It is important to note that the information I provide is based on the knowledge available . Given that the statements you mentioned are attributed to Witten, it would be helpful to have the specific context and sources where he made these claims. However, I can provide some general insights based on the theories you mentioned.
In the special theory of relativity, one of the fundamental postulates is the constancy of the speed of light in a vacuum. This principle, derived from experimental evidence, states that the speed of light is invariant regardless of the motion of the source or the observer. This postulate forms the foundation of the theory and has been extensively confirmed through numerous experiments.
The general theory of relativity, formulated by Albert Einstein, introduces the principle of general covariance, which states that the laws of physics should be expressed in a covariant form, independent of the choice of coordinates. This principle is closely related to the concept of spacetime curvature caused by mass and energy, as described by the theory. The equivalence principle, which states the equivalence of inertial and gravitational mass, is a fundamental aspect of general relativity.
Without specific context, it is difficult to comment on Witten's perspective on these principles. However, it is worth noting that theories and ideas in physics are continually evolving. While these principles have been highly successful in describing a wide range of phenomena and have been supported by extensive experimental evidence, it is possible that new theories or modifications to existing ones may emerge in the future that could challenge or extend our understanding.
Scientific progress often involves questioning established ideas and pushing the boundaries of knowledge. However, any new proposals or revisions to existing theories must be supported by empirical evidence, logical consistency, and rigorous scientific analysis to gain acceptance within the scientific community. It is through open dialogue, peer review, and empirical verification that scientific theories advance and evolve over time.