h a l f b a k e r yViva los semi-panaderos!
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JK Rowling is getting to me n I haven't yet read any of
her books
this is a multicolorable haze that glows like quantum
dots yet can be blended or divided plus goes upward
It looks like wizardy as well as making a nifty interface
to Mistrys gestural computing activity
I figured out that
the teeniest carbon container that
could have a volume of vacuum or hydrogen sufficient to
float was kind of near .000001 cm on a side; putting
quantum dots on the side plus making it an electret gives
a person a haze that can be directed (electret) around
plus floats
Making the quantum dots out of tin Se or TiSn makes
them absent toxicity yet glow like quantum dots
How big is the air...
http://www.getnitrogen.org/pdf/graham.pdf
Something about the size of nitrogen [madness, Feb 02 2011]
[link]
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What is a quantum dot, O leguminous one? |
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Buchanan Translation Services at your service again. |
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First, you make hollow carbon "nano-shells", the inside of
which is a vacuum. Beany's calculations suggest that such
a shell, 1nm (one millionth of a millimetre) across will be
able to float. |
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Then, you attach quantum dots to them. Quantum dots
are basically small clusters of semiconducting material, a
few tens of atoms across. Such clusters fluoresce at a
wavelength which is determined by the size of the cluster;
they're used as very efficient fluorescent tags in various
applications. |
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You also put a permanent static charge on the whole
structure. |
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This gives you a sort of "fog" of floating, fluorescent
particles which you could move around with an electric
field. |
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PROBLEMS:
(a) I very much doubt that a 1nm "shell" of carbon,
containing a vacuum, will be less dense than air. |
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(b) Quantum dots tend to be big (say, a few nanometres
across) and heavy. It'll be like attaching medicine balls to
a toy helium balloon. |
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why not just use dry ice and a spotlight? |
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Ah thankyou [MB], I never knew that. They sounded vaguely implausible. |
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One more thing. A rough calculation suggests that air has
on the order of one gas molecule (N2 or O2) in every cubic
nanometer. |
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Therefore, even if a 1nm carbon "shell" traps a perfect
vacuum (which I guess it would), it's not going to displace
nearly enough air to be bouyant, let alone lift a cargo of
qdots. |
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On the other hand, bouyancy probably doesn't make much
sense at these scales, where Brownian motion will
dominate. My guess is that you'd be as well off just
spraying quantum dots into the air. At a few nanometres
across, they'll drift around for a lot longer than, say, a mist
of water droplets would. |
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If they are, as you say, //used ... in various applications// then how come none of the users have tried spraying them into the air when their superviser's back has been turned? |
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Probably because they are embarrasingly expensive (qdots,
that is, not supervisors). They are pretty bright as
fluorophores go, but they're not orders of magnitude brighter
than other more conventional (=cheaper) fluorophores. |
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The main reason they're of interest is that they don't
photobleach (ie, burn out, as conventional fluorescent dyes
can do under intence illumination), and they have narrow
and tuneable emission spectra combined with broad
excitation wavelengths. |
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// Just add sentience and you've got a John Carpenter film // |
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Alternatively, just remove sentience and you've got a
Paul Verhoeven film. |
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Oh holy carp [beanangel]'s still around. I thought she'd gone the way of the Time Cube guy! |
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Hey, this was coherent for a beanangel idea. |
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There's the problem that there is some evidence
that carbon nano-structures may be toxic in a
manner similar to asbestos (research on-going last
I'd heard.
Also, I suspect constructing consistently vacant
carbon nano-structures is still some distance in
the future, as is placing nano-dots consistently on
anything other than an atomically smooth
substrate. |
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Hmmm I have wondered how small a shell will float in the atmosphere... |
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Apparently air molecules are about one-ten-billionth of a meter. |
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The carbon shell need not be complete --- a closed wire mesh will work so long as the voids are about the size of the air molecules. |
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As the shell becomes smaller the ratio of the contained radius and shell wall decreases --- which is bad. The reverse is also true which means that bigger balloons have more lift. |
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//consistently vacant// Consistency wouldn't be a problem --
you could construct a mixture of vacant and nonvacant, then
sort by density (centrifuge, or mass spectrometry, or
something) no? |
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