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| Jim Logajan... |
 Posted: Sat Apr 05, 2008 1:23 am |
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"Perry E. Metzger" <perry at (no spam) piermont.com> wrote:
[quote:ec4e0420a7]----------------------------------------------------------------------
(As an aside, I'm rather disappointed in the moderators for letting
"Mike"'s message through.
Perhaps the assumption is that since there are no postings these days,
absolutely anything, no matter how strange, should be
forwarded.
[/quote:ec4e0420a7]
It was topical. The one time that any sort of "peer review" was attempted
we had several moderators, all with relatively relevant knowledge of the
field and scads of time. As a result the moderators made a lot of requests
for rewrites from posters - and the result was that it wore moderators and
posters out, to no good end.
"Peer review" by the moderators was never part of the group's charter
anyway. (The pay sucks anyway!  ) I think it is much more educational to
the lurking public for the "peer review" to take place out in the open - in
other words for people like yourself to post just the sort of critique you
did. (That's my story and I'm sticking to it!)
And as far as strange - well, you'll just have to take my word when I say a
lot stranger things have been approved in the past. And while I haven't
seen posts submitted dealing with aliens and nanotechnology in several
years, the moderators got that sort of crazy stuff once in a great while
and had the sense to reject it. It would still be rejected.
[quote:ec4e0420a7]However, my suspicion is that no good content is posted precisely
because the bizarre content has driven serious people completely
away. (Were it not for the date on the original message, I would have
assumed it was an April 1st prank.)
[/quote:ec4e0420a7]
In the past I've compared nanotechnology-related discussion group stats and
observed that declining participation is not isolated to only the
sci.nanotech Usenet group. |
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| John Novak... |
| Posted: Sat Apr 05, 2008 1:30 pm |
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On Apr 5, 1:27 am, "Perry E. Metzger" <pe... at (no spam) piermont.com> wrote:
[quote:ba6e9f6411]mike <mikes... at (no spam) invariant.freeserve.co.uk> writes:
On a dark an' dismal Tue, 01 Apr 2008 21:31:11 -0500, in flickering
lamplight,
"Perry E. Metzger"
pe... at (no spam) piermont.com> scribed with phoenix qill :
Well.
I know i said fire away, but i wasn't expecting
a flame. The moderators are usually careful
about that....
I believe I stuck pretty strictly to the facts. You may not like the
facts, but that does not make the posting a "flame".
[/quote:ba6e9f6411]
You're a smart guy, Perry, so please don't insult *my* intelligence by
pretending that there's a non-insulting interpretation to the little
post-script you attached to your initial response. I owe Mike an
apology as the moderator who who approved your message; had I been
paying proper attention I would have either rejected it or removed the
post-script. (Since I'm not fond of editing other peoples' words
without permission, it probably would have been a rejection.)
I also stand behind Jim in his approval of Mike's initial message in
this discussion thread, for all the reasons he listed. I moderate
mostly based on topicality, not the correctness of the post; as Jim
notes, that approach did not work either. I remember this forum's
early days, including a large number highly speculative posts which
you would not care for. Hell, I remember Usenet's early days, and I
share Jim's observation that this is not the only forum in decline.
Here is a suggestion, Perry: If the present level of posts does not
meet your standards, you are perfectly welcome to submit your own
posts which do. |
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| Perry E. Metzger... |
| Posted: Sat Apr 05, 2008 6:39 pm |
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John Novak <john.novak at (no spam) gmail.com> writes:
[quote:9174a7ee26]I believe I stuck pretty strictly to the facts. You may not like the
facts, but that does not make the posting a "flame".
You're a smart guy, Perry, so please don't insult *my* intelligence by
pretending that there's a non-insulting interpretation to the little
post-script you attached to your initial response.
[/quote:9174a7ee26]
It was not intended to be insulting. The postscript was there as an
honest request that the moderators exert more editorial discretion.
I myself moderate a couple of mailing lists, including a very large
and very active one on cryptography and security. I've found that
simply blocking the inevitable "fringe" messages works just fine and
hasn't been an excessive load on me. I don't think one is obligated to
be "fair" to the fringe posters. Borderline cases certainly exist, but
that's quite different. The people who are truly over the edge I just
block and that's that.
[quote:9174a7ee26]I also stand behind Jim in his approval of Mike's initial message in
this discussion thread, for all the reasons he listed. I moderate
mostly based on topicality, not the correctness of the post; as Jim
notes, that approach did not work either.
[/quote:9174a7ee26]
My experience on my own lists (and I have the opportunity to see
subscribership statistics so I have pretty good information on this)
is that in the past, when I've allowed through messages that are
topical but quite clearly "incorrect", I've gotten significant
declines in readership. With hindsight, there's a good reason for that
-- people are busy and don't want to do public "peer review", they
want to read interesting information. When they see too much stuff
that is clearly a waste of their time, they quit reading a forum.
I have gotten direct feedback from readers on this, by the way -- it
is frequently of the form "if you let through any more of that junk,
I'm going -- I don't have time to read it." Generally speaking, I
listen when people say things like that, since my goal is to provide a
high quality communications channel for people who are interested in
the topic, and not to be "fair" or to allow "public peer review".
[quote:9174a7ee26]I remember this forum's early days, including a large number highly
speculative posts which you would not care for.
[/quote:9174a7ee26]
They weren't such a large percentage of what was going through. I just
reviewed the last six months of posts, and there wasn't anything in it
that I noticed that I would have felt bad about missing. Things were
not like that years ago.
[quote:9174a7ee26]Here is a suggestion, Perry: If the present level of posts does not
meet your standards, you are perfectly welcome to submit your own
posts which do.
[/quote:9174a7ee26]
I don't know that it is worthwhile. I don't think there are terribly
many people left reading. There is also the question of what I would
say -- and I don't have anything particularly worthwhile to bring
up. I'm not that interested in posting for the sake of posting.
--
Perry E. Metzger perry at (no spam) piermont.com |
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| Toby Kelsey... |
| Posted: Sun Apr 06, 2008 2:46 pm |
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mike wrote:
[quote:71fd490cdb]the text. Sorry for that, was intended to be all carbon.
The other things like 'normal temp' you refer to?
It's hot, that's what the laser's for, to 'keep it active' a gas.
[/quote:71fd490cdb]
Carbon vaporizes at a high temperature, which would destroy the silicon barrier
you want to feed it through. (It is estimated to melt above 4500 deg K
<http://stinet.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA112977>).
If you want reactive carbon, it would be easier to start with a reactive
carbon-containing molecule, and arrange for it to decompose or react at the
site you want it too. Lasers could be used to cause or help the reaction.
[quote:71fd490cdb]A silicon partition with six laser made perforations
(single carbon atom sized) in a hexagon pattern.
A carbon atom is order of magnitude the same size as a silicon
atom. To make a "perforation" this size in a silicon surface would
imply somehow removing individual silicon atoms with a laser.
Which i have read has been done. [might not be silicon, though]
[/quote:71fd490cdb]
Silicon is not so rigid at this scale as Perry mentioned. There are
silicon-containing materials called zeolites, with interesting small holes
(<http://en.wikipedia.org/wiki/Zeolite>) and you are right that molecule-sized
holes can make interesting reactions occur (see
<http://www.che.caltech.edu/groups/med/catmat.html> for an overview).
Having small holes, makes them a bit delicate at higher temperatures though.
So the problem is then to find the right molecules and the right sort of holes
and the right conditions for the reactions you want to happen.
Toby |
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| mike... |
| Posted: Sun Apr 06, 2008 4:55 pm |
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On a dark an' dismal Sat, 05 Apr 2008 01:27:33 -0500, in flickering lampl=
ight, "Perry E. Metzger"
<perry at (no spam) piermont.com> scribed with phoenix qill :
[quote:79769520e1]mike <mikespam at (no spam) invariant.freeserve.co.uk> writes:
Well.
I know i said fire away, but i wasn't expecting
a flame. The moderators are usually careful
about that....
I believe I stuck pretty strictly to the facts. You may not like the
facts, but that does not make the posting a "flame".
[/quote:79769520e1]
[I like facts, one is that i know only a little amount of them,
So please just stick to fact, correct my naive notions.
But please, leave out the rude comments.
Not everyone was taught as you were, and what you'd assume as
self evident can easily trip up people like me. -mike]
<<#>>
[quote:79769520e1]Right, first, i don't really know where the carbon dioxide slipped into
the text. Sorry for that, was intended to be all carbon.
The other things like 'normal temp' you refer to?
It's hot, that's what the laser's for, to 'keep it active' a gas.
Carbon doesn't generally become a gas until well past
4000K. Regardless of how you heat it, you will end up with something
that will more or less destroy anything it comes into contact
with.
[/quote:79769520e1]
Would it be ionised?
If so could it be possible to capture it in a magnetic field?
Then we might have some measure of positional control by manipulating
the field.
[quote:79769520e1]Furthermore, even once turned into a gas, a monatomic form is
not energetically favored until very high temperatures, where
entropy effects overcome the exceptionally strong carbon-carbon bond
energy, thus making your proposal even more unlikely.
[/quote:79769520e1]
I've just had a look at a copy of the Periodic table, and realised that i
actually mis-remembered where carbon is. Oops. 
Isn't there some way to build an environment that would favour the
formation of desired length nanotubes?
<<#>>
[quote:79769520e1]A carbon atom is order of magnitude the same size as a silicon
atom. To make a "perforation" this size in a silicon surface would
imply somehow removing individual silicon atoms with a laser.
Which i have read has been done. [might not be silicon, though]
I assure you that no one has yet found a way to remove single atoms in
precisely defined (that is, defined down to an atomic radius) positions
with a laser.
[/quote:79769520e1]
Sorry, i must have mis-recalled it. I thought it was work done by or for
the microelectronic's miniturisation agenda.
Perhaps i just wanted to believe it was already done, but it was just a
proposal?
<<#>>
[quote:79769520e1]You are referring to interference effects. Such effects do not involve
the creation of fields with a characteristic length tens of thousands
of times below the wavelength of the light in use. Again, what you
propose is quite clearly impossible without the use of frequencies far
beyond the ability of current technology to control.
[/quote:79769520e1]
So it might 'eventually become possible?
There's no physical barrier to it working?
[quote:79769520e1]#
Besides, it isn't clear you could even get the Si atoms to
reliably absorb the x-rays -- they'd likely pass through the surface
instead.)
Okay, what would you suggest?
I have no suggestions -- you are attempting to perform impossible
tasks. Even if I wished to, I could not provide you with ways to
perform them.
[/quote:79769520e1]
You could suggest i stay away from lasers :-)
[quote:79769520e1]Si atoms would just migrate and close your hole up.
They would move that fast? I thought we would have them vibrate
and eventually seal the holes, but i was assuming months.
Depassivated Si surfaces are notoriously reactive because they are
very energetically disfavored. The surface will spontaneously
re-arrange to minimize its energy.
[/quote:79769520e1]
That's annoying, and to me unexpected. How the devil does doping a
chip work if that's the situation, wouldn't the foreign atoms be instantly
expelled? Does that happen?
<<#>>
[quote:79769520e1]If you could magically keep it from vaporizing what it came into
contact with, it would react instantly with depassivated silicon -- it
would not "move through" holes.
[/quote:79769520e1]
Okay! alright already. Silicon is out, then.
[quote:79769520e1][Don't call them magic holes again, please.]
Why not? You need magic to make them, and apparently they have
the magic property of extruding nanotubes out the other side.
[/quote:79769520e1]
Since you have decided to respond, please accept first my thanks,
and second my request that you treat all this as lighthearted,
and friendly. [At the moment you are coming over as a bit, well, aggressive.]
<<#>>
[quote:79769520e1]Any laser capable of breaking a carbon-silicon bond would melt or
vaporize the entire silicon structure. In any case, no carbon atom
will ever travel through an impossible-to-produce single atom wide
hole in a layer of silicon because, were it not so energetic as to
damage the hole itself, it would *always* bond to the Si long before
it could get through the hole, so it essentially wouldn't matter how
often you try.
[/quote:79769520e1]
I think i was after a more softer approach, the laser was only ever
intended to be the 'stirring rod' never letting the carbon settle.
the only way out was to be a hole in the chamber...
[quote:79769520e1]Why not a hexagon? It had to be something, and that just dropped in place.
Do you have a specific reason it cannot be one?
Why not make it into a pentagon, or a tic tac toe grid, or any other
pattern? Even if you could get single C atoms to emerge in a
hexagonal pattern, what is special about a hexagon? Again, perhaps you
are under the misapprehension that a single wall carbon nanotube is
hexagonal in cross section, but it is not, so what is the purpose of a
hexagonal pattern?
[/quote:79769520e1]
I wasn't aware of anything specifically, and hexagon as i said,
'just dropped in place'.
[quote:79769520e1]Regardless, the idea is implausible. This isn't chocolate frosting
being forced through a pastry tube -- the carbon atoms, even if you
could get them to emerge from your hexagon, will not nicely queue up
and bond to each other, in a hexagonal pattern or in any other pattern.
[/quote:79769520e1]
So, if placed next to each other with a Scanning atomic microscope
they would also fail to bond? I was under the impression they would.
[quote:79769520e1]All that's important is providing the carbon with plenty of
opportunity to bind in some stable ring formation, and still be open
to linking to more from the feed side.
Why would the carbon atoms bond in any particular shape whatsoever?
If they could make it through the holes at all, they'd be arriving in
a temporally randomized pattern, with wildly different energies
(following the Boltzmann distribution for a substance at that
temperature) and would almost certainly leave the holes with quite
uncorrelated trajectories. They would not be within a typical
carbon-carbon bond length of each other, and if they became close
enough to each other there would be no particular reason for them to
form any particular pattern of bonding.
[/quote:79769520e1]
I think this is because you saw the fact that they'd have to be highly
energetic fast moving atoms, while i envisioned a slow, impossible situation
of them caught temporarily and only able to escape by bonding to an
atom caught in the holes, and being drawn through.
[quote:79769520e1]This idea is more or less as plausible as the notion that you could
make humans by forcing bits of homogenized cow through a short slot in
a piece of sheet steel.
This doesn't relate, in any way. I am talking about atoms, and that
'notion' above, as you call it is not.
It does relate, in that it is more or less an equally plausible idea.
[/quote:79769520e1]
It doesn't relate and is simply rude. Please, drop it.
<<#>> <<#>>
[quote:79769520e1]It won't work because none of it makes any sense at all.
Yet you still responded to it?
Correct. I've got the bad habit of explaining why incorrect ideas are
incorrect when I encounter them.
[/quote:79769520e1]
I do have a similar habit, and the point of this was to find out
what was wrong with it.
I'm under no illusion that, had been possible, it would've been done
long ago, i just couldn't see why it shouldn't be possible.
And since things had gotten so quiet here, i saw no harm in posting it.
<<#>>
[quote:79769520e1]I'm afraid that the archives, which are astonishingly complete, show
no previous postings from your account. Perhaps you've posted in the
past from other accounts, but I see no reason to assume the moderators
would be able to know that.
[/quote:79769520e1]
One of them does, however i have had a lot of spam and am
attempting to reduce it, you might want to try again removing 'spam'
from the email addy. But it's probably not worth it.
[quote:79769520e1]I suggest that you re-read the beginning of my original post and
then decide if that was justified.
Still, not too bad considering you didn't understand it.
I understood what you were, more or less, proposing. Unfortunately,
the proposal has no germ of a plausible idea within.
[/quote:79769520e1]
A shame, i am hoping to see the space elevator in my lifetime, it
will need various lengths of nanotubes won't it?
(At the least, they'd be handy.)
Still, even just an open ended system for making them would be nice.
I'm just frustrated that things have gone so quiet, and i hope that it's
because everyone's hard at work and a nice surprise is coming. :-)
mike |
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| mike... |
| Posted: Sun Apr 06, 2008 6:23 pm |
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On a dark an' dismal Sun, 06 Apr 2008 14:46:26 -0500, in flickering lamplight,
Toby Kelsey
<toby.kelsey at (no spam) gmail.com> scribed with phoenix qill :
[quote:a885483100]Carbon vaporizes at a high temperature, which would destroy the silicon
barrier
you want to feed it through. (It is estimated to melt above 4500 deg K
http://stinet.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA112977>).
If you want reactive carbon, it would be easier to start with a reactive
carbon-containing molecule, and arrange for it to decompose or react at the
site you want it too. Lasers could be used to cause or help the reaction.
[/quote:a885483100]
I was thinking of some form of transport mechanism, but all i can think
off at the moment is to suspend carbon atoms until they reach a specific
site (the work zone, as it were,) and encourage them to react with the lasers.
If they prove to be ionised by a laser maybe the transport method could be
magnetic....
<<#>>
[quote:a885483100]Silicon is not so rigid at this scale as Perry mentioned. There are
silicon-containing materials called zeolites, with interesting small holes
(<http://en.wikipedia.org/wiki/Zeolite>) and you are right that molecule-sized
holes can make interesting reactions occur (see
http://www.che.caltech.edu/groups/med/catmat.html> for an overview).
Having small holes, makes them a bit delicate at higher temperatures though.
[/quote:a885483100]
Fascinating things, i have only had a chance to skim through so far, but
thanks, Toby, for the interesting links
I've noted the site stinet.dtic.mil for future browsing too.
[quote:a885483100]So the problem is then to find the right molecules and the right sort of holes
and the right conditions for the reactions you want to happen.
[/quote:a885483100]
And is proving to be much trickier than i imagined :-/
>Toby |
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