I just got round to watching Interstellar and there’s a whole lot about Relativaty and how one hour on one planet is the same as one year on Earth. How does that happen?
In: Physics
Black holes bend space time. Space time is basically the fabric of the universe. Think of it like two marbles swirling down a funnel. The marble swirling at the top of the funnel takes a while to go all the way around. But the marble towards the narrow part of the funnel is going all the way around wayyyyy faster. You with me?
Our sun orbits our black hole at a freaking crazy slow rate cuz we’re super far away from it. So our concept of time is basically based on that. But closer to the black hole (narrow part of the funnel) them shits is swirling around way quicker so from our point of view they are sprinting while from their point of view we are just absolutely crawling. That’s because time is *relative* to each observing party.
I know, it’s nutty. This is how I’ve explained it to myself and I think it’s fairly on point but others can definitely correct me.
EDIT: okay so I am off base I guess. My bad. I knew you guys would let me know.
Imagine your bed, littered with little beads, same distance between each neighbouring one. We will say that is space-time.
There is usually two things we consider when talking about relativity, gravity and speed.
Gravity is a force so imagine pressing your finger into the mattress of your bed. The beads will roll tword your finger. So the space-time around your finger is more “dense”. You have more time around you so time passes slower for you.
Same thing with speed. Drag your finger across the sheet. Some beads will bunch up ahead of your finger, so the space-time it is crossing is, again, more dense.
Hope this helps, it’s all I could come up with in a few minutes
The closer you are to a massive object, the slower your clock will tick according to a person further away from this mass. The technical term for this is ‘gravitational time dilation’.
This relationship is a consequence of the **Equivalence Principle**, which says that standing still in a gravitational field (like on the earth’s surface) is exactly the same as accelerating upwards in a rocket in space (at 9.81m/s² = 1g for this example).
Let’s do an experiment in this rocketship. We have two physics enthousiasts: Bob is standing at the bottom of the rocket and Alice is standing at the top. Now, Bob and Alice want to compare how their clocks tick. So Alice comes up with the idea that she can send two light pulses towards Bob, spaced out by an interval of 1 second, and see how this compares to Bob’s clock. She sends the first light pulse, it arrives some time later at the bottom. The second pulse (which Alice fired 1 second later from her p.o.v.), will soon arrive at the bottom. But in the meantime, the rocket has accelerated upwards! Bob has ‘caught up’ to the light from Alice’s p.o.v. This means that the time interval between Bob’s reception of the two light pulses does not look like 1 second for Alice.
Now remember that the rocket-scenario is equivalent to just standing still in a gravitational field, and voilà: gravitational time dilation!
Please remember to search ELI5 before posting.
Latest Answers