Regelation is a really cool science trick where ice melts into water when you press on it, and then turns back into ice when you stop pressing. This article will show you how to do a simple experiment to see regelation in action using a guitar string and a block of ice.
To try this experiment, you’ll need:
Here’s how the experiment works:
The thin string is important because it can cut through the ice more easily.
Even though it was warm in Sydney, the experiment worked great! As the string pressed down on the ice, it started to cut through it. This showed how regelation works: the pressure from the string made the ice melt into water.
After the experiment, we saw that the string had gone through the block of ice, leaving a clear path. Amazingly, the ice was still solid! This showed that the ice melted under the pressure of the string and then refroze when the pressure was gone. This is the magic of regelation!
This experiment is a fun way to see regelation in action. It shows how ice can change from solid to liquid and back to solid just by changing the pressure. This is a neat way to learn about the basic ideas of physics and how pressure can change the state of matter.
Did you know that regelation is why you can make snowballs? When you squeeze snow in your hands, the pressure melts the snow a little, and when you let go, it refreezes, holding the snowball together. Science is awesome!
Try the regelation experiment yourself! Gather a guitar string, two bottles of water, and a block of ice. Set up the experiment as described in the article. Observe how the string cuts through the ice and discuss with your classmates why the ice melts and refreezes. What do you notice about the path left by the string?
In small groups, discuss other examples where pressure causes a change in the state of matter. Can you think of situations in everyday life where pressure causes melting or freezing? Share your ideas with the class and see if you can come up with a list of examples.
Use clay or playdough to create a model that demonstrates how pressure affects ice. You can use a string or a thin wire to simulate the pressure. Explain your model to the class and how it represents the concept of regelation.
Learn how to calculate pressure using the formula $P = frac{F}{A}$, where $P$ is pressure, $F$ is force, and $A$ is the area. Measure the force applied by the water bottles and the area of the string in contact with the ice. Calculate the pressure exerted on the ice and discuss how this relates to the melting and refreezing process.
Conduct a mini-experiment with snow (or crushed ice if snow is unavailable). Try making snowballs with different amounts of pressure. Observe how the pressure affects the snow’s ability to stick together. Discuss how this relates to the concept of regelation and the science behind making snowballs.
Regelation – Regelation is the process of melting under pressure and refreezing when the pressure is reduced. – When we pressed the ice cube with a wire, regelation occurred, and the wire slowly cut through the ice.
Ice – Ice is the solid form of water, typically formed when water freezes at or below $0^circ$C. – In winter, the pond turns into ice, and we can see the solid water covering its surface.
Water – Water is a liquid at room temperature and is essential for all known forms of life. – We used water in our experiment to see how it changes from liquid to solid when frozen.
Experiment – An experiment is a scientific procedure undertaken to test a hypothesis or demonstrate a known fact. – Our science teacher showed us an experiment to demonstrate how plants absorb water.
Pressure – Pressure is the force applied perpendicular to the surface of an object per unit area. – We learned that increasing pressure on ice can cause it to melt, even if the temperature is below freezing.
Solid – A solid is a state of matter characterized by particles arranged such that their shape and volume are relatively stable. – Ice is a solid form of water, where the molecules are tightly packed together.
Liquid – A liquid is a state of matter with a definite volume but no fixed shape, adapting to the shape of its container. – When the ice melted, it turned into liquid water, filling the bottom of the glass.
String – A string is a thin piece of material that can be used to demonstrate various physical properties in experiments. – We used a string to measure the circumference of the balloon before and after it was inflated.
Physics – Physics is the branch of science concerned with the nature and properties of matter and energy. – In our physics class, we learned about the forces that act on objects in motion.
Matter – Matter is anything that has mass and takes up space. – Everything around us, including the air we breathe, is made up of matter.
