Question

what is Big Bang Theory and theory of relativity

Answer 1

the big bang theory is the theory given by STEPHEN HAWKING which tells us about our existence how we and our universe came into existence by ab bang this theory describes that before big bang there was nothing no time. even no space no light at all just an small subatomic particle and because of the fluctuation in its gluon field it just blasted and began to expand by tremendous heat and that's when space and Time came into their existence and that event is know as the big bang
the theory of realitivity is the theory of everything according to me it explains everything and also the innovative and the real geniuses of sub conscious mind of Einstein or a great stupid mind said in small these theory explains that fundamental things of surrounding like time,length are not absolute but relative to the frameof reference in which we are observing it his theory has to part first the special theory of realitivity which explains that the laws of physics are always same for non- accelerating frames and you also showed that the speed of light is always same for every frame.and this theory only explain that time is not absolute but relative to the reference frame in which we are observing it Albert Einstein sees that his special theory fails for something very common in our life and that's the gravity and then he made his new theory the general theory of relativity and that's my favorite theory which explains that there is no such thing as gravity.what we call as gravity is just a curvature of space time

Answer 2

The big bang theory is a scientific theory about what happened at the very beginning of our universe and then how the stars and galaxies came into existence. According to the standard theory, our universe sprang into existence as "singularity" around 13.7 billion years ago. Singularities means a zone where some property is infinite. For example, at the center of a black hole.

Discoveries in Astronomy and Physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something : our universe. The big bang theory is an effort to explain what happened during and after that moment. Our universe is thought to have begun as an infinitesimally small, infinitely hot, infinitely dense, something a singularity.

After its initial appearance, it apparently inflated (the big bang), expanded and cooled, going from very, very small and very, very hot, to the size and temperature of our current universe.

Hope this helps :)