Scientists said that the Big Bang was caused by the conversion of energy into mass, according to Einstein's E=mc2 formula. But where does this energy come from? And what actually triggered the Big Bang?

My question is If we or any scientist had not discovred E=mc2 ? What changes do we have in today's life?

what are the famous equations of 21st  century ? ! not all but some recent ?

We all know that 2x/4x = 4x/8x does not tell us what x is because is cancelled out being referenced on both sides.

Describing  an egg as egg shaped does not tell us what the shape of an egg is.

So why do models gravity using a picture of a “gravity hole  in a mesh of time” as if the weight of a ball is distorting a frame of time. This, surly, is a circular reference effectively saying gravity looks like gravity. Additionally this model has some rather poor comparison’s. And if the mesh is three dimensional then what are the axis of this mesh?  Does this imply time have 3 dimension’s?  Showing a picture of a moving ball rotating around a gravity ball includes a reference to time to describe time itself. Giving two layers of self-reference.

Can anyone explain to the lay public what gravity is without using self-reference. ?

According to Einstein's famous equation E = MC2, or Energy = Mass times the speed of light times the speed of light. This tells us that anything that has mass, such as matter, is comprised entirely of energy. Any physical object with mass is therefore simply a lump of energy existing in some stable form.

As I understand it, all forms of energy, including chemical energy, kinetic energy and potential energy are covered by Einstein's equation, meaning that fundamentally all forms of energy are the same basic 'stuff' (for want of a better word). My question is, therefore, what exactly is energy? I want to get to a fundamental understanding of energy, because it seems that such an understanding would help to explain much of reality.

I'm not asking for explanations about work done etc, I'm asking at the fundamental level what is energy?