LEONThe Long Way Home
Imagine a brass and quartz machine with one lever, after H. G. Wells. Pull it back to before anything happened, then ride it home.
We were created as finished humans, separate from the rest of nature and at the center of the story.
13.8 billion years as one calendar year
Carl Sagan’s Cosmic Calendar squeezes all of history into a single year. Drag the lever.
| Fact | Number |
|---|---|
| Years since the Big Bang | ~13.8 billion |
| Years Earth has existed | ~4.5 billion |
| Years of modern humans | ~300,000 |
Our neighborhood
We aren’t at the center of a stage set. Tap outward.
One person on one small planet, the third rock from an average star.
A spiral of 100 to 400 billion stars. The Sun is about two-thirds of the way out from the center.
The Milky Way, Andromeda, Triangulum, the Magellanic Clouds and dozens of dwarf galaxies. Andromeda is heading our way.
The Local Group sits on the outskirts of the Virgo Supercluster, inside an even larger structure called Laniakea.
Sagan’s "pale blue dot": seen from far enough away, every war, love affair and empire sits on a single speck.
Made in stars
That’s literal. The carbon, oxygen and iron in your body were forged inside stars that lived and died before the Sun formed. In Sagan’s phrase, we are a way for the cosmos to know itself.
The kitchen that made us
Primatologist Richard Wrangham argues in Catching Fire that cooking changed us. Softer, richer food meant less chewing, smaller guts and energy left over for bigger brains. It’s debated, because the dates for regular fire use are contested, but it’s a strong story.
Hours of chewing every day, big jaws and big guts.
More calories with less effort, time freed up and a bigger brain to feed.
Your body keeps the receipts
Human embryos briefly show pharyngeal arches (structures fish turn into gills), a tail and a coat of fine hair. A caution: Haeckel’s old slogan that embryos replay their adult ancestors is wrong. Karl von Baer’s version is closer to the truth: related embryos share early features, then go their own way.
Are monkeys our grandparents?
No, they are cousins. Humans and chimpanzees share a common ancestor from roughly 6 to 7 million years ago. The tree branches out like a family tree rather than climbing like a ladder.
If we were created, at what stage?
Particles came first, then stars, then chemistry, then single cells for most of Earth’s history, then animals, the move from water to land, primates, and finally us: a thin slice of the record, and still changing.
Hunters, then settlers
For most of human time we were hunter-gatherers. Farming began about 12,000 years ago and settled people in one place. Traditions far apart keep telling versions of the same stories: floods, first people and journeys home. This is a comparison, not a ranking or a claim about which are true.
None of this cancels religion
Religion is one of the main ways humans organise awe, grief, justice and belonging. It built hospitals and held communities together through famine and war. That beauty doesn’t need the universe to be small or young. The facts only ask that the map of nature not be redrawn to flatter us.
We are late arrivals on a small world, related to the rest of life, still changing and still capable of awe. That is the long way home.
Rewritten from the original No Sacred Cows post for the LeonLink blog.
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