What if there was no Gravity on Earth? No Problemo. I will order my burger from space. From purely physics point of view. There would be no earth left, as no gravity means no mass. But, leaving this point aside, let’s see what else will happen. Oceans, rivers and lakes will float away. Entire atmosphere will vanish, only vacuum will be left. Everything on the surface of the earth including humans, cars, rocks, etc. Will become weightless and float away into space. Things which are rooted into earth like trees, bridges. And buildings will remain, but not for long. On a funnier note, anybody will be able to lift heavy weights. Football will become a one kick game. And there will be no need of stairs or elevators. Finally, earth will also start breaking into chunks as it is held together by gravity. What if all insects disappeared? No worries. I have their photographs. You might think insects are inconsequential, but the reality is. Without them, there probably would be no life on earth. The first life to get affected, would be plant life. Most plants in the world are angiosperms, that is, flowering plants. Without insects pollinating them, plant life would gradually disappear. Gradually, birds and mammals feeding on plants would also disappear. Further, insects are food for many birds, frogs, reptiles, etc. Without insects, they would also start dying. Then, animals eating those animals would also start dying. This would ultimately lead to a domino effect. Finally wiping out the top of the food chain, that is, human beings. Also, don’t be surprised, if you suddenly see a lot of dead things everywhere. This is because insects are decomposers. Without insects, decomposition process would take much longer. What if wheels were never invented? No problem. I’ll just use my Private Rocket. Wheels are believed to have been invented almost 5500 years ago. Ever imagined what the world would be like without wheels? How would you go to school, work or even on a holiday? Bicycles, cars, steam engines and even planes, nothing would be possible without the wheels. Yes, horses and sledges would be there. But it would be a super slow and super rough ride. Not only in transportation, but wheels are also a major component of the industrial revolution. Elevators, blinds, cranes etc., all have some form of wheel hidden in them. Now, on adding teeth to wheels, gears were invented. Clocks, grinders, car engines, bicycles and other complex machines work with the help of gears. So, basically, if wheels were never invented, we might still be living the pre-historic way. What if earth lost oxygen for 5 seconds? We would need to organize a search party. No. If it was just 5 seconds. We wouldn’t notice changes in our breathing. But do you know what would happen around us? Earth’s crust contains 45% oxygen. Without oxygen, crust would crumble. Causing the ground to crumble and we would be in freefall. Buildings, bridges and concrete structures would crumble into dust. As oxygen is the binding agent for concrete. Cars would stop. And planes would fall from sky as their combustion engines wouldn’t work without oxygen. Also, losing oxygen means losing almost 21% air pressure. This would cause our inner ear to explode, causing hearing loss. It would also become darker suddenly. Why? For sunlight to reach us, it needs to bounce off air particles like oxygen, dust etc. No oxygen means much fewer particles to bounce off, thus much darker.