The journey of physics has always been a journey of discovery, from the time of thales of maltinus to the present day physics. We can notice a rapid a evolution in physics and the equipment that is used to carry out physics experiment. The search of a single theory physics has occupied the rest of modern physics since the 20th century, and after more than 100yrs we still don't have a solution.
The holy grail of physics
The holy grail of physics is also know as the theory of everything.
Ever since the discovery of gravity by Isaac newton and the unification of Electromagnetic force and weak nuclear force, scientist has always believed that behind the complexity of the natural law, thier lies a simple single elegant theory that can give explanation to the every law of nature. After Albert Einstein united Newton laws and Maxwell electromagnetism in the form of special theory of relativity, he spent almost 30yrs if his remaining life searching for a single law of physics that could bring explanation to all natural occuring phenomenal, well even Einstein failed in his search.
The whole of modern physics is govern by general relativity and Quantum Mechanics. General relativity works perfectly in the realm of gravity and it help to understand the universe in region of both high mass and large scale.
While quantum mechanics on the other hand works perfectly on the small scales region and it help us to understand how the other three force of nature interact with each other.
Physics have experimentally confirm virtually every approximation made by quantum mechanics and general relativity which is appropriate in the domain which they are applied.
The problem.
The problem with finding the Holy grail of physics is that the two most important theory in physics do not look compatible, no matter how physicist trys to unite them together. The two theory can never be right together, it is either one is right or the other is right, but when you try to use the two theory together to solve similar problem irregularities began to pop out.
To resolve the incompatibility, a theoretical framework revealing a deeper underlying reality, unifying gravity with the other three interactions, must be discovered to harmoniously integrate the realms of general relativity and quantum mechanics into a seamless whole: the holy grail of physics is a single theory that, in principle, is capable of describing all phenomena in the universe.
The holy grail of physics still remain one of the most active area of research in physics today, theorist are divided into if it is possible to have a single law of physics that can explain everything that occurs in the universe at both small and large scales. While some physicist believe that the search for a single theory to physics is bound to failed due to the famous Godel incompleteness theorem.
One of the leading candidate of holy grail of physics is the famous string theory, which predict that all the forces of nature where all together in the beginning of the universe.
The holy grail of physics is also believe to be the end of physics. Since it can explain everything's that has ever occured and that will occur in the universe.
Is the holy grail of physics the end of physics?
Drop your view!!!
There should be more to just finding the holy grail but aye, you answered @birch 's request somehow. I hear this string theory a lot