The string theory is a theoretical framework in physics that aims to explain the fundamental nature of particles and their interactions. It proposes that the most basic building blocks of the universe are not point-like particles, but tiny one-dimensional strings. These strings vibrate at different frequencies, giving rise to the various particles and forces in the universe. The string theory can be defined on a special 2-D time, also known as "worldsheet", which is a 2-dimensional surface that describes the motion of the string.
2)The string theory is defined on a 2-D time because it is believed to be the most suitable framework for unifying quantum mechanics and general relativity. In this theory, the 2-D time represents the dynamics of the strings, while the 1-D space represents the dimensions of the universe. By defining the theory on a 2-D time, it allows for a more comprehensive understanding of the fundamental forces and particles in the universe.
3)The traditional string theory, also known as the bosonic string theory, is defined on a 26-dimensional spacetime. However, the string theory on special 2-D time, also known as the superstring theory, is defined on a 10-dimensional spacetime. This difference in dimensions allows for the inclusion of fermions, which are particles with half-integer spin, and thus provides a more realistic description of the universe.
4)Viewing the string theory on special 2-D time has several implications. One of the main implications is the potential to unify all fundamental forces, including gravity, into one theory. This could also potentially lead to a better understanding of the origins of the universe and the nature of space and time. Additionally, the string theory on special 2-D time has implications for the development of new technologies, such as quantum computing.
5)Studying the string theory on special 2-D time is a complex and challenging task. One of the main challenges is the lack of experimental evidence, as it is difficult to test the predictions of the theory. Additionally, the mathematics involved in the string theory can be highly complex and difficult to understand. The theory also faces limitations in its ability to make accurate predictions, as it is still a work in progress and requires further development and refinement.