Nanotubes as Tiny Bar-Magnets

Main Page | Report this Page

Science Forum Index » Nanotechnology Forum » Nanotubes as Tiny Bar-Magnets

Page 1 of 1

Author

Message

sanman

Posted: Fri Nov 28, 2003 2:22 am

Guest

Here's an article about graphitic carbon being turned magnetic:

http://focus.aps.org/story/v12/st20

Apparently, proton-irradiation can cause this.

Imagine nanotubes or buckyballs as tiny magnets -- think of the possibilities.
Could it mean a new generation of magneto-rheological fluids?

John Larkin

Posted: Fri Nov 28, 2003 6:16 pm

Guest

On 28 Nov 2003 07:22:34 GMT, manofsan@yahoo.com (sanman) wrote:

Quote:

Here's an article about graphitic carbon being turned magnetic:

http://focus.aps.org/story/v12/st20

Apparently, proton-irradiation can cause this.

This is offered, as is virtually every other obscure nanotube
development, as a potential cure for cancer. This drone of wolf-crying
"cure for cancer" will surely become counter-productive, if it isn't
already.

The cure for cancer begins with understanding cancer, not making tiny,
weak magnets. In that small particulates are nasty stuff to get in
your lungs, nanotubes are more likely to cause cancer than cure it.

John

erincss

Posted: Fri Nov 28, 2003 10:58 pm

Guest

Quote:

not making tiny,
weak magnets

At the same time, these nano magnets may be useful for materials science,
computers, and energy generation

John Larkin

Posted: Sat Nov 29, 2003 12:19 pm

Guest

On 29 Nov 2003 03:58:30 GMT, erincss@aol.com (erincss) wrote:

Quote:

not making tiny,
weak magnets

At the same time, these nano magnets may be useful for materials science,
computers, and energy generation

Tiny weak magnets? How? Got any proposed paths to such applications?

There have been literally thousands of nanotech discoveries that have
been announced with the stock tag line "may lead to breakthroughs in
supercomputing, energy production, and cures for disease." This has
become a ritual. If you follow up on these things a couple of years
later, their actual utility in these areas hovers around 0.00 per
cent. This leads me to suspect (horrors!) that most nanotech
discoveries are there for commercial hype, not for scientific advance.

It would be a lot better to announce phenomena without baseless sci-fi
projections of utility. Do you really think the guys who discovered
the nanotube magnets know anything about cancer?

Nanotech discredits itself daily with this silly ritual speculation.

John

John S. Novak, III

Posted: Sat Nov 29, 2003 11:46 pm

Guest

In article <bqakek01hk4@enews3.newsguy.com>, John Larkin wrote:

Quote:

At the same time, these nano magnets may be useful for materials science,
computers, and energy generation

Tiny weak magnets? How? Got any proposed paths to such applications?

There have been literally thousands of nanotech discoveries that have
been announced with the stock tag line "may lead to breakthroughs in
supercomputing, energy production, and cures for disease." This has
become a ritual. If you follow up on these things a couple of years
later, their actual utility in these areas hovers around 0.00 per
cent. This leads me to suspect (horrors!) that most nanotech
discoveries are there for commercial hype, not for scientific advance.

It certainly does seem that way at times, doesn't it?
It might be more appropriate to say, though, that basic research is
being hyped, rather than that basic research is being done just for
the hype.

It helps if you draw a broad line between popular science reporting,
which really does tend to be hype, and the serious peer-reviewed
scientific and engineering literature-- IEEE proceedings and other
journals, ACM publications, Science, Nature, etc.

The former is useful to me in fields where I'm a layman, to keep me
abreast of recent developments, and as pointers to the serious
literature. Then I can see if I can read the primary publications, or
it I have to go get a few books from the library (if it looks
interesting enough) or if it's just not likely to be worth the
investment.

The constant breathless excitement sure does wear thin after a while,
though, especially for those of us down in the trenches who know that
nothing is ever as easy as the science journalists make it seem.

--
John S. Novak, III jsn@cegt201.bradley.edu
The Humblest Man on the Net

erincss

Posted: Sun Nov 30, 2003 2:37 am

Guest

Quote:

John Larkin

This leads me to suspect (horrors!) that most nanotech
discoveries are there for commercial hype, not for scientific advance.

Take a look at this:
http://focus.aps.org/story/v8/st27

Do you consider these nearly magical (compared to inferior crap materials like
carbon steel and concrete and plastic) carbon-nitrogen buckyball/tubes to be
hype? Once these can be mass-assembled , they can make current materials used
for construction totally obsolete.

John Larkin

Posted: Sun Nov 30, 2003 4:30 pm

Guest

On 30 Nov 2003 07:37:16 GMT, erincss@aol.com (erincss) wrote:

Quote:

John Larkin

This leads me to suspect (horrors!) that most nanotech
discoveries are there for commercial hype, not for scientific advance.

Take a look at this:
http://focus.aps.org/story/v8/st27

Do you consider these nearly magical (compared to inferior crap materials like
carbon steel and concrete and plastic) carbon-nitrogen buckyball/tubes to be
hype? Once these can be mass-assembled , they can make current materials used
for construction totally obsolete.

Until somebody finds a practical use for them, I consider them
useless; that's logical, isn't it? As the article points out,
fullerenes are now into their second decade of hype.

To return to my theme, this article ends with the stock wild
speculations, including the incomprehensible claim of utility as
"semiconductors in flat-panel displays." At least nobody mentioned
curing cancer here.

Steel, concrete, and plastic "totally obsolete"? You can't be serious.
Will the next Hoover Dam be built a molecule at a time?

John

John Devereux

Posted: Mon Dec 01, 2003 12:29 pm

Guest

John Larkin <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> writes:

Quote:

On 30 Nov 2003 07:37:16 GMT, erincss@aol.com (erincss) wrote:

Take a look at this:
http://focus.aps.org/story/v8/st27

Do you consider these nearly magical (compared to inferior crap materials like
carbon steel and concrete and plastic) carbon-nitrogen buckyball/tubes to be
hype? Once these can be mass-assembled , they can make current materials used
for construction totally obsolete.

Until somebody finds a practical use for them, I consider them
useless; that's logical, isn't it? As the article points out,
fullerenes are now into their second decade of hype.

To return to my theme, this article ends with the stock wild
speculations, including the incomprehensible claim of utility as
"semiconductors in flat-panel displays." At least nobody mentioned
curing cancer here.

Hi John,

I think you are right about the excessive hype, although I don't think
this kind of thing is confined to nanotech. You also see the same kind
of thing with very many "popular science" articles about basic
research, even mathematics.

In this case, there is a way to view the "hype" as justified, in a
sense.

All these incremental "nanotech" advances may be small steps along the
pathway towards a "full blown" molecular nanotechnology. Which would
indeed be useful for "curing cancer".

Quote:

Steel, concrete, and plastic "totally obsolete"? You can't be serious.
Will the next Hoover Dam be built a molecule at a time?

No, because hydroelectric power will be obselete too, replaced by
cheap, efficient, ubiquitous, nanotech built solar cells ;)

--

John Devereux

John S. Novak, III

Posted: Mon Dec 01, 2003 12:32 pm

Guest

In article <bqc6nc028ap@enews4.newsguy.com>, erincss wrote:

Quote:

Well, this was addressed to John Larkin, not to me, but it's Usenet, so
I'll answer too.

As a practicing engineer, I draw a distinction between "cool," and
"useful." At best, this report falls in the "cool," category, and
looking through my eyes from John Larkin's position, it definitely
falls under the category of "hype."

The claims made for it right now are speculation. They may be
informed speculation, but they are speculation at best. I raise a
very jaundiced eye indeed at claims of buckyball type lubricants--
those claims were raised for the original buckyballs, and those
crashed and burned, because of a persistant misunderstanding of how
graphite lubricants actually lubricated. So sratch that one.

Semiconductors in flat panel displays? How? Why? Show me the
bandgap structure leading to this claim. Some buckyballs, under some
conditions, do have useful bandgap structures. Does this one? No
evidence is shown. Once it is shown (*if* it is shown) then the real
work begins-- how do you build even one useful semiconducting device
out of these materials? How do you build the thousands of thousands
in a regular array useful for information processing? Here's the
kicker-- how do you do so efficiently enough to make them competitive
with conventional technologies for anything, much less for display
screens? What distinguishes these from any other buckyballs or tubes?

That's asking a lot, I know, from an article in which the word
"bandgap" never even appears.

Non-metallic magnetic materials? That's a material characterization,
not a use or an application.

Let's go back a paragraph: Protective covering for medical implants.
Well, that's pretty speculative, given that the biocompatibility
results aren't even in, yet! A cynic is surprised they even mentioned
that detail. Protective coating for bearings? See above, on
nano-lubricants. Protective coatings for hard drives? Why? What is
the basis for this claim?

Now let's look at your claims: once we learn to mass-assemble it, it
will make *all current construction materials obsolete*! The
immediate engineering response to this is, "You gotta be kidding me."
These miraculous materials, not even built, are going to exceed every
current material for every possible design and every possible
constraint? A single material is going to do all that?

That, to put it mildly, is laughable. All the moreso without some
type of evidence, by someone qualified to make those judgements...
like an experienced mechanical or civil engineer with (at least)
a number of large successful designs and projects to his credit. Even
then, I'd still raise an eyebrow and wonder where his money was
invested.

All of which tends, in my opinion, to support John Larkin's point.
There's a lot of hype out there. There's hype in that article, and
you've amplified it in the process of trying to refute his position.
This is not helpful. If everything that gets reported by the media is
hype, people will disregard the media. If everything that gets
mentioned by one person is hype, people will disregard that person.
In both cases, it's for the same readon-- if the only thing that gets
reported is hype, then there's no actual information, any more, just
hype. The lack of discrimination becomes predictable, boring, and
above all, valueless.

(The same applies, of course, for the unrelenting cynic for whom no
claims are true.)

--
John S. Novak, III jsn@cegt201.bradley.edu
The Humblest Man on the Net

erincss

Posted: Mon Dec 01, 2003 2:11 pm

Guest

Quote:

John S. Novak, III)

Now let's look at your claims: once we learn to mass-assemble it, it
will make *all current construction materials obsolete*! The
immediate engineering response to this is, "You gotta be kidding me.

Well that is a good point, I have to agree. What I meant is that for most areas
where we use structural steel, nanotech-built carbon and other composite
materials could excel. Perhaps active structures would be even better. But see,
there have been some engineers on the usenet groups, who seem to believe that
bulk-smelted steel alloys will continue to be the main structural material used
by human civilization, and *that* was the claim I was speaking against.

John Larkin

Posted: Tue Dec 02, 2003 1:57 am

Guest

On 1 Dec 2003 17:29:38 GMT, John Devereux <jd1@devereux.me.uk> wrote:

Quote:

Steel, concrete, and plastic "totally obsolete"? You can't be serious.
Will the next Hoover Dam be built a molecule at a time?

No, because hydroelectric power will be obselete too, replaced by
cheap, efficient, ubiquitous, nanotech built solar cells Wink

Good point. We will all soon be living in nanotube-composite houses
made of buckyball solar cells on the outside and nanotech flat-panel
displays inside; presumably these houses will all be in the shape of a
geodesic dome, the 'home of the future' ca 1950.

John

Robert I. Eachus

Posted: Thu Dec 04, 2003 8:56 pm

Guest

erincss wrote:

Quote:

Well that is a good point, I have to agree. What I meant is that for most
areas
where we use structural steel, nanotech-built carbon and other composite
materials could excel. Perhaps active structures would be even better. But
see,
there have been some engineers on the usenet groups, who seem to believe that
bulk-smelted steel alloys will continue to be the main structural material
used
by human civilization, and *that* was the claim I was speaking against.

In the end, for most applications it all comes down to economics. Right
now a space elevator is arguably the one application where feasibility,
not cost, means that it can only be built out of some form of nanotech.

For building dams, given a choice between buckytube reinforced diamond
and steel rebar reinforced concrete, the choice will be based on cost.
Right now commercial buckytube manufacturing is in the kilograms per
year range, and the price matches. When buckytube threads in kilometer
lengths are available off the shelf, they may start to replace rebar,
and they will certainly be used in suspension bridges and other
construction. (Note that the buckytubes themselves don't need to be
kilometers long for cables spun out of them to be useful, just like the
wool and cotton threads used in clothing contain individual fibers that
average several centimeters long.) But buckytube fabric will start to
replace fiberglass well before then in building things like sailboats.
(Well I could argue that for some things like the America's Cup yachts,
carbon-carbon (graphite) has already replaced fiberglass...)

What has all this got to do with MNT or this newsgroup? Simple, the
driver for lowering costs for products that will possibly be made in the
future using some version of MNT are already here. Before buckytubes
will be used for a space elevator, they will be competitively priced for
suspension bridge use. Before that high-end yachts and other luxury
items--and even some non-luxury items like 'bulletproof' vests for
police and soldiers will take buckytube manufacture from milligrams, to
grams, kilograms, and eventually kilotons.

Or to put it simply, there already is a nanotech industry, and it is
very small at present. But it is growing and will continue to grow.

--
Robert I. Eachus

100% Ada, no bugs--the only way to create software.

Page 1 of 1 All times are GMT - 5 Hours The time now is Tue Oct 14, 2008 2:37 am Science Forum Index