What Would Happen If the Earth Grew One Centimeter Every Second
As part of their ongoingWhat If?"series, Randall Munroe of xkcd and Henry Reich of MinutePhysics explain what would happen Earth grew its radius by one centimeter every second. Munroe explains that weight would go steadily up as the pull of gravity grew stronger, but other things would start to fail.
After a year, gravity would be 5 percentstronger and the ground underneath structureswould have expanded 5%. You'd probably notice the weight gain, and you'd definitely noticethe failure of roads, bridges, power lines, satellites, and undersea cables. Your pendulum clock would now be ahead by five days. After five years, gravity would be 25%stronger. If you weighed 70 kg when the expansion started, you'd weigh 88 kg now.
After about a ten years of Earth's growth, the gravity pull would be difficult to navigate and it would be difficult to breathe.
After 10 years, gravity would be 50 percent stronger.We'll assume the atmosphere is expanding, too,otherwise there wouldn't be enough to cover thegrowing earth and the air would by now be too thin to breath. With an expanding atmosphere, surface air pressure would rise due to both increased gravity and more air,
After 100 years of growth, the environment would be completely toxic to most forms of life.
After 40 years, Earth's surface gravitywould have tripled. At this point, even the strongest humans would be able to walk onlywith great difficulty. Breathing the thick airwould be a challenge. Trees would collapse and crops wouldn't stand up under their own weight. After 100 years, we'd be experiencing over 6 G's of gravity. Not only would we be unable to move around to find food, but our hearts would be unable to pump bloodto our brains. ...On top of that, at somewhere around this point, even ordinary air becomes toxic due to higher oxygen levels.
Needless to say, as with all of these hypotheticals, the future under these conditions doesn't look very bright, but there is good news on this front. After the destruction of the moon, the Earth for a very short moment will have rings like Saturn.
As the Earth grew, the Moon would, like all our satellites, gradually spiral inward.After several centuries, it would be close enoughto the swollen Earth that the tidal forces betweenEarth and the Moon would be stronger than thegravitational forces holding the Moon together. When the Moon passed this boundary?-?called the Roche limit?-?it would gradually break apart,and Earth would, for a short time, have rings.
