eutectic should not have any other meaning than "fusible at a low melting point"

Fun With Gallium and Indium: Liquid Metal Alloy!

    
    The term eutectic should not have any other meaning than 

"fusible at a low melting point"         

                             

-The Engineering and Mining Journal (1903)

Gallium is a neat metal. It will melt in your hand! Magicians use it mold spoons, then they swirl the spoon in a glass of hot water and the spoon melts in front of the audience's eyes!

It takes a while of holding it to get it to melt in your hand. Once melted it stays a silvery metallic liquid for a while. It looks like liquid mercury.

If you bend a piece of gallium it makes a crackling sound. It "cries" when you bend it. Just like tin and indium do. It has to do with the crystalline structure of the metal "twinning" and breaking and then grating and vibrating against each other. If you keep bending you can break these metals-in which case you can melt them and let them re-solidify. Then you can bend them and make them cry all over again.

If you take some liquid gallium and put it onto a soda can, on the seam of the opening drinking hole, it will eat through the aluminum and pop open the can for you (after a while). Gallium embrittles steel and aluminum by forcing it's way (diffusing) into their grain lattice. A pretty cool way to open a pop can!

If you found a piece of gallium on a table you'd think it was a piece of lead or cooled solder. At least until it started melting in your hand. In certain applications gallium is a replacement for mercury in thermometers.

Indium is less interesting at first glance. It also "cries" if you bend it. It also looks like a piece of lead or cooled solder. To melt it you can use a blow torch and it'll turn to a liquid very easily, only to cool and solidify quickly. Okay, you'd think you'd have a huge blob of solder. Indium is used in some types of solder actually.

Sometimes indium is used to reduce the amount of mercury in dental fillings. Kind of boring huh?

Well, if you lightly rub a piece of gallium against a piece of indium THEY TURN INTO A LIQUID METAL ALLOY THAT STAYS A LIQUID! I tried it myself:

It was totally cool and really messy. I put the liquid into a glass container: mistake! This mixture "wets" glass, which means it coats it very thinly and gives it a tinted look. What good is that? Well it's how touch screens for tablets and phones are made and how newer solar panels are being produced!

A reason to care about relatively warm melting points? Liquid metal telescope mirrors! If you fill a container with a liquid and spin it, the liquid will have a low point in the center and raise up at the sides. This forms a parabloid shape that can be used as a telescope. It only has to spin at around 8 revolutions per minute-nice and easy.

[Our old nemesis Isaac Newton took credit for figuring this trick out. He had trouble spinning his container at a stable rate, so he didn't use it for telescopes.]

Of course a telescope mirror (even made of liquid metal) also has to be shiny. Mercury is used for this, but is toxic so gallium/indium liquid metal alloys are a great replacement. It's way cheaper to get a spinning vat of this liquid metal than to cast a HUGE glass mirror in a HUGE oven, grind it with tools to the curved shape, coat it with a reflective surface coating (usually aluminum) and then polish to 1/8 of a wavelength.

Of course you can tilt and swing a regular mirror telescope all around--can't really do that with a vat of liquid metal spinning around. You can look straight up with it really well though!

Looking straight up-like me! Meow.

The best place to have a telescope boringly aimed straight up would probably be at the equator. It's warm there too so the gallium indium mix would be fine and liquid.

A telescope like this at either pole might freeze...or would it? I guess that's were the "Melting Point Controversy" rears it's ugly head. I have no intent on freezing while staring at the North Star 24/7 so again, I don't care about that. Build that thing at the equator and it'll sit and spin as the stars curve by all night long. Just look carefully, because once something zings by you can't tilt a liquid telescope to follow it!

This new liquid alloy I created by rubbing gallium and indium together is referred to as a eutectic alloy. Many people mention "eutectic" liquid metal alloy in reference to any liquid metal, but eutectic refers to a mix of solid ingredients that melt at a single temperature together all at once, instead of at two different temperatures and the percentage of the elements mixed allows for the lowest melting point of those two materials possible**. 

So, I wanted to find out if my blob of liquid alloy was actually also eutectic. Research was in order!

[If you liked the liquid metal blob and want to make your own, just hit Ebay or Amazon right now and forgot the oddness that follows below.]

**I APPARENTLY HAVE NO IDEA WHAT EUTECTIC MEANS...AND I'M NOT ALONE:  

I thought I understood, but was amazed by the variety of definitions that have arisen in different fields of industry and science. So feel free to just breeze past the following:

Of course if you're manufacturing thermometers or ultra-high tech sensors or touch screens with this material its actual melting point at your usage's pressure and temperature may be quite important.

A bucket filled with cheese and hunks of steel could be heated and cheese would melt at a different temperature than the steel. Even 5lbs of butter and 1 molecule of steel would result in the butter melting at a way, way lower temperature than the steel. At the melting point of steel the butter will be melted too; however it wouldn't be uniform: the butter would melt before the steel, not with it, and varying the proportions of butter vs steel wouldn't really affect the "alloy" of butter and steel. The same thing as it cooled: the butter and steel would harden at different times/temperatures. The cheese and steel would never fuse either.

A lot of non-technical dictionaries and encyclopedias say that "eutectic" just means the mixture with the lowest melting point possible. In that case a single molecule of steel and a bunch of butter would have the lowest possible melting point mixture of butter and steel...but that's true of pretty much anything, so I'm going to go out on a limb and say that ButtSteelium is NOT eutectic. It doesn't melt as a WHOLE entity-the butter melts and then later at a higher temperature the steel melts (even if it's just a single flimsy molecule of steel).

You don't get a eutectic mixture by throwing random things into a bucket and melting them together eventually. Although I've read were this is referred to as a "Simple Eutectic System" or "Simple Eutectic"...did they just mean a "binary alloy". Are they using the old meaning "easily fusible"? Would they consider ButtSteelium eutectic? Although simple eutectic refers solidifying points and to me at least, seems to mean differing points of solidifying for the components. I've read fruit juice freezing into a popsicle being called a simple eutectic: one liquid (fruit juice) freezing into two solids (ice and slushy water vs. juice). Seems the opposite of eutectic. Hmmm...I'll keep trying to understand...

The definitions I've found all seem to conflict with each other (solidifying at different times doesn't seem eutectic, or does it?). The confusion? Eutectic reaction is used to refer to easily fusing of ingredients that turn to a liquid. Eutectic point refers to that special, lowest temperature where everything liquefies as a whole.

Indium and gallium rubbed together are both a liquid at the same (room) temperature--which is all I was interested in. If you vary the percentages of indium and gallium you can make them liquefy (or solidfy) at the lowest temperature possible for indium and gallium.

For commercial eutectic mixtures of gallium and indium you usually add some tin (and sometimes some bismuth)! Even this is a subject of controversy. It's a liquid, and under the brand name "Galinstan®" it seems to have percentages of these (and more) elements and a much lower melting point than other gallium, indium and tin (stannum) eutectic alloys.

The company that owns Galinstan® (Geratherm Medical AG) markets it with a very low melting point-other people say generic versions made by other companies have a much higher melting point even though (it is thought) that they all have very similar percentages of ingredients.

A few wisely point out that eutectic mixtures of TWO metals are defined as having the lowest melting point possible when the mixture melts as a whole, which is achieved by varying the percentages of those TWO metals. Binary (two) ingredients have a "sharp" melting point.

Others mention a requirement that: the mixed alloy has a melting point lower than either of the ingredients by themselves. This is radically different than just having the percentage mixture of ingredients that melt together at a lowest temperature for that percentage mixture.

Welders and solderers use eutectic to mean: this alloy melts completely at an exact temperature. Non-eutectic alloys melt in a range of temperature as it heats up one ingredient melts faster and the alloy turns into a mushy paste as the ingredients are acting on their own, instead of as a whole, fused eutectic thing. For welders: eutectic means the ingredients all turn to a liquid at a single temperature. Non-eutectic means some of the ingredients start liquefying while others don't yet so you get mushy, paste-like, jelly glop called a slurry...which can be useful. When looking at eutectic alloys, welders look at how stuff melts, most scientists look at how stuff solidifies.

One can speak of the eutectic point of salt water. Add more and more salt and the water can get colder and colder before freezing. Many refer to this as "lowering the eutectic of water" which means that melting point of the water is the same as the salt dissolved into it? They'll solidify at the same time? Well, I guess when you're below the normal freezing point the salt water would turn to sludge (non-eutectic) and then freeze solid. Yeah, maybe?!?! They mean the freezing point is lowered. More on this in the second bullet point below.

"EUTECTIC" ACCORDING TO VARIOUS SOURCES:

• "Many mixtures of materials crystallize into two distinct materials when they solidify. First one component forms, then the other. A system of this sort is called a simple eutectic." Seems backwards no? One THEN the other? Does this contradict "as a non-eutectic mixture cools, each mixture's component will solidify at a distinct temperature, until all material is solid."

• A mixture where both elements solidify at the same time/temperature (which is the 'V' point of a typical phase diagram from school). Even in school cooling was boring, it was the super lattice instant full meltdown mode that was neato! OK, that sounds like the eutectic point of saltwater again.

On top of these two definitions there are these that I've found in use. So, is a eutectic alloy:

The lowest possible temperature of solidification of a mix of ingredients? (Eutectiod).

The lowest possible temperature of melting  of a mix of ingredients? (Eutectic).

Eutectiod is the lowest temperature phase change (freeze or melt)?

Lowest melting point of a mix of two ingredients possible (due to percentages of each in the mix)?

The mix has a lower melting point than either of the ingredients in it do alone?

Both items in the mix melt at the same time?

Both items in the mix solidify at the same time?

The ingredients fuse upon freezing or melting?

The ingredients form a super lattice?

Any liquid metal or liquid metal alloy?

Pretty much any two things melted or fused together like ButtSteelium?

A mix that melts and freezes at a single temperature that the lowest melting point of any mixture of the same ingredients in different percentages and the melting point is lower than either of the ingredients by themselves?

A solid mix that forms a super lattice structure which instantly releases both ingredients that melt at the same temperature and time?

The lowest uniform melting point of a mixture?

A mixture that doesn't have a slurry phase (ie. no slow freeze or melt)?

The point or mixture in which the solidus and liquidus are the SAME?

A liquid freezes into two ingredients at the same time/temperature and not a range of temperatures?

These definitions encompass: eutectic, eutectic system, simple eutectic, eutectiod, eutectic temperature, eutectic point or points, eutectic transformations and/or solder specification.

Hmmm...for any definition I disagree with or that contradicts another I can find multiple "reliable" sources. These sources are college professors, technical data sheets, various shop manuals, manufacturer specs, sales specs and a whole lotta "I use eutectic item xyz everyday in my laboratory/welding shop/space station/etc. and it doesn't mean this but means that..."

I really don't care about all this, but I do find it interesting. For me in this instance: gallium and indium rubbed together becomes a liquid before your eyes. That is cool. That is fun. So yes, I have the luxury of enjoying liquid metal alloys without needing to know if they're 'truly' eutectic.

That was boring so I made a bunny out of cotton balls. It will be delicious! Meow.

THIRTY YEAR ANNIVERSARY OF CHERNOBYL

THIRTY YEAR ANNIVERSARY OF CHERNOBYL

There were four reactors at Chernobyl. In 1982 reactor #1 had a meltdown but was fixed. In 1986 reactor #4 exploded in “The Chernobyl Disaster” and was permanently shut down. In 1991 reactor #2 caught fire, the roof collapsed and it was permanently shut down. In 1996 reactor  #1 was permanently shut down. In the year 2000 reactor #3 was permanently shut down. The government of Ukraine hopes to have cleanup of the site finished by the year 2065...

What happened on April 26, 1986...

A safety inspector at the Kursk Nuclear Reactor wrote a report entitled “The accident in Block 4 of the Chernobyl power station and nuclear safety in RBMK type reactors” which blamed the Chernobyl explosion on design flaws. This was very brave-to speak the truth in the USSR! Even today it is thought that DESIGN flaws created an atmosphere in which Chernobyl exploded. It wasn’t lazy human operators.

In fact the human operators were trying to test the speed at which reactor could heat up/cool down to set up a safety system which would solve a glaring problem with the reactor. You, cold water is flowed over the reactor to cool it down. If the water flows too fast it doesn’t soak up enough heat, which causes the reactor to overheat and turn all the water into steam which blows up the reactor. If you flow the water too slowly the water gets too hot, turns into steam and blows up the reactor. If the water is at the wrong flow rate for somewhere around 435-60 seconds it’ll vaporize and blow up the reactor. Great: just set the water flow rate at the proper speed, right?

Well, here’s the problem: the water pump runs on electricity so if there is a problem with the reactor you can’t run the water pump…KABOOM! So the geniuses (not sarcastic) at Chernobyl set up a generator/water pump that ran on diesel fuel. The reactor has a problem: the diesel generators/fuel pump would kick in and keep the water flowing/flowing at the proper rate so the reactor wouldn’t completely explode. If there was a total loss of power and the control rods were all sent down and all the main reactor nuclear interactions were stopped there would still be a 7% output of heat for a time. Now, that doesn’t sound like much, but the reactor took 7,400 gallons per hour of cooling water. So you think, okay you’d only have to pump around 500 gallons of water per hour and be okay? Not quite since any voids in the cooling channels allow the water to turn to steam and blow up the reactor. Also, that would be too slow a flow rate and the water would heat up way faster than normal and explode.

So no matter what you want the water to keep flowing at its normal rate through the reactor. Thus, they put in the emergency diesel generators to keep the water flowing.  The problem? The diesel generator takes a full 60 seconds to kick in and start the water pumps. For TWO YEARS the people at Chernobyl operated the reactor knowing that any slight problem and they would have no backup! Amazingly, almost three decades later the Fukushima reactor had a similar problem: they too had diesel generators/water pumps...but there was an earthquake and a tidal wave washed away their diesel generators. KABOOM!

So, the Chernobyl scientists decided that it was time fix this problem. They came up with a really neat solution that was similar to regenerative braking systems in hybrid cars. When the reactor lost enough power it would begin the 60 second start up process of the diesel backup generators. In the meantime the steam engines powered by the reactor would turn slower and slower as they ground to a halt BUT they would still be spinning, and it was theorized that these steam engines would still produce a lot of energy as they spun slower and slower-enough to power the water system/generators for around 35 seconds. So, instead of having the reactor un-cooled for 60 seconds it’d be more like 25 seconds or less. Really a super simple and super neat idea!

Like good scientists they wanted to know their baselines: how long did it take for the reactor to lose enough power that the water flow would be affected? What was the exact power output of the steam turbines as they lost energy and moved slower and slower, but were still producing energy that could be tapped like regenerative brake systems? Basically that wanted to test all the components of their system for: how hot? How much energy? How quick? They tested this dying steam engine theory twice before and failed, but they made changes and were going for a third test.

The idea was to run the reactor (but at a reduced rate of power) and shut off the water (steam) flow to the steam engines. The water would flow over the reactor and cool it like normal. It would get hot and turn to steam like normal. Instead of then going to turn the steam engine to produce electricity it would be piped off elsewhere. This would allow the scientists to see just how long it would take for the steam engine to slow down after losing steam. This would also let them see how much energy the steam engine would still produce as it was slowing down-and thus if it was enough to power up the emergency systems for at least part of the 60 second delay until the diesel generators were going full blast.

They reduced the power of the reactor and something horrible happened. Normally when the reactor is running it produces Xenon. Xenon slows down the reactor, but because the reactor is running at full power it burns the Xenon-135 and turns it into Iodine. Great, but at the reduced power during the test the reactor wasn’t making enough power to burn up the Xenon. More and more Xenon kept accumulating in the core which kept slowing the reactor down more and more. Suddenly, the scenario of “what if we lose power and can’t keep the water cooling pumps running” became a real situation!

At that same time an engineer accidentally inserted some control rods too far. As the reactor was slowing down from too much Xenon, he slowed it down even more by hitting the brakes (inserting the control rods).

In a reactor there are many control rods. These rods “soak up” excess radioactivity and slow down the reaction. Pull the rods up and you get more radioactivity, heat, steam and electricity. Push the rods down inside the reactor and they slow down/shut off the reactor. They’re like the brakes in a normal (non-hybrid) automobile: press soft to slow down, press harder to slow faster, press really hard to stop.

At this time the flow rate of the coolant was erratic. The steam pressure and flow were not normal because they were bypassing the steam engine for the test. Everything was going crazy. Luckily they reversed course and took out some fuel rods. This let the reactor start producing more (stable) energy. They dodged a big bullet. So what did they do know? They kept fiddling with the reactor so they could get to their experiment!

They turned on a few extra water pumps. This immediately dropped the water pressure of the coolant and everything started overheating because even though more water pumps were on the water pressure was split among them and dropped creating voids and thus premature steam and heat. While it is true that this design is called a "boiling reactor" if it runs at less than 20% power the bubbles in the water become a problem because the effect of the high temperature that reduced neutron flux goes away. The reactor becomes unstable and can experience uncontrollable power surges. No problem, just increase the flow rate! They did and the reactor got too much flow and lost power again. So they decided to take out even more control rods to increase the reactor power again! Out of 211 rods they removed 193. In this reactor, even during full loss of power they were supposed to remove at most 183 rods. Clearly it was a touchy situation. They were veering from too much steam to too much power to too little power to run the cooling systems. What should they do? Why, they decided that now was the perfect time to finally START THEIR EXPERIMENT!

They shut down the steam engine. This cut off energy to the water flow. The steam engine kept spinning slower and slower, so during their experiment the water flow became slower and slower and this lead to overheating. They turned on the diesel generators. It was estimated that in 39 seconds the diesel generators would be fully running. 

The beginning of the end...

Sadly, at 36 seconds someone (not the automatic systems but a human) hit a special button. In the literature this is called the EPS-5/AZ-5 button. There are photos of this button online. It does something that sounds really good and safe: it inserts all the control rods and slows the reactor down. The problem? Almost all the control rods were taken out, so they all started dropping into the extremely overheated water in the reactor. Sounds good no? The control rods were made of a moderator called Boron. Check my previous posts and/or click on the keyword “Boron” to see the cool uses I’ve had it for in my own experiments.

However, these control rods were tipped with graphite. When all of these graphite tips hit the coolant water at the same time a weird thing happened. They displaced the cooling water by a smidge. The 193 graphite rod ends pushing out desperately needed coolant water was enough to allow a HUGE rise in core temperature and the coolant water flashed over to steam. This shattered a bunch of the control rods! Then everything got worse and the people who were there are mostly dead, but the main thing is the reactor exploded.

It reminds me of when people overheat water in a microwave: if you use a smooth coffee mug you can actually overheat the water and when you stick you a stirring spoon into the water it literally explodes and showers you with hot water! People have been seriously injured this way. Too cool too fast actually overheated things.

The structure of Chernobyl reactor #4 was mounted to the underside of a steel plate that weighed 4 million pounds. Yes! FOUR MILLION POUNDS! What happened to this top plate? It went flying through the roof of the reactor and into the sky.

Then what happened? Another explosion that was even worse!!! This sent hunks of molten core pieces flying around onto the roofs of surrounding buildings. The roofs of the surrounding buildings were water-proofed using bitumen which promptly burst into flames. The roof of reactor #3 (which was still running) also caught fire and was threatening to explode. What is bitumen? It’s basically asphalt, which is kind of like coal mixed with gasoline; although to be fair it is relatively non-flammable. Still though: why not metal roofing? Heck, why not concrete?

The Nuclear Energy Agency put out a great report that includes an in depth explanation of each step of the accident. It's title is, "CHERNOBYL: Assessment of Radiological and Health Impacts. Update of Chernobyl: Ten Years On" which is available free online as a PDF.

Soviet Design: the bitumen roofs were prohibited by the buildings codes and never should have been there in the first place. The whole reactor should have been in a containment building, but it was in a shoddy Soviet building with bitumen smeared roofs.

The graphite tips of the control rods? They caused a huge spike when used at a different reactor nearly 3 years earlier! Graphite was also used as a lining inside the core. Much is made of this graphite igniting when it was thrown into the air during the explosions. It’s simple: the graphite was red hot in the water-filled core. The core exploded and the red hot graphite flew onto the bitumen covered roofs of the nearby buildings. Red hot and no longer covered with water and now exposed to the air they simply caught fire. It was this fire which gathered up the radioactive materials and put it into the air, spreading it all over the world. Much like volcanic ash.

Button EPS-5/AZ-5: there are two scenarios that play out with the safety button that dropped all the control rods. One says that everything was fine and mellow and they decided to shut down the reactor after all the craziness of the moments before. The other says that things got even worse and someone hit the safety button. Either way it made things worse.

The reactor was a type RBMK. This type of reactor was refused a patent in the Soviet Union because of design flaws when it was proposed in 1967! Victor Bobrv who was acting Head of State Laboratory Registry of Inventions has stated that he sent back the first application for a the RBMK to be registered…but then a month later in the Soviet run newspaper Pravda it was announced that the problem of nuclear reactor design efficiency had been solved. Then from 1971 to 1975 the RBMK type reactor made up two-thirds of the Soviet planned nuclear capacity. Alla Yaroshinkskaya wrote a book titled “Chernobyl: The Forbidden Truth” which delves into this briefly.

The design was around 30% efficient and there were other problems: it used graphite and regular water (instead of heavy water) to control runaway nuclear reactions. Regular water turns to steam and thus you lose part of your moderation. A cheap but difficult way to run a reactor if things go wrong and you get too much steam. Steam creates a void. The void is empty and doesn’t help slow the nuclear reaction: leading to more heat and more steam leading to more nuclear reactions, and on and on until it explodes.

Alla Yaroshinkskaya’s book titled “Chernobyl: The Forbidden Truth” centers more on what was happening at the time: the people, the scientists, the propaganda, town hall meetings that grew heated, etc. It’s a bit hard to follow the book in parts, but I suppose that in itself reflects the mood at the time (and for years afterwards). She even lists some of the previously secret documents uncovered after the fall of the Soviet Union.

The cover up is worse than the crime! 

Although I don’t consider what the operators did foolish or criminal-the cover up which started that very day of what happened and what the dangers to the public from radioactivity were!

After reactor #4 exploded the roof of reactor #3 caught fire. The staff wanted to shut down #3 and get to safety but were told to keep working like nothing had happened. After about three and a half hours they couldn’t take it, disobeyed orders and shut down #3. Most of the #3 workers then were able to leave, some stayed behind to control the shut down and cooling off of their still intact reactor. Stay in a burning building surrounded by the worst release of radioactivity in human history. An American would say, “I’d get another job!” but in the old Soviet Ukraine “the job gets you!” The local government office would assign you a job. They would allocate your food allowance.

If people are getting sick or dying as a result of radiation levels rising past the ‘safe’ background level-just raise what is considered the ‘safe’ background level! In a classified communication (Secret Protocol #9, May 8^th, 1986) the Ministry of Health of the USSR changed the acceptable minimum radiation levels. It said, “…in certain cases these levels can e multiplied by 50…” If people are dying in a flood because the water has risen 25 feet above flood surge, just recalculate ground level to minus 25 feet: then there is no flood and nobody has died because of it.

Because the Soviet Union was so poor and because they didn’t evacuate most of the people who should have been evacuated: the farmers near Chernobyl / Kiev kept farming! The Soviet Minister of Health put out another order (Secret Appendix to paragraph 10 of Protocol #32 August 22^nd, 1986) which decided that they would USE THE RADIOACTIVE FOOD produced near Chernobyl but “distribute the contaminated meat as widely as possible throughout the USSR.”  

A Soviet man came up with a name for this trading of bad food for good: “Equilization”. The people forced to live in the radioactive area would be given clean food, their bad food would be shipped all over the rest of the USSR and given to normal people (without their knowledge). This would spread out the radiation all over. Soviet thinking: if everyone is just a little sick-then nobody is sick and everyone is healthy. If all the contaminated food is spread out, then less people would get sick from eating smaller portions of it...or something like that. I re-read it over and over and couldn't figure out why they'd feed poison to their own people.

  

Why would the people stand for this? It was a secret. Also, it was the Soviet Union. You couldn’t just go out and buy un-irradiated food. Go out? “Let’s see your travel papers comrade!” Buy some food? “Let’s see your voucher for food allowance of this particular item….sorry, but: DENIED COMRADE!” Go eat some glowing potatoes. 

Also, the government set production targets for food growth. Remember, the Soviet government owns everything-even the food you produce is theirs. They didn’t lower the farm production targets in affected areas. In one instance they actually increased the target of blood donations…from people living in an irradiated area!

The Deputy Prosecutor General of the Soviet Union, Victor Andreyev stated that between “-89 47,500 tonnes of meat and 2 million tones of milk over the permitted level of pollution were produced…a large part of these products were sent out of the contaminated zones of Ukraine, Byelorussia and Russia…” and consumed by other Soviet citizens. Other officials are on record as having allowed contaminated products to be consumed.

The Socialist government did try to help. They built brand new houses for the workers at the other reactors at Chernobyl to live in…right near the old radioactive ones. Right in the still to this day radioactive part of town! Soldiers came and killed everyone’s pet cats and dogs and pulled up the floorboards of some houses and carried away the dirt that was under the floorboards. They built a new school building in the death zone and then later came back and dug up a few inches of the soil around the outside of it and carried the dirt away. They collected the radioactive food still being farmed there and gave it to unknowing victims all over the Soviet Union to ‘equalize’ the radiation. Of course there was rumor early on that the radioactive food should come nowhere near Moscow.

There were three sets of information in those times: the lies given to the people, the half-truths given to Socialist ally countries directly affected by the radiation plume, and finally the truth! The “truth” was that tests were being done on thousands of people, but the results of those tests were never shared with the patients, or their doctors. The lab sent them straight to Moscow, who then churned out feel good, happy stories. One in particular was about birds singing in the night air above Pripyat (the town north of Chernobyl). While radioactive garbage was raining down from the sky the Soviet government decided to go ahead with the Soviet May Day Parades! All those people exposed with no knowledge! Cesium in the form of radioactive iodine has a half life of 8 days. Take iodine pills for 8 days and you don’t die of thyroid cancer. Did they do that? No, they held a parade on day 6! Keep in mind that the radiation reached Norway after passing through these people first. To be fair, one communiqué relates the desire to shorten the festivities from 4 to 2 hours. And that was just the Cesium! It has been said that the reactor belched out, “the entire Periodic Table!”

Western nations sent experts in. The experts went home and said everything was terrible; but the Soviet controlled newspapers and TV said, “the visiting experts say everything is great. Don’t worry-be happy!” The mere presence of honest experts from the west provided a photo-op that was used to disseminate lies. Look up ‘useful idiot’ in relation to propaganda. When the government controls the media, they can make anyone seem to say anything.

Manufacturing Acetylene (with a Twist of Lime!)

Manufacturing Acetylene (with a Twist of Lime!)

A raw lump of calcium carbide is a grey, slightly metallic looking object. It smells like ozone, stale air from and old tire plus sulfur. Ozone is the smell of electricity in air: the smell of slot cars and toy electric trains.

These combinations of weird smells add up to something familiar, but I couldn't remember what-until I looked at the chemical reaction notation. Then I had a "Proust Moment", only with lime and not lemon cookies. I just had this memory of the smell and seeing my fingers caked with acidic sludge. More on that later.

As you can see in the video, it will not catch fire when a flame is held to it. Once I add water with a syringe it produces Acetylene gas which does ignite. Acetylene burns so well it's used in welding torches!

Calcium carbide is CaC2, written on my sample as CaCa.
Water is H2O.

CaC2 + 2H2O = C2H2 + CA(OH)2

C2H2 is Acetylene, the gas shown burning in the video.
CA(OH)2  is a grey, sludge that smells a bit like... Plaster of Paris!

Back as an undergrad I took a sculpting class. After carving a huge limestone rock I polished it with wet sandpaper and water. The result was this same stinky sludge called slaked lime. Plaster of Paris uses gypsum, while fancier lime plaster uses slaked lime. They smell pretty similar, though lime plaster will burn your skin (as I found out while sanding my sculpture). I remember my fingers burning and that smell of slaked lime, just like Proust was inspired to write 2000 pages after he smelled a lemon Madeline cookie.

Meow-that's funny. I have a Proust Memory Moment every time I smell ferns...of people yelling at me to not kill ferns. I don't listen though.

Strangely enough, I was texturing my hallway ceiling and BOOM there was that smell again! Turns out that the stuff I was glopping on had carbide in its ingredient list.

Placing a lump of calcium carbide into a container and dripping water into it is how old miner's helmets worked (but never do this: read below).  A pipe/nozzle system allowed the acetylene gas to rise out of the water and lime sludge: this way the flame doesn't sputter like in the video.

However: miner's helmets are precision instruments with small valves. You may think, "what of he put the lid on that container with the water and calcium carbide and then poked a little hole in the top and lit it?" NEVER, EVER do that!!! I guarantee that it will instantly explode, sending pieces of the container shredding through the room!

Acetylene welding torches often pop while people are using them. It's scary and can blow through your weld-but that flame is out in the open. Contain acetylene (even just a bit, like a bowl with turned inward edges) and you get a bomb with shrapnel! People put acetylene in paper cups laying sideways and ignite them: loud bang, perforated eardrums and wads of paper embedded in your eyeball. It will be the loudest (and last) thing you'll ever hear.

Just laying a piece of paper over the container is enough to make the acetylene explode instead of burn.

If you fill a container with acetylene past 29psi it can explode all by itself-no flame needed! To be able to put acetylene into welding tanks they have to dissolve it into acetone. That lets it get up to 250psi, so it will squirt out of the tank/hose/nozzle while welding-instead of just exploding the tank.

 Acetylene in contact with brass or copper forms even more dangerously explosive compounds!

Acetylene is the scariest, most unstable thing I've ever been around...and that's coming from someone who's experimented with neutron radiation.

Leave it alone.

So, besides antique mining helmet lights and ceiling plaster what is calcium carbide and the acetylene it produces good for? Something insanely high tech:  thiol vinylation reactions which bind molecules of things like fluorescent markers to biomolecular material being studied. I love fluorescent and phosphorescent stuff!

Kind of like: the glow in the dark fluorescent stuff "clicks" onto the cancer cells. This is called "click chemistry". Thiol bind with acetylene using these methods. Click chemistry focuses (somewhat) on creating reactions that mimic nature, are modular (click together) and are one pot reaction: tons of glassware and tubes and stuff looks cool, but scientists would rather through a bunch of stuff in a bucket and get to work, not spend time synthesising things with a gillion steps.

Another cool thing the carbide and water reaction is good for? Polymers! Search around and you'll find my older posts about polymer. See: everything comes full circle over and over again for me.

Glider & Dethermalizer Timer Build

Glider & Dethermalizer Timer Build

Day 1 building a Georgia Swift 19 balsa glider and a dethermalizer timer to release an airbrake flap. The flap is needed because this type of glider can catch a thermal draft and stay up for ten minutes or longer. The timer will release the crash landing flap after about a minute so the glider doesn't fly away forever!

All the glider parts, and extra stuff (like Silly Putty!) for the dethermalizer timer. I went with Loctite CA glue instead of Elmer's. The Loctite is like Crazy Glue, only it's a little bit gel-like in consistency, instead of watery, making it easier to apply without running everywhere.

Here are the wings, boring and flat. I shaped each wing using 80 grit sandpaper, much like shaping a surfboard.

The wing airfoil profile should be a Wittman SS4 "supersweep" shape. The wing is thicker in the center, thinner at the front of the wing, and paper-thin at the trailing edge. Ron Wittman took the balsa glider world by storm the year I was born, using his blunt-nosed, high in the middle wing shapes. His glider stayed up for almost 55 seconds. He set a world record!

The 'preferred' method of shaping is to lay a line of pins in an arc from tip to base denoting the high spot. Then you sand away from that. I used a drawn line. The ruler goes from a marked point on the tip to a marked point where it touches the leading edge. Then from that mark to the base. This is very easily reproduced on the other wing by just transfering the two mark points--then you just connect them with the ruler.

The leading edge is getting rounded off.

The wings started out as balsa "planks" that were uniform thickness. Much like a popsicle stick when viewed edge-on. Here you can see the airfoil form starting to take shape.

Here's where it gets totally awesome: the wings join in a 'V" shape at the center. Then I cut off the last 1/3 of each wing and sanded those edges so that when they were re-joined back in place they'd also form a "V" shape. The wings as a whole, also aim upward, while the nose points down. Kind of like it you're driving down the road and the front hood of your car opens up--it'll try to fly away: and this forms a dihedral wing. Actually I think this may be a double-dihedral (or maybe even a triple with all the Vees?" My radio control plane has dihedral (upswept) wings on it. Dihedral makes it harder too steer (which is why jet-fighters have zero dihedral) but it makes the craft float on the air, almost like a hot-air balloon. Very little effort is expended in getting an aircraft with lots of dihedral angle in the wings up in the air and keeping it there--a jet figher on the other hand doesn't glide, they tend to fall out of the sky on lose of power. Basically jet-fighters are like flying a cinderblock, given a strong enough jet engine it'll go up. If that engine conks out it falls almsot straight down. This design is the opposite of that!

Rudder joined to the rear of the fuselage. I kinda screwed up here. I  shaped the sides of the fusealge really, really thin. Almost as thin as the rudder. This severely weakens the rear, although later on I glued carbon fiber strips along the sides, which severely  strengthened, so it worked out.

Here's another photo of the really thinned-out rear fuselage. You can see here that the rudder and the fuselage are the same, near paper-thin thickness!

I located the area under the wing where the center of gravity should be, and I poked a nail through it sideways.

I then balanced the plane on an open vice on this nail. The more clay I added to the nose, the more forward it rolled. Like a teeter-totter! I got it pretty well balanced with yellow clay on the nose. After I add the dethermalizer apparatus I'll have to re-balance, but that's just adding or removing clay from the nose.

Carbon fiber strengthening strips. I cut them short so I could add extra pieces to the ultra-thinned out tail section.

The nose slopes down, and the wings point upward: dihedral. Then the wings "V" up at the center and each winglet tip. Plenty of lift!

Here is my new baby completed and test flown in one evenning! You can see the nose and fuselage sloping downward while the wings are angeled backwards. You can also see in the photo the three Vees: center and each wing tip.

So, how does it fly? Well, it's 1 degree Farenheit outside and windy and snowy. I've seen videos posted by the owner of Georgia Balsa Gliders posted on YouTube where he lobs it up into the air and it catches a thermal and stays up for quite a scary amount of time! I went outside and tossed this plane as weakly as I could, like dumping a kitten onto a bed for a nap--the plane sailed like a laserbeam at a (luckily) low and decreasing incidence to the ground. I have no doubt that if I chucked this glider with the same vigor I'd use on a regular paper airplane I'd be lamenting the fact that this thing entered the stratosphere and sailed out of sight! It really wants to glide up and away!!

The Dethermalizer Timer

I found many plans online for "Silly Putty Dethermalizer Timers" that were similar. Martin Gregorie has a fantastic how-to build guide online with tons of background information. The best pictorial build guide online is by Tony Matthews. This is where I got my plans from. I modified the plans and workflows a little to suit my habits--also my end cap where the trigger arm attaches has a 1/8" tube over the 3/32" tube. I did this for looks (since I was having fun!) but that adds unnecessary weight and also makes the trigger end the same width as the rest of the assembly so it may rub against the fuselage if you're not careful on installation. The extra tube there does look awesome and really made it easy to drill the hole for the trigger. Without it I'd have been drilling directly into the 3/32" tube which would be a real bummer.

As you know from previous posts I've manufactured my own various non-newtonian liquids and putties in the past, but I went with the store-bought variety: peach putty in a red egg.

I also picked up three telescoping sized aluminum tubes: 1/8", 3/32" and 1/16" outside diameters. I cut them easily by rolling an Xacto blade on them and they eventually go shooting off.

Cutting them all to shape.

Crush the last 5/16" of the 1/6" tube into a flat paddle.

The paddle, which will be swirling within the Silly Putty. This will do two things: slow the timer's spin rate; and give a very consistant spin rate. It's a timer after all. It will be powered by dental brace rubberbands. You can get different sized bands for different pull strength-which means different amounts of time before the timer goes off.

A tiny piece of 3/32" tube goes over the paddle tube to act as a bearing.

Here's the paddle tube and bearing tube assembly placed inside the big piece of 1/8" tube. You can see the paddle inside. The paddle area will be filled with Silly Putty and then capped off.

My father gave me this awesome mini-vice today! It's on a wooden base with three long strips of wood. The outside two act as regular legs. the third one can be clamped into a larger vice--like it is here. Brilliant!

Not to get too confusing, but that silver drill tool is also called a vice. It's a 'pin-vice' that holds tiny drill bits the size of a pin. Spin it in your fingers and you can drill stuff. I've used this one before--it was particularly handy when I was building my submarine (featured in my other blog about the U-2540 Wilhelm Bauer) and when I was making a teeny-tiny ship in a glass bottle.
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I cut a small safety pin apart with wire cutters to get the rubberband holder / trigger part.

Packing the paddle end of the tube with Silly Putty. This turned out to be the hardest part!

The open end of the tube was filled with Silly Putty. Turning the trigger to set the timer made the Silly Putty run out of the tube. I need a plug. I had a dowel that fit, but the Silly Putty kept squeezing past it! So I took a wooden match stick and rotated it into the tube.

Here's a photo of the shaped match stick. It's only about 3/32" long. I cut if off and then glued and hammered it into the Silly Putty end of the timer assembly.

Here's the finished timer. What a beauty! A rubberband pulls on the trigger arm. The Silly Putty inside slows its turning. Eventually the arm rotates enough and the rubberband falls off--this frees up a dethermalizer / airbrake flap which causes the glider to slowly fall out of the sky. Since I can't turn off the wind-I have to turn off the aerodynamics of the glider to get it out of the sky.

The paper thin tail section of the plane warped as it was drying from it's coat of sealant. It was getting less and less warped as it dried, but for good measure I found a metal plate and flatted the tail using two huge and heavy magnets I took off some old stereo speakers a neighbor threw in the garbage.

There's the flap I cut out from some roof flashing metal. You could also just use some metal from a tin can--which might be stiffer and better. It'll be mounted on the side of the fuselage. The tail-end will be glued down to act as a hinge. The end nearest nose of the glider will not be glued. It will be held down by a dental rubberband attached to the dethermalizer timer. Once the timer goes off and the rubberband slips away the flap (which is facing forward into the wind) will be free to flap out sideways and cause the airplane to (softly) crash land. This setup keeps the plane from flying too far away.

That's quite a day's worth of work! I originally didn't care about the glider and just wanted to build a dethermalizer timer. Now that I built the glider I really like it and don't want to cut into it to mount the timer and flap! But I'm afraid to fly the glider without one. Next Sunday I'll work on this again and decide what to do.

Check back here for either: a video of my timer-less glider sailing out of sight forever; or of my beautiful glider with the dethermalizer apparatus hacked onto it.

Decisions, decisions...

Throw it to me! I can catch it good. 

GET YOUR KEYBOARD TO LIGHT UP IN LINUX MINT

HOW TO GET YOUR KEYBOARD TO LIGHT UP IN LINUX MINT

Okay, so Linux Mint uses the “Scroll Lock Key” for a lot of stuff. However, most keyboards that can light up for easier typing in the dark use the Scroll Lock Key to also turn the LED illumination on and off. Sometimes it will say “EL on/off” under the words “Scroll Lk”.

Obviously that sucks. Especially if you have an awesome keyboard like my Logisys one that glows blue. So you have to do some typing in the Terminal window in Linux to get your scroll lock key back. Although Linux has thrown me some curveballs in the past two days (Cinnamon constantly crashing until I downloaded MATE desktop and setting it as my default workspace, etc.) At least I don't have to see things like this  every few days:

Okay, Terminal is that black square button with “>-“ on it. It opens up a black screen that is a lot like the old DOS programming window.


Whenever I write “Type:” you type whatever is written after that and then click your Enter key.

1. Click on the Terminal button to open Terminal

Here’s where it gets weird. I somehow didn’t have permissions for any of my home files. Yep, I did NOT own my own files somehow. You may or may not have this problem. This second step gives you permission to read and write to your own files. I didn’t realize this because I’ve only had Linux Mint on my computer for 2 days (yet, figuring this out I feel is quite impressive). If you do already have permissions throughout your home directory you can skip to step 5.

2. Type:   Sudo

3. Enter your password

4. Type:  Sudo chown –R mike : mike /home/mike

Make sure to change ‘mike’ to your user name and pay attention to where there are spaces!

This will run a bunch of files, giving you permission to read and write to them. It’ll only take a minute to go through. So, back to fixing the keyboard.

5. Type:  xmodmap –pm

This will list a few things with numbered mod lines. Usually 3 has nothing next to it, it’s just a blank space next to the 3. So, we’ll use 3 as our Scroll Lock light button place. If you have a different number blank then use that number. Somewhere I think I read you can go up to 32 or 35. I dunno. Just make sure 3 is blank and then go to the next step.

6. Type: cd ~

That’s cd followed by a space and then the ~ tilde symbol that’s at the upper left corner of your keyboard.

7. Type:      Echo >.Xmodmap “add mod3 = Scroll_Lock”

Yes, there is a space after echo, but not after the >, and yes it’s a capital X and there is an underscore between Scroll and Lock.
You may notice your keyboard is lit up now!

8. Type: exit

This will exit you from Sudo (an elevated super user admin thing)

9. Type: exit

Yes, you exit again to exit from the Terminal program itself.


Now, restart your computer and see if your keyboard illumination light turns on right after booting up.

On my keyboard, this doesn’t actually make the Scroll Lock button work as the on/off—but it does light up my keyboard and keeps it lighted.

Alternately you can go into terminal and type:   xset led 3     which will turn your keyboard light on. You can shut off your keyboard light by typing:   xset –led 3

The xset codes get erased on rebooting. But it’s a nice option.

Another option (which just wouldn't take at the root level for me at least) was Xmodmap -e 'add mod3 = Scroll_Lock' which possibly will let you toggle your keyboard lights off and on. You'd have to add it (using "echo") to the ROOT folder of Xmodmap (I think) so the code would look a bit different in front of the .Xmodmap part. At one point it worked for me, but then stopped working. I don't mind my keyboard lights on all the time, so I just went with the simpler version without the "-e" portion, as I described in the numbered steps above.

For my next trick I’ll cut the wires from the LED backlights and solder them to a toggle switch and a point somewhere on the keyboard’s circuit board with the proper voltage. Maybe at the USB cable? That would be too high voltage? I dunno. I’ll dig around in there at some point.  I don’t mind the LED light on all the time, so I’m not too amped up about it.

That was so boring. Computer "Science" is boring. Meow!

ANOTHER GREAT LINUX MINT TIP

Minimizing / hiding Chromium or even Word files with the upper right ‘_’ minimize button makes them disappear forever. Clicking on the show desktop button only brings them back if you hide them that way…sometimes.

Click on ALT + TAB key and you’ll get a choice of all the hidden / minimized internet browsers and other things you’ve hidden and lost or forgot about. Nice!

By the way, for all of the above I’m using the MATE desktop of Linux Mint 17.3 Cinnamon!

Big deal. I can hide / unhide myself anytime I want to in this mini Coleman camping tent! Meow! ...Actually I'm not too great at zipping and unzipping it up by myself.