system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The concept of time/spacetime (seriously, like I'm 5)

Here is my confusion: I have always thought of time as a measurement of events, cycles, moments, etc. For example, 24 hours a day because of the rotation of Earth. So years/months/days/hours/minutes/seconds/etc are all human made concepts based on observable, important events to humans. Then how does spacetime fit into all of this? Time is affected by gravity and time is intertwined with space, but if time is just a measurement of events/cycles relative to other events/cycles, how is it a THING out in space away from man? Does this make sense? You can see I'm confused...
gpt
You have to think about time as another dimension of space. you can move forward and backward, left and right, up and down, and through time. The reason that we know that time is linked to space is (other than Einstein's relativity) because we have observed it in subatomic particles. Just throwing that out there to show that it is a proven fact. Anyway, what we observed and have shown through mathematics is that the faster you move in any of the three typical directions that you would think of (front and back, side to side, and up and down), the slower you will move in time. This sounded absurd to me at first, but it seems to be pretty well proven. They have proven it by accelerating tiny particles to as close as they could to the speed of light, and shown that the lifetime of these particles (because they had a very short lifetime) increased dramatically, meaning that time for them was moving much slower relative to everything not traveling at that speed.