How does gravity distort time?

[adimantium]

I understand that Einstein had the idea of space as a 2 dimensional grid with "planets" sitting of the grid, stretching it out, but I don't get why this affects time.

 

[WannabeNewton]

Well for starters that is NOT what Einstein had in mind; that isn't even a correct picture of space-time. Secondly, I assume you mean the gravitational time dilation effect? There was a thread about that before: https://www.physicsforums.com/showthread.php?t=704565&highlight=gravitational+redshift

 

[phinds]

Why does gravity affect time?

Gravity doesn't affect "time", it affects "spacetime". This is not just semantics. There are plenty of place on the internet to read about this.

 

[A.T.]

I understand that Einstein had the idea of space as a 2 dimensional grid with "planets" sitting of the grid, stretching it out, but I don't get why this affects time.

Think about it: If gravity was just distortion of space, how would it ever affect objects that are initially at rest in space? The distortion of spatial distances can only affect objects which already move through space. But why would an apple start falling from rest. Obviously the time dimension must be distorted too, to affect the apple that initially advances only through time. See animation below:

https://www.youtube.com/watch?v=DdC0QN6f3G4

See also this pictures that visualize the different effects of gravity:

http://www.physics.ucla.edu/demoweb..._and_general_relativity/curved_spacetime.html

 

[sardar]

Gravity affects time because it is one of the fundamental forces that govern the universe. According to Einstein's theory of general relativity, gravity is not just a force that pulls objects towards each other, but it is also a curvature of space and time. This means that the presence of massive objects, such as planets, causes a distortion in the fabric of space-time.

Think of space-time as a rubber sheet, with planets and other massive objects creating dips and curves in it. This curvature of space-time is what we experience as gravity. And just as a marble rolling on a curved sheet will experience a change in its path, objects moving through the curved space-time will also experience a change in their trajectory.

Now, when it comes to time, this curvature of space-time also affects it. Time is not a separate entity from space, but rather a part of the fabric of space-time. So, as space is curved by the presence of massive objects, time also gets distorted. This means that time moves slower in the presence of strong gravitational fields, such as near a black hole.

This phenomenon, known as gravitational time dilation, has been confirmed through various experiments and observations. For example, atomic clocks placed at different altitudes on Earth run at slightly different rates due to the difference in gravitational pull.

In summary, gravity affects time because it is a fundamental force that causes a distortion in the fabric of space-time, which includes both space and time. This concept is crucial to our understanding of the universe and has been confirmed by numerous experiments and observations.