Thursday 6 September 2012

A universe built for life, but how much life?


Whatever your philosophical or theological beliefs one fact cannot be denied. The universe is built for life or has come into being by some means which confers upon it the ability to sustain life. There is a website which lists 93 parameters which are all finely tuned for life. Below are the first 20, just to give an idea of the range and nature of these constants. If you are not  scientifically inclined a quick glance through is all that’s needed to get the point, one that is rarely made in popular science programs or articles.

 

1.       Strong nuclear force constant

2.       Weak nuclear force constant 

3.       Gravitational force constant 

4.       Electromagnetic force constant 

5.       Ratio of electromagnetic force constant to gravitational force constant 

6.       Ratio of proton to electron mass 

7.       Ratio of number of protons to number of electrons 

8.       Ratio of proton to electron charge 

9.       Expansion rate of the universe 

10.   Mass density of the universe 

11.   Baryon (proton and neutron) density of the universe 

12.   Space energy or dark energy density of the universe 

13.   Ratio of space energy density to mass density 

14.   Entropy level of the universe 

15.   Velocity of light 

16.   Age of the universe 

17.   Uniformity of radiation 

18.   Homogeneity of the universe 

19.   Average distance between galaxies 

20.   Average distance between clusters of galaxies


To say these are fine tuned is an understatement. For instance, the following are ‘just right for life’ to the number of decimal places stated:
 
  •  ratio of the numbers of electrons to protons: 37 decimal places.

  •  ratio of electromagnetic force to  gravity: 40 decimal places

  • expansion rate of the universe: 55 decimal places

  • mass density of the universe: 59 decimal places


  •  gravitational constant: 100 decimal places

 

  • cosmological constant: 120 decimal places

If any one of these or 88 other fundamental (e.g. gravitational contant)  and arbitrary parameters (e.g.  average distance between galaxies) had been slightly different we would not be here. Such extraordinary degrees of optimality have only been known about for the last two decades or so.

In what way do these 93 parameters enable life to exist? I list just 6 examples below. It is helpful to bear in mind that most elements needed for living organisms are made in stars by banging lighter elements together to make heavier ones and then banging these together to make still heavier ones. This is called fusion and it all has to happen in a controlled way.

  • Strong Nuclear force constant  determines how strongly the nucleus of an atom is bound together. It is fundamental to the creation of elements in stars. If it was marginally larger then most elements essential to life would be unstable. If  marginally smaller no elements apart from hydrogen (1 electron paired with 1 proton) would form. Result: no life in either case.

  • Weak Nuclear force constant governs how protons decay into neutrons. Had this been slightly larger then so much hydrogen (H) would convert to helium (He) during the Big Bang that stars would produce too many heavy elements. If marginally smaller, too little He would be formed in the Big Bang and there would be too little heavy matter. Result: no life in either case.

  • Gravitational constant is a measure of the strength of the gravitational attraction between objects and which holds large massive ones, like planets and stars, together. It is negligible in atoms and molecules. If it was marginally larger (i.e. if the last digit of a hundred decimal place number was one digit higher) the stars would be denser, hotter and too unstable to produce the elements of life. If  marginally smaller the star would be unable to start the fusion of lighter into heavier elements. Result: no life in either case.

  • Electromagnetic force constant controls the strength with which opposite charges attract. This affects the electron shells around the nucleus and much else.  Atoms more massive than boron (i.e. including those crucial to life, like carbon)  would be unstable if this constant was larger. If it was smaller chemical bonding would be insufficient to permit organic compounds to form. Result: no life in either case.

  • Expansion rate of the universe. A faster rate would prevent galaxies forming, while a slower one would cause the universe to collapse. Result: no life in either case.

  • Entropy level of the universe  is a measure of  its disorder. If it was larger stars would not form within proto-galaxies. If it was smaller proto-galxies would not form at all. Result: no life in either case.

 
The universe being tailored to life suggests that life will come into existence wherever the conditions permit, whether they be natural or supernatural or both. The fine tuning of constants are necessary for life but not sufficient. The big question is what conditions are sufficient for life to start and evolve to higher levels. If these conditions are widespread then one would expect life to be widespread.

 

If it is found anywhere else in the universe,  on planets unlike Earth and far enough away not to have been bombarded with biological debris ejected from Earth due to cosmic collisions,  and whether or not a supernatural element is involved, it may be common, though not necessarily intelligent or imbued with the qualities which make us unique - needing to receive and give love,  seeking truth, justice, and beauty and relentlessly curious about the universe, our origins, our destiny. Also, since the universe is so overwhelmingly geared to  biological life as we know it, one would not expect it to be suitable for any other form of life unless it is also tuned to enable some other form of life to evolve. This seems unlikely but even if it were so how could we detect and communicate with it?

Keep on searching!

See also ENCODE turns DNA junk into treasure


 John
 author, 2077 AD
See also
 ET life should be local
Kepler 22b: how earthlike?
Earth-like planets: is the universe teeming with life?

Reach me at cosmik.jo@gmail.com