  `What is work and what is heat' is re-investigated from the perspective of
second law of thermodynamics. It is shown that the inevitable consequence of
second law of thermodynamics and spin conservation necessitates the possible
generation of zero spin photon in pair production process, and its subsequent
decay explains the birth of neutrino and antineutrino. The proposed
neutrino-genesis, solves many riddles of physics and universe. The riddles
considered and explained are about: (i) mysterious neutrino (and antineutrino)
and its bizarre properties such as handed-ness and parity-violation, (ii)
questionable asymmetry/ excess of matter over antimatter, (iii) possibility of
existence of antimatter world and (iv) parity (P) violation and aspects of CP
and CPT violation or restoration in the universe.
