test CC
From: jrm@gnv.ifas.ufl.edu
Newsgroups: sci.optics
Subject: Re: Diode Laser Holograms ? 
Date: 10 Sep 92 19:00:56 -0500

In article <BuCGMp.L0o@bunyip.cc.uq.oz.au>, coates@newton.physics.uq.oz.au (Tony Coates) writes:
> I think that you will find that diode lasers tend to have a
> coherence length of around 30cm or 50cm or the like, which
> means that all the path lengths for the holograms would have
> to be kept rather short.  Whether this is impossibly short
> depends on the specifics of the hologram setup, of course.
> 
> 						Tony.

	Thanks for this info. A 50cm coherent length need not be
	fatal - just have to keep the whole setup small (which
	may translate into cheap & convenient). My interest is
	mostly recreational at the moment anyway. For such a
	purpose though, the cost of a nice bright gas laser is
	a great deterent. I did a few holos while in college and
	learned right away that a dim source = long exposure times 
	= vibration problems. The diode lasers offered hope of
	getting a bright source w/o the financial pain - oh well,
	as they say, you can't always get what you want.

	One 'fringe' use of holos that does interest me very much
	is how the holos can emulate the actions of real lenses
	that are holographed. I also note that computers can now
	(cheaply) calculate interference patterns which can be
	used to make holos of totally computer-generated objects.
	Think of making a corrector plate so a heads-up display
	could be projected onto the windshield of any given model
	of automobile. Pressing or grinding real lenses to counter	
	the distortion from the curving windscreen would be rather
	expensive - and could get impossibly so it one tried to
	keep up with all the model-year variations. On the other
	hand, using a holo to emulate these weird-shaped optics
	and using a computer to calculate & produce these holos
	would mean a great savings in money and time plus essentially
	infinite flexibility in coping with new products. The
	holo optics would be dimmer - but in an auto, plane or other
	heavy conveyance this would be no big deal. 

	This months issue of 'Scientific American' has a short review
	article that indicates that very cheap IR imaging arrays may
	soon be availible. Imagine laying the IR image over the wind
	screen at night using cheap heads-up optics. Visibility
	would increase nearly to daytime levels (in black & white 
	only however) yet warning lights and such ccould still be
	seen easily thru the glass. Just hazarding a guess, but I
	believe that such an arrangement would become mandated by
	law in almost every nation. [ This idea free to anyone who
	wants to steal it ] The profits to anyone involved in making
	parts for such systems would be incredible.

-- Jim Mason
From: jrm@gnv.ifas.ufl.edu
Newsgroups: sci.optics
Subject: Re: Glass grinding
Date: 11 Sep 92 18:38:02 -0500

In article <25704@castle.ed.ac.uk>, loki@castle.ed.ac.uk (A Kashko) writes:
> 
> 	I have been translating an article on glass grinding, and came across
> a statement that currently used grinding solutions contain 30% of glycerine.
> The word used could also translate as glycerol. Our library here has nothing
> on glass grinding
> 
> 	Could someone please email me as to whether grinding solutions contain
> glycerin or glycerol. Preferably soon.

	Glycerol = Glycerine. A heavy alcohol with a syrupy feel.
	Can't say about its use in grinding ... but it would tend
	to act as a lubricant and would help keep the abrasives
	in suspension better than plain water. 

-- Jim Mason
From: tomk@netcom.com (Thomas H. Kunich)
Newsgroups: sci.nanotech
Subject: Definitions
Date: 8 Sep 92 20:31:12 GMT
Organization: Netcom - Online Communication Services (408 241-9760 guest)

So, are we going to define anything small as nanotechnology?

Or are we going to specify (like Drexler) that nanotechnology
is a very specific formula that involves a specific type of
machine?

Well, is spelling AT&T on a substrate with atoms nanotechnology
or _a_ technology that _could_ lead to nanotechnology?

[To give credit where credit is due, it was IBM that was first spelled
 with 35 xenon atoms...  With respect to terminology, there seems
 to be a trend to refer to anything small as nanotechnology (regrettably)
 and Drexler is using the phrase "molecular nanotechnology" to distinguish
 the technology he's working towards.  
 Spelling with atoms is a start, but for general control one needs the 
 ability not only to move atoms and molecules to precise locations,
 but to do it quickly enough, and with enough different species of
 molecule, to build useful things--this includes particularly a good
 enough manipulability to control the formation and breaking of
 covalent bonds.  This we don't have yet.
 --JoSH]
From: josh@cs.rutgers.edu
Newsgroups: sci.nanotech
Subject: administrivia
Date: 9 Sep 92 12:58:46 GMT


I'll be away for about a week, so service will be slow.
Response to the survey has been great--thanks to everyone 
who replied.  These have slowed to a trickle, so if you 
wanted to respond and haven't, do it NOW and I'll tabulate
the results (with analysis and comments) when I return.
--JoSH
From: nickh@CS.CMU.EDU (Nick Haines)
Newsgroups: sci.nanotech
Subject: Re: photoribosome
Date: 8 Sep 92 19:47:28 GMT

I think this is a way cool idea, much more practical than a lot of the
stuff that gets posted here. Ideal for building-block assembly,
because if you have a lot of photoribosomes in a bath you can just
shine lights on the whole thing and they'll all act together in sync.
Quite possibly you wouldn't be using rhodopsin, or even anything
similar, but a photo-programmable protein constructor, based on a
ribosome with a different `read head' should certainly be possible. I
mean, you can dump the RNA altogether.

Is the ribosomal mechanism well understood? I know that the code is
known, and we know bits about the receptor sites for the different
aminos, but is there detailed knowledge of how the mechanism works? Do
we have model ribosomes in the quantum biochem simulators?

Nick
From: mshute@cs.man.ac.uk (Malcolm Shute)
Newsgroups: sci.nanotech
Subject: Re: Evolution and nanotech
Date: 15 Sep 92 21:03:16 GMT
Organization: Dept Computer Science, University of Manchester, U.K.


In article <Sep.9.08.48.58.1992.13589@planchet.rutgers.edu> tomk@netcom.com (Thomas H. Kunich) writes:
>We do know now that competitive advantage is not the only form of
>evolution. As you point out there are sybiotic relationships that
>can change the dice in this throw.

But surely this is *still* an 'us against them' competition for
survival between the members of the symbiotic team, and all the rest
of the biological world.  

Malcolm SHUTE.         (The AM Mollusc:   v_@_ )        Disclaimer: all

[In the appropriate environment, being able to cooperate *is* a
 competitive advantage.  See Axelrod's "The Evolution of Cooperation".
 --JoSH]
From: hebron@cs.sfu.ca (John Hebron)
Newsgroups: sci.nanotech
Subject: Re: First General Conference on Nanotechnology
Date: 15 Sep 92 21:18:53 GMT
Organization: Department of Mathematics and Statistics, Simon Fraser University

My friend, Dr. Pierre Zakarauskas, who lives in Victoria, recently sent me the
following message.

 >     I am interested in attending the nanoconference, but I would have
 > to go on my own time, and pay my own way.  Do you know of somebody at
 > SFU who would be interested to come and share expenses?  I would
 > drive, and probably camp on the beach.

If you are interested, you may contact him via "zak@orca.drep.dnd.ca".

--
/=================================================================\
| Dr. John S. Hebron                |                             |
| Department of Mathematics & Stats | Internet: hebron@cs.sfu.ca  |
| Simon Fraser University           | Phone:    (604) 291-3636    |
| Burnaby, B.C.  V5A 1S6            | FAX:      (604) 291-4947    |
| CANADA                            |                             |
\=================================================================/
From: ian@inf.ethz.ch (Ian)
Newsgroups: sci.nanotech
Subject: What computer simulation can't do yet.
Date: 9 Sep 92 12:58:34 GMT
Organization: Dept. Biochemistry, University of Bristol, UK

In article <Sep.8.15.47.27.1992.733@planchet.rutgers.edu> nickh@CS.CMU.EDU (Nick Haines) writes:

<Most deleted>

>
> Do we have model ribosomes in the quantum biochem simulators?
>

We don't even have any quantum biochemical simulators to put them in !

You have overestimated the current state of the art with biochemical 
simulation.  We do sometimes do quantum mechanical simulations, they 
are always approximations to limited aspects of well-known systems (eg
only a few atoms are completely modelled and a few 'broad approximations'
such as known dipoles are filled in around them; this is typically going to
produce something like the distribution of electrons between the available
energy levels in the transition state of a reaction) <Please correct me, I've
only ever watched other people do this.>.

The far more common class of simulation performed is purely newtonian, however.
Just a masses and forces implementation of the molecular system.  The average
protein has around 10,000 particles which means that the CPU time required is 
far from trivial, on the order of seconds for each time increment and as each
increment is typically a femtosecond you'll understand why the longest 
simulations ever performed have only modelled 100's of picoseconds.

As a ribosome is around 100 times larger than a typical enzyme, the answer to
your question is no, definitely not.

Having said that, we do know a bit about it's mechanism, look in any recent,
From: me@isnext9.msu.edu (My Account)
Newsgroups: sci.nanotech
Subject: Enthusiasm?  Optimism?
Date: 15 Sep 92 21:04:57 GMT
Organization: Michigan State University

Please note that there *are* FAQs for this group.  They are _Engines of  
Creation_ and _Unbounding the Future_ by K. Eric Drexler.  They work so  
well that they often answered my objections on the very next page or,  
once, on the next line.  Check it out.	

_Unbounding the Future_ p170
"The hungry, the homeless, and the hunted have little time of energy to  
devote to human relations or personal development.  Food, shelter, and  
security are not everything but they are basic.  Material abundance is  
perhaps the best-known way to build a contempt for material things and a  
concern for what lies beyond.  In that spirit, let us take a further look  
at providing heaps of basic material wealth where today there is poverty."

_Unbounding the Future_ p161-2
  "It may be fun to discuss wondrous new products, but they won't make  
much difference in the world if they are too expensive.  Besides, many  
people today don't have decent food, clothes, and a roof over their heads,  
to say nothing of fancy 'nanostuff'.
  "Costs matter.  There is more to life than material goods but without  
material goods life is miserable and narrow.  If goods are expensive,  
people strive for them; if goods are abundant, people can turn their  
attention elsewhere.  Some of us like to think that we are above a concern  
for material goods, but, but this seems more common in the wealthy  
countries.  Lowering manufacturing costs is a mundane concern, but so are  
feeding people, housing them, and building sewage systems to keep them  
from dying of cholera and hepatitis.  For all these reasons, finding ways  
to bring down production costs is a worthy goal.
  "For the poor, for the environment, and for the freeing of human  
potential, costs matter deeply.  Let's take a closer look at the costs of  
molecular manufacturing."

_Unbounding the Future_ p259
"(any critic declaring this to be an optimistic book hereby stands charged  
with having failed to read and understand the above paragraph.)"

=========SunCat++++     | kamchar@ibm.cl.msu.edu
"Society is in conspiracy against the manhood of every one of its members.  
Society is a joint-stock company in which the members agree, for the 
better securing of his bread to each shareholder, to surrender the liberty  
of the eater."
--Ralph Waldo Emerson
From: thantos@runic.via.mind.org (Paul Williams [SysOp])
Newsgroups: sci.nanotech
Subject: Re: Evolution and nanotech
Date: 8 Sep 92 19:53:19 GMT
Organization: Runic Writings / Lawrenceville, GA

hagerman@ece.cmu.edu (John Hagerman) writes:

> Bad example; evolution won't convert a dog into a songbird, either.

Oh, I wouldn't say that.  If evolution can convert a 5 foot long
dinosaur into a songbird, a dog isn't that much further away, though
I'll admit, it'll turn out very different in specific structure and
appearance.



---
thantos@runic.via.mind.org (Paul Williams [SysOp])
Runic Writings
From: ghsvax!hal@uunet.uu.net (Hal Finney)
Newsgroups: sci.nanotech
Subject: Evolution and nanotech
Date: 15 Sep 92 20:53:02 GMT

Thomas H. Kunich writes:

> If you redefine the science to be anything small you now _have_
> nanotechnology in the guise of chemistry, biotechnology and other
> sciences that are completely operational. So why talk of nanomachines
> then instead of organisms?
>
> [Why talk of cars and trucks and airplanes and ships and railroads
>  when we already have horsecarts and dogsleds?  They're all just
>  forms of transportation...  The analogy is quite close.
>  --JoSH]

I take JoSH to be saying that cars are to horsecarts as nanotech is to
biology.  And, since as we know cars have almost no resemblance to
horsecarts in their basic mode of operation, it follows that nanotech
will have almost no resemblence to biology in the way it works.

I disagree with this.  Take the system consisting of a ribosome,
messenger RNA, and transfer RNA with amino acids attached.  The
ribosome travels along the mRNA; at each point it allows only the
complementary tRNA to temporarily bond in, then transfers the attached
amino acid from the tRNA to the end of the protein it is constructing.
It frees the tRNA, advances to the next triplet on the mRNA, and is
ready to attach another amino acid.

What could be more mechanical than this?  Yet it's biology, not
nanotech.

There are many other such mechanical operations done at the nanometer
scale in biology.  Three others that I've mentioned before are the
motor which spins the flagella of bacteria (the Science issue on
nanotech a few months ago had a good description of this); the active
sliding of protein fibers which is the foundation of muscle movement;
and the active channels in cell membranes which, when an appropriate
ion attaches at one end, pull it through the cell and pop it out the
other end.

The basic mechanical principles behind these devices are not fully
understood, but the devices are small enough that they can't be too
complex.  Once we understand them, we may well incorporate these
devices into our own nanotech designs - they represent simple
solutions to simple problems.  They may analogous to the pulleys,
levers, and other elementary mechanisms out of which more complex
machines are built.

Yet I have not noticed any horse meat in my car's engine.

The basic flaw in JoSH's analogy, IMO, is that at the nanoscale, both
nanotech and biology are having to solve the same problems, the
manipulation, motion, and positioning of atoms, with the same tools,
somewhat larger clusters of atoms.  This constrains the set of
possible approaches so that nanotech may not be so different from
biology in the end.

Ironically, I suspect that nanotech will lead to the construction of
cars which have "horse meat" in them.  They may well get their motive
power from material which more closely resembles muscle tissue than
the metal gasoline-burners we use today.

So perhaps the cars of the future won't be so different from horse
carts, after all.

Hal Finney
ghsvax!hal@uunet.uu.net				...!uunet!ghsvax!hal
Permission is granted to freely reproduce this message
From: ingles@engin.umich.edu (Ray Ingles)
Newsgroups: sci.nanotech
Subject: Re: Evolution and nanotech
Date: 15 Sep 92 21:08:28 GMT

In article <Sep.9.08.55.28.1992.13631@planchet.rutgers.edu> tomk@netcom.com (Thomas H. Kunich) writes:
>In article <Sep.8.16.35.25.1992.1306@planchet.rutgers.edu> ingles@engin.umich.edu (Ray Ingles) writes:
>>
>> Umm... maybe it's just me, but I think that the developments
>>you're proposing are indistinguishable from nanotechnology.

 I understood that you were proposing competitors that were capable
of everything 'nanotech' is projected to be capable of. In that
context, whether you call it 'chemistry,' 'biotechnology,' or 'pastafazoola'
is not really relevant.
 Since the present state of biotechnology, etc. is *far* short of what
the theoretical maximums are, (as JoSH pointed out) I don't really see
where you could call them 'nanotech' in that sense. 
 I apologize if I was unclear on this point.

Sincerely,

Ray Ingles                  || The above opinions are probably
                            || not those of the University of
ingles@caen.engin.umich.edu || Michigan. Yet.
From: ingles@engin.umich.edu (Ray Ingles)
Newsgroups: sci.nanotech
Subject: Re: Evolution and nanotech
Date: 8 Sep 92 20:35:26 GMT

In article <Aug.31.01.58.27.1992.24363@planchet.rutgers.edu> tomk@netcom.com (Thomas H. Kunich) writes:
...
>Nanotech must compete economically and effectively with many other
>sciences that are presently at a much higher state of development.
>Chemistry and biotechnology are both much further along the
>development curves ...


 Umm... maybe it's just me, but I think that the developments
you're proposing are indistinguishable from nanotechnology.
("Nanotechnology"="technology on the nanometer scale," unless
I missed something...)
 If it walks like a technolgy able to manipulate materials on
the molecular level, and quacks like a technology able to
manipulate materials on a molecular level, etc.


Sincerely,

Ray Ingles                  || The above opinions are probably
                            || not those of the University of
ingles@caen.engin.umich.edu || Michigan. Yet.
From: efi!chrisp@uunet.uu.net (Chris Phoenix)
Newsgroups: sci.nanotech
Subject: How to build magnets?
Date: 15 Sep 92 21:17:49 GMT
Organization: Electronics For Imaging, Inc.

I tried to write a more complex version of this question long ago and
it had a fatal flaw which Josh luckily noticed.  So I'll keep it
really simple:

When putting down atoms of iron next to other atoms of iron, how can
you control the magnetic properties of what is formed?  Either it
wants to form a magnet or it doesn't; if you want the other result the
only way I can see to do it is to impose a stronger magnetic field in
the work area to make the new atom line up with that.  But this runs a
risk of disrupting other parts of the work.

On the topic of mutations: I didn't want to waste a post on this alone
since my news feed is a month out of date.  But if no one else has
brought it up, consider the possibility of a physical mutation not
involving the genetics at all.  For example, what if a weakness
develops in the arm of the assembler that has two effects: to cause
the same weakness in all future generations of assemblers (which will
be manufactured by the arm, so it's not a ridiculous scenario); and to
hamper the thing's ability to distinguish between good and bad cells.
Boom, it's now a fatal mutation.  I think I may have mentioned this a
couple of years ago, but I'm sure there's lots of new readers and
viewpoints now.  (Please don't get so busy quibbling about whether
it's really a "mutation" that you ignore the question of whether it
could happen.)

-- 
"The secrecy that shielded the meetings and written communications of the 
men at the top helped to perpetuate the false impression that they sought 
and weighed facts in their discussions."  
     -- Neil Sheehan, on US military leaders during the Vietnam War.

[While it's certainly conceivable to design a self-reproducing 
 machine that inherits acquired characteristics (consider the 
 self-reproducing program that disassembles its running core image)
 I don't see why you'd want to build one.
 --JoSH]