Inside Physics:

Except to my main interest in cosmology, which is the determination of the cause of cosmic acceleration and all the cosmological observations which lead us through this puzzle, I like also to know about some other topics in physics mostly in the territory of cosmology and astrophysics.

    The problem of the  Arrow of Time:  One of the interesting every day experiments is the irreversibility, the fact that future is different from past. Although this undeniable fact seems obvious, it has a serious connection with the increase of entropy and the second law of thermodynamics. the arrow of a time is a macroscopic property of the universe, in contrast the physical laws in microscopic order seems reversible. The question that why we are living in a universe with this unique property and its connection to cosmology is one of the interesting eras of physics which tantalize my mind. This is because the observed macroscopic irreversibility is not a consequence of the fundamental laws of physics, it's a consequence of the particular configuration in which the universe finds itself. In particular, the unusual low-entropy conditions in the very early universe, near the Big Bang. Understanding the arrow of time is a matter of understanding the origin of the universe. The real cosmological puzzle  is why our universe ever found itself with so many particles packed into such a tiny volume with such unrealistic low entropy. About the arrow of time you can find a FAQ page by Sean Carroll here, who recently publish a book with the name of From Eternity to here, discussing the problem of arrow of time in general science book style.                 

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