Hubble made the observation that the universe is continuously expanding. Galaxies that are twice as far from us move twice as fast. Another consequence is that the universe is expanding in every direction. He theorized that after the universe had cooled to about 3000 billion degrees Kelvin, a radical transition began which has been likened to the phase transition of water turning to ice. Composite particles such as protons and neutrons, called hadrons, became the common state of matter after this transition. Still, no matter more complex could form at these temperatures. Although lighter particles, called leptons, also existed, they were prohibited from reacting with the hadrons to form more complex states of matter. These leptons, which include electrons, neutrinos and photons, would soon be able to join their hadron kin in a union that would define present-day common matter.
There are several reasons why this theory can not be proven:
- There is no way to unite the particles. As the particles rush outward from the central explosion, they would keep getting farther and farther apart from one another.
- Outer space is frictionless, and there would be no way to slow the particles. The Big Bang is postulated on a totally empty space, devoid of all matter, in which a single explosion fills it with outward-flowing matter. There would be no way those particles could ever slow.
- The particles would maintain the same vector (speed and direction) forever. Assuming the particles were moving outward through totally empty space, there is no way they could change direction. They could not get together and begin circling one another.
- There is no way to slow the particles. They are traveling at supersonic speed, and every kilometer would separate them farther from one other.
- There is no way to change the direction of even one particle. They would keep racing on forever, never slowing, never changing direction. There is no way to get the particles to form into atoms or cluster into gaseous clouds. Angular momentum [turning motion] would be needed, and the laws of physics could not produce it.
- How could their atomic structures originate? Atoms, even hydrogen and helium, have complex structures. There is no way that outward shooting particles, continually separating farther from each other as they travel, could arrange themselves into atomic structures.
