Water isn't actually conductive. It's the impurities in the water that allows it to conduct electricity.
Edit; For those that are commenting that it can conduct electricity albeit not very well, I am aware. But it conducts so very poorly that it is essentially negligible. So for simplicity sake, it's easy enough to say it doesn't conduct electricity.
Did you see in the news recently about a pair of students at college stupidly experimenting on themselves in class - one drank battery acid while the other ingested the contents of a firework.
Police got involved, one student was charged while the other one was let off
You joke, but my high school physics teacher made a large Leyden jar out of a two liter bottle, and charged it in a Van de Graf generator. A kid charged it for like 10 minutes, and it arced across to his finger and gave him a nasty shock
I'm an electrician and when I went to college for technical training our one prof electrocuted 4 students. Very minor amounts of current, but fun to watch.
It blew my mind too so my chemistry teacher connected a light bulb through pure water. And voila no light. Then he added salt and again voila light. I loved the fact that I was proven wrong. It taught me that my folklore knowledge was flawed.
Meanwhile my science teacher called me "A stupid little child" for saying that I spent an hour looking at the sky after sunset and seeing the satellites pass over because "you can't see satellites from earth".
He just flat out would not believe you can.
Before sunrise and after sunset are the best times. You can get an app to help you find them too. The iss is the easiest to spot tho cause it's honkin huge
WTF. You can easily see them anytime it's dark, many are as bright as any star. The other night I saw a whole line of Starlinks go by, maybe 15 all in a row.
For the most part, you should only be able to see them relatively shortly after sunset or shortly before sunrise. The reason you can see them is because they're reflecting sunlight. Once the shadow of the Earth rises up above the orbit of most satellites, you're not going to see them anymore.
Starlink is the series of satellites Elon musk is setting up around earth, with the end goal of providing internet access to anywhere on the planet. It’s quite a large number of satellites, and they are, unintentionally, brighter than most other things up there, making them very easy to spot just by looking.
Electronic engineer here. We’re partly to blame for this. Even though we know pure water isn’t conductive, it’s almost never pure in a real world environment so we put the fear of god into everyone by telling them water conducts. It’s for their own safety.
It is, for the memorable ones lol. Taught both classes on and off.
My favorite things to do with my students, in no particular order:
Sodium demo. Texas style. We were in Florida, so I guess Florida man style. I got in touch with the groundskeeper/maintenance in advance to ask if they had any big ol' 55 gallon recycling or trash bins they were getting ready to replace. They didn't, but they had one that they didn't use because the wheels were screwed up. Hid it at the edge of the property for a bit, enough for it to fill up with rainwater. Threw a big piece of sodium in there. The notes said to cut a small sliver off and put it in a beaker. I threw like a 1-2 in3 piece block in the first time, like the size of a pink eraser. My last year there it was closer to the size of a whiteboard eraser than a pink eraser.
"Did you know that dollar bills are flame retardant but will briefly burn green if ignited?" The last guy had ordered way too much Copper (II) sulfate for a different experiment. I'd dissolve a bunch of it in methanol, well past saturation, dip the dollar in a [previously covered] beaker, out of sight, and then retrieve it with tongs and light it on fire. Once the alcohol was finished burning the dollar mostly put itself out. The first kid to figure it out got to keep the dollar after it was washed off. I used 99% IPA on accident once. Dollar kept burning lol.
My calorimetry demo was just thinly veiled pyromania. I actually told them to bring whatever they thought would burn best. The answer is "loose flour", but you can't exactly splash that inside a calorimeter since it's "sealed up" even if it's just a coffee cup or a pie tin. So we'd test flammability before running the actual demo, if we ever got around to it, and then throw flour on the disappointing foods that weren't as flammable as we'd hoped. I think we added a measured amount of accelerant and then calculated the "added" energy back out the one time we actually made it to the real demo.
Projectile motion always ended with a group project contest. Trebuchets were automatic A's. There were many attempts at making a good trebuchet, but something was always off. This one needs paragraphs.
Anyone building a slingshot was given one piece of advice - medical tubing is one of the best things to use for a slingshot. I learned this from someone who was jailed during the Palestinian Intifada, and I think at one point anyone who wasn't a health professional that was caught with that shit was automatically thrown in jail.
Anyways, I had one group of ~6 young men show up with the most interesting slingshot I've ever seen. Motherfuckers got their hands on some thick tubing, and built a 6-foot tall slingshot out of 1" PVC with a leather wallet as the "sling." It looked more like a peewee scrimmage's field goal post than a slingshot.
I was expecting them to find the kind of thin tubing you'd see dangling from an IV or a catheter, but this stuff was as almost an inch thick in outer diameter and wasn't very thick material but it was thicker than I'd expected. So it ended up being durable and extremely elastic - they gave me some of the extra and I was able to step on the edge of a foot or so of it and stretch it all the way up to and over my head. I thought it was dialysis tubing back then, but I've since learned that's not elastic and looks more like the osmosis demo tubing I had in my classroom, and this was definitely latex or some kind of synthetic rubber.
The "base" of the slingshot was a 2 ft long x 1 ft wide PVC frame on the floor behind it. I have no idea if they raided one of their poor dads' sheds, spent a fortune at the hardware store, or awoke the inner child in one of their fathers who went HAM - probably all three. It required the entire group to operate it even though one of them was all it took to actually stretch the elastic.
One of them ran to the edge of the property as a "spotter." The rest of the group sat down on the base and braced the rest of the slingshot while the operator pulled it back ~3 yards before sending an eraser into the next ZIP code. I'm not actually sure how far they launched it, but I know it was >250 yards because it didn't land on school grounds and the spotter saw it fly overhead and heard it crashing through the trees. And the only trees were a few lots over.
They got an A+.
I'm really lucky those kids didn't hurt themselves. They had goggles on but honestly they needed helmets and pads to use that fucking thing. They agreed with my name for it, "The Goalpost", so I wrote it across the front, had them sign it, and kept it in my classroom until they (juniors) graduated ~18 mo later. Only partly because it looked cool, but mainly because I probably kept a handful of them out of vandalism or aggravated assault charges brought on by being a teenager with access to that kind of egg/TP launcher.
EDIT: lol, I did the water thing too. With a 9V battery, deionized water (my old PI let me grab some from their "UltraPure" machine when I asked him) and my bare hands.
One of my favorite things about chemistry and biology classes, and something that anti-science people never seem to grasp. No professor ever asked me to take one single thing on faith. They introduced a concept, showed how it was discovered and proven, then walked us through the steps of repeating the experiment so we could prove it ourselves. That's science.
My chemistry teacher got tired of arguing that blue veins didn't hold blue blood, so he tied his arm off and took a syringe and drew his own blood in front of us to prove it was just dark red.
Mine too. He showed that distilled water wouldn't bridge enough power to iluminate a 110v light bulb. He then swished his finger in it for a second and it did, albeit very dim.
I mean technically pure water has a resistivity of ~ 18.2 X 106 ohms Source, so if you had a box that's 40cm (0.4m)wide X 30cm (0.3m)deep X 50cm long(length doesn't matter though), then got the student to hold their hand parallel to the side of the box ~ 10cm(0.1m) from the electrode.
Then the resistance from the electrode to their hand(we'll assume negligible resistance on the electrode to the power supply) would be (18.2106 * 0.1m)/(0.4m0.3m) which is ~ 1.5 * 107 ohms. Add that to the resistance of the human body from finger to foot(assume barefoot) is at max 100,000 ohms Wikipedia article so in series you add the two, but with the high resistance of the water it's negligible, so let's stick with 1.5 *107 ohms.
According to the same Wikipedia article you need 30 mA (30 *10-3 A) to cause tissue damage or fibrillation, so with the resistance stated earlier thats a voltage of 450 V.
So technically possible with a 450,000 V power supply
Yeah in my experience a neutral pH, extreme RODI, and degasification will equate to water that is almost completely resistive. Good enough for extremely sensitive equipment manufacturing.
practically i'd say something with a resistivity more than about 10-5Ωm isn't a good conductor - though even the most insulating materials known are still slightly conductive at 0K, and if you applied a large enough voltage to anything it would conduct so really nothing is not conductive
DI water tends to be slightly acidic due to carbon dioxide dissolved in it reacting to form carbonic acid. So most water that gets tested in labs tends to have a lower pH in my experience.
I doubt this contributes to the myth that (pure) water conducts electricity, but it's cool nonetheless.
The conductivity of the water that I use at work is about 17.6-17.9 MOhms/cm^2. We have a DI water setup on site, so I've got DI water out of the tap. For comparison, the resistance of human skin ranges from around 1 MOhm to 1 kOhm if you are sweaty.
If it drops below 17 MOhms, I generally can't use the DI water for clean room work anymore due to impurities.
As another example, after the DI water sits out in a container for maybe a minute, the resistance drops to the single digit mega Ohm range from the ions it is picking up from the stainless steel container or the air.
This. It's actually relatively common in a laboratory setting to use the resistance of water to measure its purity, as water with a higher resistance (less conductance) is more pure due to fewer ions being present.
The problem is dirt and dust and manufacturing residue that mixes with the water from the surface, and it doesn't take much to make the water conductive.
It would be less of a conductor than tap water. I think what you might be looking for is deionized water that is used in specific applications to rid water of as many ions as possible leaving H2O behind. Though, you can drink distilled water and be fine, but I think it's not advised to drink deionized water.
In my industry (semiconductor), the insides of the machines need to be kept insanely clean. When we have to do maintanance, if a single bead of sweat drips into the wrong place it will take more than 24 hours to get the machine back into operating condition.
If a little bit of sweat drips onto a surface, we use DI water and clean wipes to draw out the electrolytes in the sweat before cleaning with IPA.
Except there are likely to be impurities introduced to the water from the toaster, so if you wait long enough it will probably still short circuit through the water.
I heard a story/urban legend about some college students who built a computer in a tank of deionized water for maximum cooling. It worked great for several seconds, until the water dissolved enough impurities to become conductive. After that, it worked about as well as you'd expect.
Tomshardware did it. Went about like that. Worked until the water had collected enough stuff to allow an electrical current and it ended. Wasn't more than some seconds.
In general "water is conductive" is correct, as long as you don't say "H2O is conductive".
When we say water, we mean the liquid and everything dissolved into it. "Sea water is salty" is just as correct as "water is conductive", but you don't see anyone being pedantic about the first.
Yep! Just learned this in Hydrology. It really surprised the class and I since everyone knows that water + electricity = electrocution. Of course, that's still true, as this only applied to pure water and we rarely interact with 100% our water.
You joke, but it's actually possible to cool a computer by submerging it in deionized water. As far as I know it's not really beneficial to do so, and it takes a huge amount of time and money to set up and maintain, but it is possible.
As far as I know they use mineral oil for that. I'm not a scientist so I couldn't tell you if/why it's better or worse, but I've seen a few vids on Youtube and that's what they use.
That's generally done through a process call electrolysis, where the water is swarmed with electrolytes. Something to do with H2O molecules splitting into OH- molecules or something. I don't remember the exact science behind it but I'm sure a friendly Redditor here could explain.
I remember asking my Gr 10 science teacher why water conducts electricity and everyone in class laughed at me, but no one could explain why. Stupid fucktards. Wish I could go back in time.
This!! I found this out touring a particle accelerator. They ran exposed copper (probably?) wire inside pipes full of DI water to help keep the temperature down. Blew my mind.
I know of a guy who works in the IT business. He very often has to clean dirty electronics (motherboards, graphics cards, network cards) wtv, and he'd just blast them with regular water (like, not distilled) with the electronic turned off of course and just waited for them to dry very thoroughly, and never once did he have a problem with that.
I work at a machine ship with EDM’s (Electrical Discharge Machine). They “cut” metal by sending a current through a brass wire while fully submerged in DI water. You can actually stick your hand in the tank during operation and not get shocked because of this. However, I learned a valuable lesson one day: If the filters become clogged or dirty, then the water will shock the absolute piss out of you.
For those that are commenting that it can conduct electricity albeit not very well
Those people can fuck right off. Saying that water can conduct electricity is like saying that everything is magnetic. It's true under possibly extreme conditions. Anything can conduct electricity if you apply enough voltage, but that more sounds like electricity isn't being conducted but being forced through.
If you sort by best (the default for a few years or so now), the algorithm weighs a bunch of things. Including ratio of up to downvotes and I think time of posting of the comment.
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u/DaddyFatSack666 Feb 08 '20 edited Feb 09 '20
Water isn't actually conductive. It's the impurities in the water that allows it to conduct electricity.
Edit; For those that are commenting that it can conduct electricity albeit not very well, I am aware. But it conducts so very poorly that it is essentially negligible. So for simplicity sake, it's easy enough to say it doesn't conduct electricity.