Hi everyone, welcome back to Cody’s Lab so you may have seen the party trick where you take a glass bottle fill it most of the way up with water and then smack the top. As you can see that blows the bottom right out of the glass. So what happens here is we shove the glass downward so fast that the inertia from the water keeps it more or less in place and that creates a vacuum bubble beneath the water and then when the glass stops moving the water slams back down into the glass creating a sharp water hammer effect which blows the bottom of the glass right out. So this got me thinking what if I used mercury instead of water you see right here is 15 pounds of liquid mercury mercury is so much heavier than water that I would expect that if the water is left behind mercury will get left behind even more and mercury has a lower vapor pressure so the vacuum will be even harder.
So theoretically mercury should be the perfect material for this. Why don’t we put mercury in the bottle and find out. It’s significantly more heavy this time, so let’s hold it right there and then smack the top, that’s a lot of mercury good thing i got it contained in this big dish and here we go. I didn’t even hit that hard. Just a little tap and it just shoved the bottom right out of that bottle. Excellent! That was perfect! Did you catch it? I’ll get my sleeve here…shake everything off. All right. Let’s check the high-speed. So, watching this high-speed I don’t really see a cavitation bubble forming at the bottom of the bottle but i do eventually see the bottle break at the bottom so I suspect what’s happening here is the mercury is like sticking to the sides of the glass and you just can’t see the cavitation bubble.
But Man the the splash when the mercury hits the water sure looks amazing doesn’t it, I did this into water so that the water would splash and not the mercury. Ok so this time I have roughly the same mass of mercury as I did water as you can see mercury takes up a lot less space for the same mass because it is so much more dense let’s see if we get the same effect as we had with water lickety-spit it shoved it right out well that’s messy that time too. Okay so now we’ve proven that mercury does indeed below the bottom of the glass much better than water does in fact I want to try something that I’ve always been told not to do. You see I’ve been told that if you shake a glass bottle with mercury in it that I could cause a cavitation bubble at the bottom and cause the mercury to shatter the glass and I’ll see if I can recreate that here so. I’m just going to vigourlously shake this maybe not so much that it throws mercury everywhere let’s see if I can get the mercury to break the glass.
So, I’m not going to hit it just gonna shake it Ready on the Camera? it seemed that no matter how hard I shook it, the glass wouldn’t break due to the mercury and I think it’s because when I shove it down the mercury like kind of flows out and around and it would let air get down underneath of it and then when the mercury slammed back down there air would cushion it maybe if the right conditions happened it would break the glass but I couldn’t recreate it here today.
To finish off I’m gonna break this one more time with a little bit wider shot on the high-speed so until next time I’ll see you then. So I put some more mercury in there along with a little bit of water. Lets hit this again and see what it does. Now it broke. Did you stop it? Ok, now we’re done. [music].