-Mrutyunjaya Sahoo
ଓଡ଼ିଆ ରେ ଏହି ଲେଖା କୁ ପଢ଼ିବା ପାଁଇ ଏଠାରେ କ୍ଲିକ୍ କରନ୍ତୁ ।
THE GENERAL RELATIVITY AND THE QUANTUM MECHANICS :
Till today we have two grand theories which describe our world in two realms; first one “The General Theory of Relativity'' in macroscopic scale and another is “The Quantum Mechanics“ in microscopic scale . The former one was put forward by Albert Einstein and deals with the dynamic nature of the spacetime fabric implying the presence of Gravitational waves, Black holes etc. The latter one has contributions from a group of physicists namely Max Planck, Max Born, Niels Bohr, Werner Heisenberg, Wolfang Pauli, Erwin Schrondiger etc. It basically deals with the studies of the atoms, their quantum states, probability wave function, superposition, energy of the subatomic particles, indeterminacy etc.
THE STRING THEORY :
- Despite the success of the Two theories they are not compatible with each other. There are many processes which can’t be satisfied by both ; giving the same conclusion. One of the main reasons is that the Quantum world deals with the subatomic particles on which gravity is not having any strong impact like celestial bodies. And the theory which will solve this compatibility problem will be called The Theory of Quantum Gravity.
- Among many theories The String Theories are one of the frontiers which attempt to solve the problem.
- The theory is divided as follows :
- It talks about extra dimensions, specifically 10 according to Super String Theory. Moreover, it is mathematically elegant .
- It says at the bottom of reality there is nothing except the strings which give masses to the different particles according to their vibrations. The vibrations held on two end-on objects called D0 Branes just like a string of guitar held between two pegs.
- Moreover it says about the source of the mass as the contributions from:
- Rest mass energy
- Zero point Quantum fluctuations
- Vibrational energy
- Moreover it says about the source of the mass as the contributions from:
- The more a particle having Zero point Quantum fluctuations the more the mass of the particle will be imaginary(Having not proper existence) i.e. it plays a crucial role for mass of a particle and it smears over many dimensions.
- Vibrational energy gives the
mass and different modes of vibration give different particles.
- The beauty of this theory is that it explains spacetime from strings by analyzing a tool called Worldsheet. The Worldsheet is like a surface containing the information of the spacetime that the string has swept, ,so the string will be the curve that we will get after cutting across the Worldsheet.
- Like worldsheet there is another tool called worldline.
- Calculation with the strings gets more cumbersome for complex problems so in this case D Branes are used to solve the problems. D-branes are the locations in space where the strings end. There are 10 types of D-branes (D0-D9) as we have 10 dimensions. The D-Branes also obey String Dualities.
- D-Branes have definite mass;
the less they interact the more will be its mass because strings are continuous
in nature, so splitting and merging will also be a continuous process; hence
the more they interact strongly the more will be splitting and merging to form
the particles and so less accurate will be its mass.
- D-Branes are symmetric: D0-Brane is point-like, D1-Brane is like a string and so on for other branes. Besides this they also have another type of symmetry called Gauge Symmetry.
- It basically explains the low-energy physics that we already have in particle physics experiments, it describes the small mass of the neutrino, and describes Gravity as by the General Relativity . An important implication of this theory is our existence; Basically the three dimensions of space are expanding with time according to the observations, but the other 6 dimensions are curled up tightly with each other and remain still. That means they do not flop around so that the D0 branes will just remain still and heavy as it has less interaction and it leads to give a cosmological constant which is extremely small and allow only 3 out of 10 dimensions to unroll and expand with a particular rate with the beginning of the universe and at last that helps to form the life like us in the universe.
- Although string theory explains many unanswered aspects, it also has many drawbacks. The main one is that it hasn’t been verified experimentally. It gets more and more complicated as one dive deep into it, even it’s mathematics does not answer many central problems of itself, etc. Whether it is a failure or not, this theory explains many beautiful aspects of the nature of reality.
Sources :
- https://books.google.com/books/about/The_Little_Book_of_String_Theory.html?id=pPo7ibKhqAcC&printsec=frontcover&source=kp_read_button&hl=en&newbks=1&newbks_redir=1
- https://www.youtube.com/watch?v=_1S6KfMzOH8
- https://home.cern/
- https://youtu.be/CbPWYjnQIO8
- https://www.youtube.com/watch?v=iTTa9YcTe1k
- https://youtu.be/tzQC3uYL67U
Written By-
Mrutyunjaya Sahoo
