PHYSICS NEWS UPDATE -- Number 687 June 4, 2004 by Phillip F. Schewe, Ben Stein

While it is not economically feasible to store hydrogen as an
automobile fuel *now* I wouldn't rule it out even in the short-term.
Solid metallic hydrogen is close to being achieved:

Hydrogen metal on the horizon.
10 April 2002
"Scientists have long expected solid hydrogen to become a metal when
it is compressed, but so far electrical conductivity has only been
detected in liquid hydrogen. Now an experimental study of solid
hydrogen at pressures up to 320 GPa predicts that it will become
metallic at a pressure of 450 GPa - over four million times
atmospheric pressure. Ren LeToullec and co-workers at the CEA in
France also found that solid hydrogen becomes opaque - or 'black' -
under compression (P Loubeyre et al 2002 Nature 416 613)."
http://physicsweb.org/article/news/6/4/6

For this to be useful as a storage means, the hydrogen has to be
stable at "reasonable" temperatures. A recent study shows solid
nitrogen can be stable up to 100K:

Novel nitrogen is a semiconductor.
9 May 2001
"A new form of nitrogen that behaves as a semiconductor could be a
future source of energy, according to Russell Hemley and colleagues of
the Carnegie Institution of Washington in the US. The group compressed
nitrogen gas to create the 'non-molecular' nitrogen - an opaque solid
that releases a flood of energy when it reverts to its well-known
diatomic form (M Eremets et al 2001 Nature 411 170).
"The team then reduced the pressure on different samples at a variety
of temperatures. Remarkably, they found that the semiconducting state
persisted at normal atmospheric pressure at temperatures below 100 K.
A pronounced hysteresis effect arises because the change in phase lags
behind the change in pressure."
http://physicsweb.org/article/news/05/5/5

There are conflicting theoretical studies about whether metallic
hydrogen would retain its solid form and electronic properties when
the pressure was released. This study on nitrogen suggests that it
could.


Bob Clark

Uncle Al wrote in message ...
Sam Wormley wrote:

PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 687 June 4, 2004 by Phillip F. Schewe, Ben Stein
[snip]

while on Earth hydrogen might also play an important role as
fuel since it has the highest chemical energy density by mass.
(Tejeda et al., Physical Review Letters, 4 June 2004).

Buncha crap. There is no economic way to store elemental hydrogen at
more than about 40% the energy density (enthalpy of combustion/volume)
of gasoline - high pressure, cryogenic, chemisorbed in HYSTOR alloy,
adsorbed in porous solids or nanotubes. All crap. The absolute
densest volumetric storage of hydrogen is lithium hydride, which is
enormously hazardous and toxic as well as being expensive and an
expensive bitch to recycle. There *is* one singular case of
inexpensive, stable, relatively dense hydrogen storage - hydrocarbon
fuels.

Thermodynamics cannot be cheated within a heat engine. The
H*Y*D*R*O*G*E*N car is even more stooopid than the E*L*E*C*T*R*I*C car
- which itself was so monumentally stooopid that it didn't outlast
government subsidies by even a month.

[snip]

"Robert Clark" wrote in message
om...
While it is not economically feasible to store hydrogen as an
automobile fuel *now* I wouldn't rule it out even in the short-term.
Solid metallic hydrogen is close to being achieved:

Hydrogen metal on the horizon.
10 April 2002
"Scientists have long expected solid hydrogen to become a metal when
it is compressed, but so far electrical conductivity has only been
detected in liquid hydrogen. Now an experimental study of solid
hydrogen at pressures up to 320 GPa predicts that it will become
metallic at a pressure of 450 GPa


These are done in diamond anvil cells. Total volume is about 1 mm^3.

Don't be stupid.

"Michael Varney" wrote in message ...

"Robert Clark" wrote in message
om...
While it is not economically feasible to store hydrogen as an
automobile fuel *now* I wouldn't rule it out even in the short-term.
Solid metallic hydrogen is close to being achieved:

Hydrogen metal on the horizon.
10 April 2002
"Scientists have long expected solid hydrogen to become a metal when
it is compressed, but so far electrical conductivity has only been
detected in liquid hydrogen. Now an experimental study of solid
hydrogen at pressures up to 320 GPa predicts that it will become
metallic at a pressure of 450 GPa


These are done in diamond anvil cells. Total volume is about 1 mm^3.

Don't be stupid.




*Now*


Bob Clark

Robert Clark wrote:

While it is not economically feasible to store hydrogen as an
automobile fuel *now* I wouldn't rule it out even in the short-term.
Solid metallic hydrogen is close to being achieved:

Hydrogen metal on the horizon.
10 April 2002
"Scientists have long expected solid hydrogen to become a metal when
it is compressed, but so far electrical conductivity has only been
detected in liquid hydrogen. Now an experimental study of solid
hydrogen at pressures up to 320 GPa predicts that it will become
metallic at a pressure of 450 GPa - over four million times
atmospheric pressure. Ren LeToullec and co-workers at the CEA in
France also found that solid hydrogen becomes opaque - or 'black' -
under compression (P Loubeyre et al 2002 Nature 416 613)."
http://physicsweb.org/article/news/6/4/6

For this to be useful as a storage means, the hydrogen has to be
stable at "reasonable" temperatures. A recent study shows solid
nitrogen can be stable up to 100K:

Novel nitrogen is a semiconductor.
9 May 2001
"A new form of nitrogen that behaves as a semiconductor could be a
future source of energy, according to Russell Hemley and colleagues of
the Carnegie Institution of Washington in the US. The group compressed
nitrogen gas to create the 'non-molecular' nitrogen - an opaque solid
that releases a flood of energy when it reverts to its well-known
diatomic form (M Eremets et al 2001 Nature 411 170).
"The team then reduced the pressure on different samples at a variety
of temperatures. Remarkably, they found that the semiconducting state
persisted at normal atmospheric pressure at temperatures below 100 K.
A pronounced hysteresis effect arises because the change in phase lags
behind the change in pressure."
http://physicsweb.org/article/news/05/5/5

There are conflicting theoretical studies about whether metallic
hydrogen would retain its solid form and electronic properties when
the pressure was released. This study on nitrogen suggests that it
could.

Hey git - ignoring for a moment the intrinsic scientific obscenity of
your spew, do you plan to run a million trillion diamond anvil presses
24/7 to manufacture automobile fuel? HA HA HA' What fuels the
fuel-makers?

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!

Michael Varney wrote:

Show us the math...

http://www.islandone.org/LEOBiblio/SPBI120.HTM

Beanstalk is usually called skyhook. A short
version of the skyhook is called orbital elevator:
http://www.islandone.org/LEOBiblio/SPBI126.HTM

Skyhook has one advantage: its cargo does not
experience higher acceleration than the one
produced by the Earth's gravity (g). In every
other respect the skyhook is inferior to orbital
slings:
http://www.islandone.org/LEOBiblio/SPBI1SL.HTM
http://www.islandone.org/LEOBiblio/SPBI122.HTM

The orbital slings are smaller, cheaper, more
immune to terrorism and meteoroids, and able
to launch cargo far beyond the Earth. They will
be placed in low Earth orbit where ionospheric
conductivity is high enough for electrodynamic
tethers, and far below the damaging radiation
produced by the Van Allen belts.

PS. Do not crosspost to more than 3 newsgroups.

Andrew Nowicki wrote in message ...
[...]
http://www.islandone.org/LEOBiblio/SPBI122.HTM

The orbital slings are smaller, cheaper, more
immune to terrorism and meteoroids, and able
to launch cargo far beyond the Earth. They will
be placed in low Earth orbit where ionospheric
conductivity is high enough for electrodynamic
tethers, and far below the damaging radiation
produced by the Van Allen belts.

But at the above URL in the ROTOVATOR section you say:

High-strength plastic cannot be used because it is vulnerable
to space radiation and thermal fatigue.

Are you saying a rotovator that touches Earth's surface has to extend
into the Van Allen belts? (not arguing just was not clear)

And also at:
http://www.islandone.org/LEOBiblio/SPBI1SL.HTM
when talking about slings you say:

Although plastics are damaged by radiation and temperature extremes
of the outer space, they can be shielded by a pile of dust or rubble.

So here does "outer space" mean without the protection that low
Earth orbit gets? Do you think radiation levels at GEO or
orbiting the moon would not let spectra-2000 tethers last for years?

-- Vince

The orbital slings are smaller, cheaper, more
immune to terrorism and meteoroids, and able
to launch cargo far beyond the Earth.

You can do that with a space elevator too... it doesn't just stop at
geostationary orbit; you need a "counterweight" on the other end (such
as an asteroid). That counterweight will be out farther than the
geostationary point. Put it far enough, and you'll be above escape
velocity.

"Andrew Nowicki" wrote in message
...
Michael Varney wrote:

Show us the math...

http://www.islandone.org/LEOBiblio/SPBI120.HTM


I did not say regurgitate a web link.

Beanstalk is usually called skyhook. A short
version of the skyhook is called orbital elevator:
http://www.islandone.org/LEOBiblio/SPBI126.HTM

Skyhook has one advantage: its cargo does not
experience higher acceleration than the one
produced by the Earth's gravity (g). In every
other respect the skyhook is inferior to orbital
slings:
http://www.islandone.org/LEOBiblio/SPBI1SL.HTM
http://www.islandone.org/LEOBiblio/SPBI122.HTM

The orbital slings are smaller, cheaper, more
immune to terrorism and meteoroids, and able
to launch cargo far beyond the Earth. They will
be placed in low Earth orbit where ionospheric
conductivity is high enough for electrodynamic
tethers, and far below the damaging radiation
produced by the Van Allen belts.

PS. Do not crosspost to more than 3 newsgroups.

Blow me.

Bob Martin wrote:

The orbital slings are smaller, cheaper, more
immune to terrorism and meteoroids, and able
to launch cargo far beyond the Earth.

You can do that with a space elevator too... it doesn't just stop at
geostationary orbit; you need a "counterweight" on the other end (such
as an asteroid). That counterweight will be out farther than the
geostationary point. Put it far enough, and you'll be above escape
velocity.

Yes, you can, but space elevators are longer than
slings which accelerate cargo by the same velocity
increment. The minimum length of the sling is
determined by the maximum acceleration that the
cargo can withstand. The acceleration equals
V*V/R where V is tip velocity and R is sling's
length. If you do not transport people, the
sling does not have to be longer than 100 km.

Vincent Cate wrote:

High-strength plastic cannot be used because it is vulnerable
to space radiation and thermal fatigue.

Are you saying a rotovator that touches Earth's surface has to extend
into the Van Allen belts? (not arguing just was not clear)

No, it does not, but the skyhook by definition extends into
the Van Allen belts.

And also at:
http://www.islandone.org/LEOBiblio/SPBI1SL.HTM
when talking about slings you say:

Although plastics are damaged by radiation and temperature extremes
of the outer space, they can be shielded by a pile of dust or rubble.

So here does "outer space" mean without the protection that low
Earth orbit gets? Do you think radiation levels at GEO or
orbiting the moon would not let spectra-2000 tethers last for years?

These are the most important space tether issues that have not been
answered yet. There is no doubt that deep space radiation is much
less intense below the Van Allen belts than inside the belts or above
the belts. Plastic parts of old solar panels are often warped, and
aluminized Mylar balloon named Echo has crumbled. I guess that high
temperature does more damage to plastics than space radiation.
Fortunately, the temperature can be reduced by shading the tether.
I hope that shaded plastic tether in low Earth orbit can survive long
enough to do useful work.