In the beginning, there was light. In the first split second after our Big Bang, the entire part of space that our telescopes can in principle observe (“our observable Universe,” or simply “our Universe” for short) was much hotter and brighter than the core of our Sun and it expanded rapidly. Although this may sound spectacular, it was also dull in the sense that our Universe contained nothing but a lifeless, dense, hot and boringly uniform soup of elementary particles. Things looked pretty much the same everywhere, and the only interesting structure consisted of faint random-looking sound
In the beginning, there was light. In the first split second after our Big Bang, the entire part of space that our telescopes can in principle observe (“our observable Universe,” or simply “our Universe” for short) was much hotter and brighter than the core of our Sun and it expanded rapidly. Although this may sound spectacular, it was also dull in the sense that our Universe contained nothing but a lifeless, dense, hot and boringly uniform soup of elementary particles. Things looked pretty much the same everywhere, and the only interesting structure consisted of faint random-looking sound waves that made the soup about 0.001% denser in some places. These faint waves are widely believed to have originated as so-called quantum fluctuations, because Heisenberg’s uncertainty principle of quantum mechanics forbids anything from being completely boring and uniform. As our Universe expanded and cooled, it grew more interesting as its particles combined into ever more complex objects. During the first split second, the strong nuclear force grouped quarks into protons (hydrogen nuclei) and neutrons, some of which in turn fused into helium nuclei within a few minutes. About 400,000 years later, the electromagnetic force grouped these nuclei with electrons to make the first atoms. As our Universe kept expanding, these atoms gradually cooled into a cold dark gas, and the darkness of this first night lasted for about 100 million years. This long night gave rise to our cosmic dawn when...
...more
This highlight has been truncated due to consecutive passage length restrictions.
an elegant and beautiful description of the Universe's origin
