Life, they say, is short. But how short is
it? Well, the universe we live in is currently estimated to be 13.8 billion
years old, so our Namibian life expectancy of 64 years is quite short in
comparison. 13.8 billion years, though, is a hard timeframe to wrap our minds
around, so for an accurate comparison, we’re going to reduce that timeframe to
something the average person can understand, and see exactly how short life is
in the grand scheme of things.
The approach used was first established by
Carl Sagan in his book The Dragons of
Eden back in 1977, and later expanded upon by his subsequent television
series Cosmos in 1980. The same
device was used in Neil DeGrasse Tyson’s remake of Cosmos in 2014. We’re going to take a quick walk through what Carl
referred to as the Cosmic Calendar. In order to visualise how short our time
here is, we’re going to condense the 13.8 billion years since the start of the
universe, and compress it into a single calendar year. Every second of this
‘Cosmic Year’ is thus 437.5 years long in reality.
In the beginning, on January 1, 00h00,
there was only the universal singularity. All of time, space, everything that
has ever existed and will ever exist was in single point, infinitesimally
small. And at the first instant of time, that point exploded. It was the first
event in the universe, known as the Big Bang. This explosion ballooned outward,
expanding rapidly, and thus become less dense.
By January 10th, it had expanded
enough that gravity started to assert itself. Up until now, the universe was
dark, but the gaseous matter coalesced into larger and larger clumps, until the
first stars formed. The first galaxies formed from these clusters of stars by
13 January. Our own galaxy, the Milky Way, only formed on March 15th.
But these stars were the first generation
stars, consisting only of hydrogen and helium. But the stars grew and died,
some dying in supernovae, creating heavier elements. Strings of these occurred
over the cosmos for quite a long time, creating second generation stars. These
too had their life cycles, and in their supernovae created even heavier
elements. By 31 August in the Cosmic Calendar, three-quarter of the age of the
universe in, the cloud of stellar remnants that became our solar system grew
big enough that it too ignited a star – our sun.
The sun, a third generation star, contained
99.85% of the matter in the solar system, but that remaining 0.15% orbited it.
Repeated collisions in these gas cloud caused clumps of matter to form, and
they started to clear their respective orbits in larger and larger clumps. By
September 2nd, they had formed planets, including our very own
Earth. But at this time it was but a ball of molten rock, with a smaller one
caught in its orbit, the Moon.
But on 21 September, something miraculous
happened on this barely cooled world. Life. And life finds a way to survive. These
single-celled organisms figured out photosynthesis by 30 September, and by 29
October, the Earth had an oxygenated atmosphere. This provided life to
opportunity to blossom, and by 9 November, the first complex cells appeared. By
the 5th of December, multi-cellular life had appeared, and on 17
December, life crawled out of the oceans, and the first simple animals walked
on the earth’s surface for the first time.
Life advanced quickly. Plants on land
appeared on 18 December, with insects and seeds following on 21 December.
Reptiles appeared on 22 December, but on 23 December, life was dealt a big
blow. A massive asteroid impact triggered worldwide volcanoes and released
trapped gas from beneath the Earth’s crust, resulting in the Earth’s climate
changing and killing over 90% of all species at that point.
But life is persistent, and it evolved. On
24 December the first dinosaurs appeared, with mammals following on 25 December,
and birds on 27 December. Flowers first bloomed on 28 December, and then, on 29
December on the Cosmic Calendar, a bare 185 million years after the previous
one, it happened again. In Central America, near the Yucatán peninsula, another
asteroid impacted the earth. The impact point is today known as the Chicxulub
crater, and it caused 75% of all species to be wiped out, including all
non-flying dinosaurs.
Life, however, kept going. In the
aftermath, the first primates appeared. On 31 December at 10h15, the first apes
appeared. By 21h24 on the last day of the Cosmic Calendar, the first primitive
humans appeared, with their stone tools. Fire was first used and controlled by
23h44. At 23h52, 8 minutes before the end of the year, the first modern humans appeared.
We developed Agriculture at 23h59:32, 28
seconds before the present day. The first Egyptian civilization arose 12
seconds ago. The first laws, the Code of Hammurabi, was developed 9 seconds
ago. The classical Greek civilization, the Roman republic and the Buddha lived
6 seconds ago. 5 Seconds ago the Roman empire arose, Christianity was founded,
and the number 0 was developed. Muhammed and the Byzantine Empire was a mere 4
seconds ago, and 2 seconds ago the Mongol Empire and the Crusades occurred.
Everything since then occurred in the last second of the Cosmic Calendar.
Human life, as can be seen, is thus quite
short. On the Cosmic Calendar, our Namibian lifespan is but 1500 milliseconds. Our
country has only existed for 57 milliseconds! Life itself, even, is relatively
new, but it is remarkably persistent. When we talk about climate change, or
nuclear war or a myriad of other events possibly destroying the planet, we’re
in fact being quite arrogant. It won’t destroy the planet, or even kill life.
The planet has been through much worse, and life has survived. What it will do,
though, is kill the species known as man.
When we see how short our time has been
here, it makes one want for more. Can humanity not try to see more? To
experience more of the vastness of the universe? I, for one, am proud of what
we have accomplished as a species in this very short time frame, and would very
much like humanity to occupy a much larger space on the Cosmic Calendar. For us
to survive as a species, happy and fulfilled, does not, after all require much.
We can act to give our lives meaning by seeking happiness and knowledge, and
help others to do the same. All it requires is that we make ethical decisions
based on reason, empathy and a concern for our fellow man.
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