The First Second of Our History

The Zero Moment of the Universe

About 13.8 billion years ago, in a fraction of a second, the universe was born. The mystery of creation is hidden in this first second after the Big Bang.

How, when there was nothing, no energy, no matter, no time, did a tremendous explosion suddenly give birth to space, matter, and time?

From this first second, chaos emerged from nothingness, burning with unimaginable heat. An informal mush expanded, stretched in all directions, and slowly cooled.

This "initial moment" is ours, the beginning of our clock. Even today, we capture in the sky the trace of the first moments (380,000 years after the first second) called "cosmic microwave background radiation" or "background radiation." This low-temperature microwave radiation, close to absolute zero, reaches the Earth's surface from all directions of the cosmos.

The cosmic microwave background is part of the background of all radio sources detected by our radiotelescopes since its discovery by Arno Penzias and Robert Wilson in 1965. It is proof that our observable Universe had a beginning. The first second of our Universe remains the greatest mystery of modern science. It seems that our mathematical formulas shatter against the wall of creation. In the beginning, there was nothing, no matter, no void, time and space did not exist. The explosion of a luminous point smaller than an atom and of infinite heat gave birth to the universe.

Everything begins an infinitesimal fraction of a second after the original explosion, the Big Bang. Time begins to unfold, and within a second, the entire cosmos takes shape. There is no zero time; before time did not exist. The cosmic clock strikes its first beat at 10^-43 seconds.

The universe at this moment is an energy-dense boiling void, incredibly hot. Then, it is assumed to inflate suddenly, which is cosmic inflation. At 10^-32 seconds, during this short period, the Universe filled with particles of all kinds. Elementary particles and their antiparticles emerged from the rapidly expanding space.

The first elements of matter, accompanied by antimatter, quarks, electrons, neutrinos, and photons, bathed in a cosmic soup. At 10^-6 seconds, or one millionth of a second later, the first force, the strong nuclear force, comes into play. This force pulls quarks out of the void in threes to form protons and neutrons and create hydrogen and helium nuclei. After this mysterious first second, a very long and even more mysterious history will unfold, that of our existence.

"To understand our place in the universe, we must go back to the very beginning and see how it all formed." Professor Lawrence Krauss (Case Western Reserve University).