Saturday, March 1, 2014

Cosmic Newcomers

Humans are cosmic newcomers.

It is commonly held that our home planet coalesced from cosmic dust and gas. Carbon-based life is a relatively recent event. Life is a viral outbreak that occurred billions of years ago on Earth.

The profundity of carbon-based life is that chemical organisms replicate and grow in complexity.

Life, and more specifically human life, is a latecomer to the existential table.

Humans are a puff, a wink, or a dream.
Men come and go, cities rise and fall, whole civilizations appear and disappear-the earth remains, slightly modified. The earth remains, and the heartbreaking beauty where there are no hearts to break....I sometimes choose to think, no doubt perversely, that man is a dream, thought an illusion, and only rock is real. Rock and sun.
Edward Abbey, Desert Solitaire: A Season in the Wilderness
Many geologists think our atmosphere and oceans arrived on the Earth about 4 billion years ago either from a series of volcanic eruptions or from comets colliding with earth that released water and gases.

Evidence of Life

How long before life emerged from the chemical soup of oceans and atmosphere?

The first evidence of life, inferred from the chemical record (e.g., Carbon isotope C-12 to C-13 ratio), dates from 3.85 to 3.65 billion years ago. The first undisputed fossils appear in rocks about 3.2 billion years ago.

Human footprints appear 1,500,000 years ago. The first humans fossils known to us are from 195,000 years ago.
Artifact
Years Ago
Atmosphere and Ocean4,000,000,000
Life3,850,000,000
Fossil3,200,000,000
Human Footprint1,500,000
Human Fossil195,000

I stand for what I stand on.
Edward Abbey

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