The Fog

According to widely accepted models, the time it took for the compressed mass to become a point smaller than an atom was significantly less than a billionth of a second. After roughly the first 300,000–400,000 years, the universe began to fill with stuff in the form of a massive cloud of hydrogen that swiftly earned the nickname "fog."

Since hydrogen is the lightest known atom in the universe, it would actually be more correct to refer to the hydrogen at the time as haze, according to publications like Science magazine. This wasn't a flimsy smogbank that would vanish in the face of a strong cosmic wind. It is estimated that it took this massive cloud of hydrogen one billion years to evaporate. If the universe were a middle-aged adult, it would have been completely dark for the duration of its early years and into its toddler years. There are undoubtedly a number of parents out there who claim to be able to relate...