I sometimes ask people if they have read The Hitchhiker’s Guide to the Galaxy, and they ask back, “You mean the book by Douglas Adams?” “Yes,” I reply, “Do you remember what he said about space?” The reply is usually inaudible, so let me repeat Adams’ words for those who do not know them: “Space,” said Adams, “is vastly, hugely, mind-bogglingly big.” Adams really knew how to make a point, did he not? Just imagine this: It has been estimated that our Milky Way alone contains approximately a hundred billion stars and at least a hundred and forty billion galaxies in the universe. If galaxies are like frozen peas, then we have plenty of them to have a gala dinner the size of Royal Albert Hall. Well, that is a lot of peas you have there.
But how did such an unperceived and practically unmeasurable depth come into being? Up until fairly recently, researchers believed that if the universe were like a clock, the planets would revolve in circles in the same boring manner without end, and the physical laws would bring everything back in line. But then, a Belgian priest and scientist named Georges Lemaître told the world a new proposal of the cosmos. In 1927, he stated that the universe was initially a huge atomic bomb and all the small atomic bombs we currently witness. It must sound like something that could have been extracted from a science fiction book, does it not?
Lemaître’s theory initially did not even create a ripple on the surface of the scientific community’s conscious awareness. Then in 1929, Edwin Hubble discovered something pretty astonishing: The universe, despite not doing nothing or being inert, is actually growing. Yes, the universe is expanding! Therefore, if the universe is expanding, then naturally there must be a certain concentration of tighter mass beginning from a certain point. Some scientists embraced this line of thinking, but others, such as Fred Hoyle, dismissively labeled it the Big Bang theory. Ironically, the name stuck.
However, a few sticks in the mud like Ralph Alpher, George Gamow, and Robert Herman did not share this pessimistic outlook and speculated that if the Big Bang was real, it should have left behind an echo of sorts. Well, they were not wrong there, and to get hold of one as an American was more or less like searching for a needle in a haystack.
Enter the mid-1960s. Arno Penzias and Robert Wilson, two astronomers, were working with a radio telescope whose persistent low noise of radio interference had plagued their project. Whether they were installing a new one to replace the torn-down antenna or chasing away the pigeons that nested there, they faced this irritating noise. As it turns out, this ‘hiss’ was in fact the Cosmic Microwave Background radiation, left over from the Big Bang!
Now, what kind of process resulted in all the stars, planets, and galaxies that are present in today’s universe? Here’s the gist: between 12 and 13 billion years ago, everything in the universe began from one little dot. Such an explosion was so vigorous that the universe expanded to twice its size every 10^-34 seconds; so was space born. In minutes, there were forces such as gravity, and energy turned into a form of particles: matter and antimatter. Antiparticles and particles engaged in annihilation, most of them, while a little portion of matter remained.
Protons and neutrons first began to appear in the universe only a second after the Big Bang. After a few minutes, these particles combined and formed the first hydrogen and helium particles. About 300,000 years later, electrons finally started to combine with these nuclei, and the universe was immediately filled with hydrogen and helium gases. Skip to roughly 380,000 years into the universe’s existence, and the universe was filled with photons that Penzias and Wilson detected. Smaller fluctuations in this early light grew over time and became the foundations that make up the galaxies and clusters existing now.
Well, if this is how the universe got going, what about its wrap-up? Oh, but that is another story for another time. Next up on the cosmic drama…