You will find that when you reach the surface of the water, the small flame wobbles, as if it were in danger of going out in the next second. However, a wonderful phenomenon appeared. Not only did the candle not go out, but even when the water overflowed the candle tube, the small flame did not go out, and a magical lighting landscape appeared in the water. It was found that a thin cylindrical wall was formed around the burning groove of the candle. The wick of the candle has reached the surface. It turns out that the candle liquid is hot and the water is cold. When they meet, they will form a round protective layer around the candle. Stop water from entering the wax tank and reaching the wick, the candle will not go out, and we will see the candle burning in the water.
Candles will melt into wax oil when burning, and wax oil will solidify around the flame immediately when it meets water. Then you must be wondering, why doesn't the candle tube melt when the flame is below the water surface? Water plays a key cooling role, so that the candle near the water will not melt due to the burning of the candle core, so that the water is separated from the outside by the unburned wax layer for a long time, and the candle in the middle is protected from burning until it can burn to the bottom of the cup. This is because water can quickly take away the heat from the candle tube, so the candle tube can protect the flame from burning! The liquid pressure on the lower surface of an object immersed in it is always greater than the pressure on the upper surface, so the direction of buoyancy is vertical upward. If the object is in good contact with the bottom of the container so that the liquid can't soak into their interface, the liquid can't give upward pressure to the lower surface of the object, but the upper surface of the object will be subjected to downward pressure.