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Continuing our “what happens when you drop stuff into stuff?” series is this short video segment from the BBC.  As with dropping a magnet through a copper pipe, many of you probably know what to expect, here. But it’s nonetheless cool to see.  Mercury is so beautiful; such a shame it’s also so toxic.


Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.



  1. Anonymous says:

    When he’s not dropping cannonballs into it, what does he use the tub of mercury for?

  2. David Legnon says:

    I thought Mercury vapors were toxic?  Maybe that will be the next featured video in the series.

    1. They are.  But its vapor pressure is so low, it is almost negligible.  So it takes extended exposure to pose significant risk. 

  3. dZed says:

    Seeing videos of this never fail to amaze me for reasons completely different than the ones that are supposed to be amazing. Because I’m not holding the cannonball, I have no sense of its mass, so I’m not inherently surprised that it floats — for all I know it’s styrofoam painted like a cannonball. However, I am blown away that the cannonball doesn’t seem to get WET as it spins in that mercury. It’s like the “dry water” that appeared in one of the Oz books, a concept that I rolled around on my brain for a few days when I was 9, now here, come to life. 

    1. Yet another reason mercury is beautiful, and its toxicity so tragic, IMHO:  It does not wet surfaces.  Which makes it great for building instruments like mercury thermometers.  The instrument can’t work, after all, if the inside of the glass is covered with liquid that obscures vision. 

  4. Wade Sansing says:

    Has anyone else ever held a vial of mercury?  It’s REALLY heavy.  What in the hell is that very thin wall holding a HUGE pool of mercury made of?  Why hasn’t it collapsed and drowned him in the most spectacular heavy metal death ever?  Where the hell do you get that much mercury and most importantly, why?

    I’m kind of wanting to call bullshit on the whole video at the moment, but not really sure yet.

    1. Anonymous says:

      How did you come up with a 32″ depth?  I keep watching the video and can’t figure out where you get your 32″ figure from.

      1. Wade Sansing says:

        Waist high.  The ball sinks when he drops it, so even if it’s a raised tub I’d still have to guess at least a foot deep.  But if it’s a raised tub, only a foot deep instead of 32in that’s still, in the range of what, 7-8 tons?  Again what the hell kind of support would be under that.  If it’s actually mercury I think it would almost have to be a tub sitting on the ground and supported by earth, which means waist deep, ~32in.

    2. Anonymous says:

      Well; the “where the hell” is easy.  There was, a few years ago, an abandoned factory in (Maine?  NY?  NJ?) with barrels full of the stuff. They couldn’t get anyone to take it.  Not sure what eventually happened to it, but I am surprised there’s still someone around with a tubfull of the stuff, and curious as to what he does with it.

      Apparently one company chose to dispose of their surplus mercury by dumping it in the Baltic:,1518,434329,00.html

    3. restifo says:

       The tank could be gusseted….

  5. It would be so amazing to float on mercury, it would probably be like lying on a mattress.

    1. I’ve seen a picture of a guy doing that, from some article about mercury from the 70s.  I want to say it was in National Geographic, but I’m not sure. 

  6. Can we petition Nature to make mercury non-toxic?  It’s so damn pretty and cool; and really, who’s its toxicity helping?