EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: EEVblog on January 30, 2015, 12:06:54 pm
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This is the coolest thing I've seen in a long time, not the actual footage etc, but the fact that a science Youtuber (albeit a well respected research scientist) can change our understanding of a field. And it all started with playing around with sodium for a youtube video.
Well done Thunderf00t :-+ :clap:
I'm one of those contributors too.
Oh, and it's on-topic, to the tune of 5 billion amps!
High speed camera reveals why sodium explodes! (https://www.youtube.com/watch?v=LmlAYnFF_s8#ws)
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that is pretty dam cool. i have handled metallic sodium myself, its interesting stuff
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Dave, IMHO you didn't waste your money on this!
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I wonder if this sort of sodium explosion could be used in high-discharge applications. Currently in fusion power prototypes they use banks of capacitors to discharge into lasers to produce peak gigawatts of power. Don't know how you'd harness the discharge current though.
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Wow, amazing stuff!
It's guys like this, and you Dave, that add so much value to the internet.
O0 :-+
Who knows where this will lead to, including the transparent metal vid.
I worked in a foundry as a youngster, and over a weekend the roof developed a very small leak.
The rain fell into the sand mould for a huge stator plate, on Monday it was cast.
Soon could be a thing of the past thanks to this work.
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They mentioned crowdfunding - any details?
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That's some fantastic stuff. Interesting and well explained. :clap:
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I wonder if you wound a coil round the reaction you could measure a magnetic field resulting from the electron flow
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I wonder if this sort of sodium explosion could be used in high-discharge applications. Currently in fusion power prototypes they use banks of capacitors to discharge into lasers to produce peak gigawatts of power. Don't know how you'd harness the discharge current though.
....that could get the Flux Capacitor.....fluxing.
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They mentioned crowdfunding - any details?
He's talking about Patreon, not Kickstarter et.al
So not a funded project, just generic per-video funding from his Patrons.
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I wonder if you wound a coil round the reaction you could measure a magnetic field resulting from the electron flow
I thought the same thing, worth trying.
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Oh, and it's on-topic, to the tune of 5 billion amps!
What's the voltage? Can you put some NAK on an electrode with the other electrode in the water and try to get some of that current through something else?
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Thanks for the post, Dave. Very engrossing.
Hmm, a small toroidal coil, with some Na in the centre wired to test gear and dropped into some water? What sort of field would 5x109A on a micro scale generate?
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So if I understood the video right, the current (electric, not electron!) flows inwards from the water to the metal. But considering that it does so on all sides of the metal droplet simultaneously, wouldn't the fields just cancel each other out (or at least most of it)?
It would be interesting to see an experiment with a coil, though, but I wouldn't expect it to produce anything usable. What if only one half of a chunk of metal was submerged? :-/O
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Super cool on all counts.
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I wonder if you wound a coil round the reaction you could measure a magnetic field resulting from the electron flow
I thought the same thing, worth trying.
Another good use for those EM probes of yours >:D
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Thunderf00t? Seriously? 90% of this guy's videos are anti-feminist drivel, mostly surrounding Anita Sarkessian. I hate what the woman has/is doing to the video game industry as much as the next person, but I think he takes his videos a little too far. :-//
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Thunderf00t? Seriously? 90% of this guy's videos are anti-feminist drivel, mostly surrounding Anita Sarkessian. I hate what the woman has/is doing to the video game industry as much as the next person, but I think he takes his videos a little too far. :-//
Yes, his channel looks positively loony.
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Enjoyed this very much, thanks, Dave! :-+
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The current is obviously traveling only a very short distance, and it's not very coherently directed, so the vector sum of all the currents is going to be small. It would be hard to measure, and much harder to harness.
But I'm curious. Does any of it radiate? I wonder if it at least makes a "pop" on a radio receiver nearby? My first guess would be that five billion amps, even very disorganized, would be audible on a radio at a reasonable distance, but...
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That is awesome! Thanks for the link Dave.
Makes me want to order up some sodium and blow stuff up.
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May be an incredibly high current, but the antenna is so small that it likely only emits in microwave region, absorbed by the water. Field likely will be zero outside the metal, and likely the only way to examine it will be to have a probe embedded partially in the liquid alloy and then freeze it to keep it in place. Place a sacrificial amplifier right by the metal to provide a low impedance cable drive and do a nuclear industry test regime of blowing up your probes with the experiment. You record the tiny amount of data before the destruction to get the info that you want.
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Thunderf00t? Seriously?
Yes, seriously. You cannot deny that his science and debunking videos are absolutely first class.
90% of this guy's videos are anti-feminist drivel, mostly surrounding Anita Sarkessian.
So don't watch then.
And it's not even close to 90% as you claim. He has almost 500 videos, a very large percentage of which are science and bunking etc.
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So don't watch then.
I never said I did watch it.
Is it so wrong to have an opinion about someone? :wtf:
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I never said I did watch it.
You must watch his feminist videos to have an opinion about the videos enough to call them "dribble" and have the opinion that he "takes it too far".
Is it so wrong to have an opinion about someone? :wtf:
No, but what you have done here is effectively question my posting of a top notch science video because you don't like some of the guys videos that are completely unrelated. You are effectively dismissing all of the guys work because you don't like some of it, that to me is just asinine.
I note that you didn't refute my statement that his science and debunking videos are first class.
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Yes, his channel looks positively loony.
His channel might look loony because it's mostly about using science and reason to debunk and challenge loony stuff.
If you don't like that stuff then there is plenty of just straight science stuff.
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saw that yesterday and it's amazing , what i mostly like is how he explain the way science work from observation to experience to analysis to conclusion , and how challenging to look behind the obvious, all that with so much enthusiasm. :clap: walking this path is as valuable as the discovery it self.
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Maybe if you could find some way to make it directional - for example place it in a minature tube and wrap a separate coil around each end, you could induce a brief pulse of current. Not sure how useful it would be though.
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Maybe if you could find some way to make it directional - for example place it in a minature tube and wrap a separate coil around each end, you could induce a brief pulse of current. Not sure how useful it would be though.
Some form of ultra powerful battery that produces a pulse of power, Star wars type laser weapons comes to mind.
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The current is obviously traveling only a very short distance, and it's not very coherently directed, so the vector sum of all the currents is going to be small. It would be hard to measure, and much harder to harness.
The initial escape of the electrons happens before the drop deforms into spikes and on the side hitting the water it's straight away from the surface of the drop (current from the back will be coherent too, just mostly cancelling out EM wise).
That said, I have my doubts about the current. The current on the initial surge away from the surface is limited by the speed at which the surface of the drop enters the water, the current on the second surge is limited by the chaotic nature of chemical reactions. I'd have to see the actual calculations to buy it.
You could wet the tip of a small wire with NAK and drop it in the water to get a better radiator BTW. Equipotential and all.
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i watched the video 3 times and am not sure how he jumped to the 5 billion amps conclusion ... i guess it's the number of positive charge accelerating in the point where everything goes boom going through the total spherical surface around the point where the reaction take place, and since this reaction happen layer by layer until all the sodium decompose allowing more particulars to accelerate and to be taking in count of this current calculation he made. ... i can be talking rubbish right now :-DD
The current is obviously traveling only a very short distance, and it's not very coherently directed, so the vector sum of all the currents is going to be small. It would be hard to measure, and much harder to harness.
since a current is the quantity of charge going through a surface and if you suppose all the material go through that surface in the same time it will be easy to consider that as a current. yes he vector sum of all the currents is going to be small.
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I don't see how one could measure the current and if it does radiate, most of the radiation will be absorbed by the water. The timescale of the current pulse is in the ps range so any resulting radiation will be in the upper microwave/low IR band, which doesn't pass through water and is attenuated by even short pieces of cable by the skin effect.
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One thing about the current that nobody seems to be noticing is that it must be balanced by an equal and opposite current. Consider: the system starts out neutral. So if a large amount of negative charge accumulates in one place, an equal and opposite amount of positive charge must accumulate nearby at the same time. Since these two bodies of charge are now going to move apart and spread out simultaneously, the net movement of charge in the system will remain balanced and close to zero overall on a macroscopic scale. It is highly unlikely that an unbalanced current flows sufficient to produce EM or magnetically detectable effects.
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Now thats some impresive amps... maybe they could try calculate total power to ;)
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Rather than trying to capture the current, why not capture the energy of the pressure wave from the explosion?
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Hang on. Even if the net charge balances out over the whole system, what would happen if you isolated one portion... for example, a coil of wire on only one half of the test tube. Would you be able to measure a change in charge there?
I don't think there will be significant power available but it would be interesting to see what the discharge looks like on a scope which could have 1ns resolution.
I might just have to get me some sodium...
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One thing about the current that nobody seems to be noticing is that it must be balanced by an equal and opposite current.
Only on larger time scales, initially the flow of electrons to the water preceding and during the mechanical deformation happens faster than the chemical reaction which brings everything back to electrical equilibrium. You could not get a Coulomb explosion if the NAK wasn't at a non-zero potential.
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Hang on. Even if the net charge balances out over the whole system, what would happen if you isolated one portion... for example, a coil of wire on only one half of the test tube. Would you be able to measure a change in charge there?
I don't think there will be significant power available but it would be interesting to see what the discharge looks like on a scope which could have 1ns resolution.
I might just have to get me some sodium...
There's no way this could be used to generate useful energy because it takes more energy to isolate alkali metals from their salts than is released during the violent reaction with water.
How would an oscilloscope with 1ns resolution help when we're talking about ps timescales here and that coil of wire is huge compared to the wavelengths generated?
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If you earth a piece of Natrium and drop it in water (salt and earth the water as well while you're at it). Will it still explode?
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Well, I was talking about faster than the high speed camera which captures in 100us intervals. It would be interesting to see the field change there. And, you could use a single turn to minimise any wavelength effects (transmission line?) or tune it to the right length, although you'd need a much higher sensitivity setting.
I'm probably not a chemist for a very good reason.
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Only on larger time scales, initially the flow of electrons to the water preceding and during the mechanical deformation happens faster than the chemical reaction which brings everything back to electrical equilibrium. You could not get a Coulomb explosion if the NAK wasn't at a non-zero potential.
But the flow of electrons into the water leaves behind a positive charge on the sodium, producing a sea of negative charge surrounding a sea of positive charge. The system remains balanced at that scale.
After this happens the sodium disperses, the metal particles expanding rapidly into the surrounding water due to charge repulsion. This movement of positively charged sodium particles does represent a current flow. But there is at the same time a movement of negatively charged water molecules away from each other due to their own charge repulsion. Because water molecules are transparent the camera doesn't pick this up. But the two simultaneous movements of charged particles will tend to cancel each other out.
When fresh sodium atoms contact water molecules an electron is transferred producing a positive ion adjacent to a negative ion. In each one of these transactions the system is electrically balanced.
So it is not really correct to say the chemical reaction brings everything back to equilibrium. The transfer of an electron from a sodium atom into the surrounding water is the chemical reaction. All that happens after that is that the electron attached to a water molecule displaces a hydrogen atom (this hydrogen atom was previously donating an electron of its own which is no longer needed--the electron coming from the sodium atom gives back the donated electron to the hydrogen atom allowing the hydrogen to float free leaving an OH- ion behind). This latter reaction (H2O + e- = OH- + ½H2) is charge balanced.
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And, you could use a single turn to minimise any wavelength effects (transmission line?) or tune it to the right length, although you'd need a much higher sensitivity setting.
You'd need a very small coil. A period of 1ps, is a frequency of 1THz and a wavelength of 300um.
Only on larger time scales, initially the flow of electrons to the water preceding and during the mechanical deformation happens faster than the chemical reaction which brings everything back to electrical equilibrium. You could not get a Coulomb explosion if the NAK wasn't at a non-zero potential.
But the flow of electrons into the water leaves behind a positive charge on the sodium, producing a sea of negative charge surrounding a sea of positive charge. The system remains balanced at that scale.
Does that really mean it won't radiate?
The random motion of electrons in any substance causes EM radiation to be emitted (thermal radiation) even though the average momentum is zero.
The emitted spectrum would be interesting but unfortunately water blocks most of it so it would be difficult to measure.
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The current flow is due to the reduction potential of the metal: around 3V. It truly is a massive current. Perhaps not as massive as claimed -- a liter won't react instantaneously, as only the surface is doing anything, as noted. But also, the surface area might be fantastically wider than is apparent from the one frame of evidence provided...and the event itself might be taking place in fantastically smaller time scales than these cameras can measure!
It might produce unbalanced E&M, sensible as radiation. The peak frequencies will probably be on the order of dimensional features of the system (wavelength around the width of the droplet, or length of the spikes), or frequencies on the order of physical activity of the system (milliseconds, microseconds, nanoseconds -- femtoseconds??).
Chemical reactions generally proceed quickly, on the atomic level, because atoms are small; but there may not be much amount of reaction taking place, because of the limitations of surface area. So, maybe not femtoseconds (hell, if the instant of the explosion was going *that* fast, I'd expect to see gamma and neutron radiation resulting from hydrogen fusion!), but microseconds are absolutely on the table.
There are also frequencies due to energy levels rather than time constants, which are quantum in origin. This is actually easy to anticipate and disregard: sodium's reduction potential is around 3V, as are other molecular and atomic orbital interactions. So you'd expect visible light from the reaction; which you don't observe, except as secondary byproducts (primarily the subsequent hydrogen flare-off). That's simply because some reactions do result in emission (the colors of a candle flame are due to blue and green spectral lines of CH2 and CH radicals, and the broad yellow emission of diatomic C2), some simply don't. You could perhaps liken it to the difference between direct and indirect bandgap semiconductors, which are good and bad for LEDs, respectively.
Tim
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If you earth a piece of Natrium and drop it in water (salt and earth the water as well while you're at it). Will it still explode?
Yes.
You can perform this experiment yourself, on a much safer scale:
Obtain a piece of aluminum (any kind will do, as long as it's uncoated), and an alkaline solution (preferably NaOH or KOH in H2O; others won't be corrosive enough). For cathode, use something generic like steel or copper.
Insert the metals in solution (not touching), and observe the aluminum begins to bubble (hydrogen). Measure the voltage between the electrodes; should be something like 0.8V.
The [ideal] reduction potential of aluminum is actually something like 2V.
Short the electrodes together, and you should see some hydrogen from the cathode as well (this is due to the electrolysis current). Measure the current and you'll probably see something in the mA range -- it's a bad battery, but it does produce some power.
Now apply more than 2V (in the same polarity as measured). Ideally... this should stop, in fact reverse the reaction. But at most, you will simply cause more hydrogen to be produced (at the cathode), and not be able to prevent hydrogen production at the anode.
The reason is this: aluminum is so reactive that it is attacked by water, even when polarized with plenty of voltage. It is impossible to apply sufficient polarization to prevent attack, because the water itself will decompose above 1.2V or so. You simply can't get the necessary 2V at the metal-to-water interface -- try, and it tears itself apart. It doesn't matter whether this is applied to inert electrodes (like graphite or platinum) or by the force of a metal. It looks the same: the metal gives up electrons, with such force (electromotive force -- voltage) that the water is broken down in the process.
So, you might have an ideally 2V battery, but it only measures 1.2V (or less), and the remaining 0.8V is simply lost to heat, whether you're discharging the cell or not. So, the self-discharge is terrible, too. This is basically part of the reason why aluminum batteries aren't a thing, by the way...
You can react aluminum with an oxidant in an alternate solvent, and observe its reduction potential correctly; such solvents peak around 2.5 or 3V (something like propyl carbonate with a dissolved ionic salt), which is also necessary for lithium ion batteries, and also why ultracapacitors are rated for exactly 2.5V and little more: above this, the solvent breaks down, just as water breaks down beyond 1.2V. (You can build your own ultracapacitor, at home, using activated charcoal pads and salt water; it will have extremely high ESR because it's not optimized, and once again, 1.2V maximum before it stops working much like a capacitor. But the extreme capacity -- 10s to 1000s of farads -- is nonetheless sensible, as long as you take your time measuring it.)
Tim
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To me whether or not it takes more energy to refine the metals than is released in the reaction is almost irrelevant. After all the same could be said of the use of batteries yet their value is undeniable.
Of more interest is whether or not it is possible to utilise the undeniable energy released in a controllable/directable manner. With greater understanding of the mechanism of the reaction comes the possibility of further innovation.
I don't pretend to know how such a result could be accomplished but am reluctant to accept that it would be impossible without detailed research.
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Well, it's a cool discovery and also how it came to be is a great story.
What i really don't like are the parts of the video, where he drones on how everybody else was wrong and didn't see the obvious.
Even going as far as cutting in some scenes of the periodic table guys.
That's just cheap in my opinion.
It's inherent to the process of scientific discovery that you look at an former overlooked aspect. It's also inherent to scientific progress to confirm, disprouf or add to older theories.
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To me whether or not it takes more energy to refine the metals than is released in the reaction is almost irrelevant. After all the same could be said of the use of batteries yet their value is undeniable.
Of more interest is whether or not it is possible to utilise the undeniable energy released in a controllable/directable manner. With greater understanding of the mechanism of the reaction comes the possibility of further innovation.
I don't pretend to know how such a result could be accomplished but am reluctant to accept that it would be impossible without detailed research.
http://en.wikipedia.org/wiki/Sodium%E2%80%93sulfur_battery (http://en.wikipedia.org/wiki/Sodium%E2%80%93sulfur_battery) ?
Tim
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What i really don't like are the parts of the video, where he drones on how everybody else was wrong and didn't see the obvious.
Even going as far as cutting in some scenes of the periodic table guys.
That's just cheap in my opinion.
It's inherent to the process of scientific discovery that you look at an former overlooked aspect. It's also inherent to scientific progress to confirm, disprouf or add to older theories.
I bet if you discovered a major thing like this you'd be crowing about that no one else found it either.
If the periodic table guys did a video on this and got it wrong, then that's fair enough to point that out.
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If the periodic table guys did a video on this and got it wrong, then that's fair enough to point that out.
If you watch the video ( http://youtu.be/7IT2I3LtlNE (http://youtu.be/7IT2I3LtlNE) ), it's not like they got it wrong. They simply observed the explosions and said "Ooh! Cool!". They did not attempt to give any deeper explanation of why the explosions happened.
Someone perhaps should have asked, "Why does the reaction proceed smoothly for a while and then suddenly go bang? Why doesn't it go bang the instant you drop the sodium in the water?" We cannot know why that question wasn't asked. But perhaps the periodic videos team will do a follow up video given the recent publication.
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The reason is this: aluminum is so reactive that it is attacked by water, even when polarized with plenty of voltage. It is impossible to apply sufficient polarization to prevent attack
But I was not suggesting stopping the reaction in the first place, so the experiment safe as it may be doesn't really prove much ... it's not reaction which causes the explosion, it's the surface of the metal repelling itself. If the aluminium is grounded can the surface of the aluminium still maintain a potential?
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That's what I'm saying, not only can you not simply "ground" it to the potential of the liquid (supposing that you can make a zero-potential connection -- in electrochemistry, this is generally accepted to be the "hydrogen electrode"), you can't even apply a voltage such that you can prevent or reverse it. The potential is spontaneous and local, and so strong that it tears water apart, as well as the droplet itself.
Tim
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The reason is this: aluminum is so reactive that it is attacked by water, even when polarized with plenty of voltage. It is impossible to apply sufficient polarization to prevent attack
But I was not suggesting stopping the reaction in the first place, so the experiment safe as it may be doesn't really prove much ... it's not reaction which causes the explosion, it's the surface of the metal repelling itself. If the aluminium is grounded can the surface of the aluminium still maintain a potential?
Grounding it to prevent potential is like grounding one side of a battery and hoping that the potential to the other side will disappear.
Even if you could, this happens fast enough that the inductance of the ground connection will make it practically an open.
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But I was not suggesting stopping the reaction in the first place, so the experiment safe as it may be doesn't really prove much ... it's not reaction which causes the explosion, it's the surface of the metal repelling itself. If the aluminium is grounded can the surface of the aluminium still maintain a potential?
But yes, it is a chemical reaction that causes the explosion. The chemical reaction is this one:
2Na + 2H2O => 2Na+ + 2OH- + H2
The hydrogen gas produced has a much larger volume than the reactants, so it expands rapidly to make space for itself and in the process ejects water and molten sodium in all directions.
The speed at which this reaction can take place depends on the rate at which sodium atoms can come into contact with water molecules, which depends largely on the free surface area of the sodium. When the sodium is fragmented and pushed apart by the repulsive action of the positive charge accumulated by the initial reaction this causes a large surface area to come into contact with water very rapidly, which causes the continuing reaction to take place increasingly rapidly. A runaway reaction takes place which leads to an explosion.
This whole process is enabled by the molten state of the metal. If the metal was not molten it would not be able to spread out through the water in the way shown by the pictures. If the metal remained solid it would remain stuck together in a single lump.
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I'd be interested to know how reaction rate (time from touching-the-surface-of-the-water to moment of "hedgehog instability") varies with initial temperature, and how the surface tension of the metal varies with temperature.
This will be complicated by the reaction rate being exponential with temperature (Arrhenius' law), but that should be factorable in the reaction rate.
Tim
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You must watch his feminist videos to have an opinion about the videos enough to call them "dribble" and have the opinion that he "takes it too far".
Again, you're putting words in my mouth. The truth is, that I've seen many YT gaming channels fall into this spiral of anti-feminism in an attempt to garner views. Sad thing is, it actually works for some of them.
But overall, I'm rather disappointed in you Dave... I think I'm going to stop using your forum for a while. Bye.
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Again, you're putting words in my mouth.
LOL, when did that expression change its meaning to "direct quoted me"?
Have you ever heard of an ad hominem fallacy?
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I liked it very much, particularly their willingness to challenge conventional wisdom / "settled science": yo cannot have more settled science than sodium exploding in water -> we all saw it with our own eyes and heard all the experts telling us those convincing theories of how / why it happened.
Those guys truly understand what science is all about and are the true scientists.
Bravo!
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Tim
Thanks for the URL about the existing batteries. It would be interesting to find out whether the new insight ends up having any bearing on their design.
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This whole process is enabled by the molten state of the metal. If the metal was not molten it would not be able to spread out through the water in the way shown by the pictures. If the metal remained solid it would remain stuck together in a single lump.
Maybe, depends if the reaction creates enough heat to melt solid Natrium before the explosion. Could be some type of cascade failure, still caused by the electrostatic force and a little luck to get the surface features necessary for the surface to start to blow itself apart in small chunks (eventually it will melt, just not sure if the surface melting is the actual trigger). Did they measure the surface temperature of solid Natrium when it explodes?
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Maybe, depends if the reaction creates enough heat to melt solid Natrium. Could be some type of cascade failure, still caused by the electrostatic force and a little luck to get the surface features necessary for the surface to start to blow itself apart in small chunks. Did they measure the surface temperature of solid Natrium when it explodes?
But the sodium is molten when it explodes. By observing the progress of the reaction this is seen to be the case. When a lump of solid sodium is dropped into water it starts reacting and fizzing vigorously. Considerable heat is given off and the sodium very quickly melts and forms a ball on the surface of the liquid. The temperature is sufficient to ignite the hydrogen gas, far in excess of the melting point of sodium (about 98°C). Progress of the reaction in the various videos shows the following characteristic sequence of events: (1) fizzle; (2) molten ball; (3) flame; (4) explosion. See Periodic Videos, for example: http://youtu.be/7IT2I3LtlNE (http://youtu.be/7IT2I3LtlNE)
If we do a similar experiment with a metal having a higher melting point, for example dropping zinc or iron filings into hydrochloric acid we get vigorous effervescence and heat, but no explosion.
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You must watch his feminist videos to have an opinion about the videos enough to call them "dribble" and have the opinion that he "takes it too far".
Again, you're putting words in my mouth. The truth is, that I've seen many YT gaming channels fall into this spiral of anti-feminism in an attempt to garner views. Sad thing is, it actually works for some of them.
But overall, I'm rather disappointed in you Dave... I think I'm going to stop using your forum for a while. Bye.
The gamergate thing seem like another crock to me.
Basically a large percentage of gamers are young males, and if pulling pony tails was multiplied with rap and pop culture, this is such behaviour.
This gamergate just sounds like some hijacking by feminist nutters.
Why should protection of women's rights be the crux, why not attack all prejudice?
It seems the same here, to illustrate this point (in 1337 speak for the gamers too:P)...
Won't use transistor cos' racism?
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So this was done only with Sodium, imagine what Cesium, Rubidium or Francium might do?
Another just "what if" scenario, taking a chunk of sodium and firing a waterjet cutter at it.
Aside from what was already mentioned about trying to measure the current generated, I'd like to see this experiment take place inside a sealed pressure vessel, not so small that it would explode, but one where you could measure the pressure spike inside it.
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This whole process is enabled by the molten state of the metal. If the metal was not molten it would not be able to spread out through the water in the way shown by the pictures. If the metal remained solid it would remain stuck together in a single lump.
Maybe, depends if the reaction creates enough heat to melt solid Natrium before the explosion. Could be some type of cascade failure, still caused by the electrostatic force and a little luck to get the surface features necessary for the surface to start to blow itself apart in small chunks (eventually it will melt, just not sure if the surface melting is the actual trigger). Did they measure the surface temperature of solid Natrium when it explodes?
That's why I said
I'd be interested to know how reaction rate (time from touching-the-surface-of-the-water to moment of "hedgehog instability") varies with initial temperature, and how the surface tension of the metal varies with temperature.
Surface tension generally drops with increasing temperature, so the rising temperature as the reaction proceeds could be the threshold needed for this timebomb.
Specifically, there would be the balance between surface tension and electric surface compression, which as soon as the electric force wins out, splat, there it goes.
Tim
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So this was done only with Sodium, imagine what Cesium, Rubidium or Francium might do?
Another just "what if" scenario, taking a chunk of sodium and firing a waterjet cutter at it.
The other metals will have different parameters of surface tension, voltage (though not much more than the voltage of sodium), reaction rate and so on, so they may simply react spontaneously (probably with the same explosive mechanism), more or less.
As for the waterjet, the reaction rate will be significantly enhanced; it might simply blow away faster than it's able to explode (en masse) though! The fragments will of course react quite rapidly once they go off on their own.
Aside from what was already mentioned about trying to measure the current generated, I'd like to see this experiment take place inside a sealed pressure vessel, not so small that it would explode, but one where you could measure the pressure spike inside it.
You could also use a pressure sensor to detect the leading edge (and rise time) of the shock wave.
Besides hydrogen, steam (and maybe some sodium metal vapor, too) should be part of the blast.
And yes, another thing to keep in mind: sodium metal has a relatively low boiling point, around orange heat.
Tim
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You must watch his feminist videos to have an opinion about the videos enough to call them "dribble" and have the opinion that he "takes it too far".
Again, you're putting words in my mouth.
I'm direct quoting you!
"90% of this guy's videos are anti-feminist drivel"
"I think he takes his videos a little too far."
The truth is, that I've seen many YT gaming channels fall into this spiral of anti-feminism in an attempt to garner views. Sad thing is, it actually works for some of them.
Who talking about gamer channels? Thunderf00t's channel is nothing of the sort.
His channel is very much about calling out BS, be it in science, engineering, religion, or in recent times, the gamergate fiasco.
Again, I still note that you didn't refute my statement that his science and debunking videos are first class.
But overall, I'm rather disappointed in you Dave... I think I'm going to stop using your forum for a while. Bye.
Because I like Thunderf00t's science (and athetist) videos?
Wow, someones a bit touchy. Bye.
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"90% of this guy's videos are anti-feminist drivel"
Now you mentioned it: that thunderfoot guy is a little fixated, if his videos are of any indication.
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That's why I said
I'd be interested to know how reaction rate (time from touching-the-surface-of-the-water to moment of "hedgehog instability") varies with initial temperature, and how the surface tension of the metal varies with temperature.
In Thunderf00t's video it is mentioned that this time is unpredictable, presumed due to surface contamination and surface oxidation.
In the successful experimental procedure they used a sodium/potassium alloy that is already liquid at room temperature, they cleaned it of all contamination, and they dropped it into the water through an inert argon atmosphere so the metal surface could not oxidize. With this experimental protocol the explosion happened predictably at the moment the drop of liquid metal hit the water. Once they had removed the sources of uncertainty there was no time delay involved.
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Something that might be interesting would be to use something like an inkjet head to fire tiny droplets of water, to get the expansion effect without there being enough water to complete the explosion
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I don't watch tf00ts feminist videos; they just don't really interest me.
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I don't watch tf00ts feminist videos; they just don't really interest me.
That's the beauty of Youtube. You can like and subscribe to and even financially support a channel without liking all of their content.
Yet many people seem to be under the impression that content producers must make all their videos appeal to them ::)
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I've watched all of TF's videos on gamergate and well he picks it apart just about as well as Solar Freaking Roadways.
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It is amazing after three years of research and peer reviewed paper on Nature that so many on this forum have debunked in less than a day of seeing the video.
Interesting video and from an electrical standpoint viable, although I wouldn't go into confirming or denying. I think some people didn't watch the beginning with interest as he already look the Hydrogen explosion and used it as his reference to the final analysis. The explosion was different to Hydrogen.
As far as emitting radio wave, entirely possible as I try to measure Molecular hydrogen natural resonance at 1.42GHz all molecules will vibrate and be detected. I haven't got the website handy, but there is a whole heap of measure frequencies for different chemical elements and compound that can be detected by radio wave. It would be just a need to locate the correct frequency. The magnitude of molecular hydrogen can be detected based on strength of its nuclear reaction. More experimentation is needed and as the guy said there is still a load of unknowns left to find.
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I'm no scientist ::) but in the vid he said that they were puzzled by the sodium exploding under water because there was no air. And the fire triangle (everybody knows it) , however did they take in to consideration the air-bubbles caused by the splash caused by dropping the sodium in to the water? :-\
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There's 1000 times less stuff in a bubble of air than a droplet of water. If it's exploding due to air... nah, it's just not. :)
Tim
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Well, it's a cool discovery and also how it came to be is a great story.
What i really don't like are the parts of the video, where he drones on how everybody else was wrong and didn't see the obvious.
Even going as far as cutting in some scenes of the periodic table guys.
That's just cheap in my opinion.
It's inherent to the process of scientific discovery that you look at an former overlooked aspect. It's also inherent to scientific progress to confirm, disprouf or add to older theories.
Periodic Videos actually made a video dismissing Mason's claims during the early stages of his research, and the clips shown are from that video and I believe an earlier one. So I consider it fair for him to take a shot at someone who dismissed him early on. I like Prof. Poliakoff, and Periodic Videos, but in this case they were quite publicly wrong.
I will say, I'm also tired of Thunderf00t's GamerGate videos. I do agree with him, broadly speaking, but I'm honestly bored of the subject, and Mason gets a little too vitriolic for my taste. But rather than get pissy about it, I just ignore those videos. I stay subscribed for his science content, which is generally first rate.
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Periodic Videos actually made a video dismissing Mason's claims during the early stages of his research, and the clips shown are from that video and I believe an earlier one.
Do you have a link for that? I have watched all of the Periodic Videos and I don't recall such a video. The Periodic Videos team is very professional, and Prof. Poliakoff in particular is very open to saying "I don't know" if something is not well understood.
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I don't watch tf00ts feminist videos; they just don't really interest me.
That's the beauty of Youtube. You can like and subscribe to and even financially support a channel without liking all of their content.
Yet many people seem to be under the impression that content producers must make all their videos appeal to them ::)
What if you find them nasty and hateful and think it's irresponsible to support them even indirectly, lest you contribute to spreading his awful vitriol?
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Periodic Videos actually made a video dismissing Mason's claims during the early stages of his research, and the clips shown are from that video and I believe an earlier one. So I consider it fair for him to take a shot at someone who dismissed him early on. I like Prof. Poliakoff, and Periodic Videos, but in this case they were quite publicly wrong.
Ok, i missed that. Then his response is perfectly understandably.
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Impressive work by Thunderf00t, takes both insight and balls to say: hey, this is not right, when everyone else says: it's a well known reaction.
Good to see someone getting more than "Internet welfare" out of Patreon donations.
His other videos are both entertaining and well documented.
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Periodic Videos actually made a video dismissing Mason's claims during the early stages of his research, and the clips shown are from that video and I believe an earlier one. So I consider it fair for him to take a shot at someone who dismissed him early on. I like Prof. Poliakoff, and Periodic Videos, but in this case they were quite publicly wrong.
Ok, i missed that. Then his response is perfectly understandably.
If such a video exists. So far no link has been posted and is not likely to be posted. It is not their style to make a video with such a tone.
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Periodic Videos actually made a video dismissing Mason's claims during the early stages of his research, and the clips shown are from that video and I believe an earlier one. So I consider it fair for him to take a shot at someone who dismissed him early on. I like Prof. Poliakoff, and Periodic Videos, but in this case they were quite publicly wrong.
Ok, i missed that. Then his response is perfectly understandably.
If such a video exists. So far no link has been posted and is not likely to be posted. It is not their style to make a video with such a tone.
I have a tendency to agree, Also the quotes in the video stated the the word "MAY" or "MAYBE" in Periodical Videos shown. This suggest a lack of understanding on the Na discoverers understanding of the disputes anyway. MAY or MAYBE suggest not fully understand the concept but instead a theoretical stand point. In all it could mean I maybe wrong so proof would be good to dispute it. Well the evidence is out so it is now time for other scientist to disprove it or accept it's findings.
The word may or maybe has stuck in my mind since Cochlear Implant first come out promising that it WILL improve your hearing. After a complaint or lawsuit later Cochlear changed the wording from WILL to MAY. To many years ago to confirm this but as my wife has a profound hearing loss, I got to understand the issue over the years.
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Oh this is cool!
Sometime in my early highschool I saw a sodium-water reaction demonstrated, and the resulting explosion. Then and up till now the the explanation given for the explosion has been "hydrogen going bang in air'. But that always seemed somehow wrong to me. There are little spits of flaming stuff right from the start, so how come the hydrogen can build up enough to suddenly go bang?
It's really wonderful to finally learn the real cause. That it's another demonstration of how electrostatic effects can be massively powerful, is icing on the cake.
Ha ha... and finding that the guy who started that process of revelation has similar opinions to mine regarding the poisonous nature of radical feminism... it's a chocolate cake, with candles. Channel, subscribed!
Now, how to control the paths of charge movement during the process, to form a current loop rather than a homogenous cancellation? Because there's possibly an EMP weapon in there somewhere.
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What if you find them nasty and hateful and think it's irresponsible to support them even indirectly, lest you contribute to spreading his awful vitriol?
I don't find Thunderf00t nasty and hateful, I think he simply calls out BS whenever he sees it, much like I do, and I like that.
Be careful you don't confuse outspokenness and lack of tact for being nasty and hateful.
I don't care what you think of him or what or how he says things, that's got nothing to do with me, you get absolutely no say in who I support or why.
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I don't care what you think of him or what or how he says things, that's got nothing to do with me, you get absolutely no say in who I support or why.
Did I ever give the impression that I thought otherwise?
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I don't care what you think of him or what or how he says things, that's got nothing to do with me, you get absolutely no say in who I support or why.
Did I ever give the impression that I thought otherwise?
Yes. You expressed clearly what you think of the guy and his content, and by responding to me about my support of him you were not so subtly trying to imply that it might be irresponsible of me to support him. You were clearly trying to at least get me to re-think my support for him.
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There is thinking I have a "say" in whom you support - as in, thinking I actually have some modicum of control over it. I don't think that because I'm not stupid. There is also trying to get you to re-think something, which we normal people call "talking about things".
Your defensive conflation of the two is kind of hilarious.
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There is also trying to get you to re-think something, which we normal people call "talking about things".
Nothing to talk about. I like the guy, you hate him, the end. Continue trying if you must, I don't mind, but I won't bother responding again.
Your defensive conflation of the two is kind of hilarious.
Glad I could amuse.
I likewise found it very assuming that you thought you could insinuate that it was irresponsible of me to support someone because of what you think of them.
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So I am pondering how to make a test setup that would have the charge in "the right direction".
If you use a semi permeable membrane, and dampen it, apply it to a hunk of sodium, could you get most of your reaction going "one direction" so you could measure the charge? Though, being the nerd I am, I'd just go with trying a slightly damp paper towel. :-) That would allow us to control the amount of moisture, and hopefully just get a controlled reaction, instead of boom.
Alternatively, would something like a MRI be able to pick up on the magnetic fields generated?
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takes both insight and balls to say: hey, this is not right, when everyone else says: it's a well known reaction.
Agreed and I think his highspeed camera work is quite convincing.
Having said that, I don't think the conventional wisdom is definitively wrong. His explanation as to why the conventional wisdom is wrong is not entirely convincing to me.
The fact that a layer of hydrogen gas surrounding the medal will inhibit further reaction is correct. But in reality, you don't have a steady layer of hydrogen gas fully covering the medal -> in fact the hydrogen gassing is so violent that one can easily make a case that as long as the gassing is sufficiently strong, the conventional wisdom is likely right, or is part of the explanation.
One way to test this is to use medal chunks of differing surface area. If one solid piece of medal generates less gas than multiple medal pieces with the same surface area, thunderfoot would have a better argument against the conventional wisdom.
Without that, all he has shown is that his electron charge theory is at least one of many possible causes. ie. he has not conclusively ruled out the conventional wisdom.
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I quickly read through the 6 pages of this so my response is quick and not well formed. (It is too bad that so many comments were off topic)(..and I don't blame Dave for having to respond). Anyway, maybe measurement of the "signal" could be done in a way similar to a FID in chromatography; burning hydrocarbons in a flame and measuring the ions emitted with an electrometer? Without putting any thought into how large the signal would be, maybe this is a way to measure (if it could be figured out). FIDs easily measure current in femtoamps. Then again this is probably "noisy" as hell (and wet).
Just tossing out an off the wall guess as to how one might quantify the current in order to figure out if there is any "usefulness".
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Without that, all he has shown is that his electron charge theory is at least one of many possible causes. ie. he has not conclusively ruled out the conventional wisdom.
Considering the amount of high profile regular press this got, I can't imagine how ape all the chemists are going right now. I expect a lot of follow-up research by other teams trying to either prove or disprove Thunderf00t's hypothesis on this. That makes for great science!
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FIDs easily measure current in femtoamps.
I think he has conclusively proved his case (of electron transfers) - it is tough to envision a plausible explanation for that under the conventional wisdom.
The discussion now is about whether he has conclusively disapproved the conventional wisdom - I don't think he has.
So now there are (at least) two competing theories. The more interesting work lays ahead as to which of the two is correct, or more correct as it is quite possible and even likely that both can be correct.
In his video, he set out to "disapprove" the conventional wisdom and in my view he failed to do that.
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In his video, he set out to "disapprove" the conventional wisdom and in my view he failed to do that.
When you have a PhD in chemistry or physics, come back and let us know.
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One possible way to show high current flow might be to do the reaction in the presence of a strong magnetic field - current flow in the liquid metal should produce reaction forces that make the shape change, or affect the physical dynamics.
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One possible way to show high current flow might be to do the reaction in the presence of a strong magnetic field - current flow in the liquid metal should produce reaction forces that make the shape change, or affect the physical dynamics.
I like this idea. Use a magnetic field to align the currents. :-)
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Considering the amount of high profile regular press this got, I can't imagine how ape all the chemists are going right now. I expect a lot of follow-up research by other teams trying to either prove or disprove Thunderf00t's hypothesis on this. That makes for great science!
I don't think the majority will go ape, as it is a peer reviewed publication meaning that many chemists on the review board would have already approved it before opening to publication.
I think it is well thought out, although I am doing only and electronic engineer degree at 51yrs, I did attempt to do a physics double degree, but my age and commitments restricted how much I could do. In the small amount of physics that I learn plus the review process I think the process is well though out.
I think there is more to be done, but I believe this was mentioned in the final part of the video. He has only just touch the surface for more exploration. I also think that the electrical energy can be measure, Lightning energy can be measured using RF reception spectrum analysis and also due to the random energy output from the explosion, I perceive there is a enough to make a measurement of it energy output. It haven't seen it tried so it is just another experiment. Random energy output is highly likely not to cause cancellation but without trying it you would never know.
I also imagine IF electrical energy can be measured experimentally it would be great to get to the next level of harnessing the energy. Speculating too far at this point though but the mind and even the imagination can create many things.
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Periodic Videos actually made a video dismissing Mason's claims during the early stages of his research, and the clips shown are from that video and I believe an earlier one.
Do you have a link for that? I have watched all of the Periodic Videos and I don't recall such a video. The Periodic Videos team is very professional, and Prof. Poliakoff in particular is very open to saying "I don't know" if something is not well understood.
There's a bit more to it than that, even. Thunderf00t emailed Periodic Videos early on saying that the "conventional explanation maybe isn't quite right" and pointed out many discrepancies to them. Not too long after Periodic Videos references a "viewer question/comment (very likely that email)" about the sodium + water reaction in one of their videos, and Poliakoff dismisses this comment as if it was a perpetual motion machine that was proposed. (It really was a rude/arrogant dismissal).
I do study chemistry (biotechnology) myself, and I've been a follower of Thunderf00t pretty much from the beginning. The explanation for this reaction given in all textbooks, and taught by all chemistry teachers and professors alike, is that Na + H2O -> H2 + NaOH. Reaction is exothermic, Na melts, heats up and H2 + O2 ignites into a small boom.
Thunderf00t noticed that:
1. Reaction is just as explosive without oxygen in the air (No H2 + O2 boom).
2. Drop dropping the Na in water the explosion would happen within a few millisecond (not enough time for the reaction to produce the amount of H2 for the the size of the bang it creates).
3. While filming it in high speed he detected secondary flames 'poofs' after the initial explosion, this could only be explained by the H2 burning (and much more consistent with burning H2).
4. Under certain circumstances the sodium would release green vapour as it reacted (just unexpected, and possibly a clue to electron conduction bands and solvation stuff happening).
5. H2 only burns explosively in very specific ratios with oxygen (1:2 molar), otherwise it burns rather slow (the 'foof' kind of burn).
etc etc.
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Not too long after Periodic Videos references a "viewer question/comment (very likely that email)" about the sodium + water reaction in one of their videos, and Poliakoff dismisses this comment as if it was a perpetual motion machine that was proposed. (It really was a rude/arrogant dismissal).
I really would like to find that video, if you can remember which one it was? (It doesn't seem to be the sodium one, but maybe potassium or caesium? I'll look through them later.)
As to the original question about the explosion, it really seems to me that nobody ever thought it was remarkable, and therefore nobody tried to look any closer. This is one of the biggest mistakes to make in science and engineering, to assume there is nothing more to investigate and therefore to put an observation to one side without considering its significance.
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That's the video I remember too, but I can't find it. Maybe they took it down? I definitely remember Poliakoff dismissing any alternative hypothesis to the "fuel-coolant" reaction and hydrogen gas explosion as nonsense. It was right after Thunderf00t published a video on the subject. It actually really hurt the professor's credibility in my eyes, as Thunderf00t's high speed footage was quite compelling, and it led to me watching Periodic Videos less often.
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The archetypal nutty prof is not infallible, and admits he makes mistakes.