Origin Story: A Big History of Everything

by David Christian

it takes a lot of energy to fuse protons because their positive charges repel each other, and temperatures were falling fast just after the big bang, so it was impossible to fuse more protons to form the nuclei of larger atoms. This explains a fundamental aspect of our universe: almost three-quarters of all the atoms in it are hydrogen, and most of the rest are helium.

the dark lines were the result of light from the sun’s core being absorbed by atoms of different elements in the sun’s cooler outer regions. This reduced the energy at those frequencies, leaving dark lines on the emission spectrum. We call these dark lines absorption lines, and different elements generate different patterns of absorption lines.

cosmic microwave background radiation (CMBR). This is the radiation released when the first atoms formed, about 380,000 years after the big bang.

Structured flows of energy are known as free energy, and unstructured flows are known as heat energy.

roughly speaking, more complex phenomena need more dense flows of energy, more energy per gram per second.

entropy demands more energy from an entity if it tries to get more complex; more complex things have to find and manage larger and more elaborate flows of free energy.

These were the only elements created in the big bang.

Hertzsprung-Russell diagram,

Most stars will spend about 90 percent of their lifetimes at some point on the main sequence.

If you try to lift a teaspoon of white-dwarf stuff, you’ll fail, because it weighs at least a ton.

Perhaps the most famous example of a core-collapse supernova lies at the heart of the Crab Nebula. Betelgeuse could go supernova at any time in the next million years.

A neutron star just twenty kilometers across would weigh twice as much as our sun, and a teaspoon of neutron-star stuff would weigh a billion tons.

Rotating neutron stars are known as pulsars. Soon after the first pulsar was discovered, another one was detected in the heart of the Crab Nebula, the remnants of a supernova observed by Chinese astronomers in 1054. The Crab Nebula pulsar is about the size of a city and rotates thirty times every second.

For the most massive stars, there is another, even stranger, denouement. Their cores implode so violently that nothing can resist the collapse, and they turn into black holes,

Even today, about 98 percent of the mass of interstellar dust clouds consists of hydrogen and helium.

Confusingly, astronomers term all elements heavier than helium metals.

no interstellar molecules detected so far have more than about a hundred atoms.

an individual mobilizes about 120 joules every second. This is the “power rating” of a human being: 120 watts,

all living organisms are informavores. They all consume information, and the mechanisms they use for reading and responding to local information—whether they are eyes and tentacles or muscles and brains—account for much of the complexity of living organisms.

as organisms increase in complexity, they need more and more information, because more complex structures have more moving parts and more links between their parts.

Most modern definitions of life on Earth would include the following five features:

we should expect the most interesting chemistry to be on planets whose average surface temperatures lie roughly between zero and one hundred degrees Celsius,

Life appeared early in the history of planet Earth, and that suggests that creating simple forms of life may not be too hard where the right Goldilocks conditions exist.

Though they don’t know exactly what it looked like, biologists refer to the first living organism as Luca (or LUCA, from “last universal common ancestor”).

The proteins Luca made suggest that it lived at the edge of alkaline oceanic vents, probably inside tiny pores in lavalike rocks, and it got its energy from nearby gradients of heat, acidity, and flows of protons and electrons.

She [Luca] was not a free-living cell but a rocky labyrinth of mineral cells, lined with catalytic walls composed of iron, sulphur and nickel, and energised by natural proton gradients. The first life was a porous rock that generated complex molecules and energy, right up to the formation of proteins and DNA itself.

Every group of three letters codes for a particular amino acid or contains an instruction, such as Stop reading now. Thus, the sequence TTA says, Add on a molecule of the amino acid leucine, while TAG is a sort of punctuation mark that says, Okay, you can stop copying now.

To give Estha and Rahel a sense of Historical Perspective… Chacko… told them about the Earth Woman. He made them imagine that the earth—four thousand six hundred million years old—was a forty-six-year-old woman.… It had taken the whole of the Earth Woman’s life for the earth to become what it was. For the oceans to part. For the mountains to rise. The Earth Woman was eleven years old, Chacko said, when the first single-celled organisms appeared.

Hot magmas rising from deep within the Earth circulate under the crust, like water boiling in a saucepan. It is these convection currents of semiliquid rock and lava that move the tectonic plates floating above them.

divergent margins,

convergent margins,

transform margins.

Stars like our sun emit more and more energy as they age, so the amount of heat arriving on Earth has slowly increased. When Earth was young, the sun was emitting 30 percent less energy than today.

There is a balance between the two halves of this mechanism because higher temperatures generate more rainfall, which accelerates erosion, moving more carbon back into the mantle. But if the Earth cools too much, rainfall will dwindle, less carbon dioxide will be buried, carbon dioxide levels will build up as it is pumped up through volcanoes, and that will warm things up again.

Today, biologists classify all living organisms into three great domains: Archaea and Eubacteria, which consist entirely of single-celled prokaryotes, and Eukarya, which consists of more complex single-celled organisms and also multicelled organisms such as ourselves.

On and within your body, there are probably more prokaryotic cells than cells with your own DNA. But we ignore them (until they give us a stomachache or cold) because they are so much smaller than our own cells. This vast shadow world that we share with prokaryotes is known as the microbiome.

E. coli bacterium, for example, has four different types of sensor molecules embedded in its membranes, and together they can detect about fifty different types of good or bad things in the neighborhood.

The general formula for respiration is CH2O (carbohydrates) + O2 → CO2 + H2O + energy.

Respiration gives you the energy of fire without its destructiveness.

many bacteria show herdlike behavior, which implies some sort of rudimentary communication system.

modern slime molds. Dictyostelium is an amoeba. Most of the time, its cells live independent lives. But when food is short, thousands of cells will gather together to form a slug,

So significant was the cold spell that began about seven hundred million years ago that in 1990, geologists added a new period to the geological timeline: the Cryogenian period. This started about 720 million years ago and lasted 85 million years. Kilometer-deep glaciers spread over the land and oceans; surface temperatures may have fallen to negative fifty degrees Celsius and photosynthesis would have largely shut down.

One possibility is a sudden shift in Earth’s axis of rotation, which would have altered the position of all continents relative to the poles. Such events are known as true polar wander events, and they have happened at least thirty times in the past three billion years. A geological hiccup on this scale could have been caused by the sudden movement of huge masses of molten magma inside the Earth, or perhaps by an asteroid impact.6

The extreme cold ended about 635 million years ago, and it ended suddenly.

To nineteenth-century paleontologists, life seemed to pop up, fully formed, which delighted those who believed in a creator god. Now we know that life had already been around for three and a half billion years; it was just hard to see the evidence.

Most showed up in the astonishing ten-million-year interval starting 530 million years ago. In this period (a split second to a paleontologist) was concentrated perhaps the most rapid stretch of biological innovation in the past six hundred million years.

The modern marine invertebrates called lancelets, which have nervous systems but no real brains, may bear some resemblance to our earliest vertebrate ancestors.

Mass-extinction events reshuffled the genetic deck of cards, created new evolutionary spaces for survivors, and set up new evolutionary experiments. They were always followed by adaptive radiations, periods of rapid experimentation during which new biological products were launched in the mass market of a changing biosphere. Many of the more exotic experiments would quickly vanish, leaving behind only the most successful.

When Earth burped, the biosphere shuddered. By some estimates, oceans may have been as warm as thirty-eight degrees Celsius, hot enough to kill most marine organisms and stop nearly all photosynthesis in the seas.

The first vascular plants, with tissues that could circulate liquids and nutrients, showed up on land about 430 million years ago. Fungi and animals soon followed them.