Fire tornado
Did you know that hot air rises? Imagine you have a candle. The flame of the candle warms the air around it, and warm air always wants to rise. As it rises, it draws new, cooler air towards the flame.
Now, if we place a metal tube around the flame and rotate it, something really cool happens! The rotating tube pulls the air around the flame in a circular motion.
And now comes the fun part: there is a special law in nature (the law of conservation of angular momentum) that says that when something rotates, it can spin faster as it gets closer to the axis of rotation. It's just like when you are on a merry-go-round and get closer to the centre, you spin around faster! So, as the cold air is pulled towards the centre of the spinning tube, it starts spinning faster and faster. This way, the flame will spin and you get a cool fire tornado.