I am trying to grasp the concept of cosmic background radiation, specifically why we can still see it today. As the name implies, it is very faint radiation from the very early universe.
What I don’t get: if a very distant star stops emitting radiation then it will disappear from our view.
As far as I understand it, CBR originated with the recombination. That phase took a few hundred thousand years, then it stopped. So why can we still see the photons emitted then?
Thanks for illuminating me.
In: 6
Imagine you have a time machine that can take you back to the very first moment of a grand fireworks show. As the fireworks explode and light up the sky, they create beautiful bursts of colourful light. Now, imagine that instead of staying in the past, you hop back into your time machine and fast forward to the present day.
Even though you’ve returned to the present, you can still see some faint traces of those fireworks in the sky. The light they produced, even though it happened a long time ago, is still traveling through space and reaching you in the present. That lingering glow is like the Cosmic Background Radiation (CBR).
The CBR is like the afterglow of the Big Bang, the spectacular event that started our universe. Just like the fireworks’ light travels through the sky, the photons from the Big Bang have been traveling through space for billions of years, reaching us now. Scientists can detect these ancient photons using special tools, giving us valuable information about the early universe and how it all began, much like studying the afterglow of the fireworks show helps us understand the initial explosion.
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