[Elsie]

Big Bang...

Isn't that the same as....

---

"Let there be LIGHT!"

?

[RadioAstronomer]

Not quite. Photons were not free to travel (what we commonly call the electromagnetic spectrum or light) until about 300,000 years after the Big Bang. The photons existed, however they were "bouncing" amongst the electrons and could not freely travel. (In other words, the universe was opaque prior to this event that is called "matter radiation decoupling")

This "allows" us only to "See" to about 300,000 years after the big bang happened.