History of Earth - Before Earth Existed

A long time ago, there was a universe but no Earth. We know this fact from geology which tells us that the earth are made up of heavy elements, in other words elements with relatively high atomic masses. Only supernovas(exploding stars) could have caused these elements to form, therefore they had to exist before the earth came into existence.

To understand this argument, some knowledge of chemistry and astrophysics is necessary. We'll start with the atom, the most basic building block of any material object. An atom is made up of protons, electrons and neutrons. Electrons have a negative charge and orbit the nucleus of an atom, which is made up of protons and neutrons. Protons repel each other because they have a positive charge, and they therefore need neutrons acts as a glue to keep them together in the nucleus.

The simplest atom, elemental hydrogen, consists of one electron orbiting one proton. The next atom, elemental helium, consists of two electrons orbiting a nucleus of two protons and two neutrons. Elemental Carbon consists of six electrons orbiting a nucleus of six protons and six neutrons.

In the early universe, the first and most abundant element was hydrogen. It was evenly spread out at first, but after a while began to clump together due to random motion and the pull of gravitational forces. Eventually some of these clumps became dense enough for nuclear fusion to begin, the process by which stars burn matter to form energy.

The simplest form of nuclear fusion involves two hydrogen atoms forced together to form a single helium atom. For most stars fusion ends at this point, but within the core of very large stars fusion continues. Helium is forced together into carbon, carbon into oxygen, and so forth. The last element in this chain is iron, which can't be fused into anything.

When a star has used up all of its energy, fusions stops and the star begins to contract. The awesome gravitational forces involved compress the core more than matter can allow which results in a supernova. The energy of the supernova forces more atoms together, producing heavier elements still. Therefore, without supernovas there would be no elements heavier than iron and also no earth.

Thus, the fact that the earth is composed of heavy elements caused by the explosion of a star, means that there was once a universe without an earth.

Source: The Bedside Baccalaureate