What Everyone Gets Wrong About Gravity

[Music] this video was sponsored by caseta by lutron according to the general theory of relativity gravity is not a force there are no gravitational fields gravity is kind of an illusion and in this video i will prove it to you by blasting off into outer space in three two one albert einstein said the happiest thought of his life was imagining a man falling off the roof of a house what made einstein so happy about this wasn't shot in freuda it was the realization that this man while he was falling wouldn't feel his own weight he would be weightless and anything he dropped on his way down well it would remain stationary relative to him or moving in uniform motion the whole situation would be just like if you were in deep space not near any large masses with your spaceship at rest or coasting along at constant velocity here you would feel no weight objects would remain stationary relative to you or if you give them a push they would move in a straight line at constant velocity and you would be the very definition of an inertial observer you're not accelerating not in a gravitational field all the laws of physics apply in your reference frame meaning there is no experiment you could do to distinguish your inertial reference frame from any other now here comes the big leap einstein looks at these two scenarios and says they are equivalent not just similar physically they are exactly the same thing which means man falling from roof is not in a gravitational field there are no gravitational fields and he is not accelerating he is an inertial observer just like rocket man whoa whoa whoa i mean okay i can see how both of these observers feel weightless but man falling from roof is clearly in a gravitational field i mean he's right next to the earth and he's obviously accelerating his speed is increasing by 9.8 meters per second every second a fact that will become painfully apparent when he crashes into the ground i know that these two situations look very different but einstein's equivalence principle tells us the one thing to focus on the experience of the observer if they feel weightless then they are in an inertial frame of reference every bit as good as rocket man's out drifting through deep ...