h a l f b a k e r yRecalculations place it at 0.4999.
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Vacuum cleaners are simple devices, in spite of Mr Dyson's
attempts to over-complicate matters. They're basically a
tube feeding into a filtration system, with a high-volume
vacuum pump behind it. The only REAL innovation in that
time was to put the pump BEHIND the filter. Anyhow, you
can
witter on about cyclones all you want but motor
horsepower plays a big part.
Now, because the USA has an electrical grid based upon
the ravings of a disturbed gentleman, you can only squeeze
about 1600W out of a regular outlet. This gives dirt and
dust WAY too much choice in where it ends up.
Now, here in Philadelphia, we have a 240V 2 phase system
that's left over from Edwardian times or something, it
could feasibly supply enough power... but it's not very
widespread.
Now, here's the solution: Leave the vacuum cleaner
plugged in. This charges a nifty LiPo battery pack. The
battery powers one of those disturbingly powerful
electric ducted fans (EDF) so popular with the model
aircraft crowd. The EDF is fitted in series with a regular
vacuum cleaner motor, its actions are triggered by a
button on the handle to supply supplementary power.
Because vacuuming is rarely a continuous process, there's
often gaps of a few seconds to allow the dog to escape or
move a chair. No need for full power all the time.
EDFs are pretty low drag when they're not running so the
regular motor should operate just fine through a ~90mm
2000W EDF.
I consider this as a temporary stopgap until proper
electricity (415V 3 phase) is fitted for all domestic
appliances, including pencil sharpeners and nose hair
trimmers.
I'm not familiar enough with the band to know if that's the original singer...
http://thenotorious...01/ac_dc-640-80.jpg
ACDC [normzone, Oct 21 2013]
Neutron cross-section
http://en.wikipedia...utron_cross-section
Study carefully, you will be asked questions later. [8th of 7, Oct 22 2013]
[link]
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bah! they'll be even more of a maintenance
nightmare than the whole "bagless" debacle. Sure,
remove the bag and replace it with a clogable
pedal bin with cheap seals and about a million
filters. |
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The black hole solution will require all sorts of
messing about, you'll have to account for Hawking
radiation... how much mass it's gobbled recently,
nightmare. |
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They could, however solve the whole carbon-
capture problem quite well. |
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// I consider this as a temporary stopgap until proper electricity (415V 3 phase) is fitted for all domestic appliances, including pencil sharpeners and nose hair trimmers. // |
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If you run for President, we will vote for you. At last, a candidate with a realistic agenda ... forget healthcare, the deficit, jobs, defence - what's genuinely needed in the world is more 3-phase 415V distribution (100A per phase, minimum, and no penalties for running unbalanced). |
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More than enough - how do you stop it sucking all the air out of the room ? |
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Besides, small black hones are unstable, and evaporate quite quickly. |
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Good for dealing with cat fur, though. |
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//They could, however solve the whole carbon-
capture problem quite well.// |
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Now that has the makings of an idea. |
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Out of interest, how many orders of magnitude
are we away from creating a black hole - for
example, by the pressures at the centre of an
exploding fusion bomb? |
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//what's genuinely needed in the world is more 3-
phase 415V distribution (100A per phase, minimum,
and no penalties for running unbalanced)// |
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300 Amps will make electric car charging somewhat
simpler. In addition, a bathroom fan capable of
dealing with my brother's prodigious output will be
closer to reality - also a job for a black hole..... I hold
3 phase and black holes in equal regard actually. |
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//how many orders of magnitude are we away
from
creating a black hole - for example, by the
pressures
at the centre of an exploding fusion bomb?/// |
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I don't think we've even managed to achieve
neutron
degeneracy yet, so we've got a long way to go. I'll
admit I'm not sure what that means in numbers. |
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ETA: Meh, I lie. Apparently we've achieved or
approached Quark Degenerate matter in particle
accelerators, so we've only got Preon degenerate
matter (if it exists) and then singularity. I still
suspect it's many orders of magnitude. |
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There was a short story by Clarke (or was it Asimov?) with the premise of a portable consumer grade black hole device used for rubbish disposal. |
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//According to some mad german guy// |
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Not Dr Hans Zarkov, formerly of NASA by any chance? |
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Probably not, based on their track record
NASA prrefers to recruit Nazis rather than
Russians. |
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Nah, it's difficult to confuse those two, one's known
for their work in space, the other one designs
mattresses and relies on 60's Russian tech to supply
their 0-G washcloth experiments. |
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//We start noticing small holes in things and then
a hole in the ground and then earthquakes and
then it gets really bad. The counter argument to
that (a program [8th] also obviously watched, was
"nah, small black holes evaporate really quickly".// |
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David Brin examined it rather thoroughly in, I want
to say, "Earth", although I may be misremembering
the title. |
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The thing to realize is that even if we are wrong
about the evaporation rate of microscopic black
holes, it really doesn't matter. Any singularity
created in the LHC will have a mass of no more
than the particles collided, and probably
significantly less. It has no more gravitational
attraction than any other object that mass, and
the thus rate at which it could possibly suck up
additional particles is vanishingly slow. If black
holes don't evaporate at all, it would still be
centuries or millenia before an LHC produced black
hole produced visible holes in objects. |
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Consider, purely for the purposes of discussion, that a black hole of one proton mass and zero charge is created. |
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Let us also attribute non-zero translational momentum and zero rotational momentum (initially) to said black hole. |
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The black hole will therefore move freely through space, subject to Earth's gravity, much like a neutron. However, sooner or later it will come into range of another particle and swallow it. |
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Let us assume that this particle is another proton. The mass of the black hole will immediately double. It will be at the base of an extremely narrow but very deep gravity well. |
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Despite the fact that atoms are mostly empty space, the wandering hole will suck up everything that comes within range, and may gain electrostatic charge, adding to its ability to attract oppositely charged particles. |
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Now, what is the nuclear equivalent cross-section of a proton black hole <link> ? It is therefore necessary to consider both the mean free path of the object, and the probability of directly intersecting another particle. |
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In the near-vacuum of the LHC tube, there's nothing much for it to interact with, so like as not it will go scooting off into the chamber wall, where large heavy nucleii are more plentiful, and it will gobble them up. |
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So, based on a Schwarzschild radius appropriate to one proton mass, nil charge, a vacuum of 10E-9 mBar and a tube diameter of 100mm, calculate how long it will be before it All Goes Horribly Wrong. The extrapolation is relatively trivial and is therefore left as an exercise for the reader. |
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The Schwarzchild radius of a proton mass black
hole is 2.48x10^-54 m. |
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The ratio of nuclear to atomic radius is roughly
1x10-5. |
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The first thing I cannot determine, what is the
effect of a direct impact from a black hole on a sub
atomic particle, when said hole is many (~39)
orders of magnitude smaller than the particle in
question. Especially since the various forces
involved in holding the nucleus together are much
stronger than gravity. Thinking about this
logically, it seems that the result would be the
absorption of a very limited number of elementary
particles. |
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The second thing I cannot determine is what is
the probability of said yoctoyocto black hole
passing through an atomic nucleus without a
direct encounter. It seems to be fairly high, but I
can't find the math. |
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ETA- Since this is smaller than the planck length,
and the planck length relates to the expansion of a
black hole due to it's minimum possible absorption,
I am far from certain that such a black hole can
actually exist. I therefore bow to any advanced
theoretical physicists in the crowd. |
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Further ETA- No, it cannot. The smallest possible
mathematical description is apparently
approximately the Planck
mass (2.17651(13)×10^-8 kg), with sufficient
concentration of anything smaller than that being
impossible due to the compton wavelength of the
material in question. |
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//may gain electrostatic charge, adding to its ability
to attract oppositely charged particles.// |
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This ignores the fact that it would (typically) self
neutralize with the first such absorption, since we
are dealing with a scale where the electrostatic force
overwhelms the gravitational. This means that it will
repel like charges until such time as it has absorbed
just enough opposite charges to neutralize itself.. |
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ugh... now my head hurts. |
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// The first thing I cannot determine, what is the effect of a direct impact from a black hole on a sub atomic particle, when said hole is many (~39) orders of magnitude smaller than the particle in question. Especially since the various forces involved in holding the nucleus together are much stronger than gravity. Thinking about this logically, it seems that the result would be the absorption of a very limited number of elementary particles. // |
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Without translational energy of its own... wouldn't a smaller singularity then orbit the more massive particle until it could absorb enough matter to make the matter then orbit itself? etc. etc.? |
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The black hole won't have zero translational
energy, so it would most likely pass through. |
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Let's discuss a slightly larger scale for the
moment, because the whole planck length limit
means that the hole will be significantly more
massive than a proton, so that case doesn't
matter. |
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However, a planck mass black hole orbiting an
absurdly supermassive nucleus would not pull
subatomic particles out unless the tidal energy
could overcome the nuclear bonding equivalent of
the Roche limit. I don't know how close it would
have to orbit in order for that to happen, but it
would be extremely close. |
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There was an episode of the Simpsons the other
night where there was a black hole, used on the end
of a stick as a vacuum cleaner... The writers are
stealing our ideas! |
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