Where do humans come from and how do we fit into the big universe? A motivator of both science and religion, this question has surely been on our minds for nearly as long as we have walked Earth, far before recorded history, perhaps before our genus Homo evolved from Australopithecus 2 million years ago. A good definition of humankind might be "the creatures who ask about their place in the universe."
The modern answer is even more beautiful than the wonderful pre-scientific tales. Here is a brief rendition.
Fourteen billion years ago a large random "quantum fluctuation" in empty space caused a particular high-energy quantum field (analogous to magnetic and gravitational fields) to spring into action. This field interacted with itself in a process that increased its volume exponentially; it expanded much faster than light speed. After a trillionth of a trillionth of a trillionth of a second, the universe was the size of a grapefruit. The expansion then slowed to light speed and continues today.
This early "inflationary" process created huge amounts of gravitational and other forms of energy. Because gravitational energy happens to be inherently negative, while the other forms are inherently positive, the big bang was able to create matter and energy from literally nothing by simultaneously creating negative gravitational energy and positive material energy.
That grapefruit of energy was nearly uniform, but with tiny lumps of higher or lower energy. During the first three minutes, this grapefruit expanded to 30 million miles and cooled sufficiently to form hydrogen and helium atoms. High-energy lumps became gravitational centers that, over the next 200 million years, drew hydrogen and helium together to form the first stars. These huge early stars were unstable and quickly exploded. This process "cooked up" the heavier elements that, along with hydrogen, form most of your body, and spewed them into the surrounding universe to eventually be incorporated into later stars such as our sun and its planets. Thus we are stardust, children of the universe.
Our sun and planets formed 4.5 billion years ago from great clouds of dust and gas that gravitated together. It took only 100,000 (0.1 million) years to form the solar system, but another 50 million years for gravity to heat the sun sufficiently for it to "turn on" as a normal star that creates radiant energy from nuclear fusion (like a hydrogen bomb) operating at its center.
Our little rocky planet happened to have the proper temperature and atmospheric conditions to form oceans of liquid water. Once you have liquid water and a few other chemicals, plus the wide range of energy sources on a young planet, many processes can produce the organic chemical building blocks of life. Such processes occurred surprisingly early in Earth's history resulting in the first life forms as early as 3.8 billion years ago.
Life remained single-celled for billions of years, gradually evolving complexity and more effective energy processes until suddenly, a billion years ago, multi-cellular plants, and then animals, flowered. With a little luck (such as a big rock from space that killed off the non-flying dinosaurs 65 million years ago), the mammals prospered and evolved into humans when we evolutionarily diverged from the other primates 7 million years ago.
This story raises many questions: How do we know all this? How certain is it? Is there life, intelligence, or technology, elsewhere? What does the future hold? Certainly, we are not going to live long and prosper unless all humans gain wisdom from our current culture's answer to the world's oldest question.
Yet the general public learns little of this story. Science courses seldom mention these topics, while history courses touch nothing prior to 10,000 years ago -- an eye blink in time. Some folks would like to change this, and have created a high school course called "Big History" (it's online, built to Common Core standards) to do just that. It's developed mainly by the Oxford-educated American historian David Christian (watch his Ted Talk "The history of our world in 18 minutes") and supported by the computer magnate Bill Gates. Roughly the first half of this course becomes "pre-history," based on scientific evidence rather than historical records.
Courses like this need to be tried in public schools. It's easy to visualize a college course along these lines, but it would need a small team of scientists and historians. At the least, college world history or western civilization courses should begin with a series of lectures on pre-history. Humankind needs to know its roots.
Commentary on 01/19/2016