I have a glass water bottle with some water in it and I have a container of really hot water and I will place this water bottle into this hot water container. So let's do that. Okay, now at this point I want you to predict if anything will happen to the level of the water inside the water bottle. Will it stay the same? Will it rise? Will it fall down? What will happen to the level of the water inside the water bottle? Take a prediction. Alright, let's see. So this is the level of the water at the beginning. Okay, I have sped up the video so it this video took around 5-6 minutes but I have sped it up. So you see it in a much shorter duration. Well, what do we see? The level is rising, right? The water level is rising inside the bottle. This is the new level of the water now. How is that happening? Think of it. Why do you think of an explanation?