Timeline Summary
Notation: yr=years, B=billion, M=million, k=thousand, CE=Current-Era, BCE= Before-Current-Era=Before-Christ. Reference: now (2019)=2019CE = 0 years (we are at about one-half of our Solar system’s projected life).
The Universe was born (Big Bang): -13.8 Byr
Sun evolved: -4.6 Byr
Earth evolved: -4.5 Byr
Life evolved: -3.5 Byr
Apes evolved: -10 Myr
Hominid (Chimpanzees split) evolved: -5.5 Myr
Homo Sapiens evolved: -300 kyr
Agriculture, Social organization, Writing (evolved/invented globally): -10 to -3 kyr
Christianity, European Culture appeared: -2 kyr
Now: 0 yr
Human individual’s lifespan; 100 yr
Possible events to cause the end of Life: 0, 10, 100k yr
Definitive End of Life due to solar evolution: 1 Byr
Definitive End of Sun and solar system due to solar self-consumption: 5 Byr
End of solar evolution: Sun -> Red Giant (5 Byr) -> White dwarf (??) -> Black dwarf (10^15 yr)
End of contact between not-gravitationally-bound clusters, visible Universe shrunk to what is
gravitationally bound, "redding-out", due to not-gravitationally-bound objects receding
from each other in the dark-energy-driven expanding Universe at speeds greater than the
speed of light (cold and empty Universe): few-100 Byr ~ 10^12 yr
End of contact between not-gravitationally-bound clusters, visible Universe shrunk to what is
gravitationally bound, "redding-out", due to not-gravitationally-bound objects receding
from each other in the dark-energy-driven expanding Universe at speeds greater than the
speed of light (cold and empty Universe): few-100 Byr ~ 10^12 yr
Proton half-life: 10^32 yr
End of the Universe: ?? (Never??)
Discussion
Discussion
Dornbusch’s Law says that events take a long time to evolve, but then they happen faster than expected. (https://en.wikipedia.org/wiki/Rudi_Dornbusch) He formulated this law most likely regarding financial crises, but it applies to many easily observable major natural disasters, global and everyday events. For example, earthquakes, asteroids striking the Earth, bringing water to boil, etc., all obey this law. ( Note: all my repeated internet searches of Dornbusch’s Law, including the above shown Wikipedia reference, ended sending me back to Paul Krugman, who referred to this law in one of his columns. I could not find an original reference source; thus, this maybe Paul Krugman’s Dornbusch’s Law. In any case, whoever’s a law it may be, it is a good description of the evolution of most calamities.)
But what is (are) the timescale(s) of event evolution(s) that matter? It depends!
My love has evolved over the years, my children gestated for 9 months, and they were born over a few hours.
The Universe was born 14 billion years ago, right after The Big Bang. Where the Big Bang came from and how long it took to develop, we do not know. It is a fact accepted by scientific consensus that the Universe was born in a sudden event and has been evolving ever since. (What came before the Big Bang, or what caused it, currently has no definitive scientific understanding; religions are welcome to address the mystery of the Universe before the Big Bang.)
But what is (are) the timescale(s) of event evolution(s) that matter? It depends!
My love has evolved over the years, my children gestated for 9 months, and they were born over a few hours.
The Universe was born 14 billion years ago, right after The Big Bang. Where the Big Bang came from and how long it took to develop, we do not know. It is a fact accepted by scientific consensus that the Universe was born in a sudden event and has been evolving ever since. (What came before the Big Bang, or what caused it, currently has no definitive scientific understanding; religions are welcome to address the mystery of the Universe before the Big Bang.)
The age of our solar system is about 5 billion years. Thus, the Universe had been evolving for about 9 billion years before it gave birth to our Sun and its associated planetary system, including our Earth.
Life on Earth started about a billion years after the Earth formed. Thus, the Earth evolved for about 1 billion years before it gave birth to Life. It then took several billion more years before the genus Homo evolved.
Mammals appeared on Earth about 200 million years ago. Primates came 75 million, Homo (humans) 2.5 million, Human speech 1.75 million, Homo Sapiens about 0.5 million (or maybe more, if we include the Neanderthals with us) years ago.
Based on an analysis of the genes of 1,200 Sardinian males, we are all descendants of an Adam and an Eve, both the original Eve and the original Adam lived between -200 and -180 kyr. But they were not necessarily contemporaries and very unlikely did they produce us simply together. (https://www.nature.com/news/genetic-adam-and-eve-did-not-live-too-far-apart-in-time-1.13478) In any case, we all share some part of our genes that we inherited from both this Eve and this Adam.
We all have 2 parents, 4 grandparents, 8 great grandparents, or m generations ago we had 2^m forebear. Assuming 4 generations/century, 1,000 years or 40 generations ago we, each of us living today, would have needed to have had 1 trillion forebears. There were not that many people alive 1000 years ago. In fact, in all of history, there were not that many of us humans.
The resolution of this apparent quandary is that our predecessors were interrelated, and we are all related and we all descended from all who lived and had surviving children (about 80 % of the people who lived then) at some point in the past. When was that?
The statistical estimate (Joseph T. Chang: ”Recent Common Ancestors of All Present-Day Individuals”, http://www.stat.yale.edu/~jtc5/papers/Ancestors.pdf) is that if there are n of us today (n=current population), then our most recent common ancestor (MRCA) lived lgn generations ago, where lgn is the base 2 logarithm of n (MRCA=lgn generations). There are about 8 billion of us now. Thus, according to the above formula, our MRCA lived about 33 generations, or about 800 years, ago. The statistical analysis also shows that at a generation 1.77 times MRCA everyone who lived then and reproduced, was our common ancestors (CA=1.77*MRCA generations). Thus, about 56 generations, or 14 centuries ago, or at about year 600, all who lived then and successfully reproduced were our common ancestors; all of us now alive are related, and we all are descendants of them. Of course, all who lived before the above-calculated CE (and had surviving off-springs) were also common ancestors of all of us now living.
Thus, we have scientific proof that we, all of us living today, are descendants of emperors and prophets, as well as of aristocrats, commoners, serfs, and slaves.
But the first Americans already split from their Siberian forebear about 25 thousand years ago. (https://www.nationalgeographic.com/science/2018/11/ancient-dna-reveals-complex-migrations-first-americans/#close). Thus, they can only share common ancestors with Europeans, Asians, and Africans from before about -25 kyr. At that time the population of the Earth was likely to have been significantly less than 10 million, maybe even under 1 million. (https://www.census.gov/data/tables/time-series/demo/international-programs/historical-est-worldpop.html) If we assume that 10 million people lived at -25 kyr, then their CA lived 41 generations, or about 10 centuries (1000 years), before them. Thus, the common ancestors of all us, Europeans, Africans, and Asians together with the original Americans, lived about 26 thousand years ago.
We started growing food for ourselves, instead of simply hunting and gathering it, about 12 thousand years ago. Writing, to keep records and communicate, is 5 thousand years old. Once we knew how to grow our food and how to keep records and communicate, we were ready for social organization.
The earliest known organized societies were in the Nile and Tiger river valleys, they evolved about 5000 years ago.
The Indus Valley and Yellow River Valley civilizations, early India and China, came somewhat, maybe about a thousand years, later.
Mesoamerican civilization evolved on its own, somewhat later than the above four river civilizations. There was no known contact between the Indigenous early Americans and the rest of the world for many thousands of years, till the 15-th century Columbus voyage. Thus, the civilizations that the Conquistadores and pioneers found in the Americas obviously had to evolve on their own.
While in detail these early civilizations were very different from the modern civilization of our current times, in general outlines how we now live, our society, is a direct result of evolution from these early civilizations. If again we assume that in a century about 4 successive generations of humans follow each other, then our modern social organization spans about 2000 generations.
I personally, before I die, will have known 5 generations: I knew 3 of my 4 grandparents and probably I know already all my grandchildren. I am now 81 years old; I shared a snippet of my grandparents’ lives and will share most likely a snippet of my grandchildren’s lives. All my grandparents were born in the 19-th century and all my grandchildren in the 21-st. Thus 4 generations per century seem to be true for me too, even though I came from a family of late bloomers. (My paternal grandfather was close to 50 when my father was born, my father was 50 when I did, and I was 40 when my son was born; on maternal lines, we delayed less, my grandmothers and mother were all born to much younger mothers than were we men to our older fathers). Thus, I have lived already, and thus before I die I am likely to will have lived, for about 1/500-th, or close to 0.2% of all generations that lived since human communities evolved into organized societies, since the concept of society was formed, and ever since it existed.
The Industrial Revolution was started about 250 years ago by the steam engine of James Watts. About 100 years later the invention of the Otto engine initiated the widespread deployment of the internal combustion engine. These two inventions led to a rate of utilization of fossil fuels, coal and oil and later natural gas, that the Earth’s biosphere cannot support.
Currently, humanity’s ecological footprint significantly exceeds the biocapacity of our Earth. The last year when the Earth was able to meet humanity’s growing need was 1970, or -49yr. ( https://data.footprintnetwork.org ) For the past half-a-century, we have been consuming more than the Earth can support.
Carbon is the main culprit. Fossil fuels produce more CO2 than the photosynthesis of all the Earth’s plants can recycle. Currently, we would need about 1.7-times the available biocapacity to support us, i.e., to continue living as we currently do, we would need a 1.7-times bigger Earth than the one we have. Without Carbon use, we would only need about 70 % of the available biocapacity to support us. However, for sustainable recycling of the Carbon we now use, we would need a full Earth; as if, we just stopped eating and living, then we could continue to burn all fossil fuels at the rate we now do. Since we can’t stop eating, we must cut back on fossil fuel use.
This excessive fossil use results in an accumulation of CO2 in the atmosphere that results in a greenhouse effect, that leads to global warming. Global warming leads to environmental changes that bring disasters to human habitats globally. Unless we rapidly convert to renewable energy sources, reduce our dependence on fossil fuels and/or deploy large-scale CO2 sequestration, major disasters are expected within the next few decades, certainly within the next century. Starting with melting glaciers and rising sea levels, followed by food shortages and massive population displacements, Life on Earth will massively change for the worse. Our species, much diminished in numbers and with a much-changed lifestyle, may survive, but not society as we know it.
Let us not kill ourselves, not with environmental disasters, not by violent means. We, humans, can kill ourselves totally today. Using our nuclear weapons capability, we have the means to extinguish ourselves. Our ultimate destiny on Earth is our extinction due to predictable natural causes, but we do not need to hurry up the process.
The Sun will exhaust its Hydrogen energy supply and expand into a Red Giant in about 5 billion years. At that time, it will envelop the Earth, but the Earth is likely to become uninhabitable by humans much earlier. Assuming no man-made, or nature induced catastrophic events, human Life is expected to end on Earth (and on any nearby planet, should their colonization occur) in less than 1 billion years due to the natural life-cycle of the Sun and its solar system. That is a definitive and unstoppable “end of our World” event. Other, man-made or natural Life-extinguishing events may occur sooner, such as massive tectonic plate movements and earthquakes, or asteroid collisions, maybe within this century or within a few millennia. But the definite end of our solar system is predictable, and this prediction stands on no weaker foundation than the well-substantiated most-fundamental law of conservation of energy.
All physical processes either consume or produce energy. Life is a physical process that consumes energy. Energy is needed to sustain all Life and this energy is provided by the Sun. Life on Earth depends on the steady insolation of about 1 kW/m^2 reaching the surface of the Earth; much less than this, we would freeze, much more, we would boil or burn.
In the process of producing energy, inexorably the Sun consumes itself. It consumes continuously its Hydrogen, in which its energy is stored. In this consumption, the stored energy is released by Hydrogen fusion. This fusion energy is converted into radiation (Sunshine) that is radiated out and lost into space; some of this radiation reaches Earth and this is our Life-sustaining insolation. Eventually, all the Sun’s stored energy will be consumed, radiated away, and there will be no energy to support Life on Earth.
It is a curious fact that in this process before everything goes cold, the Sun’s heating of Earth will increase. It is this heating that will kill all Life on Earth in less than 1 billion years from now. As the Sun consumes itself, its gravitational force decreases. Because the decreased gravitational force the radius (size/volume) of the still-hot Sun grows and this results in increased insolation on Earth. This will increase the surface temperature on Earth to a level where Life will not be sustainable. (Note: now our comfort zone is around a temperature of 300 degrees K, at 373 K water boils; at boiling temperature no Life as we know it survives.) The temperature of our Earth is expected to rise much above boiling.
Long after Life has ended, in about 3.5 billion years from now, before our Sun completely disappears, this growth leads to its evolution into a Red Giant that will embrace our Earth. This Red Giant then will morph into a hot White Dwarf, which will be followed by a cold Black Dwarf in the evolving Universe.
The ultimate end of the Universe is not known. Clearly, every star, like our Sun, progressively consumes itself. The very big ones turn into giant Black Holes, the smaller ones into Black Dwarfs.
According to some theories, ultimately even elementary particles, like protons, and also electrons, decay. Black holes also evaporate eventually. What will be left then? TBD.
Life on Earth started about a billion years after the Earth formed. Thus, the Earth evolved for about 1 billion years before it gave birth to Life. It then took several billion more years before the genus Homo evolved.
Mammals appeared on Earth about 200 million years ago. Primates came 75 million, Homo (humans) 2.5 million, Human speech 1.75 million, Homo Sapiens about 0.5 million (or maybe more, if we include the Neanderthals with us) years ago.
Based on an analysis of the genes of 1,200 Sardinian males, we are all descendants of an Adam and an Eve, both the original Eve and the original Adam lived between -200 and -180 kyr. But they were not necessarily contemporaries and very unlikely did they produce us simply together. (https://www.nature.com/news/genetic-adam-and-eve-did-not-live-too-far-apart-in-time-1.13478) In any case, we all share some part of our genes that we inherited from both this Eve and this Adam.
We all have 2 parents, 4 grandparents, 8 great grandparents, or m generations ago we had 2^m forebear. Assuming 4 generations/century, 1,000 years or 40 generations ago we, each of us living today, would have needed to have had 1 trillion forebears. There were not that many people alive 1000 years ago. In fact, in all of history, there were not that many of us humans.
The resolution of this apparent quandary is that our predecessors were interrelated, and we are all related and we all descended from all who lived and had surviving children (about 80 % of the people who lived then) at some point in the past. When was that?
The statistical estimate (Joseph T. Chang: ”Recent Common Ancestors of All Present-Day Individuals”, http://www.stat.yale.edu/~jtc5/papers/Ancestors.pdf) is that if there are n of us today (n=current population), then our most recent common ancestor (MRCA) lived lgn generations ago, where lgn is the base 2 logarithm of n (MRCA=lgn generations). There are about 8 billion of us now. Thus, according to the above formula, our MRCA lived about 33 generations, or about 800 years, ago. The statistical analysis also shows that at a generation 1.77 times MRCA everyone who lived then and reproduced, was our common ancestors (CA=1.77*MRCA generations). Thus, about 56 generations, or 14 centuries ago, or at about year 600, all who lived then and successfully reproduced were our common ancestors; all of us now alive are related, and we all are descendants of them. Of course, all who lived before the above-calculated CE (and had surviving off-springs) were also common ancestors of all of us now living.
Thus, we have scientific proof that we, all of us living today, are descendants of emperors and prophets, as well as of aristocrats, commoners, serfs, and slaves.
But the first Americans already split from their Siberian forebear about 25 thousand years ago. (https://www.nationalgeographic.com/science/2018/11/ancient-dna-reveals-complex-migrations-first-americans/#close). Thus, they can only share common ancestors with Europeans, Asians, and Africans from before about -25 kyr. At that time the population of the Earth was likely to have been significantly less than 10 million, maybe even under 1 million. (https://www.census.gov/data/tables/time-series/demo/international-programs/historical-est-worldpop.html) If we assume that 10 million people lived at -25 kyr, then their CA lived 41 generations, or about 10 centuries (1000 years), before them. Thus, the common ancestors of all us, Europeans, Africans, and Asians together with the original Americans, lived about 26 thousand years ago.
We started growing food for ourselves, instead of simply hunting and gathering it, about 12 thousand years ago. Writing, to keep records and communicate, is 5 thousand years old. Once we knew how to grow our food and how to keep records and communicate, we were ready for social organization.
The earliest known organized societies were in the Nile and Tiger river valleys, they evolved about 5000 years ago.
The Indus Valley and Yellow River Valley civilizations, early India and China, came somewhat, maybe about a thousand years, later.
Mesoamerican civilization evolved on its own, somewhat later than the above four river civilizations. There was no known contact between the Indigenous early Americans and the rest of the world for many thousands of years, till the 15-th century Columbus voyage. Thus, the civilizations that the Conquistadores and pioneers found in the Americas obviously had to evolve on their own.
While in detail these early civilizations were very different from the modern civilization of our current times, in general outlines how we now live, our society, is a direct result of evolution from these early civilizations. If again we assume that in a century about 4 successive generations of humans follow each other, then our modern social organization spans about 2000 generations.
I personally, before I die, will have known 5 generations: I knew 3 of my 4 grandparents and probably I know already all my grandchildren. I am now 81 years old; I shared a snippet of my grandparents’ lives and will share most likely a snippet of my grandchildren’s lives. All my grandparents were born in the 19-th century and all my grandchildren in the 21-st. Thus 4 generations per century seem to be true for me too, even though I came from a family of late bloomers. (My paternal grandfather was close to 50 when my father was born, my father was 50 when I did, and I was 40 when my son was born; on maternal lines, we delayed less, my grandmothers and mother were all born to much younger mothers than were we men to our older fathers). Thus, I have lived already, and thus before I die I am likely to will have lived, for about 1/500-th, or close to 0.2% of all generations that lived since human communities evolved into organized societies, since the concept of society was formed, and ever since it existed.
The Industrial Revolution was started about 250 years ago by the steam engine of James Watts. About 100 years later the invention of the Otto engine initiated the widespread deployment of the internal combustion engine. These two inventions led to a rate of utilization of fossil fuels, coal and oil and later natural gas, that the Earth’s biosphere cannot support.
Currently, humanity’s ecological footprint significantly exceeds the biocapacity of our Earth. The last year when the Earth was able to meet humanity’s growing need was 1970, or -49yr. ( https://data.footprintnetwork.org ) For the past half-a-century, we have been consuming more than the Earth can support.
Carbon is the main culprit. Fossil fuels produce more CO2 than the photosynthesis of all the Earth’s plants can recycle. Currently, we would need about 1.7-times the available biocapacity to support us, i.e., to continue living as we currently do, we would need a 1.7-times bigger Earth than the one we have. Without Carbon use, we would only need about 70 % of the available biocapacity to support us. However, for sustainable recycling of the Carbon we now use, we would need a full Earth; as if, we just stopped eating and living, then we could continue to burn all fossil fuels at the rate we now do. Since we can’t stop eating, we must cut back on fossil fuel use.
This excessive fossil use results in an accumulation of CO2 in the atmosphere that results in a greenhouse effect, that leads to global warming. Global warming leads to environmental changes that bring disasters to human habitats globally. Unless we rapidly convert to renewable energy sources, reduce our dependence on fossil fuels and/or deploy large-scale CO2 sequestration, major disasters are expected within the next few decades, certainly within the next century. Starting with melting glaciers and rising sea levels, followed by food shortages and massive population displacements, Life on Earth will massively change for the worse. Our species, much diminished in numbers and with a much-changed lifestyle, may survive, but not society as we know it.
Let us not kill ourselves, not with environmental disasters, not by violent means. We, humans, can kill ourselves totally today. Using our nuclear weapons capability, we have the means to extinguish ourselves. Our ultimate destiny on Earth is our extinction due to predictable natural causes, but we do not need to hurry up the process.
The Sun will exhaust its Hydrogen energy supply and expand into a Red Giant in about 5 billion years. At that time, it will envelop the Earth, but the Earth is likely to become uninhabitable by humans much earlier. Assuming no man-made, or nature induced catastrophic events, human Life is expected to end on Earth (and on any nearby planet, should their colonization occur) in less than 1 billion years due to the natural life-cycle of the Sun and its solar system. That is a definitive and unstoppable “end of our World” event. Other, man-made or natural Life-extinguishing events may occur sooner, such as massive tectonic plate movements and earthquakes, or asteroid collisions, maybe within this century or within a few millennia. But the definite end of our solar system is predictable, and this prediction stands on no weaker foundation than the well-substantiated most-fundamental law of conservation of energy.
All physical processes either consume or produce energy. Life is a physical process that consumes energy. Energy is needed to sustain all Life and this energy is provided by the Sun. Life on Earth depends on the steady insolation of about 1 kW/m^2 reaching the surface of the Earth; much less than this, we would freeze, much more, we would boil or burn.
In the process of producing energy, inexorably the Sun consumes itself. It consumes continuously its Hydrogen, in which its energy is stored. In this consumption, the stored energy is released by Hydrogen fusion. This fusion energy is converted into radiation (Sunshine) that is radiated out and lost into space; some of this radiation reaches Earth and this is our Life-sustaining insolation. Eventually, all the Sun’s stored energy will be consumed, radiated away, and there will be no energy to support Life on Earth.
It is a curious fact that in this process before everything goes cold, the Sun’s heating of Earth will increase. It is this heating that will kill all Life on Earth in less than 1 billion years from now. As the Sun consumes itself, its gravitational force decreases. Because the decreased gravitational force the radius (size/volume) of the still-hot Sun grows and this results in increased insolation on Earth. This will increase the surface temperature on Earth to a level where Life will not be sustainable. (Note: now our comfort zone is around a temperature of 300 degrees K, at 373 K water boils; at boiling temperature no Life as we know it survives.) The temperature of our Earth is expected to rise much above boiling.
Long after Life has ended, in about 3.5 billion years from now, before our Sun completely disappears, this growth leads to its evolution into a Red Giant that will embrace our Earth. This Red Giant then will morph into a hot White Dwarf, which will be followed by a cold Black Dwarf in the evolving Universe.
The ultimate end of the Universe is not known. Clearly, every star, like our Sun, progressively consumes itself. The very big ones turn into giant Black Holes, the smaller ones into Black Dwarfs.
According to some theories, ultimately even elementary particles, like protons, and also electrons, decay. Black holes also evaporate eventually. What will be left then? TBD.
