The question of whether unifying efforts between Quantum Field Theory (QFT) and gravity are futile is a topic of active research and debate in theoretical physics. While there is no definitive answer at present, I can provide you with some insights into the challenges and considerations involved.
One of the main difficulties in reconciling QFT with gravity is that these two theories have different conceptual frameworks and mathematical descriptions. QFT successfully describes the behavior of particles and their interactions at small scales, while gravity, as described by Einstein's theory of General Relativity, explains the behavior of spacetime and gravitational interactions on cosmological and macroscopic scales.
In attempts to unify the two, such as in the quest for a theory of quantum gravity, researchers face several challenges. One major challenge is the lack of experimental data or direct observational evidence that could guide the development of a theory of quantum gravity. This limitation stems from the fact that gravity is extremely weak compared to other fundamental forces, making it difficult to directly probe gravitational phenomena at quantum scales.
Additionally, the early universe, where conditions were extreme, might have witnessed phenomena that could have affected the nature of both gravity and quantum fields. For instance, during the early stages of the universe, the energy densities and temperatures were incredibly high, potentially leading to effects that could have modified the behavior of particles and the gravitational field. Understanding these effects and their consequences is an active area of research, but it remains challenging to gain direct observational evidence or experimental data from that era.
However, it is important to note that the lack of direct evidence or measurement does not necessarily imply that unifying efforts are futile. Theoretical physicists use various approaches, such as mathematical consistency, symmetries, and conceptual arguments, to explore the possibilities of unifying gravity and quantum mechanics. These efforts involve proposing new theoretical frameworks, such as string theory, loop quantum gravity, or other approaches, to provide a consistent description of both gravity and quantum phenomena.
Ultimately, the question of whether unification is possible or not is an open and ongoing research topic. It is possible that future experimental advancements, new observational data, or theoretical breakthroughs may shed light on the fundamental nature of space, time, gravity, and quantum fields, leading to a unified framework that encompasses both.