Video "fishing under ice" secrets
Oliver Edwards | Published on 4/1/2024
Some Finish divers decided to create a very funny (and intriguing) video entitled "fishing under ice". Take your time to figure out what's happening in this one. It displays a lot of diving physics. SPOILER ALERT! I'm going to give (my take) on what's happening and how it was done below. I recommend you try to figure it out by yourself first.
you made it. Here's my take on what happened and why.
First of all (and the easiest to figure out) the video is shown upside down. So all the divers are walking upside down on the underwater surface of a frozen lake.
How are they doing this? They adjusted their buoyancy so that the were (I assume very) positive. That means they float, so that their feet push up against the ice, and they can (very carefully) walk upside down on it.
What's that strange fluid "falling down" from them and rolling around their feet? Of course, that's the air they are exhaling, rising in the water column trapped against the bottom of the lake ice.
What does the wheel barrel have in it? That's air also. Notice the diver "shoveling" up the air by their feet, pouring it into buckets, then emptying the bucket into the wheel barrel.
But, How does the air stay in the wheel barrel? Everything's upside down so the air is rising and is pushed into the wheelbarrel (which is upside down in reality).
But, but, how does the wheel barrel stay stuck upside down on the bottom of the ice sheet? The buoyancy of the air holds it up there.
Notice what happens to the air trapped on the ice sheet when one of the divers augers a hole up through the ice! It drains "down" the hole (actually up through the hole) through the ice to escape out of the lake.
Then perhaps the climax! A diver "pours" the air out of the wheel barrel, it drains "down" the hole, and the the wheel barrel "rises" away and disappears. I imagine many of you who were paying attention and thinking about this knows why this occurs. Once the air is out of the wheel barrel, it loses its buoyancy, and so it falls, presumably to the bottom of the lake.
What a great concept! Hope I didn't bore you in this explanation. It took me some thinking so I though I'd share. Please feel free to send me comments or corrections. (newsletter@aquatutus.org)