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Beezwax
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Can somebody explain why this happens? Capacitor discharge through a piece of foil shatters a ceramic tile
https://www.youtube.com/watch?v=L95sbD4cBg4
The explanation in the comment section is that the water-aluminum reaction increases the power output by several times.
Now I'm familiar with the interaction between hydrogen and aluminum for things like energetic materials, but this usually involves h2o2 rather than
plain old tap water.
What really amazes me is that so much force is generated by an extremely low density piece of foil, with a relatively large surface area, submerged in
several ml of water.
So what is really happening here at the atomic and chemical levels?
1.) I would also like to know if this reaction would have been different if the water had contained aluminum with a lower surface area, but greater
suspension, such as aluminum nanoparticles.
2.) What if the weight-ratio of water to aluminum has been reversed: for example, imagine if something like this object here was made of aluminum and
each "square" was hollow, and injected with h2o2:
https://m.media-amazon.com/images/W/IMAGERENDERING_521856-T1...
If an electrical current was discharged in to it, would you get a stronger or lesser effect?
[Edited on 4-5-2023 by Beezwax]
[Edited on 4-5-2023 by Beezwax]
[Edited on 4-5-2023 by Beezwax]
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Metallophile
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I kind of doubt that the aluminum and water reacted chemically. The water was just there to transmit the shockwave into the tile, from the exploding
aluminum strip. All the explosive energy came from the electric charge.
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Beezwax
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Quote: Originally posted by Metallophile  | I kind of doubt that the aluminum and water reacted chemically. The water was just there to transmit the shockwave into the tile, from the exploding
aluminum strip. All the explosive energy came from the electric charge.
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Don't you think that the extreme heat and electrical charge could generate both hydrogen and oxygen atoms?
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
http://www.sciencemadness.org/whisper/viewthread.php?tid=321...
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Admagistr
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Don't you think that the extreme heat and electrical charge could generate both hydrogen and oxygen atoms?
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
http://www.sciencemadness.org/whisper/viewthread.php?tid=3214[/rquote]
Certainly, for the decomposition of water in its elements, a temperature of over 2000 C is sufficient and sparks electrical discharges have a
temperature of over 10 000 C.
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Metallophile
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| Quote: Originally posted by Beezwax |
Don't you think that the extreme heat and electrical charge could generate both hydrogen and oxygen atoms?
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Maybe, but I don't think it would add any net energy to the blast. Whatever energy is gained from detonating H2 and O2 would have first been absorbed
in splitting the H2O. My hunch is there wasn't enough time for this to even happen.
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Beezwax
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Thanks very much for your comment ^_^
According some guy on Wikipedia even just 3000 celsius is sufficient for a significant water decomposition
https://en.wikipedia.org/wiki/Water_splitting#Thermal_decomp...
"At the very high temperature of 3000 °C more than half of the water molecules are decomposed, but at ambient temperatures only one molecule in 100
trillion dissociates by the effect of heat.[15]"
In my opinion if the individual had used less water they would have gotten better power, since it is unlikely that 30ml of confined water can be
decomposed by a spark. A water cloud, on other hand...
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Beezwax
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| Quote: Originally posted by Metallophile | | Quote: Originally posted by Beezwax |
Don't you think that the extreme heat and electrical charge could generate both hydrogen and oxygen atoms?
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Maybe, but I don't think it would add any net energy to the blast. Whatever energy is gained from detonating H2 and O2 would have first been absorbed
in splitting the H2O. My hunch is there wasn't enough time for this to even happen.
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Consider this: when the capacitor is discharged it should be converting the oxygen in the water near the aluminum in to positively charged oxygen. So
we're not just talking about splitting regular water; the hydrogen bonds are weakened. I also think that this will produce oxygen free radicals and
ionic separation. I'm pretty sure the addition of an electrolyte would have greatly enhanced this effect.
[Edited on 4-5-2023 by Beezwax]
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Beezwax
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Pages 180-181 talk about the timescales of free radical production (and OH2) in these kinds of explosions
https://sci-hub.se/https://www.jstor.org/stable/98998
[Edited on 4-5-2023 by Beezwax]
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unionised
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The likely explanation is simply the shockwave caused by the boiling of the foil.
But the reaction between water and aluminium (as vapours) will also generate heat and contribute to the net energy available to cause damage.
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charley1957
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Go to capturedlightning.com to see what’s happening to the foil. On that website they use a copper coil to shrink quarters with a high powered pulse
discharge and the copper coil often disintegrates violently such that it has to be enclosed in a heavy steel enclosure. Believe me, there’s a LOT of
power available in a pulse discharge, so it’s no wonder the tile is shattered in your video, and it has absolutely nothing to do with dissociation
of water.
You can’t claim you drank all day if you didn’t start early in the morning.
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Beezwax
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| Quote: Originally posted by charley1957 | | Go to capturedlightning.com to see what’s happening to the foil. On that website they use a copper coil to shrink quarters with a high powered pulse
discharge and the copper coil often disintegrates violently such that it has to be enclosed in a heavy steel enclosure. Believe me, there’s a LOT of
power available in a pulse discharge, so it’s no wonder the tile is shattered in your video, and it has absolutely nothing to do with dissociation
of water. |
You're saying that a virtually massless spark was able to shatter a thick glass bottom and a ceramic tile; both of which are extremely effective
insulators, with enornous compression strength. That's unlikely.
Seems more likely to me that we are dealing with a hitherto unexplained phenomenon whereby an electric charge makes atomic particles unstable and
explosive. In this case, hydrogen and oxygen molecules are probably being separated, charged, and absorbed by aluminum and plasma, generating a kind
of ionic explosion.
https://www.pnas.org/doi/10.1073/pnas.2207858119
[B]In this work, we show that when sessile droplets of the newly discovered ferroelectric nematic fluid phase are deposited on a ferroelectric solid
substrate, they can become suddenly unstable and disintegrate though the emission of fluid jets. The instability is due to the coupling between the
polarizations of the liquid and solid materials, which induces the accumulation of polarization charges on the droplet–air interface and thus, the
buildup of a repulsion pressure that eventually overcomes the surface tension. This kind of polarization-induced Rayleigh instability crucially
depends on the unique combination of polarization and fluidity of the ferroelectric nematic and might provide the basis for electrohydromechanical
applications.
Abstract
We investigated the electrostatic behavior of ferroelectric liquid droplets exposed to the pyroelectric field of a lithium niobate ferroelectric
crystal substrate. The ferroelectric liquid is a nematic liquid crystal, in which almost complete polar ordering of the molecular dipoles generates an
internal macroscopic polarization locally collinear to the mean molecular long axis. Upon entering the ferroelectric phase by reducing the temperature
from the nematic phase, the liquid crystal droplets become electromechanically unstable and disintegrate by the explosive emission of fluid jets.
These jets are mostly interfacial, spreading out on the substrate surface, and exhibit fractal branching out into smaller streams to eventually
disrupt, forming secondary droplets. We understand this behavior as a manifestation of the Rayleigh instability of electrically charged fluid
droplets, expected when the electrostatic repulsion exceeds the surface tension of the fluid. In this case, the charges are due to the bulk
polarization of the ferroelectric fluid, which couples to the pyroelectric polarization of the underlying lithium niobate substrate through its
fringing field and solid–fluid interface coupling. Since the ejection of fluid does not neutralize the droplet surfaces, they can undergo multiple
explosive events as the temperature decreases.
[Edited on 4-7-2023 by Beezwax]
[Edited on 4-7-2023 by Beezwax]
[Edited on 4-7-2023 by Beezwax]
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Beezwax
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One argument against this being the result of a spark or mere boiling water is that this appears to have had a direct impact on a point, as
conventional primary explosives do, rather than an area. It's very clear that most of the energy was sent directly downard in to the tile, rather than
against the thin walls of the glass as we would expect from boiling water or the spark.
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Sir_Gawain
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When the aluminium strip is vaporized it expands thousands of times in an incredibly small amount of time. When I was testing my EBW setup I
discharged it through a copper wire in a beaker of mineral oil. The mineral oil was ejected violently from the beaker. My capacitor bank is 50 times
smaller so it didn't break the beaker.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
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Beezwax
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| Quote: Originally posted by Sir_Gawain | | When the aluminium strip is vaporized it expands thousands of times in an incredibly small amount of time. When I was testing my EBW setup I
discharged it through a copper wire in a beaker of mineral oil. The mineral oil was ejected violently from the beaker. My capacitor bank is 50 times
smaller so it didn't break the beaker. |
We all know these things have enormous energy; threy are used as detonation devices. But they simply don't have enough mass to shatter glass bottoms
and ceramic tiles or beakers imo. There's just no way a strip of aluminum was going to shatter such dense objects on speed alone; it needs more mass
to transfer energy to what was beneath it. The reason your beaker didn't break might be because you used mineral oil which lacks oxygen and contains
anti-oxidants.
If there was a primary out there that could weigh as much as that strip of aluminum and cause this level of damage, people would believe it is
impossible. Why is the strip of aluminum any different? Seems much more likely to me that this energy is coming from the water itself. Water molecules
are being charged, separated and detonated here. Imagine if there was an electrolyte like aluminum nanoparticles suspended in the water; you could
have gotten even more oxygen and hydrogen to detonate.
[Edited on 4-7-2023 by Beezwax]
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Sir_Gawain
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While the water/aluminium plasma effect you're talking about does exist (see Sam Barros' Powerlabs' Electrothermal Gun), in this case it is not the major factor. When the aluminium strip explodes, the plasma fireball occupies space the water did
previously. The extremely fast moving water slams into the plate and smashes it. This is due to the hydraulic property of water.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
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unionised
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| Quote: Originally posted by Beezwax |
But they simply don't have enough mass to shatter glass bottoms and ceramic tiles or beakers imo.
[Edited on 4-7-2023 by Beezwax] |
Reality shows that your opinion is wrong.
The glass of water clearly does have enough mass to shatter things.
(And the glass, propelled by the water, has enough energy to shatter the tile.
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Rainwater
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Many important details are missing from this experiment to properly prove what is observed. Tho assumptions could be made with accuracy.
The following would be nessacery for proper calculations.
Length, width, thickness, alloy composition of the aluminum or total resistance
Capacitance value - 50uF
Length, composition of test leads
Switch closed resistance
Switch off-on delay
Initial voltage - 6kV
Final voltage
Water temperature
Water volume 30mL
So 50uF charged to 6kV = about .36 coulombs
That is a lot of energy.
Assuming leads and foil have a total resistance of .1 ohms and the switch is ideal
A 90% discharge will produce an initial current of over 60000amps
Given aluminums thermal coffecent being +0.0429 and completely guessing at the size and shape, thats over a 10000c temperature rise in a period of
2.5uS
All that is just idealistic theory,
I doubt that the discharge would procede that far with the conductive path intact. Most likely would be the explosive expansion of the foil do to
thermal stress then the production of plasma arcs.
Knowing the final discharge voltage and inital resistance a timeline could be formed showing when the conductive path altered
[Edited on 7-4-2023 by Rainwater]
"You can't do that" - challenge accepted
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Beezwax
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| Quote: Originally posted by unionised | | Quote: Originally posted by Beezwax |
But they simply don't have enough mass to shatter glass bottoms and ceramic tiles or beakers imo.
[Edited on 4-7-2023 by Beezwax] |
Reality shows that your opinion is wrong.
The glass of water clearly does have enough mass to shatter things.
(And the glass, propelled by the water, has enough energy to shatter the tile. |
Keyword: water.
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Beezwax
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| Quote: Originally posted by Rainwater | Many important details are missing from this experiment to properly prove what is observed. Tho assumptions could be made with accuracy.
The following would be nessacery for proper calculations.
Length, width, thickness, alloy composition of the aluminum or total resistance
Capacitance value - 50uF
Length, composition of test leads
Switch closed resistance
Switch off-on delay
Initial voltage - 6kV
Final voltage
Water temperature
Water volume 30mL
So 50uF charged to 6kV = about .36 coulombs
That is a lot of energy.
Assuming leads and foil have a total resistance of .1 ohms and the switch is ideal
A 90% discharge will produce an initial current of over 60000amps
Given aluminums thermal coffecent being +0.0429 and completely guessing at the size and shape, thats over a 10000c temperature rise in a period of
2.5uS
All that is just idealistic theory, |
Compression strength ceramic tile : 20,000 psi
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Rainwater
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Drop it on its corner. Compresive strength is given under a very specific situation. It is mitigated by the malibulity or ductile strength of the
material. It also only applies to sub harmonics stress propagation speeds. If the shock wave excedes the speed of sound through the material, a
standing wave forms creating multiple high and low pressure points.
Besides, tiles are easy to break.
Chemical reactions are taking place but are a result of the extream temperature and pressure. At least while a conductive path exist through the
metal. Once that path is broken, electrolysis can occure
"You can't do that" - challenge accepted
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Texium
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@Beezwax: in the title of this thread you ask for an explanation of this phenomenon. However, it seems you are unsatisfied with the explanations
everyone is providing, and in fact already had your mind made up. If you are going to keep disagreeing with everything that doesn’t support your
foregone conclusion, you’re going to need to present some more substantial evidence to support your position. Otherwise I’m going to have to close
this thread.
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charley1957
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Beeswax, I see you didn’t bother to check out the link and find out what’s going on. You’d see that they are using a capacitor discharge through
copper coils to actually shrink coins down to almost half their original size. There’s a complete explanation of the physics involved and the forces
generated to do this. It’s not exactly the same, as they were using copper coils and not a strip of foil, but the process is basically the same and
the forces generated are tremendous. And not a drop of water in sight.
[Edited on Apr04-7-2023 by charley1957]
You can’t claim you drank all day if you didn’t start early in the morning.
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Beezwax
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| Quote: Originally posted by charley1957 | Beeswax, I see you didn’t bother to check out the link and find out what’s going on. You’d see that they are using a capacitor discharge through
copper coils to actually shrink coins down to almost half their original size. There’s a complete explanation of the physics involved and the forces
generated to do this. It’s not exactly the same, as they were using copper coils and not a strip of foil, but the process is basically the same and
the forces generated are tremendous. And not a drop of water in sight.
[Edited on Apr04-7-2023 by charley1957] |
The ballistic forces are not tremendous at all; the "steel enclosure" you speak of was two 0.25inch thick plates of stamped steel with two pieces of
particleboard that could have been penetrated by a 22 bb gun. It's intended to prevent sparks from hitting people and in no way contained any
significant pressure.
https://www.youtube.com/watch?v=U6mMWTsg56w
[Edited on 4-7-2023 by Beezwax]
[Edited on 4-7-2023 by Beezwax]
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Beezwax
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| Quote: Originally posted by Texium | | @Beezwax: in the title of this thread you ask for an explanation of this phenomenon. However, it seems you are unsatisfied with the explanations
everyone is providing, and in fact already had your mind made up. If you are going to keep disagreeing with everything that doesn’t support your
foregone conclusion, you’re going to need to present some more substantial evidence to support your position. Otherwise I’m going to have to close
this thread. |
Why? Everbody is giving a different answer and I have provided the only sources in the thread, which haven't even been discussed.
Summary of responses so far:
Metallophile & Charlie1957: It has nothing to do with dissociation of water, everything to do with spark, no way water and aluminum reaction
contributed net energy to explosion
Unionised & SirGawain: it is due to the hydraulic effect from water, consumption of oxygen from water plays some role, heat from aluminim +,water
reaction did contribute net energy to explosion
This is clearly an unsettled matter that ought to be discussed rather than shut down...
[Edited on 4-7-2023 by Beezwax]
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unionised
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To a good approximation, nothing ever fails in compression.
What's the tensile strength?
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