Until now, my coverage of Carl Sagan’s The Dragons of Eden has been on a chapter to chapter basis presented in the “Read Along” section of the blog. As mentioned in my last post, I will be scrapping this in favor of exclusive reviews on selective books I wish to discuss, henceforth. So, without further delay, let’s bring the curtains down on The Dragons of Eden.
The premise of the book is clearly stated in the subtitle: “Speculations on the Evolution of Human Intelligence.” Sagan wishes to explore the various facets of human intelligence by calling to motion a simple question: why are humans, humans? He attempts to investigate, in what has been a shared effort by the academic community, a conclusive answer to this question from a purely scientific viewpoint while entertaining “occasional excursions into myths, ancient and modern.” The title of the book supports Sagan’s approach in a compilation of ideas on the “unexpected aptness” of various different myths when compared to scientific theories.
Beginning with time immemorial at the Big Bang, we ride the waves of time flowing toward the current epoch of human civilization. Human evolution is often described in the form of a metaphor, an “abstraction of beasts,” as Sagan uses various comparative arguments to build the foundation of his work in the earlier chapters, particularly in Chapter 2 – Genes and Brains (which I provided a full summary of in the Read Along), before settling into the pivotal point of his work which focuses on the evolution of human intelligence in the subsequent chapters describing the characteristics of the human brain and its evolutionary growth.
Following the footsteps of his predecessor in Jacob Bronowski, whose work in The Ascent of Man is an account of how human beings and human brains evolved, Sagan has presented his own unique approach to the same subject in his book. While we don’t necessarily discover an absolute answer on the origin of human intelligence, Sagan’s book is nevertheless an exhilarating journey that offers his insight into the brains of man and beast, the plethora of recent discoveries in science supporting the theory of human evolution, and most interestingly how they serve to be the function of our most familiar myths, and legends.
Sagan’s work doesn’t end there. His arguments and words serve as microphone toward the need for intellectual rigor, and a rejection of the absent skepticism prevalent in modern-day society. Altogether, The Dragons of Eden is an excellent book that talks about all kinds of things, from the reasons for sleeping and dreaming to the definition of death in what is a fascinating and delightfully short compendium of knowledge that should be read by everyone alike. Sagan was an influential science communicator (one of my favorites), if not one of the best; his works are well worth the effort of reading for anyone interested with or without a scientific background.
With the veritable amount of evidence that has been laid out before us, why is it that people aren’t concerned about global warming? Despite scientific consensus on the subject, some people think global warming isn’t happening at all. There are several reasons for this, and they cover various overlying and conflicting themes on global communication, and an incentive towards environmental action.
Beginning with the common lay-person, a popular speculation is formulated in the form of this question: If simple forecasts can’t get next week’s weather right, how is it that we can trust the predictions that have been made on the basis for decades or centuries from now?
The answer to this is quite simple, and once again highlights the necessity towards scientific communication, and public education. Weather and climate are not the same. Weather relates to individual, and day-to-day changes in the atmosphere; climate is the statistical average of such changes. Weather is short-term, and of a chaotic nature, thus making it inherently unpredictable beyond a few days. Meanwhile, climate is long-term average weather, controlled by the composition of the atmosphere, and is thus more predictable on the time-scales considered. A simple analogy is provided at the Climate Communication website,
While it is impossible to predict the age at which any particular man will die, we can say with high confidence that the average age of death for men in industrialized countries is about 75. The individual is analogous to weather, whereas the statistical average is analogous to climate.
Stepping beyond the individual, we encroach upon a global dialogue between, and within political and scientific institutions. While most scientists recognize the phenomenon that is global warming, there still remain a few who believe that there is nothing to be worried about. The latter argue that the Earth is more resistant to climate change than proposed. Many of the consequential changes are, in their opinion, not disastrous, and that cutting down the emission of greenhouse gases may result in economic damage far more potent than any of the effects of global warming.
The uncertainty that exists within the scientific community has been carried over to the political realm. Skeptics use it to argue for postponing action, while contenders point out that there are various other facets of life that require action in the face of uncertainty, such as buying health insurance. The IPCC has also pointed out that confronting a large-scale task such as climate change will not occur in an economic dissolution. As quoted from the 2014 report by the IPCC’s Working Group III,
Climate policy intersects with other societal goals, creating the possibility of co-benefits or adverse side effects. These intersections, if well-managed, can strengthen the basis for undertaking climate action.
Ultimately, what can we do about it? It isn’t possible to simply “stop” climate change. Even if we turned off every fuel-burning machine on Earth, the planet would warm at least another 0.5 degrees Celsius as the climate adjusts to the greenhouse gases that already have been emitted. Nevertheless, progressing toward the future, we can still make efforts in decreasing activities that may help propagate and positively reinforce global warming.
On a local level, we can do this basically by not using as much of the stuff that creates greenhouse gases as well as using less energy. Electricity governs much of the modern world, and much of the electricity that operates many of the devices in our homes comes from a power plant, which most likely burns fossil fuels to generate that power. The simple action of turning off lights when they are not in use, and using a fan or an air-conditions only when necessary can help. Similar initiatives can be taken in the view of using public transportation, efficient recycling and waste management, reforestation etc. Beyond all of this, we need to develop non-fossil fuel energy sources. Hydro-electric power, solar power, hydrogen engines, and fuel cells could help in this initiative towards a global change in energy sources.
In conclusion, much of this is easier said than done but that doesn’t mean we should give up. Given the global nature of the climate problem, we all have a hand in contributing to the solution, and in confronting the necessary alternatives and options we must also be willing to face agreements and disagreements in faith of positive communication. The real power to enact significant change rests in the hands of those who devise national and global policies. International and scientific collaboration on technology sharing, effective communication and education of the public supplemented by an efficient transition toward alternative, and green-energy initiatives would help make a difference in the long run.
Climate change is a global issue that has wedded science to politics while simultaneously transcending the social responsibilities held by both institutions. A polarizing subject in many ways, climate change is considered as one of the most daunting challenges humanity currently faces; at its crux is an initiative towards global communication, and environmental responsibility.
To this day, there remains a schism between the public, and the scientific community when it comes to understanding climate change, and what it essentially means for our world. In a manner that follows the development of various other issues over the course of history, climate change highlights a certain measure of conflict in science, and ignorance.
Investing the time to learn the basics can prove the difference in being knowledgeable and informed or confused and manipulated. This is particularly crucial as climate change is a phenomenon that has wide implications to civilization, and overtly emphasizes the need for humanity to collaborate with each other in tackling the problem.
In this three-part series, we will address various facets of this issue ranging from the basics of the science behind the phenomenon as well as the consequential symptoms or effects of climate change for the present, and the future. We will conclude by discussing the optionsthat we must consider in our transition to achieve progress.
Dissecting Weather and Climate
Le’ts review the difference between weather, and climate. Simply, weather is local, and short-term while climate is long-term, and doesn’t relate to one single location. More precisely, the climate of an area defines the average weather conditions in the given region over a long period of time. The time period being considered generally involves changes taking place over tens of thousands of years. So, whenever we pass by a few winters that aren’t as cold as usual, it does not necessitate a change in climate. Such events are rather anomalies that don’t represent any long-term change.
Moving forward in our discussion, it is also imperative that we don’t underestimate the effects of small changes in climate. To put in perspective, the “Ice Age,” often talked about by scientists involved a world where the Earth’s average temperature was only 5 degrees Celsius cooler than modern day temperature averages. Small changes in climate can equate to major effects around the world.
Climate Change or Global Warming
We often hear the phrases climate change, and global warming used interchangeably in describing climate transitions but there is a subtle difference. In the early 20th century, scientists used the term climate change when writing about events such as ice ages. But once scientists recognized the specific risks posed by human-produced greenhouse gases on the Earth’s climate, they needed a term to describe it.
Wallace Broecker’s paper in the journal Science, in 1975, entitled “Climate change: Are we on the brink of a pronounced global warming?” introduced the word global warming into the public lexicon.
Soon enough, the phrase global warming gained currency, and the term global change emerged as a way to describe all modes of large-scale impact on the planet, including issues such as the Antarctic ozone hole.
The planet as a whole is warming, but scientists prefer the term global change or global climate change. The reasoning behind this is that global warming can be interpreted as a uniform effect (warming everywhere on Earth), while a few regions may in fact cool slightly even if the planet were to warm up. In fact, it is a popular opinion that climate change sounds less frightening to the ear than global warming; the latter though catches more attention in the public eye. A few scientists, and activists also prefer to use global warming to imply human involvement in the process of describing climate transitions.
So, is the planet really warming up?
The short answer: YES! After laboriously working through a century’s worth of temperature records, various independent teams of scientists have converged on a rise of 0.8 degrees Celsius in the average surface air temperature of Earth when comparing the periods from 2003 – 2012 to 1850 – 1900. While this degree of warming may not sound like a big deal, it does make a big difference when it is in place everyday. Small changes can become amplified into bigger ones. Any warming can serve as a base from which heat waves can become worse. The effects are particularly pronounced in certain locations like the Arctic which has experienced an overall warming. Apart from the numbers, there’s a wealth of environmental evidence to bolster the case in favor of the Earth’s warming up. Without going too much into detail,
(1) Ice on land, and at sea has melted dramatically in many areas outside of interior Antarctica and Greenland.
(2) A lengthening of the growing season around much of the Northern Hemisphere.
(3) The migration of various forms of life, including mosquitoes, birds, and other creatures to higher altitudes, and latitudes due to the increasing warmth. Likewise, the migration of many forms of marine life moving poleward (the shift in ranges is 10 times the average for land-based species).
Other observations from the Intergovernmental Panel on Climate Change (IPCC) highlight the warming trend of the last 50 years being nearly the double of the last 100 years; a vast increase in ocean temperature to greater depths (the oceans absorb 80% of the heat of Earth’s climate system); increasing droughts; increased precipitation in eastern regions of the Americas, and northern regions of Europe, and Asia; drying trends in Africa, and the Mediterranean etc.
How Global Warming Works?
Global warming is caused by an increase in the greenhouse effect. The greenhouse effect is not bad on its own, and is in fact a natural circumstance of the Earth’s atmosphere. It is also the reason why the Earth is warm enough for life to survive.
The greenhouse effect, in essence, involves a play of energy balance on the Earth’s. When sunlight reaches our planet, 30% of its gets reflected or scattered back to space by clouds, dust, or the Earth’s surface. More than 20% of the sunlight is absorbed in the atmosphere, mainly by clouds, and water vapor. Lastly, almost 50% is absorbed by the Earth’s surface including land, forests, pavement, oceans etc.
Now, all this energy doesn’t stay permanently on the Earth. If it did, the Earth would literally be on fire. In fact, the Earth’s oceans, and land masses re-radiate the heat, some of which makes it into space. Most of it though is absorbed by clouds, and greenhouse gases which in turn radiate the heat back to the surface, and some out to space. Since the heat doesn’t make it out through the Earth’s atmosphere, the planet becomes warmer. It is basically an energy imbalance scenario where there is more energy coming through the atmosphere, than that leaving the Earth.
The two main components of air include nitrogen (78%), and oxygen (20%) gas, both of which aren’t efficient in absorbing radiation from the Earth due to their two-atom structure. On the other hand, other gases with three or more atoms can capture energy far out of their scant presence. These are the greenhouse gases, the ones that keep Earth inhabitable. That’s all well, and good, but the same gases also warm the Earth. The more greenhouse gases we add to the atmosphere, the more our planet warms. The major players involved include: Carbon dioxide, Nitrous oxide, Methane, and to a lesser extent, Water vapor.
Greenhouse Gases: What’s Happening?
The greenhouse effect is driven by naturally occurring substances in the atmosphere. This is predicated by a necessity for balance referring to the radiation cycles of the Earth mentioned earlier. Unfortunately, since the Industrial Revolution, humans have been pouring huge amounts of greenhouse gases into the atmosphere thus tipping the balance toward an amplified warming of the planet.
Carbon dioxide makes up less than 0.04% of the Earth’s atmosphere, most of which is due to early volcanic activity in the planet. Today, we are pumping huge amounts of the gas into the atmosphere as the gas is produced when fossil fuels are burned, as well as when people, and animals breathe, and when plants decompose. Extra carbon dioxide results in more energy absorption, and an overall increase in the Earth’s atmosphere. In fact, the average surface temperature of the Earth has gone from 14.5 degrees Celsius in 1860 to 15.3 degrees Celsius in 1980.
Nitrous oxide is another important green house gas, and while we don’t release great amounts of this gas through human activity, nitrous oxide absorbs much more energy than carbon dioxide. For example, the use of nitrogen fertilizer on crops releases nitrous oxide in great quantities.
Methane is a combustible gas, and the main component of natural gas. It also occurs naturally through organic material decomposition. Other man-made processes that produce methane include: extraction from coal, digestive gases in large livestock, bacteria in rice paddies, and garbage decomposition etc. Like its fellow compatriot greenhouse gases, methane also absorbs infrared energy, and keeps up the heat on Earth.
Apart from their devastating effects, it takes a long time for the planet to naturally recycle these various gases. For example, a typical molecule of carbon dioxide can stay airborne for more than a century. Thus, greenhouse gases have both a potent, and a long-standing impact on the Earth’s ecosystems. A few other gases that make up for the rest of the greenhouse players include the Chlorofluorocarbons (CFCs), water vapor, ozone etc. Water vapor is particularly interesting, as it isn’t a very strong greenhouse gas, but makes up for this in sheer abundance. As global temperatures rise, oceans, and lakes release more water vapor, up to 7% more for every degree Celsius of warming, which adds to the warming cycle.
In conclusion, the mechanisms involved in climate change, or global warming, are largely positive feedbacks that amplify the warming of the planet: the evaporation of water from the oceans doubles the impact of carbon dioxide increase, and melting sea ice reduces the amount of sunlight reflected to space etc. While not all feedbacks are certain, it is a grounded truth that the planet has to constantly readjust to the changes we make in our environment, in the case of global warming, the consistent addition of greenhouse gases into the atmosphere. So far, I have laid the basic groundwork for the symptoms we can expect to see, as a consequence of global warming, in our environment. Moving on in Part II, we will consider those changes in greater detail, and what they entail for the future of our planet.
The average lifespan of a human being is approximately 80 years. This number pales in comparison to the lifespans of celestial bodies such as the stars, luminous spheres of plasma that illuminate the night sky (Figure 1).
The lifespan of a star depends on its mass. Interestingly, it is found that the more massive the star, the faster it fades away. The Sun, for example, is about 4.6 billion years old, and will last another 9 billion years. Stars that are 10 times the mass of the Sun burn only for 100 million years. On the other hand, stars one-tenth the mass of the Sun burn 100 billion years or longer. Those are some large numbers being thrown about, but in astronomy, these orders of magnitude are quite common. To put this in perspective, our ancestors have been around for about six million years, but the modern form of humans, or homo sapiens evolved only about 200,000 years ago. Human civilization is a recent enterprise of 6000 years, with industrialization beginning only in the 1800. Our existence is a fleeting instance compared to the lives of stars, a rich history woven through several evolutionary stages of enormous extravagance, which begs the question, what happens when a star dies?
Colors of an Explosion
Stellar evolution is the process by which a star changes over the course of time. As mentioned earlier, the more massive a star, the faster it burns out. All stars are born from nebulae, clouds of gas and dust, and over the course of millions of years, these proto- or infant stars settle down, and transform into what is known as a main-sequence star. The Sun is a typical main-sequence star (Figure 2).
The death of a star is intrinsically related to the energy source that powers a star for most of its life: nuclear fusion. If one were to peel open a star, they would find a ring structure like that inside an onion. Initially, the energy generated by a main-sequence star is through the fusion of hydrogen atoms at its core. Hydrogen atoms fuse to produce Helium resulting in an abundance of the latter, and the depletion of the former fuel. Eventually, the star begins to fuse the Hydrogen fuel along a spherical shell surrounding a mostly Helium core. This process causes the star to grow in size, and evolve into what is known as a Red Giant. Stars with half the mass of the Sun can also generate Helium fusion at their core, while more massive stars fuse heavier elements in a series of concentric shells. In general, the more onion rings, the more massive the star (Figure 3).
Once this nuclear fuel has been exhausted, a star like the Sun collapses into a dense, small body known as a white dwarf, with much of the outer layers of the Sun being expelled into a planetary nebula (Figure 4).
We learn about the stars by receiving and interpreting the messages which their light brings to us. The message of the Companion of Sirius when it was decoded ran: “I am composed of material 3,000 times denser than anything you have ever come across; a ton of my material would be a little nugget that you could put in a matchbox.” What reply can one make to such a message? The reply which most of us made in 1914 was—”Shut up. Don’t talk nonsense.” – Sir Arthur Eddington
The word “planetary nebula” is a misnomer. It does not mean clouds of gas and dust consisting of planets. The word originated in the 1780s when astronomer William Herschel viewed these objects through his telescope, naming them so because they resembled the rounded shapes of planets.
Stars more massive than the Sun can explode in a supernova releasing much of the material that they were composed of in a shock-wave into the vacuum that is space. By releasing the bulk of the chemical elements that they had originally sustained in their core (the list includes: Hydrogen, Helium, Carbon, Neon, Oxygen, Silicon, and Iron), stars enrich the interstellar medium. The resulting shock-wave produced from a supernova also helps trigger the formation of new stars. The cores of such massive stars collapse into an extremely dense neutron star, and in certain cases, a black hole (Figure 5).
A normal-sized matchbox containing neutron-star material would have a mass of approximately 13 million tonnes, or a 2.5 million m3 chunk of the Earth (a cube with edges of about 135 metres).
The decisive factor is always the mass of the star, which in simple terms, is proportional to the strength of its gravity.
Gravity is a one-dimensional force, in that it is always attractive, and tries to pull things together. We are held to the surface of the Earth by the planet’s gravitational force. A black hole is born when an object is unable to withstand the compressing force of its own gravity. Stars use their nuclear fusion to maintain a tremulous balance, for several million years, in an exhaustive fight against gravity. The Sun will never become a black hole, as its gravity isn’t sufficient to overpower the force produced by its nuclear furnace. But in more massive stars, gravity ultimately wins.
Then what are hypernovas?
Even Bigger Explosions
Simply put, hypernovas are pretty much the same thing as supernovas, just on a much grander scale. Hypernovas are extremely energetic supernovas, and though their formation is similar, they are both distinct phenomena (Figure 6).
In a supernova, a star sheds its outer matter leaving behind a dense core in a neutron star. In a hypernova, the force of the explosion tears the inner star apart as well. Hypernovas only occur in stars with greater than 30 times the mass of the Sun. Like in a supernova, the star runs out of fuel, unable to support itself under the weight of its own gravity. As it collapses, the star subsequently explodes, spewing matter in all directions. The energy released within mere seconds of this explosion is greater than the energy that the Sun will release in its entire lifetime.
Time for an analogy. The sun radiates ~ 3.83 x 1026 W of energy. The standard light bulb for a table lamp has a wattage of 60 W. Thus, the sun radiates energy equivalent of 7 x 1024 light bulbs. Supernovas shine with the brightness of 10 billion suns (1 sun = 7 x 1024 light bulbs, then 10 billion suns = 10 x 109 x 7 x 1024 light bulbs = 7 x 1034 light bulbs), their total energy output being ~ 1044 J, which is the total energy output of the sun in its 10 billion year lifetime. Hypernovas release energy in excess of this amount. That’s a lot of light-bulbs!
Two plausible reasons currently conceived on the formation of a hypernova include:
A massive star (rotating at a very high speed or encased in a powerful magnetic field ) exploding, resulting in the inner core being ripped apart.
Two stars in a binary system colliding, forming one gigantic mass, and exploding.
The result is ultimately clear: a black hole is produced, and a huge amount of energy is released in the form of a gamma-ray burst, one of the brightest known events in the universe. The light released in a hypernova is several million times greater than all the light of the stars in the Milky Way galaxy put together.
Introducing the Universe
The world is very old, and human beings are very young. Significant events precede our appearance on Earth in what is an awesome vista of time. But in our vanity, we find the stubborn pride which motivates our claims, and actions as a higher organism on this planet. Thus, we are blind to the overwhelming reality that our existence on Earth, and the very existence of the planet itself, is nothing more than a single thread woven into the rich tapestry that is the universe. There, beyond the confines of our world and among the stars, lies unfathomable mysteries of great wonder. Hypernovas are a small shade of that enormous spectrum of amazing phenomena in our universe.
Mankind is poised midway between the gods and the beasts. – Plotinus
Plotinus’ quote is symbolic of a fundamental biological principle illustrating that man is descended from some lowly organized form, and which serves as the backdrop to the discussions Carl Sagan (Figure 1) presents in The Dragons of Eden. In order to provide a description of nature, and human growth, Sagan begins by discussing this principle, one that distinctly identifies the field from other physical sciences, evolution by natural selection.
Let’s digest that last bit, piece by piece. The word evolution is commonly used to describe the gradual development of something, from a simple to a more complex form. In scientific terms, evolution is the change evidenced in hereditary characteristics that are carried over successive generations in biological populations. It is the fundamental process that has led to biodiversity within species, and individual organisms.
Natural selection was the brilliant discovery of Charles Darwin and Alfred Russell Wallace (Figures2-3), detailed in the publication of their joint works in 1858. It is the theory that describes evolution, and is the preferential survival and reproduction of organisms that are by accident better adapted to the environment.
Natural selection is due to differences in the phenotypes of individual organisms. A phenotype is basically a composite description of an organism’s traits and characteristics including its physical and biochemical properties, as well as morphology, development, and behavior. An organism’s phenotype is a consequence of an organism’s genetic code, or genotype, along with environmental factors, and the collective influence and interaction of the two. It is important to differentiate natural selection from artificial selection, or selective breeding, where humans use animal and plant breeding to “select” for the development of particular characteristics by choosing which males and females of animal and plant species will sexually reproduce, and have offspring together.
In The Dragons of Eden, Sagan, much like Jacob Bronowski (Figure4), best remembered as the presenter and writer of the 1973 BBC television documentary series, The Ascent of Man, wants to provide an account of how human beings and human brains “evolved” or grew up together. By understanding the evolution of human beings and human brains, Sagan intends to provide a platform from which he can speculate on the nature of human intelligence, its evolution, and its future.
For starters, he addresses the role of knowledge and learning in a species’ ability to survive, and adapt to its environment. In order for an organism to survive, it must have the basic ability to extract and manipulate information from the environment. Most organisms depend on their genetic information to survive, but in their lifetime, they can also collect extragenetic information. On the other hand, humans and mammals exclusively depend on extragenetic information.
Mammals are warm-blooded (maintaining a constant body temperature compared to the temperature of the environment), vertebrate (have a backbone or spinal column) animals distinguished from other animal classes by their possession of hair or fur, the birth of live young, and the secretion of milk by the females for the nourishment of the young.
While our genetic history does exert a significant influence in our behavior, our brains allow for us to interact at a higher level with what we learn from the environment. This has drastically enhanced the chances of survival of the human species. Human beings have also invented extrasomatic knowledge, or information that can be stored outside our bodies, writing being a notable example. As Sagan points out, our dependence on extragenetic, and extrasomatic information is crucial to the survival of our species. Since the timescales involving evolutionary or genetic change is far too long, we cannot depend on a process that may take place over hundred thousands to millions of years in order to keep up with the changes that we encounter in the world. In fact, we now live in a time where our world is changing at an unprecedented rate. To deal with an unknown and perilous future, Sagan insists it will be necessary for humans to actively consider the changes in our environment, and learn to adapt, control, and adjust our lifestyles accordingly. Our survival relies on the evolution, growth, and sensitivity of human intelligence, which has been a solution and a cause to the many problems and changes that afflict our species (Figure5).
Sagan’s interests in addressing the evolution of human intelligence is also an extension of the work he accomplished at SETI (Search for Extraterrestrial Intelligence) as the insights we derive from an investigation of terrestrial intelligence will help in our search for extraterrestrial intelligence.
Both the existence of those other civilizations and the nature of the messages they may be sending depend on the universality of the process of evolution of intelligence that has occurred on Earth. – Carl Sagan, The Dragons of Eden
Ultimately, his treatment of the evolution of the brain will assume that its workings, or what can be called the mind, are a result of its physiology and anatomy. His primary goal in addressing the evolution of human intelligence is to dissect the various aspects of a subject that touches base with various other scientific fields. By understanding the evolution of human intelligence, he stresses the insight that can be gained from the interactions between brain physiology, anatomy, and human introspection.
With this approach, Sagan considers the “mind” to be the result of collective processes of the components of the brain, and chooses to not entertain the hypothesis of what is called the mind-body dualism (Figure 6). The mind-body problem deals with various arguments about how mental states, events, and processes can be related to physical states, and likewise, with the governing assumption that the human body is a physical entity, while the mind is non-physical. (The Stanford Enyclopedia of Philosophy is a wonderful primer’s read-through of this highly detailed topic.)
And that’s all there is to the introduction! While it may read as a book review, the introduction is a concise summary of what we will see later in the book. Now, to reiterate, Sagan’s work in The Dragons of Eden is presented against the backdrop of the theory of evolution. Since its induction in science, evolution has garnered its share of controversy, and disagreement. To all my readers, by reviewing this book, I am in no way forcing these views, and arguments on you. Science is not dogmatic, neither should it be in its endeavor to discover the nature of our world, and our place in it. It is an open stage, and thus, I leave it to you, my readers,to decide on the views you wish to accept, and decline in my review of the book.
Sagan, Carl. The Dragons of Eden: Speculations On The Evolution of Human Intelligence. Ballantine Books, 1977.
Great news everyone! As of yesterday, I have successfully completed the first draft of my second book (Agent X, as we decided to call it on my last post).
It took a few hours…Well, actually, an entire day of exhaustive writing, and by around 10 p.m., I was typing the last words of the epilogue. The rush of emotions that accompanied the completion of my second work was exhilarating, and in a way, bittersweet. I spent the rest of the night reminiscing about the two year journey over the course of which I had written the book.
Of course, there is still much that remains to be done. I will now proceed with the most arduous task of content editing my work. On the other hand, the end of this project brings up the excitement of various future prospects. Apart from the accompanying art work I intend to do for Agent X, I will now slowly make my transition into Manga school, while brainstorming my next three writing projects.
I will also be making a few changes to the content presentation on this blog. The purpose of this blog is to provide a free space where I can express my thoughts, as well as share my knowledge with all of you. To further help facilitate these discussions in an interesting manner, I intend to go about categorizing my daily posts. I’m hoping that a few months from now, I will have set up several categories of posts in subjects ranging from:
(1) Critical thinking
This will primarily involve weekly discussions on an interesting article of my choice in science, politics, philosophy, and just about anything that can wrack my brain.
(2) Teaching & Problem-solving
This will be a two-fold approach that would help complement my current duties as a student tutor at the university, where I typically face the following scenarios:
and which I try to resolve in due fashion, with ample flair,
I have yet to decide on how to organize this part of the blog, but it may predominantly involve discussions or solutions to the most interesting questions I encounter with my students on a weekly basis, or any other cool puzzles that catch my eye!
(3) Book reviews/Read-along
This is something I have always wanted to do. So far, I have done one book review (Star Wars, The Old Republic: Revan), but I would also like to try something new where I would provide a summarized read-along discussion of sorts of the books I read. An immediate choice that I will provide posts about in the near future is Carl Sagan’s Dragons of Eden, which I’m currently parsing through.
(4) My daily adventures & lots of writing!
This is fairly simple. It is what I’ve been doing so far, and will be the primary form of my communication with everyone. There is a lot to life, and everyday proves to be a grand adventure!
And that’s basically it for my update. The purpose of this post was to keep you all informed. The changes will be gradual, but I hope that you will all come to enjoy the myriad selection of posts this blog will host in the coming days!
Electricity is an ubiquitous phenomenon. It is now ingrained in the various facets, and activities of our daily lives, to the point where its existence, and influence is very much taken for granted, with nothing more than a modicum of appreciation, for the singular force that powers the technologies that serve as the foundations of modern-day society. So, what exactly is electricity?
Honestly, it’s a difficult question. In my opinion, one of the greatest delights of being a physicist, involves a deep admiration for the unknown, and an acknowledgment of my own lack of knowledge. It has motivated me to persevere, and strive hard to learn as much as I can about the world that we occupy, and its myriad mysteries.
Electricity is one such mystery.
If I were to teasingly paraphrase Master Kenobi’s words,
“Electricity is what gives technology its power. It’s an energy field…it surrounds us, and penetrates us. It binds the galaxy together.”
In a way, this is true (a more precise statement would substitute electromagnetism for electricity), as we find electricity everywhere: from the lightning overhead, to the crackling static sparks of warm laundry, and even the functional impulses of the human nervous system. Electricity powers our world, and our bodies.
In this article, I’ll try to illuminate, to my best effort, the nature of electricity, its origins, and its practical applications.
Off to Miletus
Science finds its origins in the experimental method, which in ancient times, largely concerned the observation, and analysis of the surrounding world. The Greeks were stalwarts of both ancient philosophy, and science, and among them lived a philosopher of high regard, named Thales of Miletus (624-546 B.C.).
Thales was one among the legendary Seven Sages of Greece, a title given by ancient Greek tradition, to seven early 600 B.C. philosophers, statesmen, and law-makers who were renowned for their wisdom throughout the centuries.
Now, while the Greeks didn’t fully understand electricity, they certainly were aware of its existence. Thales is considered to have been the first human to have studied electricity. He found that by rubbing amber, or fossilized tree resin, with fur, he was able to attract lightweight objects like dust, and straw. He also noticed that lodestone (a naturally magnetic material) attracted bits of iron (magnetism is a close friend of electricity, but much about that later.) The word electricity is coined from the Greek word elektron, which also means amber. Thales’ work involved the first experiments of electrostatics, the study of stationary electric charges or static electricity.
Centuries would pass until electricity would find a foothold in modern science, and engineering. During this transition, and particularly in the 1700s, electricity was conceptualized to be a fluid. Familiar names such as Luigi Galvani, who asserted electricity to be the source of animation or animal motion, William Gilbert, an amateur scientist, who repeated Thales’ experiments, and Ben Franklin, who proved that lightning is electric in nature, and is constituted of positive, and negative elements, are among the many personalities who helped the scientific community form a clearer picture on how electricity works.
In the end, it was a French scientist named Charles Augustin de Coulomb, who summed up the work of his peers, and through his experiments, formulated what is now popularly known as Coulomb’s Law.
Coulomb’s law states that like charges repel, and opposite charges attract, with a quantified electric force that is proportional to the product of the two charges, and inversely proportional to the square of the distance between them.
Despite all this progress, the fundamental nature of electricity still eluded the scientific community.
Enter the Atomic Theory
Matter, as we now know, is composed of atoms. An atom is in itself composed of subatomic particles such as protons, and neutrons, concentrated in a nucleus, and surrounded by orbiting electrons. (A particle physicist may offer a slightly different description, as we have now found that protons, and neutrons are also made of constituent particles called quarks.)
Scientists discovered the existence of electrons in the early 19th century. This discovery set the stage for the rise of subatomic theory, and the beginning of the modern era of electricity, followed immediately by a rush of advances in technology.
There are various types of materials, but in the world of electricity, there are two primary categories: electrical insulators, and electrical conductors. Electrical insulators are materials that don’t conduct electricity very well. Wood is a wonderful example of an electrical insulator. Material or matter interactions are predominated by the sharing or exchange of electrons. But insulating materials are very reluctant in sharing electrons. This is because the electrons in insulators are tightly bound to their atoms.
Conductors,as you may have guessed, allow for this interaction, as their electrons can detach from their atoms, and fly about freely. These loose or free electrons make it easy for electricity to flow through these materials, aptly confirming their namesake as electrical conductors. Most metals are conductors. The motion of electrons transmits electrical energy from one point to another.
This simple premise opens the gateway to the many applications of modern day electricity each of which was the answer to a fundamental question:
(1) How can we make electricity flow from one point to another? Generators
(2) How do we make electricity? Power plants
(3) How do we contain this electricity? Circuits
Electricity is the flow of electrons. A generator helps stimulate this flow, using a magnet! We’ve often observed how we can move paperclips, and small bits of metals about a surface using a magnet. This is the principle behind the working mechanism of a generator. The motion of the paper clip is in response to the motion of electrons induced by the magnetic field.
Electricity, and magnetism are equal proponents of the other, as by running electricity through a metal wire, one can form a magnetic field around the wire! Such observations are definitive of a link between electricity, and magnetism, which eventually culminated in the successful formulation of Maxwell’s Laws of Electromagnetism.
But for now, let’s focus on electricity! Ultimately, the generator is a device that uses a magnet near a wire or conducting material to create a steady flow of electrons, and is the foundation of a power plant where electricity is made!
Power is the rate of doing work. It is defined as the ratio of energy consumed per unit time. To cause a particular change in a system, a necessary amount of energy is required, along with a specified interval of time in which the change is allowed to occur.
In physics, it is common to confuse work with power but they are distinct quantities. Work is the net change in the state of a system. A person carrying a crate up a set of stairs does the same amount of work whether he runs or walks, but more power is required for running while carrying the crate up the stairs, as the work being done is accomplished in a shorter period of time.
Power plants make use of this concept. They work to provide electricity over a period of time. But to do so, a power plant requires a generator. Michael Faraday conceived an early form of a generator where coils of copper wire are rotated between the poles of a magnet to produce an electrical current. In order to rotate the disk, a crank was utilized. This would be similar to the motions of using a pencil sharpener.
These old fashioned pencil sharpeners consist of a wheel, an axle, and a wedge. The handle serves as the axle that turns a wheel that is attached to the gears inside the sharpener to sharpen the pencil.
Now, imagine using a similar apparatus to crank out electricity for a neighborhood! It isn’t practical or viable! We would have to put a lot of work over a long period of time to generate even a reasonable amount of electricity! We have a generator, but the challenge is to apply the technology in an efficient manner to provide mass outputs of electricity.
In order to convert the input of mechanical (of cranking the handle) energy to a viable output of electrical energy, power plants seek the help of mother nature. There are many sources of electrical energy from hydro-electrical energy, to wind energy etc. All these technologies function using a fundamentally similar approach towards a common goal of producing electricity in mass.
Falling water has often been used as an energy source in ancient farms to modern day dams, and hydro-electricity plants, that use the enormous kinetic energy (or moving energy) delivered by falling water to crank out electricity. Engineers begin by building a dam across a river to create a reservoir. This reservoir of water is allowed to flow through the dam wall along a narrow channel called a penstock. At the end of a penstock, there is a turbine, or a large propeller. The shaft from the turbine goes up into the generator. When water moves across the turbine, the propellers spin, causing the shaft to rotate which in turn causes the copper coils of the generator to rotate. As these copper coils spin about the magnets, electricity is produced. Power lines carry this electricity from the plant to homes, and distant areas. Et voilà!
Now, while we have been successful in using a generator to “generate” electricity, there must be a means to contain this system of moving electrons. The answer to this involves the use of electrical circuits!
An electrical circuit helps monitor the flow of electricity. A simple circuit would look like this:
Circuits are pretty much analogous to subway maps. The more complicated the circuit, the more complicated the map. During my early years in Edmonton, I felt quite confident about my ability to get around the city, using the LRT (Light Rail Transit). This was partly due to how simplified the system was,
I remember proudly mentioning to Leina, my partner, that if I were to ever travel to Japan, I should not have a problem finding my way about the city, only for her to show me the Tokyo subway map, and challenging me to find a particular route:
My answer speaks for itself. But, just as we gain familiarity with our knowledge of our daily routes to work/school through the frequent use of public transport, by understanding the central principles of circuit theory (which sometimes, depending on how deep you want to go in the field, may involve a good undergraduate degree in electronics or so), one may eventually find their way about a circuit board like this,
Now, what does this all have to do with electricity? Circuits are necessary to monitor, and regulate electricity. No matter the source of electricity, be it a battery, a fuel cell, or a solar panel, the source of electricity generally has two terminals, a positive, and a negative terminal.
With reference to the simple circuit shown at the beginning of this section, electrons are pushed out of the negative terminal at a certain voltage (think of it as a force/pressure used to push the electrons, similar to how we may use a pump to push water out of a pipe). The electrons then flow from the negative terminal to the positive terminal through a conductor of choice (like copper wires). These wires form a closed path from the negative to the positive terminal, forming a circuit.A load, such as a light bulb, in the middle of the circuit may use the electricity flowing through the wire as a power source to generate light. While electrical circuits can get exceedingly complex, these basic principles of electron motion from the source generator, through a load, and back remain the same.
This concludes our discussion. Generators are the core mechanisms involved in making electricity, and are housed in power plants, which distribute the output electrical power to homes, and businesses, via power lines, and electrical circuits.
So what’s the point of all of this?
The point is…electricity is awesome!
My Masters thesis focuses on a simple circuit involving what is called a Single Dielectric Barrier Discharge (SDBD) Plasma Actuator. While I could write a book (which I have indeed, namely, my thesis) on the device, and its mechanisms, a simple description should be good for now.
An actuator is a device that converts an electrical input to produce a mechanical output (like the human body, neural “electrical” impulses from our brain, translate to our mechanical actions.) The SDBD plasma actuator does the same but does so using a medium known as a plasma, which is basically a soup of charged particles. Placing this device on an airplane wing, and turning it on, helps modify the airflow over the wing, reducing turbulence, and drag, while enhancing lift.
What’s this drag? For example, when you’re in a car, and you reach out the window, you can feel the force of the air against your open palm. This force is often referred to as the “drag” that your hand feels as air flows past it. It’s the same as when you walk through water, you feel its resistance, making your collective motions slower.
Airplanes are no different, feeling this frictional drag as they move through the atmosphere. The SDBD plasma actuator helps nullify this drag to a certain extent, aiding in the airplane’s motion through the air. But, in order to get the device to work in the first place, we need an electrical current! The SDBD plasma actuator is a Micro-Electro-Mechanical (MEM) System. Electricity is practically everywhere!
My goals for this review had been to talk about this physical force that is the primary benefactor of our daily lives, and a central principle behind the future of a technologically advanced human civilization. I hope I haven’t left anyone behind in the explanations provided above. I’ve tried my best to make the discussion concise, and enjoyable for those with, and without a scientific background. I hope everyone enjoyed reading this article!
“Electricity.” Britannica Encyclopaedia. August 22, 2016 https://www.britannica.com/science/electricity
Young, Hugh D., Freedman, Roger A., Ford, Lewis. University Physics. 2008.
Gundersen, P. Erik. The Handy Physics Answer Book. Visible Ink Press. 2003.