By Cory Doctorow at 10:14 pm Mon, Apr 6, 2009
Twenty six seconds' worth of science: a cannonball floating in mercury!
Cannonball in mercury
Shouldn’t that guy be worried about mercury vapor?
I think this guy’s got something wrong – his gloves protect him from skin exposure to mercury (small danger) while he leans over the vat where mercury vapors may be (large danger). Any chemists care to chime in?
Cool video, though I would’ve been a lot more careful dropping the ball. Mecury is nasty stuff to be splashing around.
Video is not available already :[ Could just be my brower, maybe. Sounds cool, though.
I recall a pic in National Geographic many years ago of a guy floating on a pool of mercury. It looked like he was sitting on a sheet of aluminum foil; he was just barely sinking in.
I haven’t seen a Mercury splashdown like that since 1963.
That is a crapload of mercury – enough to pollute the great lakes.
The mercury vapor danger (from mining and such) is when mercury is heated and vaporized, IIRC. At room temperature, I don’t think it poses any breathing hazard (though he’s wise to wear gloves).
What I like best is how the mercury doesn’t wet the ball – it rolls around freely in a “cup” of mercury too heavy to be pulled up the sides of the ball as it rolls!
Quicksilver (liquid metallic mercury) is poorly absorbed by ingestion and skin contact. It is hazardous due to its potential to release mercury vapour. Animal data indicate that less than 0.01% of ingested mercury is absorbed through the intact gastrointestinal tract; though it may not be true for individuals suffering from ileus. Cases of systemic toxicity from accidental swallowing are rare, and attempted suicide via intravenous injection does not appear to result in systemic toxicity. Though not studied quantitatively, the physical properties of liquid elemental mercury limit its absorption through intact skin and in light of its very low absorption rate from the gastrointestinal tract, skin absorption would not be high. Some mercury vapour is absorbed dermally but uptake by this route is only approximately 1% of that by inhalation.
In humans, approximately 80% of inhaled mercury vapor is absorbed via the respiratory tract where it enters the circulatory system and is distributed throughout the body. Chronic exposure by inhalation, even at low concentrations in the range 0.7â€“42 Î¼g/m3, has been shown in case control studies to cause effects such as tremors, impaired cognitive skills, and sleep disturbance in workers.
Long term exposure could be dangerous. At room temperature, a single day’s exposure is unlikely to be significantly dangerous.
Youtube video is down, see the video here instead:
Since when did BB become a repository for all the internet flotsam I saw five years ago.
I feel like I’ve entered some weird time warp to the past.
That explains why the T-1000 sank when they pushed it into that vat of molten steel instead of just cooking on the top like most things would. Now if only someone could explain why Gollum sank in magma while an unbearably heavy ring of solid gold sat on top…
Brainspore: evil floats (see witches).
No kidding. That’s an insane amount of Mercury to keep around in one place.
Why does he have so much?
The ring was unbearably heavy because it was more a spiritual burden than a physical one. Gollum sank because he weighed more, physically than the ring, and both of them survived as long as they did because of the magic in the ring. It was only in the fires of creation that such a mighty enchantment could be undone. Somehow I don’t think this is the place for a lengthy discussion of the metaphysics of Middle Earth, so I’ll stop where I am.
It is the vapour from Mercury when heated that is dangerous/harmful.
Hatters used to use it in the treating of moleskins to make top hats and it sent the workers insane.
Thus Mad Hatters.
INterstingly, the massive lighting apparatus in old light houses was rotated by being floated on a mercury bath.
This was about a ton of brass and glass spinning on the mercury bed all powered by a very small crawler gear cog on the edge of the bath that drove the massive cog that ran around the light housing.
you could spin the whole thing with the strength of one finger.
Because he wants to throw a cannonball in it, obviously.
@ Error404 #15 – You’ve topped a great video with some awesome triviata. I am in awe – thanks for a great start to my Tuesday morning, it can only go downhill from here!
@ SCHMOD #14
I don’t know, but with large quantities of chemicals like that, the white gloves and a knowledge of science, it’s more likely than not he’s a terrorist.
Remember: if you suspect it, report it.
Though I know it would be infinitely horrible for my insides, I can’t help but wonder what a tall cold glass of mercury would taste like.
I know. I need help.
My dad used to hold a spoonful of it in his mouth while walking to school, he said he just liked the “heavy feeling”. Hes 56 now.
not that bad,they used to give you a slug of it to clear bowel blockages.
Science, it works bitches!
“Now if only someone could explain why Gollum sank in magma while an unbearably heavy ring of solid gold sat on top…”
#8 At a guess, it’s so dense that surface tension is very strong.
Some people here have expressed concerns over the mercury vapor. In Australia the documentary this is an excerpt from played as part of open education on one of our gov’t channels.
The whole doco is about the science history of mercury and is quite interesting. Anyway, he’s at a Mercury smelter (if that’s the right term) and explains that a vat of Mercury as you see there is not something you’ll find outside such a place and he explains that the room he’s in would be impossible to be in without the major ventilation system above the vat.
That vat has got to weigh a lot. Like, a LOT, a lot.
The 10 ton 100 inch Hooker telescope at Mt Wilson Observatory floats on mercury.
We used to use Mercury baths on some TV commercials.
I would make a 1″ deep 12″x12″ pan of mercury and reflect some image into it.
Through the lens of the camera the image appeared flawless and not like a reflection.
Once the hi-speed camera was rolling, I would drop a Cherry (or whatever the job required) onto the surface, the resulting footage of course blowing your mind and making you want to buy whatever it is what advertised.
Nowadays of course we use computers!
I still have a small, very HEAVY jar of mercury from one of these shoots. We used to buy it from a specialty metals place and then return it to them. They just cleaned it up and resold it.
Now if I want to return this small jar, I have to buy a special cleanup kit from them (required by law). Kit costs around $80 I think last time I checked. I think I might just leave it on their doorstep, ring the bell and run away.
Looks to be about two metres by two metres by a metre deep, and mercury is 13 tonnes per cubic metre, so I’d guess about 50-ish tonnes. So, yeah, probably not on the second storey of the building.
If I had really good balance, could I walk across a pool of mercury?
correction: The 100 ton…
Mercury does not stick to things because it prefers to stick to itself more than it likes to stick to other things. Forces of cohesion are stronger than adhesion. Thus a meniscus in a thermometer that rounds outward instead of inward like water does. (Convex with mercury, concave with water.)
Remember those old fashioned mercury thermometers?
Random info: when I was in 1st grade (many many years ago) we actually played with mercury as part of our science lessons. The biggest fear at that time was that someone would spill it and it would end out rolling all over the floor as little balls that were just impossible to pick up.
Wow, a hooker telescope. What a strange world we live in.
Because it wasn’t made of gold? There seemed to be plenty of evidence that it wasn’t. Or, indeed, as #19 pointed out, Magic.
Anyway, I still enjoyed the clip. Thank you. Those sorts of practical demonstrations are so much more useful than any amount of lectures.
@13 and 19: The Ring didn’t allow itself to sink until Frodo gave up on reclaiming it. Once Frodo looks away and accepts Sam’s help, the Ring sinks.
Oh, wait, that was just a joke, wasn’t it. Sorry.
@ #25 – I found a solution to the problem of picking up little mercury balls as a kid when I dropped a mercury switch. You just hook a couple of wires up to a big battery and watch the cool blue arc as you vaporize each ball! =]
Doesn’t seem to have done me any long-term harm (others might disagree) but it does freak me out a little when I remember leaning over the vaporizing balls.
As for the giant vat of mercury, you can also put a layer of oil on top of it to keep it from evaporating. I believe that’s done with mercury telescopes at least.
Can somebody please decipher what he is saying? Does he say portable? And short? .
..”because the Tarachellie(sp?) experiment is portable. And it’s portable because mercury can’t be short.”
Is that really what he’s saying? BTW all flat glass is formed over a bed or mercury as well. Same with aluminium foil I believe.
50 tons! No wonder cans of tuna are so heavy.
Blacksmiths used to keep huge tanks of mercury around for certain types of heat-treating. They’d float a 1/4″ thick steel plate on top to reduce the amount of loss from vaporizing. If you stick a white-hot piece of metal in a bathtub of mercury, you get some vapor formation. I’ve always wanted a mercury tank.
Yes, I had a science teacher who would dump out a vial of mercury in a wooden tray and invite us to splash it around with our fingers.
Of course, he also used to toss chunks of sodium into the water fountains, so, not a particularly good role model there.
seems a good resource to begin making your mind up about how much is too much:
Methyl mercury is dangerous, as is chronic exposure to mercury vapor. The critical word here is ‘chronic’.
I grew up in the 60s and 70s, and the children of today are impoverished by being so protected from even the tiniest *appearance* of risk.
Poking your fingers into a dish of mercury, or holding a blob of it in your palm, is a lost wonder of childhood.
I think mercury at room temperature has low vapor pressure.
I heard if you drop gold into mercury the gold soaks up the mercury like a sponge and gets messed up.
…and apparently it’s true…
Because I, for one, have never seen it before. But kudos for using flotsam to describe a floating object. Shame that it probably wasn’t intentional.
One more nerd retort and I’ll drop the LOTR thing:
Gollum sank because he weighed more, physically than the ring…
Things don’t float or sink because of how much they weigh, they float or sink depending on how dense they are in relation to the surrounding matter. Gold is denser than stone (molten or otherwise) while meat-based creatures such as Gollum are not.
Though this is probably one of those situations where I should just let it go with the “magic” explanation.
so a cannonball dropped over the side COULD theoretically be jetsam.. on the right planet.
The narrator is saying the Torricelli experiment is portable because the mercury column is short’
> why gollum ring lava
Because it’s just a movie and they got all kinds of things wrong. Gollum sank because the only liquid screenwriters ever splash around in is water and people mostly sink in water. Though not entirely. You could tell yourself Gollum didn’t sink, his body was just burned and vaporized from the bottom up, but that would be giving the movie too much credit. The ring didn’t sink immediately because that wouldn’t be dramatic enough. Though Gollum screaming as he burns to death with the ring in his hand would be pretty dramatic.
Way worse than the ring not sinking fast enough:
The hobbits weren’t small enough. They were supposed to be 2Â½ or 3 feet tall, not 4 like the dwarves, that’s why they are exempt from fighting, they’re too tiny, like small children.
The bizarre “subplot” about Arwen being magically imperiled like Sleeping Beauty by the Ring War going badly, just to shoehorn Liv Tyler into the climax as a damsel in distress, made no damn sense and served no purpose.
Sauron’s “Great Eye” is a spiritual horror at most visible to wraiths and other people with Rings on, and a metaphor for his network of spies, not a literal great big glowing red eye in the sky. The literal big glowing red thing in the sky over Mordor is Mount Doom. A second big glowing red thing in the sky was totally redundant.
NTROPI, mercury will stick to copper. When I was a young boy, the dentist would give me a dollop of mercury to take home. Rolling it around in our hands was fun, but eventually it would get dirty and we would slowly lose bits here and there. However, the most fun was dipping pennies, the mercury would coat the pennies making them shiny like brand new silver dimes.
Torricelli, the short version: Torricelli filled a glass tube with mercury, sealed one end and raised it up out of a bath of mercury. The gap created at the top was indeed a vacuum, which was a highly controversial subject at the time (Thanks Pope!).
He also observed that the level of the thin column of mercury would rise and fall, which he attributed to the “weight of the air” pressing down on the vat of mercury. Essentially, the worlds first barometer. For this reason, we still (in the US) use the outdated measurement “inHG” for pressure.. each inHG being the weight of a column of mercury 1 inch in height at 32 Â°F at the standard acceleration of gravity.
He’s also the namesake of the “Torr”, a unit of pressure equal to one mmHg.
As another matter of fantasy nerd trivia, the Torricelli vacuum experiment is featured in the novel “Eldest” by Christopher Paolini. (King Orrin of Surda is kind of a science geek).
Re #50 et al,
All I get from this subject is the mental image of Gollum skittering around on the lava like a drop of water in a hot frying pan.
I don’t know if an audience what be disgusted or it would just get a huge laugh.
#54 Tharklord – I won’t be able to listen to sizzling bacon now without thinking about “Gollum skittering around on the lava” as that has got to be what the sound effect would be. Too funny!
Ooo… bobbing for cannonballs! Breaks the ice at parties!
Here is a page with that guy sitting on the mercury as well as some other cool photos and information,
So would I be able to bathe in a pool of mercury without dying a horrible toxic death? After reading all this I’m starting to think I could. I don’t want to do it everyday, just once to see what it’s like.
minamisan @ 56 – only if you’re very dense ;)
#51 Your dentist would GIVE you some mercury to play with?! That reminds me of that old SNL bit with Irwin Mainway and his Mr Skin Grafter Kit.
#39: Actually, plate glass is floated on tin, not mercury.
The one ring is intelligent and can make people invisible. Clearly the magical AI indwelling, used up all of its power reserves in a last-ditch effort to lower the local entropy and save itself. (It must err on the side of caution, or have a generous supply of energy; it used the same trick even when thrown into a mere fireplace.)
Right as the ball hit the water I swear I had a nerdgasm. There’s just something about large quantities of mercury that just gets me every time, so much (slightly dangerous) fun. It just seems to defy normalcy in a near magical way. I guess corn starch and water plasticity could come very distant second.
#58 – You can do something similar, but not quite as awesome, by swimming in the Dead Sea. The salt and other mineral content of the water is far denser than regular water, thus you float really strangely. Like you walk out and suddenly when the water is near your waist you lose traction on the bottom. While floating in it, half your body is exposed – I pretended to read a newspaper and realized how “doable” that would be.
For what it’s worth, I would imagine it’s easier and more realistic to buy a ticket to Israel than it would be to buy the mercury yourself or find a place that has the mercury and would be willing to let you bathe in it.
One side note – I’m sure the mercury tastes better than Dead Sea water – I got one drop in my mouth and couldn’t spit enough to get the taste out for several minutes.
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