You may be the type where a simple mention of the word “fishing” conjures up memories of mind-numbing hours spent staring at the end of a glorified stick. It’s been done and you’ve crossed it off your list…to never be done again. Or perhaps you enjoy the simple pleasures and relaxation unique to angling. This experiment involves fishing, but none of the boredom/quiet, smell, slime, hooks and foul live-bait that may or may not strike your fancy.
What you’ll need for this experiment is a large glass full of ice and topped off with water, some twine, and some salt. Cut about eight to twelve inches of the twine and let your crew know that they’re going to use it to catch some ice. Have a kiddo hold on to one end of the twine and drop the other into the water between the ice cubes. Encourage your angler to let the twine sit for a bit and then have them pull it out to see if they’ve caught anything (barring an unexpected surprise, they won’t). Allow for lots of attempts and various strategies at landing a catch.
After you feel that the unsuccessful attempts have run their course, it’s time to adjust things just slightly. Once again, the twine goes into the water and ice, but this time keep the twine on the top of the water, resting on the ice that’s at the surface. Once your twine is coiled on top, sprinkle a good amount of salt into the water. Let things sit innocuously for fifteen or twenty seconds and then slowly have your little fisher lift up their twine. If you’ve done things right, they should pull in numerous ice cubes stuck to their twine. A mighty, magical catch.
The explanation here is simple: the salt you dropped on the ice lowered the freezing point causing bits of the ice to melt. As the salt melts deeper into the ice and water covers the top of the ice, the surface of the ice refreezes and – where the twine was in contact – a frozen catch was made.
Our introduction to At-Home Science is here; our penny-cleaning experiment is here. Scavenger hunts may or may not have anything to do with science (it’s up to the Hunt Master), but we think they’re great.