River of Time

This is a time thought experiment

You can make it into a field trip by visiting a river of your own and repeating the ideas in your mind while:

Imagine the river from the perspective of the water molecules in it.

To us, standing on the shore, it looks like the water is flowing fast here, slow there. But to any one water molecule, the other water molecules next to them are moving at the same velocity as they are. They would experience acceleration and turbulence, but the molecules would experience this together. Perhaps temperature would seem - on the molecular level - the most notable ambient force.

As we flow along, it seems to us, that the bottom, the rocks, are always flowing in one direction relative to us. As we come close to objects in the river, or as we flow from a narrow stream into a lake, we notice a change in the level of excitement of the molecular community as the water molecules are pushed this way and that by the rocks.

Looking at a rock in the river, from an outside viewpoint, we can see that when the water comes against the rock it pulses - sending a series of waves up current, against the flow of the river and against gravity