See the universe as a type of cube. (It's a 4d hypercube, but don't worry about the 4th dimension just yet.) The cube is vastly bigger at one end, like a horn.

See the universe as a type of cube. (It's a 4d hypercube, but don't worry about the 4th dimension just yet.) The cube is vastly bigger at one end, like a horn. An explosion occurred at the narrow end of the box/horn. We, the Earth, the Sun, solar system, Milky Way, everything we can see are the particles flying away from the explosion. The path we're tracing are the world lines. Indeed, these can be seen as tunnels, and we are a charged force propagating through them. We perceive time as a cross section of the cube/horn. But things slow down where they gather. And so the actual cross section would be very lumpy. But not to our limited perception.