How and why do we cough? It’s an old form of yoga dude. No. Before explaining the how part, let’s first understand why we cough. Coughing is body’s protective mechanism. Which helps us clear our breathing passage of dust, microbes, irritants, etc. There are two types of cough, wet and dry. They maybe caused due to common cold, flu, allergies, smoking, etc. Now, let us see how we cough. When anything irritates our breathing passage, our brain activates the cough response. First of all, we gasp in, a large volume of air into our lungs. Next, the epiglottis closes off the windpipe. Then, the rib and abdominal muscles contract, putting pressure on the lungs. But, as the windpipe is closed, the air can’t move out, so pressure builds up. Finally, the epiglottis opens and air forcefully rushes out. Carrying the irritant and thus, producing a cough. Why are gold and platinum used to make jewelry? Because I commanded. No. It is because gold and platinum are malleable and ductile metals. Malleability is the property by which metals can be beaten into sheets. While ductility is the property by which metals can be drawn into thin wires. These properties allow gold and platinum to be molded into a variety of designs. In addition to this. Gold and platinum are very rare as well as lustrous, meaning, they have a shiny appearance. These qualities make them even more attractive and enticing. Besides this, gold and platinum are noble metals. Noble metals are a group of metals which are not very reactive. They resist corrosion and oxidation. Hence, the jewelry made of gold and platinum doesn’t easily lose its shine. Why do bubbles pop? Because they like to make pop music. No. A bubble is basically a pocket of air surrounded by a thin tenuous layer of soapy water. This thin layer can be of just water too, but such bubbles don’t float. Now, bubbles form because of a special property of water molecules to attract and stick to each other. These attractive forces between water molecules produces what’s called surface tension. This surface tension along with the air pressure from inside and outside the bubble. Create a fragile equilibrium and keep the bubble from popping. However, since the equilibrium is fragile. Just a gust of wind or our dry finger easily breaks the surface tension. Thus breaking the tenuous layer and causing the bubble to pop. Besides this, dry air also causes the water to evaporate from the tenuous layer. Hence, it gradually gets thinner and thinner and eventually, the bubble pops. Why are tennis balls yellow and fuzzy? Because they like to show off. No. Earlier, tennis balls were white. But later, they were changed to yellow because. Studies showed that yellow balls were easier to see on televisions. Now, tennis balls are fuzzy because the fuzz helps them slow down. When a tennis ball moves through air. Every fibre of the fuzz acts like an obstacle for air. This increases the drag, thus slowing it down. Besides this, the fuzz also increases the spin. Imagine a ball spinning in clockwise direction. Now, above the ball, the direction of air is same as the direction of rotation. However, below the ball, it is opposite. This opposing force combined with the fuzz increase the drag below the ball. Hence, the pressure below becomes much higher than it is above.