Below is the missing webpage of the MPI cited in the comment below:
bboyer wrote:Posted: Thu Aug 02, 2007 10:51 am Post subject: ELECTRICITY involved in the formation of planets?
OP "davesmith_au"
Giday all.
After following the links from lite-brite's post here: <old forum link no longer valid> to the Max Planck Institute for Extraterrestrial Physics;
http://www.mpe.mpg.de/pke/PKE/Results1_e.html I kept reading the article and came across one of the experiments with plasma being carried out on the International Space Station:
coagulation_sm.jpg
During this experiment the plasma is turned off. Within a fraction of a second after the injection some 100,000 particles get together to form a big agglomerate (big blob in the center, magnified in the right image [below]) together with many smaller clusters (with totally the same mass as the big one). This result indicates a "run-away process". Further investigations showed that the clusters were charged, positively or negatively.
http://1drv.ms/1oEdmdR
DustyPlasmacoagulationcloseupBE22Ca.gif
th_DustyPlasmaoscillations.gif
http://1drv.ms/1kXcMgu .
http://1drv.ms/1kXcYwu
(original caption)
Superposition of several video frames. You can clearly see the oscillations of
single particles, which means that they carry an electric charge...
Due to this experiment we might soon understand what happens in the early phase of planetary formation in a protoplanetary disk and how from microscopic particles finally planets like the Earth form - with the help of electrical charging.
I think Science Apologist and a few of his mates are going to soon have to re-think their notion of "There is electricity in space, but it doesn't do anything..."
Thoughts, anyone?
Cheers, Dave Smith.
_________________
PlasmaResources.com
"If you are not prepared to think outside the square, you will always be confined within it..." Dave Smith.
-the link for the Max Planck Institute above is dead/broken. Here is what that page looked like in 2005:
PKE Nefedov
More Results (1)
Koagulation Koagulation
Coagulation Experiment
The following movies show a charge enhanced coagulation process as it has been observed during an experiment of PKE Nefedov on board the International Space Station.
Download MPEG movie: low quality (3.5 MB), high quality (11.5 MB).
During this experiment the plasma is turned off. Within a fraction of a second after the injection some 100,000 particles get together to form an agglomerate (big blob in the center, magnified in the right image). We assume that a charge enhanced enlargement of the particles' cross section leads to this run-away growth ('gelation').
http://1drv.ms/1oEdmdRhttp://1drv.ms/1oEdmdR
Oscillating particles Phase-shifts
http://1drv.ms/1r5H8Qo
Superposition of several video frames. You can clearly see the oscillations of
single particles, which means that they carry an electric charge (left). A
comparision of the oscillation phases shows that there exists nearly the
same number of positive and negative charges (right).
Due to this experiment we might soon understand what happens in the early phase of planetary formation in a protoplanetary disk and how from microscopic particles finally planets like the Earth form - with the help of electrical charging.
Further experiments on coagulation are planned.
De-charging of particles
In the "decharging experiment" the rest charge on the microparticles was measured after the plasma was switched off. To measure this, the particles were exposed to a sinusoidally varying electric field (at low frequencies around 0.5 Hz) and - if they remain charged - one can simply determine the charge from the oscillation amplitude shown in the figures below.
http://1drv.ms/1r5H8Qo .
http://1drv.ms/1kwSrhI
Vertical position Oscillation amplitude
Figure a) shows the particle motion upwards separately for particles
in the periphery and the centre. The time when the plasma is switched
off is shown in the graph. Subtracting the thermophoretic from the
oscillatory motion we receive the oscillation amplitude in b).
On Earth such a measurement is practically impossible - the particles fall down too quickly and charge measurements are consequently very difficult to perform. This decharging experiment showed that the particles are not totally discharged after the plasma is turned off. They retain a "frozen" charge after the plasma electrons and ions have disappeared. This is a new insight from complex plasma physics and might be important for many other processes, including industrial applications.
Publication: A. Ivlev, M. Kretschmer, M. Zuzic, et al., Phys. Rev. Letters Vol.90 No.5, Feb. 2003
Updated: 2004-11-11
Contact: Michael Kretschmer mail
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