A question about the big bang

[The 321 Anomaly]

Okay, so I recently started looking at a book on astronomy. The name of the book is Astronomy, and the author is Ian Ridpath.

 

In the part of this book that gives information about the big bang theory, it states that a hundred billionth of a yoctosecond after the beginning of time, the temperature of the universe was 1,800 trillion trillion degrees.

 

What I'm wondering is - how do astronomers know this?

[J.C.MacSwell]

Okay, so I recently started looking at a book on astronomy. The name of the book is Astronomy, and the author is Ian Ridpath.

 

In the part of this book that gives information about the big bang theory, it states that a hundred billionth of a yoctosecond after the beginning of time, the temperature of the universe was 1,800 trillion trillion degrees.

 

What I'm wondering is - how do astronomers know this?

 

They don't know.

 

They are extrapolating backwards based on present observations and best assumptions.

[Tolmosoff]

I think that our universe is like an empty cylinder waiting to be filled. Also its begining is like a buttom put on a string that when you spin it also it viabrates in its spinning motion.

Our universe recycled its self from a previous universe that wiped out everything that was before.

Its called ( The Big Crunch ). Universes can collaps back into its self and go into recycle mode creating a brand new universe each time.

 

Your car goes through the same thing.

Your new car is driven 300 thousand miles and then become a junker that is melted down into molten metal.

 

You then go shopping for a new car and find out that the metal in your new car ( Was your old Junker ) less the seeds, coins and penncils under the seat.

 

Astro biologists call the new singularity that makes the Big Bang was from a previous universe.

[Martin]

... after the beginning of time, the temperature of ...

 

There is no strictly scientific reason to imagine that time had a beginning.

Certainly no reason to assume that time began at the big bang!

 

Different pre-bang models are currently under study and say different things about conditions leading up to the big bang. Predictions can be derived from the models to compare with precision observations we can either make today or will be able to make with more advanced instruments. It will eventually be able to distinguish between the models observationally, and rule some out---by testing. So far we can't pick a winner, so it will take more work.

 

MacSwell is right. Astronomers cannot say. However even if they do not believe that the start of expansion was the beginning of time, they still use the imaginary big bang singularity as a convenient time-mark.

This is well explained at Einstein-Online.

A Tale of Two Big Bangs

The link to E-O website is in my signature. It is the public outreach site of a top research institute, and is more up-to-date than the other cosmology public outreach that I know of on the web.

 

Here is the link for A Tale of Two Big Bangs:

http://www.einstein-online.info/en/spotlights/big_bangs/index.html

 

You might find several other things of interest at Einstein-Online if you browse around some there.

=============================

 

Is this the Ridpath book?

http://www.amazon.com/Astronomy-Universe-Equipment-Eyewitness-Companions/

Don't worry if a book like that over-simplifies some, or is slightly out-of-date. It will still provide lots of useful (approximately correct) information.

 

Just take what they say about the temperature (right after the start of expansion) with a bit of a grain of salt. There's a lot more work to be done about that.

Edited July 29, 2009 by Martin

[The 321 Anomaly]

Thanks for filling me in, guys.

 

When writing my previous post, I had forgotten that many physicists maintain that our universe started after the death of another universe. When I asked someone the question from my last post, he told me that astronomers found out the temperature of the universe so soon after the big bang by using cosmic microwave background radiation. Upon researching that, I learned that cosmic microwave background radiation reveals the beginning of the structure of the universe one hundred thousand years AFTER the big bang.

 

Martin, I believe the book in that link you posted was the book I was referring to. I recall seeing "Eyewitness Companions" on the cover, so that must be it.

[Alan McDougall]

They do not know that was a wild guess. The figure should be infinite or absolute zero entropy

 

If we are to believe our universe comprises everything in existence then at the moment before the big bang the supposedly infinitesimal tiny singularity it also was infinitely large. I mean at that point before time with no other object in existence to compare itself to the point particle we call the primordial singularity could be considered for all purposes to be both infinity small and infinitely huge, size then like time and space was meaningless The same can be said of the temperature it was not hot or cold, it was the coldest place in existence, but also the hottest, thus using terms like temperature for the singularity is utterly meaningless, because there was no other thing in existence to compare this primordial state to.

 

Alan

Edited August 6, 2009 by Alan McDougall
Added second paragraph

[tar]

...thus using terms like temperature for the singularity is utterly meaningless, because there was no other thing in existence to compare this primordial state to.

 

Alan

 

Well we do have something to compare it to now! Us! "We" (some precursors of the particles that make us up)were there at the time, and we are still there but now we are humans, that stand a meter or two high, see photons that vibrate in the THz range, hear sound waves of a certain lengths/frequencies, feel vibrations, taste and smell chemical, have memories and brains that developed tools and equipment to enhance all our senses. We live about 80 years and write stuff down and tell each other about what we experienced and figured out. We figured out the earth is round, and rotates on its axis and faces the sun repeatedly in the same period of heartbeats, and seasons of hot and cold repeat themselves about 365 times before the stars look the same again...etc. We have us to compare against what we sense, and we have our minds eye and the power of analogy, to look into the past, and the future. And we have photons streaming in from every corner of the universe, that we can ponder on, and compare. We can call the sun hot, and the voids of space cold, and we can estimate the temperature it was around here when "we" were 10 to the -whatever seconds old.

 

Regards, TAR