Eli5: How does gravity affect time, dumb it down for me as much as possible
In: 286
Ok, this is really ELI5 so using basic ideas.
Time is the measurement of things happening. You describe stuff happening by describing the time it takes.
Gravity, as you know, makes everything “heavier.” Heavier things do stuff more slowly – it takes more effort to do things when you’re heavy so it takes you longer. Think of movie scenes where someone is speeding in a car or rocket so fast they struggle to lift their arm. Acceleration is the same as gravity.
TL;DR: the more gravity there is, the slower things move because it takes so much more energy.
A little more explanation… gravity affects EVERYTHING, including space and time. So while you yourself may feel heavier in more gravity, the underlying, invisible fabric of reality also itself feels heavier, which affects, well, reality.
You know how it’s faster and easier to walk on a flat surface than it is to walk down a steep dip and then walk all the way up the other side, even if they’re the same distance? Gravity is the depth of the dip.
Lots of explanations here already. One thing I wanted to add is that it’s a relative effect. If you were to go near a black hole you would still perceive time as going at the normal rate. But your time would be changing differently to everyone that wasn’t near the black hole
Think of time like a bunch of waves that are washing over you. Those waves still have to travel through space to get to you. Gravity can smoosh or stretch space so that those waves may get to you sooner or later then other places that are “equally” far away.
When you’re near heavy things, space gets thicker. It’s like you’re walking through water, only instead of having to push harder you’re experiencing a longer time. To everyone else it looks like you’re running in slow motion but to you you’re running normally and everyone else is going really fast
Gravity pulls things to it. Including the fabric of the universe itself. This make it literally stretch. Since it’s stretched towards the hea u thing everything just takes longer. It’s like stretching a rubber band. Same amount of stuff but stretched out and longer. So everything just takes longer because it’s stretched out.
BTW this is a terrible explanation but I tired to keep it super simple.
Let me take a crack at it.
How does gravity affect time.
So you can think of a space and time as the same thing.
So how does gravity affect space?
Gravity bends space which then makes any object effected have to travel a longer route to get to its destination.
The fastest route to any destination is a straight line and gravity makes everything bend and thus take the slower route. The closer you are to a massive gravity producing object the more of the bend.
And since space and time are the same thing. When gravity bends space and makes that path longer/slower what we perceive as people is the after effects which is time dilation.
Think of the earth, you can drive straight around our planet and never notice the curvature. An outside observe can look and say that the earth isn’t flat but from your perspective it’s flat.
That’s the difference in time for two people, one affected and one that observes.
The person who observes sees you moving thru the bend in space time. (not visually bending)
But rather taking the longer route which is slower.
So to an outside observer you are moving slower thru space/time because welp you are.
So how does gravity affect time?
Gravity effects space and since space and time are the same, gravity effects time in the same way of extending the travel it takes to move towards a destination.
Here’s how I understand it–and it could be totally wrong so someone please correct me if I am.
It’s not so much that gravity “affects” time, it’s that time is part of how gravity works. For example, if I jump up into the air I am leaving earth at a velocity that slows down time (however minuscule). Even though it slows down time I am not going at enough of a velocity to surpass the warp in spacetime around the planet. This is because the warp in spacetime causes time to move slower closer to the ground and faster as you move away from the ground. So even though I’ve jumped into the air, I haven’t jumped fast enough or far enough into the air for time to increase enough so that my trajectory increases exponentially in speed because of the difference in time. I get “pushed” back down because time is moving slow and low enough that spacetime sets a limit on my speed upwards relative to the force I’ve exerted upwards.
[Gravity wells](https://images.app.goo.gl/FYRGJyrMBvEYU6m68) can help to visualize what is happening.
This isn’t the science behind it and the math is very estimated, but just an attempt to bring some ELI5 level understanding.
Imagine each section on that image had a width of 1 unit and would take 1 day to cross. But to travel across those gravity wells you actually have to go down each well and up the other side. Let’s estimate the first image as 1 width, 1 unit down the well, 1 unit back up = 3 total units traveled. To an outside observer it would take you 3 days to cross. If the well depth was 2 it would look like it took you 5 days to cross (1 across, 2 down, 2 back up) but to the person crossing only 1 day would have elapsed in both cases.
Hopefully that helps understand what is happening. Why it works that way is complicated to say the least. I’m not sure I can ELI5 but if I come up with anything I’ll edit this.
This is the first time that I read all of the comments on an ELI5 question and still not sure what the answer is
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