What do you think about the idea of time? Is it real, or is it an illusion? I think the question that needs to be asked is, how can you be certain that time is real?
What does it mean to really move through spacetime?
Intuitively, space and time are 2 sides of the same coin
I’ve often wondered if space and time are two sides of the same coin, like electricity and magnetism. For example, are gravity and mass two sides of the same coin? If so, if we made an anti-gravity field generator, could we not go out into space, turn up the power, and create a warp bubble? Would that warp bubble act as time dilation, or would we just be sitting still with space warping around us and not gaining much speed?
It’s really hard to picture these ideas.
Time is like sound and light, you see. At any given moment, a person or object can only exist where it is in space and time. If it moves in any direction through space or time, it stops existing everywhere else but where it is now.
Facing gravity in 4D, but in the other direction, it’s easier to move backward
This model fascinates me. It means that backward travel would be significantly more difficult than forward travel. Forward travel only requires greater speed, above that of light. In contrast, reverse travel would require, at the very least, defying the “force” that relentlessly pushes us forward into the future.
To move truly backward, we’d have to overpower the force pushing forward since even if we figured out how to re-orient ourselves in a backward direction, we’d be swimming upstream. Regardless, we’d still have to move forward, but slowly.
We are 3d beings in a 3d (at minimum) space. But how do you actually orient yourself in 4D? It’s not as simple as just “turning left or right,” as with the 2d man in the 3d space. The video illustrated the concept by notching things down a dimension. However, the earlier question of what line is drawn after X, Y, and Z are still open.
Is time a real thing?
Italian Scientist Carlo Rovelli says that time is an illusion and that space-time is a flexible manifold that changes shape based on how fast you are moving or how close you are to a mass.
Rovelli is one of the people who came up with the loop quantum gravity theory. This theory tries to bring together quantum mechanics and general relativity.
Rovelli proposes the idea of “physics without time,” which comes from the fact that some quantum gravity equations can be written without any mention of time.
The book is divided into three parts. The first part shows how well-known theories of physics break down our everyday ideas of time and space.
Rovelli gives good explanations of classical physics, modern physics through the eyes of Einstein and quantum mechanics, and Bayesian probability theory, but I disagree with some of his claims, like the one that space-time is quantized.
Carlo Rovelli says that events, not particles or fields, are what make up the world, and that time and space only exist because of how events interact with each other.
Rovelli uses parts of thermodynamics and quantum mechanics to explain how we get false ideas about time, and he says that the reason is that we can’t see the world in all its details.
The Order of Time is a small, elegant book that brings together the ideas of philosophers like Martin Heidegger, Émile Durkheim, Edmund Husserl, and William James, a psychologist. I’m not sure if I agree with Rovelli’s ideas about loop quantum gravity or the thermal time hypothesis in the end.