The opposite of the theory of relativity would be a theory that fundamentally contradicts or opposes its key principles and predictions. However, it's important to note that the theory of relativity is a well-established and extensively tested scientific theory that has consistently provided accurate predictions and explanations in a wide range of phenomena.
There have been alternative theories proposed over the years, such as various forms of aether theories or other attempts to modify or extend the theory of relativity. However, these proposals generally aim to refine or supplement the theory rather than outright oppose it.
It's worth mentioning that the scientific community operates on the principle of empirical evidence and consensus-building through rigorous testing and verification. For any theory to be accepted as an alternative to the theory of relativity, it would require substantial evidence and successful experimental confirmation, as well as the ability to explain and predict a wide array of observed phenomena better than the theory of relativity.
there is no widely accepted and substantiated scientific theory that is considered the opposite of the theory of relativity. The theory of relativity remains the prevailing framework for understanding space, time, and gravity in the context of modern physics.