COULD TIME GO BACKWARDS?
In principle, nothing would stop you from going back in time, according to general relativity, albeit it does not appear to be very plausible.
Space-time can be thought of as the location where all of the events that have occurred and will occur can be found. We can think of space-time as a block with three spatial dimensions and one temporal dimension (for simplicity, think of it as a package of sliced bread with only two spatial and one temporal dimensions).
When a measurement is taken, the observer is watching events as “her time” passes. It’s
as if we’re chopping the block into spatial slices, with each slice representing an image of what she can see in a split second.
Things will appear differently to an observer moving at a constant speed with regard to the observer. Because the speed of light propagation in a vacuum must be the same for the observer and the observer, this indicates that “their time” and “their succession of images” are different; in it, it will be the observer who moves.
This means that depending on one’s relative speed, the estimations of time intervals and distances between two events will be different for each individual who sees them.
According to special relativity theory, time and space intervals are relative, meaning that the observer can sense that two occurrences are closer together or farther apart than the observer, and that other events that are simultaneous for him will not be for her.
If it is difficult to transfer a light signal from one event to the other, we can say that the gap between two events (points of space-time) is spatial. If this light signal may be sent, the distance between these events is not spatial; whether the signal travels from one to the other or from one to the other is determined by the perception of time.
Because the space-time interval is invariant, the separation between two occurrences for the observer and the observer continues to have the same character (spatial or not). All occurrences that could or could be connected with me by light signals (with my self at this moment, interpreted as an event) are contained within what we refer to as “my cone of light” in space-time.
It’s actually two cones, one with the vertex at the place in space-time where I am right now and the other with the height along my timeline, but the past cone of light (my past) expands in the opposite direction than the future cone of light (my future)… of course. We won’t be able to adjust the direction of these cones.
But if we take it a step further and factor in gravity, we’re in for a shock. General relativity is not just a theory of gravity, but also a theory of space-time, which when bent by material substance becomes a physical reality. this set of cones.
The light cones will not all be orientated in the same way, rather they will be distorted and have varying orientations depending on the point.