Cosmology From The Beginning

Credit NASA and ESA

Cosmology from the beginning – Part Twenty-Seven

Because Astrophysicists have discovered that the universe is apparently expanding, and have measured the rate of this expansion, they can run the clock backwards at that rate and calculate the age of the universe.  Using the latest, most accurate, information it appears to be 13.77 billion years old, or 13,770,000,000 years old.

Other very reasonable conclusions to draw from these findings is, that in the very distant past, the universe must have very much smaller than it is today. In fact, the logical conclusion is that everything we see today originated from the same point. Very much earlier on, the universe must have been extremely dense, compact, and incredibly hot. Conclusions such as these lead to the hypothesis that the universe had a definite beginning, it was therefore not eternal and unchanging, as had previously been thought by most prominent scientists.

So, the prevailing ‘steady state’ theory was gradually replaced by the ‘big bang’ theory where everything is said to have come into existence from a miniscule point of origin. All of space, matter, and even time itself, was created in a hugely expanding fireball of energy, cooling and condensing as it grew rapidly.

In this very early phase, the universe was energy dominated, and as the expansion plus associated cooling progressed, the first forms of matter came into being from the hugely energetic maelstrom. Only hydrogen and helium existed in these very early times, some traces of lithium and other very light elements were also present, but nothing that could form into planets etc., and so any form of life was likely impossible.

Strong evidence for the description of these events being correct does exist, and the best example is the afterglow of the so-called big bang which is the Cosmic Microwave Background Radiation (CMBR). The CMBR has been mapped out in exquisite detail by three successive space telescopes i.e., COBE, WMAP and Planck.

For life, as we know it, to exist very many other elements needed to come into being. Oxygen, carbon, nitrogen, iron, and the countless other elements necessary for water, planets, atmospheres, and much later on life to exist, were all formed as a result of many generations of star formation, life cycles, and their often-spectacular deaths.

As more stars formed, they gathered together in ever bigger clusters we call galaxies. Now, it is one of the major tasks for the James Webb Space Telescope (JWST) to look back into to the farthest reaches of space, and time, to see if the earliest stars and galaxies look as scientists expect them to, and hopefully verify their expectations. (As an aside we prefer the name Just Wonderful Space Telescope.)