EDIT: Not sure why the video isn't playing, it works on YouTube:
EDIT 2: works now!
Hey Hubski! Check out the video. I'm trying out a little experiment with the book writing process. I think it will both motivate me to finish and allow me to share my thoughts with you all before it is complete. I'm excited to hear what people think -- as I say in the video this is just the opening of the first chapter. Hopefully it is thought provoking and interesting -- that is its intended purpose.
Here is a quote from the creator of Vsauce, Michael Stevens, that really incapsulates my own views on science and the reason for writing the book:
"We have the mysteries of the universe. We will never be able to understand all of them. We will never be able to answer every single question. But walking around in those questions, exploring them, is fun. It feels good.”
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Frontiers: Science's Biggest Mysteries Universe, Life, & Mind
Chapter 1:
“Sometimes nature guards her secrets with the unbreakable grip of physical law. Sometimes the true nature of reality beckons from just beyond the horizon.” - Brian Greene, Physicist
We are a species that desperately searches for our origins. We want to know where we came from. For many people this search includes the construction of a pedigree chart – a family tree. During a university course in anthropology one of my assignments was to gather as much data as I could about my own pedigree chart and see how deep I could push my family origins. Like most people I found that with each successive generation it became exponentially more difficult to find reliable data of my ancestors. However, I was lucky that my maternal granddad had retained a lot of letters, images, and documents from his history, which made it easier for me to extend my family tree.
While growing up I remember my granddad always told me that our family had a biological connection to the 19th century author Charlotte Bronte who wrote Jane Eyre and Wuthering Heights. I had assumed that such a connection was unfounded but thought it would make the investigation more exciting if I could demonstrate scientifically whether the connection was real or imagined. To my surprise, my granddad and I did reveal a connection (although not biological). In the fifth generation of my pedigree chart, my great, great, great, granddad had an uncle, Arthur Bell Nicholls, who married Charlotte Bronte. However, we also found out that Charlotte Bronte died before giving birth to her first child, so there was no biological relatedness.
After these connections discovered in the fifth generation I was unable to find any other reliable data regarding my own family tree. I think this disappointed my granddad, but it didn’t really matter to me. Your actual biological connection to any ancestor in the sixth and seventh generation is more culturally imagined than biologically real. Statistically speaking, you have inherited only 1/64th of your genetic material with a sixth generation ancestor (a great x four grandmother/father), and only 1/128th of your genetic material with a seventh generation ancestor (a great x five grandmother/father). Past the seventh generation human genealogy really ceases to mean anything at all because the degree of kinship has dropped well below one percent. By the eighth generation you have 256 great x six grandparents. Even if you can technically trace your ancestral lineage down your mitochondrial deoxyribonucleic acid (DNA) or Y-chromosome, it tells you nothing about which one of your ancestors provided the rest of your genome. Genetic probability dictates you are a complicated mix of all 256, so what does it really matter if your mitochondria was in England 500 years ago, or modern day Uruguay 2,000 years ago, or in modern day Iraq 30,000 years ago? It only matters insofar that you have constructed it to matter.
As someone who is deeply concerned with origins this simply means we need to scale up our connection to the rest of nature. Evolutionary anthropologists can help us piece back our human origins with the help of genetics and archaeological evidence of material culture and fossilized human remains. We know when particular cultural groups established settlements and when large populations migrated throughout the world at fairly specific times. Attempting to search for one personal path through this maze of settlements and migrations is simplified and misguided. But I find it awe-inspiring and uplifting to know that our knowledge of the human past can help us realize that we equally share the human story. From a biological perspective “French history”, “Chinese history” “Native American history”, or “African history” are all really just collective human histories. That means they are equally “mine”; and they are equally “yours”. All human pasts can help you situate yourself within 21st century human society.
But as a species can we push back further?
Indeed we can. In 2004, evolutionary biologist Richard Dawkins released a now classic book titled The Ancestor’s Tale in which he details a pilgrimage to the dawn of life itself, from the perspective of our evolutionary branch. Technically you could do this with any species, regardless of kingdom. This is because modern genetics has revealed a continuum of genetic relatedness between all extant species. This continuum of relatedness is a result of life’s shared common ancestry stretching back 4 billion years in time. If we had a time machine we could journey back 2 million years and find the common ancestor of all members of the genus Homo (e.g., Homo neanderthalensis, Homo floresiensis, Homo heidelbergensis, Homo ergaster, Homo erectus, etc.). If we journeyed back ten million years we would find the common ancestor of the African great apes (e.g., chimpanzees, bonobos, gorillas). If we journeyed back 55 million years we would find the common ancestor of all primates. If we journeyed back 100 million years ago we would find the common ancestor of all mammals. And so on, and so on until we found our common ancestor with plants, archaea, and eventually even bacteria. The further you journey back the more species you would encounter that share common ancestry with extant groups of organisms.
Unfortunately for evolutionary science, we do not have time machines with which to go back and study these extinct species. Theory, fossils, genetics, and biogeography must be our tools to uncover these connections. Using this approach has proved fruitful; we now have a well-developed understanding of the evolutionary history of life on earth. Isn’t it bizarre that extending our individual family genealogy back only eight generations is meaningless, but extending the genealogy of life back trillions of generations, is insightful! And just as understanding all human pasts can help you situate yourself within 21st century human society, understanding all life helps you situate yourself within the 21st century biosphere.
It may seem ridiculous to propose, but can we push back further? The answer is undoubtedly ‘yes’. All life on earth is based on DNA, which is a complex molecule responsible for encoding all genetic information on the planet. DNA is the language of life, and that language is written in carbon atoms (with some help from oxygen and nitrogen). Earth scientists still debate why and how the earth developed the chemical composition it did, but it is well known how complex molecules like carbon formed and became abundant throughout our galaxy.
Stars are essentially chemical factories. All of the chemicals in the universe other than the majority of hydrogen, helium, and lithium were forged via transmutation in the centers of stars. When a molecular cloud (of mostly hydrogen) collapses due to gravity with sufficiently large quantities and within a sufficiently dense area, thermonuclear fusion begins: a star is born. Fusion forces atomic nuclei to merge together creating ever more complex chemicals. For most of a stars life, hydrogen is converted to helium. This type of transmutation requires the lowest temperature and density of any thermonuclear transmutation process because hydrogen and helium only have one and two proton nuclei respectively. As a consequence, a weaker version of the thermonuclear force is required to overcome the electrical repulsion of the positively charged atomic nuclei.
Once helium predominates in the core of a star a two-step process can begin which leads to even more complex chemicals. When two helium atoms are forced together, they form beryllium. But beryllium is highly unstable and almost immediately decays back into simpler atoms before a more complex, stable atom can form. However, occasionally two helium atoms fuse with a third helium atom. This reaction creates the chemical backbone of all known life: carbon.
As a result of this process, low-mass stars like our Sun are left with cores of carbon, but with only trace elements of more complex chemicals. It requires the thermonuclear power of higher mass stars to produce even more complex chemistry. In higher mass stars chemical complexity spirals out of control, with carbon nuclei leading first to nitrogen (7 protons), then to oxygen (8 protons), and all the way up to iron (26 protons). This process takes a high mass star its entire life (typically multiple billions of years). But once a high mass star has an iron core, there is no more energy to be gained from thermonuclear fusion. The gravitational force of gravity that built the star from a diffuse molecular cloud into a multi-billion year old giant sphere of complex chemistry eventually pushes too far. Implosion results. This implosion, within seconds, creates all chemicals on the periodic table of greater complexity than iron. Such an implosion results in an outwardly extending spherical blast wave of star stuff: a supernova. Supernovas have filled our universe with the chemicals necessary for planets and life.
So we can trace our origins to the cores of stars that have scattered their carbon-enriched guts into the cosmos. We can be sure of this not only because the process of thermonuclear fusion is well understood, but also because a significant component of our early solar system was composed of carbon. This carbon acted as the substrate for the first replicating molecules (carbon is the best known molecule-forming atom). If we want to push our origins back even further, we need to explain how the first atoms formed. It may be strange to think about, but there was a time in the universe’s history before atoms. In the past, the universe was much smaller, hotter, and denser. In fact, the further back in the past astronomers observe, the smaller, hotter, and denser the universe becomes, without variation. And if astronomers could look 13.8 billion years into the past, they would in theory be observing an infinitely small, hot, and dense universe: a singularity.
There extreme early conditions created the first atoms in a two-step process spanning hundreds of thousands of years. Step one occurred when the first atomic nuclei formed. The building blocks of these nuclei, protons and neutrons, formed a mind-numbing 10^-6 seconds after the Big Bang from a soup of nature’s fundamental building blocks: quarks, gluons, and leptons. This process has been experimentally confirmed now that we have recreated the temperatures and densities of the early universe on earth in particle colliders.
Before 10^-6 the universe was a seething fundamental particle battlefield of matter and anti-matter pairs. The temperatures were so high and the density was so great that fundamental matter particles were created and instantaneously destroyed. But once the universe cooled to approximately 1 billion degrees Kelvin, creation of new matter/anti-matter pairs ceased. For an unknown reason, there was a slight matter/anti-matter asymmetry in the early universe, and so protons and neutrons survived this era, and all anti-matter particles were destroyed. The same happened between electrons and positrons. The phase of particle pair annihilations was over.
From this early period of about 10^-6 to about 3 minutes post-Big Bang, the universe reached temperatures conducive to the formation of the first atomic nuclei. As quarks and gluons had formed protons and neutrons, protons and neutrons formed atomic nuclei. Approximately 25% of the available protons joined neutrons to form helium and deuterium (heavy hydrogen). The rest of the protons remained in a form of plasma that would later attract electrons to become hydrogen-1.
Step two of the process required the universe to reach the temperature and density necessary to slow electrons down into an embrace with the positively charged atomic nuclei. Luckily, over the millennia between the formation of the atomic nuclei and the formation of the first true atoms, the universe was still expanding (and thus cooling) rapidly. When the universe was approximately 380,000 years old, it was approaching the size of our local supercluster of galaxies and had cooled to 3,000 degrees Kelvin. These conditions were sufficient to slow down electrons. Over a period of 20,000 years they fell into an eternal embrace with atomic nuclei, giving birth to the first atoms.
This knowledge gives us an even deeper sense of our origins. All of the cells that make us unique are of course composed of atoms. But can we push our origins back further than the first atoms? Such a question leads us close to the edge of human knowledge. The quark-gluon soup of elementary particles were produced after a hypothesized inflationary epoch between 10^-37 and 10^-32 in which the universe itself expanded faster than the speed of light by a factor of 1026. Current knowledge can’t take us back in spacetime much further or deeper. But many theorists speculate that this inflationary epoch is the period when the four known forces (i.e., gravity, electromagnetism, strong nuclear force and the weak nuclear force) separated. This force breaking may have produced the matter/anti-matter asymmetry of the quark-gluon particle soup. Pushing back further takes us to the mysterious “Plank era”, which is hypothesized to have existed 10^-43 seconds post-Big Bang. During this era, even theory cannot help us because the entire universe would be operating at the scale of the quantum, which cannot be described by Einstein’s theory of general relativity.
To pull our quest for origins back into focus, we can say that the combined knowledge of anthropology, biology, chemistry, and physics allows us to properly situate our existence within a continuum of fundamental particles, atoms, molecules, genes, and memes that extends back nearly 13.8 billion years. Fundamental particles of matter formed atoms; atoms formed complex chemistry; complex chemistry allowed for the storage of genetic information; and genetic information eventually produced organisms that could encode information in the form of memes (or cultural units of information).
This leads me to believe that we are the result of a very complex layering process that began with space and time itself. The focus of many scientific subjects is deeply concerned with understanding the relation and interaction between these layers. But for the purposes of this chapter, it seems quite evident that we can push our origins back very far in both space and time. This knowledge, in my opinion, should make us both overawed and humble. Astrophysicist Neil deGrasse Tyson expressed his sentiments our cosmic origins perfectly:
“When I look up in the universe. I know I’m small. But I’m also big. I’m big because I’m connected to the universe, and the universe is connected to me.”
As interesting as this perspective on our origins is, it also leaves mystery, and an inescapable question: If the Big Bang was the start of our universe, setting off a chain of events that eventually produced our species, what caused it?