How was the Universe recession velocity (faster than light)Determined?

Answer 1

I think you're asking about something scientists call "cosmological inflation." Basically, inflation theory says that immediately after the Big Bang, when the universe was about the size of a pea, it expanded faster than the speed of light until it was about the size of a grapefruit. At that time inflation ended and 'normal' expansion proceeded. This faster-than-light expansion is possible because it was space ONLY that expanded at that velocity and relativity in no way prohibits this.

The actual mechanism that caused inflation is extremely complex and deals with such ungainly topics as scalar fields and quantum physics. Essentially though, inflation is thought to have happened due to the separation of the four fundamental forces of nature -- electromagnetism, strong nuclear force, weak nuclear force, and gravity.

Answer 2

I'm sorry I don't quite get your question. Recession velocity? The universe hasn't recessed.

However, if you are talking about the Big Bang some scientists believe that in the first few seconds/minutes of the universe as the Big Bang happened the universe expanded faster then the speed of light.

Now nothing can can move faster then the speed of light, when I challenged my professor on this he kinda glazed over the question since it's only a theory that hasn't been proven.

They came to this conclusion (or theory) to help justify the age of the universe, since there seems to be a problem with how old it should be. It's something like 500 million (don't quote me on the age) year difference, it should be older but it's not.

SO to explain this difference they theorized that the Big Bang's explosive force isn't a constant rate, that in the beginning it exploded faster, expanding the universe very fast in those few minutes thus explaining why some calculations show the galaxy is half a billion years younger then it should be.

Kind in mind though that this isn't proven and it's only in response to some contradictory data about the age of th universe.

If you want to know how they measure the age of the universe, it's what we call background radiation. When the first mircowave dishes were built in the late 50s they got this nasty low hum interferring with the signal and no matter what they did they couldn't get rid of that interference. Later they realized that that hum wasn't from the equipment but from space, space itself is emitting low levels of radition.

Now the BIg Bang was HUGE, radition would have been expelled along with heat but as the universe expanded and thus cool the decay of radition would drop along with the heat levels. Now we can measure the currently heat/radition levels and then back track all those billions of years.