The microwave Background

Certainly, the redshift of galaxies wasn't the only proof that the big bang existed 14 billion years ago. As we mentioned before the cosmic inflation that started the universe have released a tremendous amount of power and heat in the universe, but where did all this energy go?
Don't worry It still glows even now because nothing is lost unless it's transformed into matter according to the theory of relativity E=mc² that I already mentioned in a previous article.Unfortunately this glow doesn't appear to the naked eye because it belongs to the invisible domain of the electromagnetic spectrum and wasn't discover until the creation of sophisticated telescopes that can detect what's left from these radiations, these telescopes mostly use infra-red cameras to give us a glance about the heat distribution of cosmic energy in the shape of what's called a microwave background:

This cosmic microwave map indicates the temperature distribution within the scanned radius. Although the big bang was the most energetic phenomenon that has ever occurred, the blue areas show a freezing temperature at the neighborhood of the absolute zero this is due to the cosmic expansion that caused the intense heat that was once concentrated within a single spot to be diluted and propagated all over the cosmos and it almost vanished or gathered into a more or less concentrated areas that are graduated from sky blue to red which represents the hottest areas.