The tough outermost layer of the skin is made up of dead Keratin cells formed from the protein Keratin. While a person is in the pool or a bathtub for a long time, the dead keratin cells absorb water. This absorption causes the surface of the skin to swell. But as the outer layer of skin is tightly attached to the skin underneath, it results into wrinkling.
WHY IS IT HARD FOR KETCHUP TO FLOW INSTANTLY? Ketchup has a strange property of changing from a gel-like thickness to a free flowing liquid. This is termed as 'Thixotrophy'. The word is derived from Greek 'thixis' meaning the act of handling and 'trope' meaning change. This happens because of the ketchup molecules which are in the form of long chains. When the ketchup bottle is left untouched for some time, the molecule chains coil up together in a jumble. When the bottle is shaken, the molecules break apart and become loose allowing the ketchup to flow.
WHY DO GEESE FLY IN V-SHAPE?
Geese fly in a V-shaped formation while migrating as it conserves energy. Each bird flies slightly above another in front, resulting in a reduction of wind resistance. They take turns being in the front, falling back when they get tired. In this way, they can fly for a long time before they stop for rest. Secondly, the V-formation helps to keep track of every bird in the group. Fighter pilots often use this formation for the same reason.
WHY DOES WATER STAY COOL IN EARTHEN POTS?
This is because of a physical process known as evaporation. When a liquid changes to a gaseous state without boiling, it is known as evaporation. An earthen pot is made of mud and has many minute pores. The pores remain the same no matter how tightly you pack the mud. These pores absorb heat from the water inside the pot. Due to this process of continuous absorption of heat from the water inside the pot, the water in the earthen pot remains cool...
WHY DO WE BLINK? Blinking is an involuntary action that protects the eye. It's a kind of safeguard mechanism. Besides it lubricates the eyes wiping out any minute particles of dust keeping the front portion clear for good vision. The eyelid, through suction, automatically draws the fluid we cry with from the well we refer to as the tear duct over the eyeball, to irrigate, and to moisturise the eye. Sometimes, blinking is also an expression reflecting nervousness, loud noises, stress and tension.
WHY DON"T WE FALL OUT WHEN A ROLLER COASTER GOES UPSIDE DOWN?
When a roller coaster is in motion, a lot of Kinetic energy is generated to pull the train up and go down again. When the train goes upside down, it's the inertia that keeps you seated. Interia is the force that presses your body to the outside of the loop as the train spins around. Although gravity is pulling you towards the earth, at the very top the acceleration force is stronger than gravity and is pulling upwards, thus counteracting gravity.
WHY DO PEOPLE SAY 'GOD BLESS YOU' WHEN SOMEONE SNEEZES?
This account is supposed to have originated in Rome when the Bubonic plague was spreading through Europe. One of the symptoms of the plague was coughing and sneezing. A sneeze was believed to be a sign of impending death. It is believed that Pope Gregory VII suggested saying "God bless you" after a person sneezed as "a way of commanding his soul to the care of God."