Glass transition

Imagine your favorite juice box. When the juice is cold, it's all contained inside the box and stays solid. But when it's hot outside, the juice starts to melt and turns into a sticky liquid that can spill everywhere!

Now, let's focus on the box. This box is made of a special material called plastic. At a certain temperature, the plastic starts to change in a weird way - it becomes soft and rubbery, like gum. Scientists call this special temperature the "glass transition temperature".

When the plastic is below this temperature, it's like the solid juice - it keeps its shape and feels solid. But when it reaches the glass transition temperature, something weird happens. The plastic feels like it's starting to melt, even though it's not really getting hotter.

This weird property is important for all sorts of things we use in our lives, like the plastic in our phones, toys, and even our clothes! The glass transition temperature helps scientists and engineers figure out when a material will start to change in weird ways, like melting or bending, which is really helpful for making things that work well and last a long time.