Big Steps in the Story of Big History – Part 1

The evolution of everything, told through the most dramatic steps in the story.

In a previous essay series, we looked at what’s called “Big History,” which is the study of things on a very, very large scale, over a very long period of time.  As I wrote previously, “Big History” should bring not only understanding, but contentment as well:

Thinking about [Big History] puts our current moment (whatever that moment is) in the largest context of all: human and universal history.  If we just took a few moments to think about that every once in a while, that context would often bring contentment, along with a deep appreciation of what we all have – not relatively, but absolutely -- and where we all are -- not geographically, but temporally.

Since that essay series, Brian Villmoare has written a new edition of the first textbook on “Big History” – The Evolution of Everything: The Patterns and Causes of Big History -- and it’s worth mining it to examine some of the brilliant and fascinating gemstones that reflect the major causes of all the changes that led up to the “here and now.”

As Villmoare explains:

When we examine a historical event such as World War II, we frequently look at it from the perspective of the individuals involved in the conflict. For example, we may read about D-Day from the viewpoint of a soldier on a beach in Normandy, facing a barrage of incoming machine gun fire. Or we may read about the women building tanks and airplanes on the assembly lines, and their material contribution to the war effort. Or we may read an account by African American veterans from the 761st Tank Battalion, who had to fight racism in segregated combat units. This form of history is called “narrative,” in which we try to understand a broader event by seeing it from various perspectives, with the hope that, by reading enough narratives and seeing as many perspectives as possible, we will acquire a thorough knowledge of the events. Today this is probably the most common form of history, and one reason is that it is so personally compelling. Narrative allows us to “feel” what it might have been like to be involved in those historic events, and it is natural that we would enjoy this form of history. But narrative, for all its emotional reward, will not necessarily help us understand the broader forces that drove the events. To understand the causes of past events, we need to step back and examine the events from a distance.

And what a distance it is:

One issue we have when examining questions is picking an appropriate scale. For example, when we want to know about the power of a star, we need to look at the atomic or subatomic scale where nuclear fusion occurs. Very specific forces apply at those tiny scales. But when we want to predict how stars move through space, we pull back and look at how large bodies are affected by gravity. At this level, many subatomic forces no longer apply.

Last year, when I was a substitute teacher in a sixth-grade science class for a week, I tried to convey to the students the mind-boggling scales involved from the perspective of the universe, as well as the subatomic.  I pointed out that there are about 100 billion stars in our galaxy.  And there are about 100 billion galaxies in the known universe.  And there are about 100 billion neurons in each of our brains, which we use to contemplate all this.  And in each and every one of our neurons, there are about 100 billion atoms that compose it.

Regarding the scale of just our own universe, I used a baseball to represent the sun and a speck of chalk to represent the Earth.  I put the Earth about 15 feet away from the sun.  Then I took an eraser from the end of a pencil and threw it about 60 feet away from the sun.  That’s the planet Jupiter.  Neptune would be a couple blocks out from there.  And the next star close to us would be about the size of an orange, but it would be out in Minneapolis, Minnesota, about 1,000 miles away.  And there’s another orange in Sacramento, California, and a grapefruit out in Hawaii, and a couple more oranges in Singapore and Hong Kong.  And 100 billion others scattered around at those type of relative distances.  And we observe it all from that little bit of chalk dust (the Earth) over in one small corner of a classroom in Alexandria, Virginia.

Then I used a clear plastic baseball display box, about a tenth of a meter on each side, or a little over three inches on each side.  I asked the students to imagine a series of steps in which we see this box growing, increasing by a factor of 100 at a time — increasing by 100 along its length, width, and height, meaning each new, bigger box will contain 1 million times the volume of the previous box (because 100 times 100 times 100 equals 1 million).  The first larger box is ten meters on each side, about 33 feet on each size.  That would hold a small two-story building.  The second larger box is 100 times larger and would hold a small town or college campus.  The third larger box is 100 kilometers on each side, which could hold Washington, D.C. and its surrounding suburbs.  The fourth increment goes to 10,000 kilometers on a side.  It would almost hold the entire Earth.  The fifth larger box is 1 million kilometers on a side.  It would hold the Earth and the full orbit of the moon.  The sixth box takes us to distances so long that you really have to use the distance light travels as a way to measure it.  The speed of light is 187,000 miles per second, which translates to about a billion kilometers an hour.  So in the sixth box we have a box 100 million kilometers, or about six light seconds on a side.  This box would hold the Earth and either Mars or Venus on its closest approach to the Earth.  Now we go to a seventh box nine light hours on each side. That’s a box 10 billion kilometers on edge.  If we put the box around the sun it would encompass almost all the planets in our solar system.  The eighth box would be about 40 light days on each side.  It would encompass not only the entire solar system, but everything within the gravitational reach of our sun, like all the comets and other objects much more distant, but nothing else.  The ninth box is about ten light years on a side, which would includes the solar system and the brightest neighboring stars — Sirius and maybe 100 other less bright stars.  The tenth box is a thousand light years on each side and would include a small part of the Milky Way galaxy, with hundreds of thousands of stars.  The eleventh box is a hundred thousand light years on a side, and it would almost include the entire Milky Way Galaxy, with 100 billion stars.  The next box, the twelfth box, is ten million light years on a side, which contains dozens of galaxies.  The next box is a billion light years per side, and holds hundreds of millions of galaxies.  And the entire known universe is about 100 times that large, about 93 billion light years across, and contains 100 billion galaxies.

A reader of this Substack mentioned a quote summarizing the unity of science in the following way: all biology is chemistry, all chemistry is physics, and all physics is math.  In that sense, math is the mother of all sciences.  As Villmoare writes:

There is no math in this book, so don’t worry about that. But it is worth exploring, just in a superficial way, why math is critical for a scientific understanding of the Universe and humanity … Fairly simple math helps explain why Godzilla and King Kong cannot exist. If you look at an animal like a deer, which is a herding grazer, and compare it with an elk, which is also a herding grazer, you will notice that although the elk is less than twice as tall, it is more than four times as heavy. Why is this? The answer is that animals are three-dimensional things, so increasing size increases size in multiple dimensions. Look at a cube of three feet along each side. It is 3 × 3 × 3 feet = 27. If you double that, it is not 27 × 2 = 54, it is 6 × 6 × 6 = 216. This simple law means that getting larger makes an animal very heavy, and being massive is hard work. A gorilla is only about 30 percent taller than a chimpanzee, but it is three times as heavy (maybe 400 pounds for an adult male). This is why you could never have a gorilla as large as King Kong – a 25-foot gorilla (about five times as large as a normal gorilla) might weigh 25 tons (400 lbs × 5 × 5 × 5). A gorilla skeleton would have trouble supporting that! If you look around at nature and find really big animals, much of their bodies are legs. This is why Tyrannosaurus rex (at a mere 15 tons) had huge legs and tiny arms. And to be really big we have to look for aquatic animals, where water supports the weight.

But let’s go back to the beginning, namely the Big Bang, that first step in the history of the universe when everything spewed out from there:

The temperatures over this time period were enormous but dropping rapidly as the Universe expanded, starting at perhaps 1 × 1035 degrees centigrade right after the Big Bang, and dropping to 1 × 1010 degrees by 1/10 of a second (by comparison, our Sun is only 5,700 degrees). By the end of that 1/10 of a second, the Universe was already a light year across, and here, the energy was no longer as dense, and the generation of subatomic particles ceased. This 1/10 of a second threshold is critical, because, from this point on, the number of subatomic particles in the Universe is fixed – there will be no new generation of these particles, and they are simply shuffled among different atoms in the Universe for the next 13.8 billion years.

After the first 1/10 of a second of the universe, as Villmoare writes:

From here on, physics follows the relatively familiar patterns that we still see across the Universe – subatomic particles, such as neutrons, protons, and electrons, forming atoms, and those atoms undergoing changes to become other atoms, to produce the Universe we see today. The Universe has continued to expand over the last 13.8 billion years, and today it is so large that even our largest telescopes cannot see to its edge. The observable Universe is 93 billion light years across, but that is simply how far we can see, not how large it is. In essence, we can see stars 46.5 billion light years away in any direction, even as we know it is larger – potentially much larger.

Math again helps explain the context here:

You may have noticed something a little funny about the math in that last paragraph. If the Universe is at least 93 billion light years across, and we can see stars 46.5 billion light years away, that would seem to mean that the light waves we see left their stars 46.5 billion years ago. Yet the Universe is only 13.8 billion years old. How could this be? The answer is that the Universe is still expanding. The most distant light waves we see were emitted billions of years ago, yet we are continuing to drift away from the source, very rapidly. For example, the very distant galaxy GN-z11 is roughly 32 billion light years away, but the light we see from it is only 13.4 billion years old. Roughly 400 million years after the Big Bang, that galaxy emitted light that we are only picking up today. And over those 13.4 billion years since it emitted its light, we have drifted an additional 18.6 billion light years apart. It is a little like tossing a baseball between two cars that are moving away from each other – when the baseball was tossed, the cars might have been 20 feet apart, but as they pulled away the distance increased so that, when caught, the cars might be 50 yards apart.

A final side-note on this point about my substitute teaching experience.  I illustrated how we came to know that the universe was expanding by using a balloon.  Back in 1929, astronomer Edwin Hubble observed that far-away galaxies looked redder than you would expect.  He concluded that the “red shift” of galaxies was directly proportional to the distance of the galaxy from earth. That meant that things farther away from Earth were moving away faster. In other words, the universe must be expanding, and as parts of the universe move further away from each other at increasing speeds, the expanding space tends to stretch the light waves, making them appear to have longer wavelengths and to consequently look redder to us, as red light has a longer wavelength (a longer distance from wave peak to wave peak) than blue light.  This effect can be illustrated by drawing a wave on the side of a balloon, blowing up the balloon, and seeing how the stretching of the space along the side of the balloon makes the wavelength of the wave you drew on the balloon stretch out, which is how we see the red-shifted light emanating from far-distant stars.

As Villmoare continues:

This expansion [of space in the universe] is an especially interesting phenomenon. One fact that still confounds astronomers is that the expansion is accelerating. Normally, when we think of the laws of motion, objects, once in motion, tend to stay at their velocity unless something applies force to it. For example, comets keep a roughly constant pace, as do planets, satellites, and other similar objects. But stars and galaxies are actually increasing their speed away from each other, dispersing at an ever greater rate. In fact, the expansion of the Universe is itself faster than the speed of light. To date, astronomers still argue about the source of energy causing this acceleration, because they cannot see any specific source that could cause such acceleration. (If you want to become a famous astronomer, solve this problem!)

Scientists have posited something called “dark matter” to explain what’s causing this accelerating expansion (but the existence of dark matter has yet to be proven).

Finally, Villmoare writes:

One thing that is difficult for some students to understand is the idea that it is not the objects in space spreading out into space, but it is space itself expanding. The Universe is not simply the objects in the space, it is the space. There is no “place” outside the Universe – there is nothing beyond the edge of the Universe, because there is no “beyond.” This also means that there is no “center” to the Universe – no place where the energy or matter is denser from the center point of the Big Bang. Every place is expanding away from every other place, not just the objects or energy but the space in which the objects are situated.

And our knowledge of all this is ever-expanding as well.  In the next essay in this series, we’ll explore the evolution of the elements and the planets.