ASTR 1210 (O'Connell) Study Guide

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9. SCIENCE, TECHNOLOGY, & SOCIETY

For an essay version of this webpage, click here

US hydrogen bomb test, 11 megatons, 1954.

The image above is probably what leaps to mind when the subject of "science and society" is raised. Nuclear weapons are the most dramatic embodiment of the power of science, and they evoke strongly negative emotions. Science, however, pervades almost all aspects of our society, and its net effects are highly beneficial.

In fact, we live in a scientific civilization. By that I don't mean simply that some people are scientists or even that most people appreciate science (because they don't). Instead, I mean that, whether we know it or not, we depend on science for our wealth and well-being; that almost all of our critical technologies are based on science; and that without science, we would be living in a very different, and much less comfortable, world. We are benefitting today from the intellectual capital produced by hundreds of thousands of scientists and engineers.

In this special lecture, not covered in the textbook, we discuss the effects of science and technology on society and how our understanding of the basic structure and operating principles of the universe has affected human lives.

A. Distinctions

It will help to be clear about the terminology:

• Science: By my definition, science is the attempt to understand the universe, to build a conceptual framework. This is often called "fundamental," "pure," "unapplied," or "basic" research. Most research in astronomy falls in this category. Important examples of scientific accomplishment are Newton's theory of gravity, Maxwell's discovery of electromagnetic waves, Leeuwenhoek's discovery of microorganisms, or NASA's planetary exploration missions.

• Technology: Technology is the application of basic concepts to solve practical problems (e.g. shelter, food, transport, energy, medicine, tools, weapons). Technology may use our basic scientific understanding but doesn't necessarily in itself contribute to it. The word "invention" is often applied to innovations in technology but not normally to scientific discoveries. Engineering is applied science/technology. Examples: structural and civil engineering, aeronautics, pharmacology, or the Internet.
  Technology always has a societal motivation, whether for ultimate good or ill, but the main motivation for "basic" science is simply curiosity and the desire to understand.
  Job descriptions:
  Scientist: "Be curious"
  Technologist: "Be useful"

  There is a strongly symbiotic relationship between the two: Science <==> Technology. New technology provides new tools that enable better scientific understanding and vice versa. Some of the technologies essential to modern astronomy are described in Study Guide 14.

B. Conversion of Basic Science to Technology

• Science now usually precedes technology
  This was obviously not true for the early technologies (e.g. fire, stone tools, cloth, ceramics, metalworking, glass), which were developed through trial and error, building on intuition drawn from everyday personal and societal experience. Trial and error certainly still features in technology development, but the essential foundations for experimentation since about 1800 have come from science.

• Critical Conceptual Path: For each important new technology, we can construct a "critical conceptual path" of the main steps leading to its realization. Almost all modern technologies depend on a long list of discoveries in basic science. Most will go all the way back to Newton and Kepler.
  Individuals like Galileo, Einstein or Pasteur have made important breakthroughs, but progress in science inevitably depends on the contributions of many people. For instance, a recent study of the development of a new drug to fight metastatic melanoma concluded that its critical conceptual path extended back over 100 years and involved 7000 scientists working at 5700 different institutions. Most of this path involved basic research disconnected from immediate commercial or clinical applications.
  The recent development of vaccines for the COVID-19 virus is a perfect example of how basic research underpins essential technology. With older technology, it normally took years to perfect viral vaccines. However, the discovery of the structure and function of the "messenger RNA" molecule in 1961 began a chain of research that ultimately led to the very rapid development, in only a few months' time, of COVID-19 vaccines that use mRNA to induce human immune system resistance to the virus.

• Key contributions of science to technology:
  Methods: critical thinking, skepticism, rational analysis, empirical testing, calculus, statistics, double-blind medical trials, etc.
  Knowledge: Newton's Laws of Motion (mechanics), thermodynamics, electromagnetism, chemistry, biology, hydrodynamics, structure of matter, etc.

• The enabling discoveries in the critical conceptual path are often motivated by curiosity rather than potential applications.
  This is why politicians and opinion-makers who insist on the "relevance" of scientific research, especially in terms of near-term applications, are misguided --- and may even inhibit progress.
  "There is no 'useless' research."
            ---- Nathan Myhrvold, Chief Technology Officer, Microsoft Corporation

  

  Experimental cathode-ray tube (ca. 1875): forerunner of X-ray and TV tubes.

• The time scale for conversion of basic discoveries to useful technologies varies enormously
  • Examples
    • X-Rays (1895): X-Rays were accidentally discovered by Roentgen in the course of basic research on the physics of electromagnetic waves using cathode ray tubes like the one above. Click here for a sample 1896 X-ray. Conversion time to medical imaging applications: 1 year.
      This is a good example of a technological problem that couldn't be solved by trying to solve it. A direct engineering approach to devising a non-invasive mechanism to examine internal human anatomy would have failed utterly.

    • Human Space Flight (1961): The basic scientific concepts needed to build rockets and navigate them through space had been known since the 19th century, so the investment of large amounts of $$$ (in both the US and USSR) solved the remaining technical problems within 5 years of a political decision to go forward. Conversion time: 280 years (from Newtonian orbit theory, the essential conceptual foundation of space flight).

    • CD/DVD Players (1982): Here, the critical conceptual path includes Einstein's work on induced transitions of electrons in atoms (1916), which was the essential idea in creating the lasers that are used to convert digital recordings into electronic signals. (Similar lasers are the basis of data transmission by fiber-optic cables, now the main technology used to drive the Internet.) Conversion time: 66 years.

• Technology is a fundamental test of the validity of scientific ideas
  Modern technology is applied science. As pointed out in Study Guide 1, if our science was not right, then most of our technology would simply not work. Even though it's not readily visible to us, our everyday experience in modern societies depends on the quality of our scientific understanding of nature on scales from the atomic to the cosmic.
  By the way, this is also the best answer to the notion of "social constructivism" -- popular with some philosophers and social scientists -- that prevailing scientific theories are more a product of social conventions, political currents, or a power hierarchy than objective data from the real world. Scientists emphatically reject this argument. They accept that they are subject to all the same social pressures, foibles, and character flaws as other people. They make mistakes, exercise bad judgement, and can have strongly subjective biases (mostly in favor of their own ideas). However, the difference in terms of the results of science is that the demand for empirical verification provides an external standard for determining which ideas have merit, and this ultimately produces robust interpretations of nature, which can be used to benefit all mankind. If the lights come on, the airplane flies, the antibiotic cures, then the "socially constructed" argument goes down the drain.

C. The "Big Four" Benefits of Science/Technology to Society

INFORMATION TECHNOLOGY

None of the refined, modern versions of human technology would exist without the ability to record vast amounts of information and transmit it from person to person and generation to generation. Through medieval times it was possible to convey knowledge on a modest scale by laborious manual writing and copying and some scattered experiments with printed material. However, only the advent of mass-produced printed books based on Gutenberg's design of printing presses using movable type (ca. 1440) opened the doors to the information revolution. Within 150 years, an amazing 200 million volumes had been printed.
Books ushered in the modern age. Science depended on them. Universities flourished because the ability to deal with large amounts of specialized information in books became essential to society. Beginning in the mid 19th century, information transfer proliferated thanks to the automated rotary press and inventions like the telephone and the linotype machine. In the last quarter century, the Internet and other electronic technologies have accelerated the spread and creation of information, but their societal impact has not yet matched the monumental watershed established by the printed book.

AGRICULTURAL GENETICS

"Genetic engineering," the creation of artificial life forms, is nothing new. It has been going on for thousands of years (long before we even recognized the existence of genes). You will be shocked when you click on this picture of the most familiar artificial life form. Almost all the food we eat is derived from deliberate human manipulation of plant and animal gene pools. (The main exception is wild seafood.) Until the mid 20th century, the techniques employed were cross-fertilization, selective breeding, population culling, and other "natural" methods. As our understanding of genetics matured (ca. 1900-1950), these techniques became science-based. Eventually, it became possible to directly manipulate cellular material (ca. 1970+). Molecular biology now offers an ultimate genetic control technology.

CONTROL OF INFECTIOUS DISEASE

The control of the microorganisms (bacteria, viruses, fungi, parasites) that cause infectious disease is one of the most important contributions of science & technology. In fact, many of us would not be alive today without it because a direct ancestor would have died too early. The COVID-19 pandemic serves as a grim reminder of the almost-forgotten dire threat of infectious diseases like bubonic plague, smallpox, tuberculosis, malaria, cholera, polio, and AIDS. These often swept through human populations, killing huge numbers of individuals. But as recently as 350 years ago, communicable disease was thought to be produced by evil spirits, unwholesome vapors, "miasmas," or other mysterious agents. No one imagined that it was caused by invisible lifeforms until Leeuwenhoek in 1676 used the newly-invented microscope to discover microscopic organisms. Widespread production of agents -- "antibiotics" and "vaccines" -- that could attack specific types of harmful bacteria and viruses or prevent infection in the first place was one of the most important advances in medical history. "Public health" consists mainly of systematic methods for controlling microorganisms.

ELECTRICITY

Electricity is the primary tool of modern civilization, yet few people appreciate this or have any idea of how electricity was discovered or converted to useful technologies. We explore the development and contributions of electricity in the next section.

D. Electricity: A Case Study

Electricity is ubiquitous today in all but the most primitive societies. The most obvious manifestation of electricity is in sophisticated electronics: smart phones, DVD players, personal computers, HD TV, video games, and so forth. But these are luxuries, and it should be easy to imagine being able to live comfortably without them---in fact, people did so only 35 years ago. We don't really need fancy consumer electronics, but we do need electricity. Our reliance on electricity is profound, and its use is so deeply embedded in the fabric of civilization that we mostly take it for granted. At least until there's a power failure.

Electricity supplies almost all of the power we depend on and is essential for manufacturing, agriculture, communications, transportation, medicine, household appliances, and almost every other aspect of modern life. It's easy to overlook the ubiquity of electricity by thinking only in terms of obviously "electrical" devices:
One crucial example: all the internal combustion engines used in cars, trucks, locomotives, ships, and planes require electrical ignition systems.
Two others: refrigeration and water distribution and purification systems. Imagine the challenges in providing food and medication to the world's population today in the absence of electrically powered refrigerators. Anyone who appreciates hot showers taken indoors is an unknowing admirer of electric pumps.

Aside from the power itself, electricity is also the basis of nearly all of the critical control systems we use.
The most powerful control systems in use today are, of course, computers and microprocessors. These outperform human brains in raw processing speed by factors of many millions and have advanced to the point of duplicating or superseding human performance in games like chess or in operating an automobile. They are used on a scale that would have been inconceivable to people only 75 years ago. Nonetheless, that generation also depended on electricity for control systems: think of the telephone operator plug-boards of the "one ringy-dingy" era.

If our knowledge of electricity could be somehow magically subtracted from the contents of your classroom, virtually everything you see would disappear, except a bunch of naked people.
More seriously, if we somehow became unable to use electricity, our economy would collapse overnight, taking our Gross Domestic Product back to the level of about 1900. More than half of the population would probably die off within 12 months, mostly from starvation and disease.
The 2012-14 NBC-TV series "Revolution" showed an action-oriented version of what a fictional post-electricity world might be like (though one where everybody still manages to have good hair).
An all-too-real threat to our electrical infrastructure is posed by magnetic activity on the Sun, particularly "coronal mass ejections." In July 2012 the Earth only narrowly missed a CME from a solar superstorm that could have devastated our electrical grid.

Development of Electric Technology

Electricity is the everyday manifestation of electromagnetic force, the second kind of inter-particle force (after gravity) that scientists were able to quantify. Here is a very brief history of our understanding of EM force, divided between "basic" and "applied" developments:

• ca. 1750-1830: Coulomb, Orsted, Ampere, Volta, (Benjamin) Franklin, and other physicists explore the basic properties of electric and magnetic phenomena. Orsted and Ampere show that an electric current moving in a wire could produce a magnetic field surrounding it. Basic.

• Faraday (1831) (experimental physicist): discovers electromagnetic induction. Basic.
  Faraday discovers that a changing magnetic field could induce an electric current. Together with the fact that an electric current could induce a magnetic field, this demonstrates the symmetry of electromagnetic phenomena.
  This is also the key to the development of electric generators and motors, which convert mechanical force to electrical force, and vice-versa, using magnetic fields. These are two of the essential technologies of the electric age.
  Since 1850 most large-scale electrical generators rely on steam engines to help convert mechanical energy into electrical energy. (Various types of wood- or coal-burning steam engines had been developed in Great Britain in the period 1760-1800 and were so effective at increasing economic productivity in commercial mining and textile manufacturing that they became the basis of the Industrial Revolution.) Today, steam turbine engines are most commonly used in large electric generators. Applied.

• Edison (technologist) and others (1830--1900) develop practical electrical generators, motors, distribution grids, and appliances. Applied.
  Many people think Edison "invented" electricity. He didn't. He invented a large number of electrical appliances---including the electric light, tickertape machines, the motion picture camera & projector, etc. But these all depended on a pre-existing supply of electricity and the knowledge of how to use it---all contributed by basic research in physics.

• Readily available electricity stimulates the invention of the telegraph (1830's) and telephone (1870's), fundamentally changing human communications (and, needless to say, behavior). Applied.

• Maxwell (physicist): in 1865, Maxwell deduces equations giving a complete description of the observed electrical and magnetic (EM) phenomena. From these, he predicts the existence of electromagnetic waves traveling at the speed of light and thereby demonstrates that light is an electromagnetic phenomenon, one of the most important discoveries in the history of science. Basic.
  The fact that these EM waves can have arbitrary wavelengths implies the existence of a broad electromagnetic spectrum, which includes the regions we now use for radio and television. No one had even suspected the existence of this vast spectrum, which is mostly invisible to our eyes.

• Hertz (physicist, technologist): accomplishes the first generation & detection of artificial radio waves (1887). After he demonstrated the existence of radio waves, Hertz admitted that he could not see any practical applications for them. Eight years later, as described above, Roentgen discovers the X-ray region of the EM spectrum, the practical applications of which, by contrast, were immediately apparent. Both Basic and Applied.

• Tesla, Marconi and many others develop methods for routine transmission and reception of EM radio waves. Just as important are new inventions -- such as vacuum tubes (1907) -- for modulation of EM waves so that an intelligible signal could be impressed on them. This leads to commercial radio (1920) and television (1936). All of our "wireless" technology today is similarly based on radio waves. Applied.

• The development of quantum mechanics (Basic) after 1925 leads to the miniaturization of electrical circuits using solid-state materials like silicon and the invention (Applied) of the transistor (1947) and integrated circuit (1959), which are the central components of all the electronics in use today.
  The quantum-based technologies are probably responsible for at least 50% of our Gross Domestic Product today -- so one of the largest contributors to our economic well being was developing an understanding of how electrons move in chunks of silicon. Who could have predicted that?

Faraday's laboratory (ca, 1840), the real birthplace of the iPhone

E. A Brave New World

The cumulative effect of science-based technologies, including the myriad applications of electricity and electromagnetic waves, has been profound. Living conditions for most human beings have been radically transformed for the better since 1500 AD.

By every measure -- freedom, equality, wealth, health, safety, comfort, opportunity, meaningful work, and so on -- the present circumstances for the great majority of all people are an unprecedented improvement over the past. They are an improvement even over the lifestyles of the most privileged individuals in earlier history --- there aren't many sensible people today who would trade indoor plumbing for rubies and emeralds.

These six charts show the dramatic improvement over the last 200 years in important indicators like poverty, child mortality, and literacy.
The long-term historical decline in violence among human societies is illustrated in this slide presentation.

It's worth taking a moment to contemplate how different life was 500 years ago. You may not know who your ancestors were in the year 1500, but you do know two things about them: their lives were mostly not very good and not very long. The miseries of the 16th century are graphically depicted in this extraordinary 1562 painting by Pieter Bruegel. His visualization was, thankfully, exaggerated for effect. But look at the charts above as you ask yourself what your own life might have been like if you had been born in, say, 1900 -- a date only an instant ago in the context of all human history.

In this vein, also think about this: When you get some kind of injury or malady and you go to a doctor, you automatically assume you will be effectively treated and usually cured. That's a new assumption. It wasn't true throughout all of human history until about 100 years ago. In fact, one historian of medicine noted that before about 1850, "most people were fortunate in being unable to afford treatment" --- because medical care then was often counterproductive, brutal, and dangerous.

Technology alone is obviously not responsible for all the improvements of the last 500 years, but it is central to most of the changes in our material surroundings, and these are transpiring at an ever-increasing pace.

• Up to the late 18th century, implementation of new technologies rarely occurred in a period shorter than a human life.

• Today, technological change is much faster and therefore more obvious. The best recent example: smartphones, introduced only 15 years ago, have already dramatically changed the daily behaviour of billions of people.

• It is hard to visualize how rapidly modern technology has emerged --- in only about 200 years out of the 200,000 year history of our species.
  Picture even the most far-sighted thinkers of the 18th century -- Thomas Jefferson or Voltaire, say -- trying to figure out how a television set works. It is utterly foreign to the familiar technologies of their era. Its operation would appear to be "magic."

Examples like these demonstrate how important existing technologies are in shaping our behavior, our intuition, and our imaginations -- in fact, our entire outlook on the world around us.

F. Technological Excesses

The Dilemma

Technology is never an unalloyed good. Given its rapid emergence, it is not surprising that modern technology has produced numerous unforeseen side effects and difficulties. All technology carries risk. Powerful technologies are obviously capable of both great benefits and great harm -- the example of fire being the historical standard. They will frequently rechannel human behavior, with consequences that are hard to predict and can be deleterious. Technologies convey important advantages to groups or societies that possess them, and they can be used to oppress or exploit other groups -- as in the case of the Aztecs (see Study Guide 5).

As appreciative as we ought to be of the technologies that are the foundation of our material lives today, and as impressive as are new medical therapies or innovations in entertainment, there is a strong thread of discontent with technology that runs through our society. Some of this stems simply from frustration when technologies -- usually complex ones -- fail to work well or don't live up to inflated expectations.

But in the last 50 years, dangers attributed to science and technology have often been given more prominence than their benefits. People these days are often more suspicious than appreciative of science and technology.

The perceived threats include environmental pollution, habitat destruction, environmental disease, global warming, nuclear weapons, nuclear poisoning, artificial intelligence, human cloning, and genetic engineering, among others. Such problems have often been vividly portrayed in literature and other media going back to "Frankenstein," written by Mary Shelley in 1816, such that the notion of unthinking scientists unleashing disasters on the world has become a staple of popular culture in the burgeoning genre of dystopian fiction. Some examples:

All these threats, whether real, exaggerated, or imagined are consequences not of basic science but instead of the societal choices that are involved in developing any new technology -- which is always based on some perceived need or demand in society. The threats are mostly inadvertent---i.e. unforeseen by those who implemented the new technologies or grossly amplified by widespread adoption.

"Boomerangs," paradoxes, and ironies abound in the history of modern technology. Here are some telling ones:

• A classic case of "irrational exuberance" over a new and initially highly beneficial technology was the unthinking widespread application of the insecticide DDT. Early use of DDT during World War II accomplished a miraculous suppression of the mosquitos that transmit malaria, one of the greatest historical killers of human beings. But by the 1950's its use had been taken to truly absurd levels and led to serious unanticipated environmental damage. That, in turn, was the genesis of the book that founded the environmental protection movement, Silent Spring (1962), by Rachel Carson.

• A related rapidly emerging threat: the flourishing of organisms (bacteria, viruses, agricultural pests) that are resistant to the chemicals normally used to control them because of overuse of the control agent. By eliminating their natural enemies, overapplied agents allow resistant strains to proliferate. An all-too-common example: people demand antibiotics to try to control a viral infection -- but antibiotics work only against bacteria, not viruses. Hospitals are more dangerous places today than they were 30 years ago because of the overuse of antibiotics. Industrial agriculture contributes to the problem by the unnecessary introduction of antibiotics to animal feed and by massive applications of pesticides and herbicides.

• An important unintended technological threat, one which played a central role in the 2016 presidential election but which was unrecognized by most voters, is the widening displacement of human labor by machines and computers. Although these reduce drudgery and improve efficiency, they have also produced major changes in employment demographics, suppressed wages, and increased social stress. Those difficulties will only multiply over the next decades. Recent advances in the capabilities of artificial intelligence (AI) software are raising growing concerns over displacement.

• Nuclear weapons were, of course, always intended to be destructive, and they were used as intended by the US to attack Japan in 1945 and bring World War II to an end. But the long-term dangers of radioactive fallout -- downwind deposition of radioactive particles and the most serious large-area consequence of using nuclear weapons -- were not fully understood until well after their first use. Uncontrolled fallout effects greatly increase the destructiveness of these weapons. In the wake of the US attacks and subsequent controversies over weapons, fallout, and nuclear power plants, many people came to wish that these technologies had never been invented. Some argued that our knowledge of nuclear physics is a bad thing.
  But nuclear physics also created nuclear medicine -- for example, using radioisotopes as biochemical tracers -- without which modern pharmacology, radiation therapy, and magnetic resonance imaging (MRI) wouldn't exist. Biomedical applications of nuclear physics save millions of lives each year. Vastly more people have benefitted from nuclear technology than have been harmed by it (so far).

• A major but rarely discussed danger to a highly technological society like ours is its vulnerability to potential disruptions. A pivotal feature of modern society is how complex, interdependent, and highly specialized it is. It takes tens of thousands of people working in coordination to produce and deliver even a single item. No one person could build a radio, or a lawn mower, or even a box of Cheerios from scratch. There is a highly integrated system involving scores of specialities across a dozen different industries behind the production and distribution of any of those things. Without being conscious of it, we live in a huge web of specialization and expertise. Such a system is inevitably fragile and can be easily disrupted by incompetence or by natural, political, malevolent, or cultural interference. The COVID-19 pandemic exposed some of the fragilities of modern societies.

• There may be no more timely example of a technological boomerang than the clearly emerging negative social and political consequences of wildly popular social media Internet sites, which provide vast audiences for unfiltered human expression. The Internet today bears some unpleasant similarities to the fictional Krell Machine, which wiped out its creators overnight in the 1956 movie "Forbidden Planet."

These are all examples of appropriately recognized technological problems. But the hazards of technology and our ability to control them are often not objectively assessed. There are many cases where overreactions by the media, the government, or activist groups needlessly alarmed the public -- for example: asbestos, Alar, power transmission lines, breast implants, or infant vaccinations. Public concern in such areas was out of proportion to the actual danger. It became counterproductive and diverted attention from more serious problems.

Mitigation

How should we respond to adverse technological "feedback"? A first impulse might be to argue that the associated technologies are so threatening that we ought to suppress them --- but this ignores the abundance of benefits they bestowed in the first place. The problem, a difficult one, is to achieve a healthy balance that preserves most of the advantages while mitigating the serious disadvantages of important technologies.

Societies have been wrestling with this for the last 200 years. A fundamental obstacle to intelligent planning is the inevitable time lag between introduction of the new technology and the appearance of its major drawbacks --- especially if it has been widely adopted in the meantime. Another is that amelioration often demands a change in human behavior, not just the technology. The need to reduce our "carbon footprint" to mitigate global warming is a contemporary example.
It's important to appreciate that many of the negative effects of technology are only identifiable because of modern technology itself. Without our sensitive instruments and diagnostic tools, we would be poorly informed about the impact of environmental pollution on water or air quality, the ozone layer, global warming, induced diseases, and so forth. And achieving amelioration of the negative effects will also depend on science and technology themselves. A retreat from modern science or technology would produce vast suffering.

Technology could, in fact, solve many of the environmental problems we face --- assuming it is carefully designed and properly applied. Failures to adequately address such problems are rarely caused by serious technological barriers.

As an example, consider the fact that modern technology has made it possible to take one of the most toxic materials known (botulinum toxin, 1000 times more deadly gram-for-gram than plutonium) and turn it into the cosmetic Botox that thousands of people happily have pumped into their faces every day.

Instead, continuing threats from technology are usually the product of greed, incompetence, indifference, absence of foresight, or lack of political will. That certainly applies to the central environmental threat facing us and that we take up next.

G. Technology's Ultimate Threat: Population Growth

The root of almost all of our environmental problems is not any one technology. Instead it is the inevitable product of all of them, and it is something that almost everyone agrees is a good thing: modern technology keeps people alive. Life expectancy at birth has roughly doubled since 1850. Without a corresponding downward adjustment in birth rates, the increase in the human life span creates an imbalance between birth and death rates.

The response to this imbalance is exponential population growth:

Obviously, the increase in the population in any year will be proportional to the population itself.
In any situation like this where the rate of change of a quantity is proportional to the quantity itself, the solution of a simple differential equation shows that the value of the quantity will "exponentiate", as follows:

q = q_oe^gt, where e = 2.72, t is time, q_o is the quantity at the start, and g is the constant of proportionality.
In the case of population, g is the net birth rate, i.e. the fractional excess of births over deaths in a year.
As long as g is positive, the result is that q grows continuously and at an ever increasing rate.
The figure to the right shows the simplest exponential function, the case where g=1.0 and q_o=1.0.
See this article for more information.
A similar formulation applies to a number of other real-world situations: for example, to a savings account subject to compound interest and to the interest owed on student loans. All college students would be smart to take the time to understand exponential growth.

The population will "run away," or grow without limit, as long as the net birth rate does not go to zero.
Note that exponentiation cannot be avoided for any finite positive growth rate; it is simply slower for smaller rates.

Exponential growth is insidious. A tiny 2% excess of births over deaths implies a "doubling time" for the population of only 35 years.

A doubling time of 35 years implies that the population after three doubling times (105 years) would be 2x2x2 = 8 times as large as the starting population.
The doubling time is inversely proportional to the growth rate g.
2% is close to the actual growth rate for the human population between 1960 and 1999. At that growth rate, starting from 6 billion people in the year 2000, the total population would be 44 billion -- 7.4 times larger -- by the year 2100. It would be 330 billion by 2200. If ASTR 1210 scaled in proportion, there would be 8000 people in this class!
For an instantaneous estimate of the US and world populations, click on the: US Census Bureau POPClock.

The actual growth of the human population over the past 10,000 years is shown in the graph at the right (click for enlargement). The sudden increase in the growth rate since industrialization and the introduction of simple public health protocols around 1800 is obvious. And we have added over two billion people to the planet since the year 2000.

This graph should scare you. For a little more context, consider that the spike shown there constitutes only 0.00001% of the history of planet Earth. And yet the humans born in that spike have already begun to transform the Earth's physical character.

The potential dangers of population growth in the face of finite natural resources had been recognized since the time (1798) of the political economist Malthus:

Any fixed resource (water, land, fuel, air), no matter how abundant, is ultimately overwhelmed by continuous growth of population.
Of course, as we approach exhaustion of any such resource, there will be a negative feedback effect which will drastically increase the death rate until the population stabilizes or decreases. That will stop the exponentiation, but we obviously would prefer not to rely on that solution.
We may not yet have reached the "carrying capacity" of the Earth, but we are getting closer. We are probably already well in excess of the population that is compatible with easy resource sustainability.
The "Green Agricultural Revolution" has allowed us to stave off the widespread famines that would have been inevitable if we had been limited to 1950's technology over the past four decades. Nonetheless, demand from the growing human population has already crossed critical local resource thresholds in many areas, as attested by famines and other privations scattered around the world.
One of the most dramatic of these is the catastrophic collapse of some world-class fisheries (e.g. Atlantic cod), previously thought to be inexhaustible. Another is the surge of African refugees into southern Europe, precipitated by a decrease in arable land and mean birth rates that are as high as 7 children per woman. And human contamination of the Earth's atmosphere is already affecting the climate in the form of global warming.
The confrontation between finite resources, population growth, and the possible mediating effects of technology has been the source of many controversial studies over the last 50 years. For a contemporary view, see The Great Disruption by Paul Gilding.

Fortunately, as of 2019, the human population growth rate had slowed to about 1%. That's an important reduction, implying a population in the year 2100 of "only" 11 billion, compared to the present 8 billion or the 42 billion that would result from a 2% growth rate. But even this improvement will not be enough to prevent serious resource exhaustion over the next century.
For instance, at this rate, we must find the wherewithal to feed a minimum of an additional 80 million people (one quarter of the population of the USA) each year, every year.

Since we have begun to bump up against global resource limits here on Earth, the idea of interplanetary migration has been raised as a solution. For instance, why not colonize Mars? Mars has a surface area equal to the land area of the Earth.

At first, this sounds like a fine way out, assuming the technical problems of travel to Mars and sustenance once we are there can be solved. But simple migration to other planets cannot cure the exponential population growth problem.
At a 1% growth rate, the doubling time for the human population is only 70 years, less than a typical human lifetime. Suppose we reach the limits of Earth's resources in the year 2100 and immediately start sending the excess population to Mars. In only 70 years (i.e. in 2170) we will have reached the limit of Mars as well, despite the tremendous financial investment made to move people there. Migration doesn't offer much respite in the face of exponential population growth!

There is no doubt that unchecked population growth is the biggest technology-driven hazard facing the human race today.

Population control is not a technologically difficult problem; effective innovations like the birth control pill are readily available. There are, of course, serious ethical, not to mention political, quandaries in attempting to control or reduce the human population, but it is becoming obvious that these must be intelligently confronted soon.
Needless to say, prospects here are not good. The "zero population growth" movement that flourished in the late 1960's has faded in the face of misguided optimism and political resistance. You would be hard pressed to find American politicians for whom population control is a serious issue, let alone a high priority. In fact, policies on all sides of the political spectrum, including those embedded in the current federal tax code, are to encourage population growth.

H. Science and Technology Policy

"Technology moves faster than politics" --- Yuval Harari

Can an enlightened government channel developments in science and technology in beneficial directions?

• Obviously, it must first be able to recognize important needs and to predict useful sci/tech initiatives

• Unfortunately, the track record of technological prediction is dismal. For example, consider a 1937 US National Resources Council prediction of important inventions for the following 25 years (1937--62):
  • A few hits---e.g. TV, plastics---but many more misses.

  • The leading predicted technology was the "mechanical cotton picker." Hmmm...

  • Among the technologies not predicted but actually developed during just the following ten years were: antibiotics, nuclear weapons, nuclear medicine, jet aircraft, nylon, radar, and digital computers. Oops.

  • Perhaps the key technology missed in the NRC study was the transistor, invented in 1947 based on developments in the quantum mechanics of solid state materials. This was later transformed into integrated circuits, microprocessors, and the myriad of other electronic components that drive our high-tech world today..

• But the private sector can be just as nearsighted as any lumbering government bureaucracy.
  In 1994 Microsoft, the Godzilla of software corporations, decided the Internet was a passing fad and planned to ignore it in product development. QED.

• In the early 21st century we are entering an era of technological transformation, similar to that produced by physics and chemistry in the 20th century, based on molecular biology, hyper-scale information processing, artificial intelligence, nanotechnology, and bio-electronics. Few, if any, scientists, government officials, or corporate leaders are perceptive enough to accurately forecast what this will bring only 25 years from now. As always, both benefits and risks have the potential to be enormous.

Conclusion: technology transfer and trends are difficult or impossible to predict. Apart from obvious crises, the best policy for government is good, broad support of basic scientific research and moderate (but alert & intelligent) regulation/stimulation of technology in the private sector.

And there is another fundamental obligation of a democratic society in a technological age: high quality public education. The danger of an uninformed electorate --- or, worse, government --- was nicely summarized by Carl Sagan in this 1995 quote:

"We've arranged a global civilization in which most crucial elements profoundly depend on science and technology. We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces."

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Reading for this lecture:

Study Guide 9
1937 NRC Study: Technological Predictions vs. Reality
Optional exercise: Try to identify something in your home that was produced and delivered to you without the use of electricity.

Reading for next lecture:

Supplements II and III

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Web Links:

An essay version of this webpage
Brandt's timelines of key developments in science and technology to 1993
A biography of Faraday (Royal Institution)
The Edison Papers
Exhibit on cathode ray tubes and discovery of the electron
Information on electric power generation (from How Things Work by L. Bloomfield)
Information on electric motors (from How Things Work by L. Bloomfield)
Invention of the transistor
UVa Virtual Lab (guide to transistors, integrated circuits and other modern electronics)
Britney's Guide to Semiconductor Physics Smarter than you thought?
Wikipedia Online Encyclopedia entries:
Michael Faraday
Electricity
History of Radio
Radio
X-Rays

Here's a bizarro monument proposed by a leading 1920's enthusiast for the wonders wrought by electricity
Invention of nuclear weapons
The Nuclear Weapons Archive
The threat of "nuclear winter"
The Making of the Atomic Bomb by Richard Rhodes (QC773 .R46 1986 in UVa Library)
A sampling of dumb quotes about technology (P. Ekstrom)
Top-30 Failed Technology Predictions (Listverse)
"What's the Use of Basic Science?" (article by C. H. Llewellyn Smith, former director of CERN)
1937 NRC Study Technological Predictions vs. Reality
Fundamentals of Population Growth and Resource Exhaustion (A. Bartlett)
The Wizard and the Prophet, by Charles Mann, describes the two divergent paths toward confronting human population growth
Bill Maher on population growth and Malthusian limits (video)
Guns, Germs, and Steel by Jared Diamond: review by J. Bradford DeLong of this important book about the influence of environment and technology on societies
The Visual History of Decreasing War and Violence (from OurWorldinData.org)
The Return of the Krell Machine (by Steven Harris) -- an ultimate instrumentality from science fiction. A portent of a modern social media meltdown?
"Colossus - The Forbin Project" -- a classic 1970 science-fiction film warning about the dangers of artificial intelligence.

"Did You Know?" -- a video that vividly illustrates technological change in the 21st century: "we live in exponential times."
"The Coming Singularity" -- a talk by Ray Kurzweil that explores the implications of exponential growth in high technology

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Last modified November 2023 by rwo

Text copyright © 1998-2023 Robert W. O'Connell. All rights reserved. These notes are intended for the private, noncommercial use of students enrolled in Astronomy 1210 at the University of Virginia.