The subject of symmetry is quite fascinating. I learned about it when I was in high school and ever since I have had a certain fascination towards it. A symmetry is a *principle of invariance*, meaning that some feature in a physical system is preserved after making a *transformation*. For example, some well-known symmetries in physics include:

- Lorentz symmetry
- Duality symmetry
- Gauge symmetry

As to why nature seems to be so symmetrical, no one really knows! But you may find amusing the Feynman video on symmetries in the RHS of this paragraph.

For the past years, I have been collecting papers (not necessarily very technical) about symmetries and their extraordinary role in physics.

- D. J. Gross, The role of symmetry in fundamental physics, PNAS, 93, 14256 (1996).
- D. J. Gross, Symmetry in Physics: Wigner’s legacy, Physics Today, 48, 46 ,(1995)
- R. P. Feynman, R. B. Leighton, and M. Sands. Symmetry in Physical laws, The Feynman Lectures on Physics, chapter 52.
- R. P. Feynman, The Character of Physical Law, (Book based on lectures given at Cornell University).
- R. P. Feynman, The Great Conservation Principles, The Character of Physical Law, chapter 3.
- R. P. Feynman, Symmetry in Physical Law, The Character of Physical Law, chapter 4.
- R. P. Feynman, Seeking New Laws, The Character of Physical Law, chapter 7.
- S. Weinberg, Symmetry: A “Key to Nature’s secrets”, New York review of books,
- F. Wilczek, In search of symmetry lost, Nature, 433, 239 (2005).
- M. Livio, Why symmetry matters, Nature 490, 472 (2012).
- K. Brading and E. Castellani, Symmetry and Symmetry Breaking,
*The Stanford Encyclopedia of Philosophy*(Spring 2013 Edition). - J. Rosen, The concept of symmetry, Symmetry Rules: How Science and Nature Are Founded on Symmetry (Springer 2008 ).
- E. P. Wigner, Symmetry Principles in Old and New Physics, Bull. Amer. Math. Soc. 74, 5, 793 (1968).
- H. Wyel, Symmetry, (Princeton Univ. Press 1952).
- J. Wess, From symmetry to supersymmetry, Eur Phys J. C, 177, 2009
- J. Maldacena, The symmetry and simplicity of the laws of physics and the Higgs boson, Eur. J. Phys. 37 (2016)