Lois & Clark Forums Forums General Discussion Off Topic The Big bang and the Universe, part 7: Your TV knows

Well, let me just post a picture of your knowledgeable TV before I dive into the more technical details of this post!



A knowledgeable TV, channeling into the secrets of the cosmos!

I'll return to the TV static later on. For now I want you to imagine that we are watching a movie on this TV, a movie about the expanding universe.



This is not a movie, but imagine that it was. It would be a pretty boring movie, because all you could see would be galaxies flying apart!

But imagine now, instead, that you could run the movie in reverse. You would see the galaxies "returning to the pen", as it were, sort of going home to roost. They would all be approaching one another, all of them closing in on one another, forming a tighter and tighter group until... yes, until what? Until they had all bunched up so tight and close that they were all touching each other? Until they were all gathered in a single point?

Have we run the movie about the universe in reverse until we got to the starting point of it all? To the point where the universe got going?

To the Big Bang?

It was the discovery that the universe was expanding and thus had an outward-moving direction that made astronomers start asking themselves what had happened in the past. If the universe is growing ever larger today because it is expanding, then it must have been smaller in the past. How much smaller? Was it possible to imagine that everything that now exists in the universe had once been gathered in a single point? And had that "point in space" "burst" at a certain moment in time and "spewed forth" the universe?



Is this what we would see if we could run the history of the universe in reverse? The universe growing smaller and more crowded and compact until...?

When the idea about a definite beginning of the universe "out of nothing" was put forth, many astronomers were extremely skeptical. One astronomer, Fred Hoyle of Great Britain, coined the term "Big Bang" as a derogatory expression, meant to convey how ludicrous the idea was.



Fred Hoyle, a great astronomer and a non-believer in the Big Bang.

Still, the idea of a possible Big Bang inspired some speculation. Three American astronomers, George Gamow, Ralph Alpher and Robert Herman worked on the theory and predicted that if a Big Bang had really happened, then the entire universe would resonate with an echo of this mighty event. This echo would be present as a soup of radio waves filling the entire universe, and the energy of this radiation would correspond to a temperature of five degrees Kelvin above absolute zero.



Geroge Herman on the left, Ralph Alpher on the right and George Gamow as the genie coming out of the bottle. They predicted that the universe would be filled with an all-permeating echo of the Big Bang. Were they right?

Stay tuned for the next chapter, and find out what that TV had to do with anything anyway!

Ann