alt Hacker News"Einstein cast gravity not as a force but as the geometric bending of space and time. In a popular analogy, the fabric of space-time is like the flat expanse of a mattress, and a massive object like a star is like a bowling ball sitting on top. The weight of the bowling ball compresses the mattress, forming a dimple — matter tells space-time how to curve.
In this analogy, a planet is like a smaller ball. If it rolls close enough to the bowling ball, its path will be altered by the dimple in the mattress — space-time tells matter how to move."
This analogy is wrong in a way that even people who've studied physics often don't realize.
On an everyday scale like the Earth orbiting the Sun, almost none of that gravitational interaction is from the bending of space. Far beyond 99% (actually, about 99.999999%) of it is from the bending of time.
Replies
Could you be more specific? How does bending time cause the Earth to orbit the Sun?
Aka the Einstein tensor
I never liked the mattress analogy, because if gravity is the bending of the mattress, what is pulling the ball down the slope?
i agree with you but i'd go even further
time and gravity are the same thing, the history of understanding physics is basically of the same nature, understanding that two things are actually one thing, which is more like philosophy but with physical confirmation
What’s an example where it would be accurate to say 99%+ of the interaction is from the bending of space?