MythBusters Episode 19: "Killer Quicksand"
Air Date: October 20, 2004
"Killer Quicksand" like in the movies (i.e. quicksand that slowly sucks any person or animal unlucky enough to fall into it under) really exists.
busted
Quicksand is denser than water; the greater the density, the greater the buoyancy of objects within. Any victims found in quicksand likely died for some other reason (i.e. exposure to the elements).
One can be killed by dropping an electrical appliance into a bath full of water.
confirmed
The current in most electrical appliances is well above the levels the human body can withstand. The electrocution effect is increased if the appliance drops farther from the drain or if the water has more salt in it (such as due to urine or epsom salts). They also proved that devices (and probably by extension, sockets) with GFCIs are effective at preventing these electrocutions, as a GFCI-equipped hairdryer cut off on contact with the water.
Tattoos can explode when exposed to an MRI.
busted
The compounds in the pigments of most tattoos simply do not react to magnetic fields. Old pigments of the color black, which had iron in the composition, could cause some discomfort at most.
The current in the appliance is irrelevant, since it’s in the appliance, not in the person. The voltage in the appliance (at least 110 volts) is what matters.
June 23, 2007 at 7:33 PMThat statement doesn’t make sense bryan. Humans can withstand quite high voltages. If there is no current behind the voltage it wont kill you. Current kills, volts dont.
June 24, 2007 at 4:39 AMUm…wikipedia saya that quicksand could be pretty dangerous, it may not be the most reliable, but, according to it anyway it wouldn’t be called a ‘myth’ and especially not one that’s been busted.
June 25, 2007 at 10:32 AMWhile that’s true, Tim (and you make more sense than Bryan does), amps and volts are obviously related. It’s like arguing that it’s not the gun that kills you, it’s the bullet. Obviously that’s true, but without the gun the bullet is harmless (I know it’s not a perfect analogy, but it illustrates that there’s a relationship there). Higher voltage for a given resistance results in higher current. It’s like if you tape your mouth to a hose and turn it on–you’re going to get hurt by the water flowing through (analogous to the current), but without the water pressure (analogous to voltage) no water will even flow. Having indicated all this, the thing that’s really the biggest factor here is the resistance. I can stick my finger into a small electrical appliance & it will hurt but probably not kill me, as my dry skin has a high resistance. But when my skin is wet the resistance drops to maybe a tenth of what is was originally, and the current increases dramatically (of course the actual measured resistance depends on several factors, but this is the general idea). When the water is salty, there are a greater number of ions conducting the electricity (meaning resistance drops), meaning more current will flow. Of course, the inside of your body is an excellent conductor–run that electricity directly into an open wound, and fuggedaboudit! As a side note, I wonder if you would get hurt at all if you were bathing in distilled water (it’s a poor conductor by itself)?
June 30, 2007 at 5:10 PMIf killer quicksand is busted, please explain to me how bear grills from man vs wild was just in some up to his neck and could barely move. he only escaped due to his knowledge from survival experts.
July 9, 2007 at 11:07 PMRe: nikk
Easy. 2 Reasons:
1)He had to try to pull himself that deep. 2)River “quicksand” is usually a mud/sand mix. The mud does not flow like the sand and prevents water/air from replacing the mass of the sinkee, forming a vacuum, making escape much more difficult.
Granted in the Mythbusters episode, the quicksand they created was way too watery (way too much water pressure at the bottom. The QS was really just sand being stirred up by the upflowing water), even the mud/sand/water mix still exceeds human density and you will not sink below chest level without helping it.
Also, the myth was that the QS would pull the victim under. Again, it cannot without the victim helping. You may not be able to escape, but you wont go under either.
July 10, 2007 at 4:37 PMi actually encountered a very small amount of quicksand on a beach with large grains of sand, i was wearing wetsuit booties and didn’t feel as much pressure as i normally do from that depth of water. i don’t know how this occured, but there was running water (probably fresh) about an inch or two under the sand, and when i lifted my foot out the sand, it returned to a smooth undisturbed surface. this occured at fort ross, for those that are northern california divers, or ab divers.
July 16, 2007 at 7:33 PMI am still not convinced of the electrocution effect in a bathtub. For excample most bathtubs today are covered by enamel or are made of plastic and the drain is also plastic. So I don’t see the current going anywhere. Do you?
August 10, 2007 at 11:35 AMI disagree with the quicksand myth. In most places where you would find quicksand it’s not just sand and water mixed alone. Usually there would be mud and maybe even clay mixed with it. I myself have been trapped in quicksand and have sunk up to mid thigh within 10 seconds. Nor could I get out under my own power. Someone had to pull me out with all of their strength and mine. And you also won’t sink any deeper than that unless you try to get yourself out which by moving will sink you even deeper.
August 21, 2007 at 12:28 PMOkay, please explain this as i’m smart, but maybe just as stupid.
I took an 2-prong extension cord and plugged it into a house wall-socket, non-GFC.
I then put the socket end into a wide-mouthed plastic bottle full of clean water and shook the plug end for a awhile to get out any trapped air and to assure electrical contact with the water.
I put my finger in the bottle’s water - nothing. Nada, no AC 125V shock.
So, i started putting in salt, both epsom and table salts, as i did this i’d keep testing the water with my finger, nothing.
Finally, after mucho salts i started hearing a humm from the bottle, and the cord started to warm up, so i unplugged the cord and removed the plug from the bottle.
Itasted the water, which was extremely salty, like maybe 5x to 20x what sea water tastes like, no one is going to take a bath like that normally.
The Humm i think was the Hertz of the AC, it actually vibrated the bottle.
The Warmth was caused i believe by the Resistance decrease in the brine solution i created by adding those metal salts.
I was bare-foot on a linoleum tiled bathroom floor, i lacked a grounding rod or pipe, i used my finger not my whole body, i have experienced shocks before from touching bare metal contacts in household AC, but i did not experience shock in this test (as i expected).
I have taken huge amounts of volts at very low amps for fun, remember that carnival machine where you’d hold onto the two metal handles to see how much you could take? Well, i have little problem holding on till the max, it was a fun thing!
Somebody explain what is actually the shocking factor here.
August 30, 2007 at 2:58 PMIn killer quicksand surely where quicksand would be found there would be a fairly large amount of water and sand present. So i find it difficult too believe the experiment to be true. In the test they used a large container,pumped watr into that container but the airated sand would just settle under adams weight in the container because there is no where for it to go in the confines of the big tank. If you walked into quicksand there would be more chance too sink further coz the sand and water mix would be able to spread further away from the person sinking.
September 2, 2007 at 3:01 PMIt is the amperage which kills. 300 mA (.3 Amperes) is enough to kill you, if it is across the heart. Current makes the muscles contract. Without the chemical message to relax, the muscles continue to contract - hence the heart stops pumping. Otherwise larger amounts of current are required for electrical burns. We (science teachers) regularly use up to 100,000 volts safely in classroom demonstrations from Van de Graff generators, but with very little current (almost none). Chemically pure water will not conduct a current, it must have something dissolved in it for conduction. If everything is nonconducting, then a current should not flow. HOWEVER, do not run a risk - DO NOT temp fate. Drinking water is not chemically oure, and any leak connecting to a metal ground will conduct a possible fatal current.
October 19, 2007 at 9:28 AMStephen got it right. It is the resistance that determines fatality not voltage or current alone. The 300mA figure quoted by Michaud is the average current needed to disrupt the heart rhythm of a human being. This number is based on the average resistance of a person when the contact points are on either side of the person. You can’t just inject 300mA of current into an object. You have to raise the potential across the chest to a point where current will flow. Depending on the contact resistance of the person this could be a low voltage (a few dozens) or a high one (a thousand). As a pragmatic matter every voltage source also has a compliance limit (current limit) that determines how much current can flow out. Demo Van Der Graff generators have a built in limit based on the size of the sphere and the charging mechanism. No matter how much voltage you have there is an upper limit on how much current can flow out of the device when a circuit is completed.
The other piece missed by many in these articles is that you must complete a circuit for current to flow. This is how a GFI does its job. A GFI trips because the flow out of the hot side doesn’t match the return from the low side. A large enough difference means there is a “leak” and causes the breaker to trip.
Getting electrocuted requires more than proximity to a voltage; it requires being in the path to ground. So, yes, if the toaster is dropped in close to the drain then the person might live*. If it is dropped in on the far side so the current has an opportunity to flow through the person then they are toast.
* Note the “might.” In a typical entry level physics lab students put electrodes on either side of a small tray of salt water and measure the potential at various points about the tray. The numbers lead to a determination of something called the electric field in the tray. If you are positioned in just such a way so that the change in electric field strength over the width of your body is large enough then even if you are not in a direct path between the toaster and drain then you might get nailed anyway. Electric fields can take on some unusual shapes given weird electrode geometries and the material in between the electrodes but, in general, they decrease along the path from high to low.
Personal note: I have experienced a 10,000V shock from a laser power supply that wasn’t adequately discharged. The capacitors were fully charged and the rating of the device was was such that it was capable of delivering plenty of current (big laser require big power supplies). I survived because the bolt of lightning went across my hand and not through my body. I was lucky, there were no lasting effects. People do survive getting struck by lightning. They live to tell the tale because enough current is conducted around the person and the electric field is not steep enough across the body to induce 300mA across the heart.
October 20, 2007 at 7:36 AMeven still the drainpipes in most modern houses is not metal and I do not see a good path to ground. Furthermore I do not believe Mythbusters ever mentioned weather a standard circuitbreaker was in line with the appliances they tested.
October 27, 2007 at 8:28 AMEnyone have any comments on this???
yes I agree, my drain is not metal, nor is it grounded to anything. My water valves are not attached to the tub, and the feedpipe is isolated with a nylon gasket and my tub is coated with nonconducting enamel and it too is not grounded to anything. I also understand that electric fields may have some effect but they have a tendency to cook my food and not electrocute it. All theory aside I believe it is reasonable to assume that you must have a completed circuit for current to flow and it needs to be the path of least resistance. It seems to me that if I had a hot wire and a return(ground) wire that were seperated by at most a few inches, that the path of least resistance would still be between hot and return and not to a metal grounded pipe that may be three feet away if it exists at all. finally I am not sure weather putting copper paddles into the chest of a dummy is an accurate way to measure current flow accross the heart of a human. Perhaps Mythbusters has more explaining to do.
October 28, 2007 at 7:20 AMYes Max and this would explain the results that Cor’e got in his experiment as explained above. He is a braver man that I.
October 28, 2007 at 7:24 AMHey, i’m back! =)
Thanks for the additional insights, my whole experiment was ungrounded (pun) and having a house fuse inline just keeps the wiring from turning into toaster elements, which saves a house from burning down, fuses do little more than that to save a life.
To save a life you’ll need a quality GFC. GFCs work well in a controlled environment, like a insulated-wired house, but consider that there is an ongoing movement of energy all over the Earth, between Earth and Air, and all living things inhabit this shifting energy field environment, few have noted that even our skin is adaptable to these energies, continued small electrical shocks to most living flesh will actually create a higher resistance, which will recover again to a lower resistance some time after the shocks pass.
Consider that fiberglass or enamel (glass+pigment bonded to a metal base) is an insulator(stove, washer, dryer, bath), plastic pipes are insulators, water to a large degree is an insulator, woods are to a very large degree insulators, most tiles are insulators, dry cement foundations are insulators, even most paints are insulators, on-and-on. Seems like we are well insulated by our house, many an engineer made it this way to protect you!
In fact, a house built to code these days should have only two very long metal rods penetrating the Earth near the foundation used as grounding (most water companies have stopped using metal pipes to connect to your home water meter) and those two rods need to hit a source of soil moisture to actually ground and bleed off a lighting strike, or static surge, or electrical fault.
Tasers are quite common for defense, physics labs are common to schools, and kids love to stick metal things into the wall or toasters, and for that reason maybe we should educate ourselves to the facts rather than myths. What will or will not harm or kill you is actually very helpful and intersting to learn about. Since there are so many myths put in the minds of people it is actually dangerous to live with these people’s irrational fears.
So, i felt no electricity i think for several reasons: not being close enough to electrical field and a lack of grounding where the field could possibly go (plastic bottle). As i added metal-salts the field enlarged, but still i felt nothing because also my skin was not sensitive enough. To be sure, the sound of energy turning into an audible hum and heat was a clear signal that i was going to trip the house breaker. And up to last bit of salt added i felt no sensation of the current or voltage from my fingers, but unplugged the cord to save a fuse trip.
I do not think i could have gone as far with a GFC outlet, nor would i want to try this with a properly grounded 3-prong extension cord for some reason - though i do not know what that reason may be yet… Hope some one learned something useful with all this stuff. Be safe, take cares. Happy Holidays too. (Be careful touching wet Xmas lights). =)
November 4, 2007 at 5:03 PMQuicksand can also be combined with escaping gases, CO2, methane and the like - and Mythbusters proved that escaping gases in water can sink a ship. That would change the density of the quicksand so a human body could sink much more rapidly, and totally.
December 16, 2007 at 8:40 AMOne can be killed by dropping an electrical appliance into a bath full of water.
Bryan H: is right, the current in the appliance is not what kills you. It is the current that passes through your body.
Voltage is important because you can not effectively develop current in the human body with low voltage. Most appliances used in the household are 110 to 120 volt by design. In most of Europe the voltage for appliances is 220 volts!
January 3, 2008 at 7:48 PMif you have a high voltage combined with enough amperage it can kill you also low volts high amps kills as well. you just need the right combination of each
January 9, 2008 at 10:20 PMI watched the Quicksand Episode and they changed their limit on what would stop a heart from 60mA to 6mA, wouldn’t this be incorrect? In episode three The Barrel of Bricks they measure 60mA as a lethal current, what gives?
January 17, 2008 at 12:32 AMWhomever came up with that conclusion is wrong. The reason is the path from the “hot lead” to “ground” would not be through a human body being in the bathtub. The path would be between the two or three leads within the appliance. ALSO, what they did not account for, is the fact that electrical outlets in bathrooms are equipped with GFCI “ground pulse” sockets, which would trip the circuit breaker immediately even before a short circuit.
While the voltage and amperage from an electrical socket is enough to be fatal to a person, it would never go through that person’s body.
Bryan H. is correct. The amperage is irrelevant. The reason is Ohm’s Law, E=IR
“I”, which is the current, varies with the voltage and the body resistance. You can have all the current in the world AVAILABLE or non-existent, and that will change when the circuit is completed. When it is completed, the amperage is dependant on the voltage and resistance.
I am a retired electronics technician with a 2nd class FCC license
February 20, 2008 at 6:04 PMrussian:>
if you have a high voltage combined with enough amperage it can kill you also low volts high amps kills as well. you just need the right combination of each.
Bobby> Partly correct… If you have high voltage, the resistance of your body will determine the amperage. Ohm’s Law is E=IR or the voltage = Resistance multiplied by the amperage. Since the voltage and the resistance are constants or known, I=E/R or amperage is determined by dividing the voltage by the resistance.
Low voltage normally will not kill you because the human body dry, has about 20,000 ohms.
February 20, 2008 at 7:50 PMS D Michaud:>
It is the amperage which kills. 300 mA (.3 Amperes) is enough to kill you,
Bobby> Going by Ohm’s Law, if you have ZERO volts, you will have ZERO amps. If you have ZERO amps, you have an open circuit or an infinite amount of resistance. E=IR If “E” or Voltage is Zero, then the product of “I” and “R” must be ZERO. While the Resistance can be anything, (it will be an open circuit) “I”, or the amperage must be ZERO.
February 20, 2008 at 7:57 PMTim: >
That statement doesn’t make sense bryan. Humans can withstand quite high voltages. If there is no current behind the voltage it wont kill you. Current kills, volts dont.
Bobby> Again, using Ohms Law, the only way you will have no current, is if you have an open circuit or infinite resistance IF you have EMF or voltage. You can have an infinite amount of voltage with no current only if you have an infinite amount of resistance or an open circuit. High voltage WILL kill you, because if you complete the circuit, you will pass lethal current through your body.
February 20, 2008 at 8:02 PMConclusion: Dropping an electrical device such as a hair drier into a bathtub filled with you and water will NOT be lethal.
The “confirmed’ by Myth Busters is wrong.
February 20, 2008 at 8:04 PMHere is an experiment that you can try to verify my claim that Mythbusters is wrong. Get an aquarium with water, add some salt in it, and a live fish. Then drop any appliance into it. I will bet a dollar to your dime that the fish will not die, or even react to the electricity.
You do not have to use a GFI (Ground pulse) outlet.
February 24, 2008 at 12:43 AMI know that it is possible to die from dropping a appliance into a tub of water. But, there are too many varibles. The water needs to be salted. The current if you happen to have a outlet that if the socket is not the gfci type. And you need to be close enough that your heart is in the water low enough or close enough to the path of the current. Meaning that if your just standing in a tub of salty water, you may just end up makeing your calf muscles stronger.
Bobby Im pretty sure that it can kill a person but like I stated there are a lot things to be in place.
March 1, 2008 at 12:58 PMRandy,
I think you may be confused on this. 110 vac can be lethal. HOWEVER, when dropped into a tub of water with impurities such as salts or conductive material, what you must remember, is that all of the water in the tub is conductive.
This would be similar to stripping the insulation of an electrical cord and touching it. Unless you can provide a better path to ground, you will not feel any electrical sensation.
The electricians of old, would pigtail splice 2 wires with their hands after making the contact. The reason is the electricity will take the easiest path to ground.
As I pointed out, try adding some salt into an aquarium, place a fish in there, then put a lamp without a bulb in it but turned on into the aquarium. You will see that the fish will be unharmed unless it happens to swim into the bulb socket.
The Myth Buster’s conclusion is wrong. While the 110 vac can be lethal, dropping it into a soapy or salty bathtub filled with water will NOT be lethal.
March 2, 2008 at 11:08 AMHi Bobby,
You are correct about the electric cord, but, I have to disagree with you on the bath tub. If your heart is hit with the current before it finds a path back down, it will be enough to stop your heart.
Please let me know what you think,
thx
March 2, 2008 at 12:08 PMRandy> Hi Bobby,
You are correct about the electric cord, but, I have to disagree with you on the bath tub. If your heart is hit with the current before it finds a path back down, it will be enough to stop your heart.
Please let me know what you think,
Bobby> The shortest path to ground from the hot lead within an appliance will be withing the appliance, so no measureable current would pass through your body in a bath tub if you are in it.
Now, if you had the hot lead only at one end of the tub in the water with you in it, with the closest path to ground being the drain, the electricity’s path to ground would be the water. With you in it, you would be a part of the water, but it would make no difference because the water, not you, would complete the circuit.
You might try a similar experiment. Take the two leads from an electrical outlet. Put one lead on one side of an aquarium filled with water and a live fish in it, with the other lead in the water at the other end. You will find that the fish would not be affected in any way.
March 2, 2008 at 10:07 PMI think you might be missing something, have you ever had eletro back therapy. where they use elecriciy to strengthen back muscles by contracting them with electrical current.
Well the appliance in the bath tub will provide a effect like that but much greater. If you can imagine the current contracting your heart and this is probably how its leathal. I am certain of the shock when the appliance is innitially submerged.
Please dont try it but I sure you can get hurt or die,
thx,
Randy
March 2, 2008 at 10:25 PMRandy,
When you do that type of therapy, (and I have had it) you are placing the electrodes on different parts of your body, which forces the return to go through that part of your body. There is a huge difference there. When in a bath tub, and an appliance is dropped into it, nothing but the 110 vac forces the electricity through your body, and you must remember that the tub has conductive water in it. (PURE WATER does NOT conduct electricity).
Your body may pass a small amount of electricity, but at 110 VAC, you would feel practically nothing.
Now, if lighting hits a pond, and you are in it that would be a different story, you will most likely die because the lightning will be MILLIONS of volts. 110 vac is very much less than a million.
March 3, 2008 at 12:02 AMBobby
HI Bobby,
If the bath water is salted it will, and getting back to my point it can be leathal.
But there are so many varibles,
thx
March 3, 2008 at 11:09 AMNo Randy,
Because the electricity will take the shortest path to complete the circuit. If the bath water is salty, then the shortest path would be the water. You being in the water would make no difference. You would feel nothing.
As I said, try the experiment with the acquarium and the fish. Certainly, if the electricity will kill a human, it will gill a little fish in an aquarium correct?
You will find that it will not kill the fish. 110 vac in a tub of water, salted or soapy is NOT lethal if you are in the water unless you are touching the only source to ground, and the water is not.
March 3, 2008 at 11:17 AMA better experiment would be to use brine shrimp, which you can get in most pet shops for fish food. Because brine shrimp already lives in salt water, it should make the experiment easier, plus they are less expensive. Surely, if the appliance will not kill a little shrimp in an aquarium, a human should survive much easier.
March 3, 2008 at 2:03 PMBoddy,
I am telling you that I have first hand knowledge of this and fish are not the same as pplz.
fish tank is the same as a bath tub, so you need to do it in a bath tub
March 4, 2008 at 11:52 AMRandy,
March 4, 2008 at 2:29 PMFor your information, I am an electronics technician. While a fish tank is not a bath tub physically, the water is the same.
Bobby
You miss 1/3 of the stuff need to create quicksand.
March 11, 2008 at 1:13 PMYou miss the trap gases altogether
Leaves and things fall in the water/sand and start to rotting forming Gases
The gas get trapped by the leaves above when you step into the Quicksand
The gas is released and therefore the person sinks very quickly
You stop moving the gas stop getting release but if you move around more gas is release
Daniel,
In this case, you also disagree with Mythbusters? I can see your point. Mythbusters says that killer quicksand does not exist. It is possible that they are mistaken again if there are a lot of gasses trapped, because that would make the “quicksand” far less denser than a human or animal.
No quicksand where I am from though.
March 17, 2008 at 2:37 AMQuicksand was not busted, its a known fact to anyone who works in any sand industry that quick sand is not made with sand, but clay btw.
Come to Timmins Ontario, I’ll show you quick sand, the kind that takes your boots and pants even if you get help to get out.
April 22, 2008 at 1:54 PMThough it may or may not kill you, I can say I will not be stepping in to a bathtub and dropping something electrical into it. =P
April 30, 2008 at 11:12 AMJdog: > Though it may or may not kill you, I can say I will not be stepping in to a bathtub and dropping something electrical into it. =P
Bobby> Well, I wouldn’t do that either. While it will not kill you, as an electronics technician, I have felt 110 vac. It is not a wonderful feeling. There is a remote chance that you might feel some of it.
Still, Mythbusters is wrong when they confirmed the myth. The least they could do, is try to prove it by trying to kill an animal like that. The person in charge of Mythbusters did not do a good job on this one.
May 9, 2008 at 9:55 PMRobert Boucher,
May 9, 2008 at 9:59 PMWhile I don’t know much about quicksand, I agree with you. Mythbusters is NOT a very good program because they do make errors.
Quicksand is a mixture of sand, water and salt. The salt is essential in creating the behaviour. There are other forms of mud that can act similarly. However, in virtually all cases, they are more dense than water and the human body, so you float. You can be seriously stuck, and die of exposure, starvation, or drowning if water flows on top (eg in tidal areas). But you won’t go under like in movies.
One exception is peat bogs. Peat is low density, so the mix can be less dense than water, meaning you could sink. The Bear Grylls video however seems to be a bog that’s mostly water, nothing like ‘quicksand’.
Another way to actually go under is if you’re carrying weight. For example if you’re an archaeologist with a backpack full of gold artefacts.
And of course taking a dive head first into quicksand is a bad idea.
May 21, 2008 at 5:01 PM“qucksand” is dangerous in the great outdoors its more clay than fine sand
July 6, 2008 at 10:18 PMand slimy I had a branch handed to me to drag me out I suppose its like a peat bog
because you do sink. I think the “sand” is a dried fungus that looks like sand - this occured in the swamps of Maryland
quicksand is not safe
i am only 11 years old from South Africa, and i did not read anyhting bout you guys typing bout the ummm the…… i think it was somehting bout the tatoo and MRI thing.
September 3, 2008 at 10:30 AMwhy did you not ask any questions bout that?
it’s ampage that kills not volts.
October 21, 2008 at 9:32 AM