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Author Topic: How old is the Earth - really?  (Read 4086 times)

Offline RealEarthling

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How old is the Earth - really?
« on: 26/04/2010 11:54:37 »
Things I have heard or read over the years:  Matter cannot be created or destroyed.  The universe is 13.4 billion years old.  The earth is 4.5 billion years old.  If everything in the universe eminated from the Big Bang, then it seems to me that all of the materials on earth must also be 13.4 billion years old.  What am I missing?


 

Offline BenV

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How old is the Earth - really?
« Reply #1 on: 26/04/2010 12:08:35 »
I don't think you're missing anything!

As a simplistic view, the first matter would have been principally hydrogen and helium.  These are fused in stars to produce larger elements, which get scattered out in supernovae.  Ths process repeats, giving different types of stars (because they have different starting materials), and allowing some of the material to clump together and form planets like Earth.

So yes, the material for Earth has been around since the big bang, and been cooked in stars, but has only come into this configuration some 4.5 billion years ago.
 

Offline LeeE

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How old is the Earth - really?
« Reply #2 on: 26/04/2010 19:01:37 »
As I understand it, all hydrogen (and tiny amounts of of some of the other light elements) is primeval and was created in the latter stages of the Big Bang.  All of the rest of the elements were created via nucleosynthesis.
 

Offline Geezer

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How old is the Earth - really?
« Reply #3 on: 26/04/2010 20:22:39 »
Considering that we consist of a large amount of hydrogen (in the form of water) it's not unreasonable to conclude that a large percentage of the atoms that make up our bodies are as old as the Universe itself.
 

Offline RealEarthling

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How old is the Earth - really?
« Reply #4 on: 26/04/2010 23:23:38 »
I thank the three of you for the enlightenment.  So nice of you to take the time to respond to my question.  Larry
 

Offline LeeE

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How old is the Earth - really?
« Reply #5 on: 27/04/2010 15:53:32 »
Actually, the proportion of He produced in the BB was much greater than I thought and most of the He around today is primeval too.

There aren't many Helium compounds though, and most of them are unstable, so most He is still in an elemental form.
 

Offline graham.d

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« Reply #6 on: 28/04/2010 13:14:38 »
Are there any Helium compounds Lee?
 

Offline Bored chemist

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How old is the Earth - really?
« Reply #7 on: 28/04/2010 20:49:18 »
Are there any Helium compounds Lee?
It's a matter of definition. Probably best not to go there.
 

Offline Emilio Romero

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How old is the Earth - really?
« Reply #8 on: 29/04/2010 13:47:40 »
Actually, the proportion of He produced in the BB was much greater than I thought and most of the He around today is primeval too.

There aren't many Helium compounds though, and most of them are unstable, so most He is still in an elemental form.

 ???
Who is "He" and how is he produced in a BlackBerry? ;)
 :D ;D ;D
 

Offline LeeE

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How old is the Earth - really?
« Reply #9 on: 29/04/2010 16:52:03 »
 

Offline RealEarthling

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How old is the Earth - really?
« Reply #10 on: 01/05/2010 18:46:51 »
So now I am thinking:  During those long 9 billion years that it took the Earth materials to start hanging out together, there might have been similar materials in another galaxy (or even in ours) that were less patient.  In other words, there could be Earth-like planets in the universe that formed several billion years before Earth.  This would give alien life forms a serious amount of time through which to occur and propagate ahead of Earthlings.  No?
 

Offline chris

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How old is the Earth - really?
« Reply #11 on: 06/05/2010 08:55:01 »
The first stars were burning over 12 billion years ago - three times longer ago than the Earth's current age; so yes, there's been plenty of time for other forms of life to evolve. Also, the sheer scale of the Universe - containing 60 sextillion stars (22 zeros!) makes it inconceivable that there aren't other propitious life-nurturing niches out there somewhere...

Chris
 

Offline norcalclimber

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How old is the Earth - really?
« Reply #12 on: 06/05/2010 20:13:55 »
Things I have heard or read over the years:  Matter cannot be created or destroyed.  The universe is 13.4 billion years old.  The earth is 4.5 billion years old.  If everything in the universe eminated from the Big Bang, then it seems to me that all of the materials on earth must also be 13.4 billion years old.  What am I missing?

Is it true that matter can not be destroyed?  When we refer to matter we are talking about a particle with mass, right?

So the only reason matter can not be destroyed, is because matter and energy are interchangeable and when matter is annihilated it simply reverts to energy?  So really, it is more like energy can not be destroyed, because it is energy which is at the core of it all?
 

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How old is the Earth - really?
« Reply #12 on: 06/05/2010 20:13:55 »

 

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