The big bang theory says that around 13.7 billion years ago, all the matter in the entire universe was squeezed into a space smaller than an atom, and this intense pressure created intense friction which in turn created inconcievably intense heat that blasted every particle in existence outward at the speed of light. The cyclic theory is very similar but states that the universe is continually expanding and contracting, and every time the universe reaches the peaknof it's expansion, it begins to shrink down until it's that tiny size again when the entire process repeats itself. The big bang theory say that the universe continually expands and never contracts back on itself and that moment 13.7 billion years ago was the precise moment when time and space and everything came into existence. After each great expansion (or the only great expansion, depending on which theory you're talking about), the universe is basically a soup of countless hydrogen atoms, which eventually pull together under the force of their own gravity once they've cooled from a million degrees and form giant clouds called nebulas. These nebulas gradually grow in size until their gravity is so great that they fall inwards, creating such intense friction/pressure/heat that they ignite, creating stars. In the core of stars, the heat is so great that hydrogen atoms are fused together into basic atoms like helium. In larger stars, once they run out of hydrogen atoms to fuse and use for fuel, they lose their structural stability and cave inwards, creating heat so intense that it blasts every particle within the star outward at the speed of light. This is called a supernova, and it's during supernovas that the heat is so intense, it fuses hydrogen atoms together into heavier elements like platinum and uranium ad everything else. These elements in turn get pulled together by gravity to form planets and asteroids and other objects in a process called accretion. That's how earth and every other planet in the universe was formed. And there kids, is a basic overview of your worldly origins.