Friday, April 20, 2012

From where the hydrogen?

The Ring Nebula M57
From hydrogen to iron ... and then Bang!!

So we have followed in very generic way the life cycle of stars - why they call it stellar evolution? - and learned about the important cosmic limit of iron with atomic number 26.

Cold mother hydrogen molecule gas is ignited and atom nuclei are fused into helium and more nuclear reactions occur in star factories generating energy and heavier elements - until they reach iron. When the iron producing red giant reaches the boiling point it explodes generating the rest of the elements we know from the Period Table.

But from where comes the oridinal hydrogen that floats in those dusty gas clouds in the nebulae forming those majestic Pillars of Creation where young bright stars are born as in the dagger of Orion visible to naked eye?

Big Bang!
We all know the catchy term for the Beginning somewhat jokingly introduced by Sir Fred Hoyle to ridicule the theory in a BBC program 1949 - Big Bang!

Especially in a blog discussing Astrotheology it is nice to notice that it was a Roman Catholic priest, Georges Lemaître, who first suggested in an article published 1927 the expansion of the Universe and suggested a "Primeval atom" from which the entire cosmos begins.

Lemaître is an example that religion does not have to stifle scientific study despite the fact that it can and does in many cases.

So what happens in the Beginning according to modern science?

From where the simplest atom, hydrogen?

Big Bang theory 

The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe.

According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the Universe to cool and resulted in its present continuously expanding state. According to the most recent measurements and observations, the Big Bang occurred approximately 13.75 billion years ago, which is thus considered the age of the Universe.

After its initial expansion from a singularity,
  • the Universe cooled sufficiently to allow
  • energy to be converted into various subatomic particles, including protons, neutrons, and electrons. 
While protons and neutrons combined to form the first atomic nuclei only a few minutes after the Big Bang, it would take thousands of years for electrons to combine with them and create electrically neutral atoms.

The first element produced was hydrogen, along with traces of helium and lithium.

Giant clouds of these primordial elements would coalesce through gravity to form stars and galaxies, and the heavier elements would be synthesized either within stars or during supernovae.

No comments:

Post a Comment