PHYSICS IS AN INTERESTING SUBJECT

Physics is an fantastic subject where many facts make us wonder.I wanted to share that i read in an article.If you find yourself in an cold weather where there is no possibility of making fire then choose a block of fresh water ice and chop off a chunk of ice about a foot in diameter and ground it down with sharp tool and polish it with hand to make it convex shaped ice.Now expose the surface of ice towards sunlight,keep a paper or flammable material on the other side then immediately you can notice that the fire is ready.You can try this in your home if you have a refrigerator and concave shaped vessel to fill the water.Another interesting experiment that you can try is to take a cigarette paper of length 6 cm and breadth 4cm and fold it down the middle along length and breadth and again unfold it.The point where two folds meet should be the center of gravity of that paper.Now fix a needle on a table and keep the center of gravity of the paper on the head of the pin.Bring your hand near the edge of the paper.The paper begins to rotate and picks up speed slowly.The heat of your hand sets the convection current that forces the paper to rotate.