1. For a comprehensive overview and detailed references on the big bang theory and the origin of the Universe, see "Introduction to Big Bang Theory," Bowdoin College Department of Physics and Astronomy.
Print sources on the big bang theory include: Joseph Silk, A Short History of the Universe (New York: Scientific American Library, 1994); Joseph Silk, The Big Bang (San Francisco: W. H. Freeman and Company, 1980); Robert M. Wald, Space, Time & Gravity (Chicago: The University of Chicago Press, 1977); and Stephen W. Hawking, A Brief History of Time (New York: Bantam Books, 1988).
2. The strong force holds an atomic nucleus together. It is called "strong" because it needs to overcome the powerful repulsion between the protons in a nucleus with more than one proton.
3. The electroweak force combines electromagnetism and the weak force responsible for beta decay. In 1968, American physicist Steven Weinberg and Pakistani physicist Abdus Salam were successful in their unification of the weak force and the electromagnetic force using a mathematical method called gauge symmetry.
4. The weak force is responsible for beta decay and other slow nuclear processes that occur gradually.
5. Albert Einstein, Relativity: The Special and the General Theory (New York: Crown Publishers, 1961).
6. The laws of thermodynamics govern how and why energy is transferred.
The first law of thermodynamics (postulated by Hermann von Helmholtz in 1847), also called the Law of Conservation of Energy, states that the total amount of energy in the universe is constant.
The second law of thermodynamics (articulated by Rudolf Clausias in 1850), also known as the Law of Increasing Entropy, states that entropy, or disorder, in the Universe never decreases (and, therefore, usually increases). As the disorder in the Universe increases, the energy is transformed into less usable forms. Thus, the efficiency of any process will always be less than 100 percent.
The third law of thermodynamics (described by Walter Hermann Nernst in 1906, based on the idea of a temperature of absolute zero first articulated by Baron Kelvin in 1848), also known as the Law of Absolute Zero, tells us that all molecular movement stops at a temperature called absolute zero, or 0 Kelvin (2273°C). Since temperature is a measure of molecular movement, the temperature of absolute zero can be approached, but it can never be reached.
7. "Evolution and Behavior" contains an excellent collection of articles and links exploring the theories of evolution. Print sources include Edward O. Wilson, The Diversity of Life (New York: W. W. Norton & Company, 1993); and Stephen Jay Gould, The Book of Life (New York: W. W. Norton & Company, 1993).
8. Four hundred million years ago, vegetation spread from lowland swamps to create the first land-based plants. This development permitted vertebrate herbivorous animals to step onto land, creating the first amphibians. Along with the amphibians, arthropods also stepped onto land, some of which evolved into insects. About 200 million years ago, dinosaurs and mammals began sharing the same environment. The dinosaurs were far more noticeable. Mostly the mammals stayed out of the dinosaurs' way, with many mammals being nocturnal.
9. Mammals became dominant in the niche of land-based animals after the demise of the dinosaurs 65 million years ago. Mammals are the more intellectual animal class, distinguished by warm blood, the nourishment of their children with maternal milk, hairy skin, sexual reproduction, four appendages (in most cases) and, most notably, a highly developed nervous system.
10. Primates, the most advanced mammalian order, were distinguished by forward-facing eyes, binocular vision, large brains with a convoluted cortex, which permitted more advanced reasoning faculties, and complicated social patterns. Primates were not the only intelligent animals, but they had one additional characteristic that would hasten the age of computation: the opposable thumb. The two qualities needed for the subsequent emergence of technology were now coming into place: intelligence and the ability to manipulate the environment. It's no coincidence that fingers are called digits. The origin of the word digit, as used in Modern English and appearing first in Middle English, is from the Latin word digitus, for "finger" or "toe"; perhaps akin to Greek deiknynai, "to show."
11. About 50 million years ago, the anthropoid suborder of primates split off. Unlike their prosimian cousins, the anthropoids underwent rapid evolution, giving rise to advanced primates such as monkeys and apes about 30 million years ago. These sophisticated primates were noted for subtle communication abilities using sounds, gestures, and facial expressions, thereby allowing the development of intricate social groups. About 15 million years ago, the first humanoids emerged. Although they initially walked on their hind legs, they used the knuckles of their front legs for balance.
12. Although it is worth pointing out that a 2 percent change in a computer program can be very significant.
13. Homo sapiens are the only technology-creating species on Earth today, but were not the first such species. Emerging about five million years ago was Homo habilis (i.e., "handy" human being), known for his erect posture and large brain. He was called handy because he fashioned and used tools. Our most direct ancestor, Homo erectus, showed up in Africa about two million years ago. Homo erectus was also responsible for advancing technology, including the domestication of fire, the development of language, and the use of weapons.
14. Technology emerged from the mists of humanoid history and has accelerated ever since. Technologies invented by other human species and subspecies included the domestication of fire, tools of stone, pottery, clothing, and other means of providing for basic human needs. Early humanoids also initiated the development of language, visual art, music, and other means for human communication.
About ten thousand years ago, humans began domesticating plants, and soon thereafter, animals. Nomadic hunting tribes began settling down, allowing for more stable forms of social organization. Buildings were constructed to protect both humans and their farming products. More effective means of transportation emerged, facilitating the emergence of trade and large-scale human societies.
The wheel appears to be a relatively recent innovation, with the oldest excavated wheels dating from about 5,500 years ago in Mesopotamia. Emerging around the same time in the same region were rafts, boats, and a system of "cuneiform" inscriptions, the first form of written language that we are aware of.
These technologies enabled humans to congregate in large groups, allowing the emergence of civilization. The first cities emerged in Mesopotamia around 6,000 years ago. Emerging about a millennium later were the ancient Egyptian cities, including Memphis and Thebes, culminating in the reigns of the great Egyptian kings. These cities were constructed as war machines with defensive walls protected by armies utilizing weapons drawn from the most advanced technologies of their time, including chariots, spears, armor, and bows and arrows. Civilization in turn allowed for human specialization of labor through a caste system and organized efforts at advancing technology. An intellectual class including teachers, engineers, physicians, and scribes emerged. Other contributions by the early Egyptian civilization included a paperlike material manufactured from papyrus plants, standardization of measurement, sophisticated metalworking, water management, and a calendar.
More than 2,000 years ago, the Greeks invented elaborate machinery with multiple internal states. Archimedes, Ptolemy, and others described levers, cams, pulleys, valves, cogs, and other intricate mechanisms that revolutionized the measurement of time, navigation, mapmaking, and the construction of buildings and ships. The Greeks are perhaps best known for their contributions to the arts, particularly literature, theater, and sculpture.
The Greeks were superseded by the superior military technology of the Romans. The Roman empire was so successful that it produced the first urban civilization to experience long-term peace and stability. Roman engineers constructed tens of thousands of kilometers of roads and thousands of public constructions such as administrative buildings, bridges, sports stadiums, baths, and sewers. The Romans made particularly notable advances in military technology, including advanced chariots and armor, the catapult and javelin, and other effective tools of war.
The fall of the Roman empire around 500 a.d. ushered in the misnamed Dark Ages. While progress during the next thousand years was slow by contemporary standards, the ever tightening spiral that is technological progress continued to accelerate. Science, technology, religion, art, literature, and philosophy all continued to evolve in Byzantine, Islamic, Chinese, and other societies. Worldwide trade enabled a cross-fertilization in technologies. In Europe, for example, the crossbow and gunpowder were borrowed from China. The spinning wheel was borrowed from India. Paper and printing were developed in China about 2,000 years ago and migrated to Europe many centuries later. Windmills emerged in several parts of the world, facilitating expertise with elaborate gearing machines that would subsequently support the first calculating machines.
The invention in the thirteenth century of a weight-driven clock using the cam technology perfected for windmills and waterwheels freed society from structuring their lives around the sun. Perhaps the most significant invention of the late Middle Ages was Johannes Gutenberg's invention of the movable-type printing press, which opened intellectual life beyond an elite controlled by church and state.
By the seventeenth century, technology had created the means for empires to span the globe. Several European countries, including England, France, and Spain, were developing economies based on far-flung colonies. This colonization spawned the emergence of a merchant class, a worldwide banking system, and early forms of intellectual property protection, including the patent.
On May 26, 1733, the English Patent Office issued a patent to John Kay for his "New Engine for Opening and Dressing Wool." This was good news, for he had plans to manufacture his "flying shuttle" and market it to the burgeoning English textile industry. Kay's invention was a quick success, but he spent all of his profits on litigation, attempting in vain to enforce his patent. He died in poverty, never realizing that his innovation in the weaving of cloth represented the launching of the Industrial Revolution.
The widespread adoption of Kay's innovation created pressure for a more efficient way to spin yarn, which resulted in Sir Richard Arkwright's Cotton Jenny, patented in 1770. In the 1780s, machines were invented to card and comb the wool to feed the new automated spinning machines. By the end of the eighteenth century, the English cottage industry of textiles was replaced with increasingly efficient centralized machines. The birth of the Industrial Revolution led to the founding of the Luddite movement in the early 1800s, the first organized movement opposing technology.
15. Primatologist Carl Van Schaik observed that the orangutans of Sumatra's Suaq Balimbing swamp all make and use tools to reach insects, honey, and fruit. Though captive orangutans are easily taught to use tools, the Suaq primates are the first wild population observed using tools. The use of tools may be a result of necessity. Orangutans in other parts of the world have not been observed to use tools, basically because their food supply is more easily accessible.
Carl Zimmer, "Tooling Through the Trees." Discover 16, no. 11 (November 1995): 4647.
Crows fashion tools from sticks and leaves. The tools are used for different purposes, are highly predictable in their construction, and even have hooks and other mechanisms for finding and manipulating insect prey. They often carry these devices when flying and store them next to their nests.
Tina Adler, "Crows Rely on Tools to Get Their Work Done." Science News 149, no. 3 (January 20, 1996): 37.
Crocodiles can't grip prey, so they sometimes trap prey between rocks and/or roots. The tree root acts to anchor the dead prey while the crocodile eats its meal. Some people have attributed the crocodiles' use of stones and roots as using tools.
From the "Animal Diversity Web Site" at the University of Michigan's Museum of Zoology.
16. An animal communicates for a variety of reasons: defense (to signal approaching danger to other members of its species), food gathering (to alert other members to a food source), courtship and mating (to alert members of its desirability and to warn potential competitors away), and maintenance of territory. The basic motivation for communication is survival of the species. Some animals use communication not only for survival, but also to express emotion.
There are many fascinating examples of animal communication:
- A female tree frog found in Malaysia uses its toes to tap on vegetation, alerting potential mates to her availability. Lori Oliwenstein, Fenella Saunders, and Rachel Preiser, "Animals 1995." Discover 17, no. 1 (January 1996): 5457.
- Male meadow voles (a small rodent) groom themselves in order to
produce body odors that will attract their mates. Tina Adler, "Voles Appreciate the Value of Good Grooming." Science News 149, no. 16 (April 20, 1996): 247.
- Whales communicate through a series of calls and cries. Mark Higgins, "Deep Sea Dialogue." Nature Canada 26, no. 3 (Summer 1997): 2934.
- Primates, of course, vocalize to communicate a variety of messages. One group of researchers studied capuchin monkeys, squirrel monkeys, and golden-lion tamarins in Central and South America. Often these animals are unable to see each other through the forest, so they developed a series of calls or trills that would alert members to move toward food sources. Bruce Bower, "Monkeys Sound Off, Move Out." Science News 149, no. 17 (April 27, 1996): 269.
17. Washoe and Koko (male and female gorillas, respectively) are credited with acquiring American Sign Language (ASL). They are the most famous of the communicating primates. Viki, a chimpanzee, was taught to vocalize three words (mama, papa, and cup). Lana and Kanzi (female chimpanzees) were taught to press buttons with symbols.
Steven Pinker reflects upon researchers' claims that apes fully comprehend sign language. In The Language Instinct: How the Mind Creates Language (New York: Morrow, 1994), he notes that the apes learned a very crude form of ASL, not the full nuances of this language. The signs they learned were crude mimics of the "real thing." In addition, according to Pinker, the researchers often misinterpreted apes' hand motions as actual signs. One researcher on Washoe's team who was deaf noted that other researchers would keep a log of long lists of signs, whereas the deaf researcher's log was short.
18. David E. Kalish. "Chip Makers and U.S. Unveil Project." New York Times, September 12, 1997.
20. For additional views on the future of computer capacity, see: Hans Moravec, Mind Children: The Future of Robot and Human Intelligence (Cambridge, MA: Harvard University Press, 1988); and "An Interview with David Waltz, Vice President, Computer Science Research, NEC Research Institute" at Think Quest's web page. I also discuss this subject in my book The Age of Intelligent Machines (Cambridge, MA: MIT Press, 1990), 401419. These three sources discuss the exponential growth of computing.
21. A mathematical theory concerning the difference between information and noise and the ability of a communications channel to carry information.
22. The Santa Fe Institute has played a pioneering role in developing concepts and technology related to complexity and emergent systems. One of the principal developers of paradigms associated with chaos and complexity has been Stuart Kauffman. Kauffman's At Home in the Universe: The Search for the Laws of Self-Organization and Complexity (Oxford: Oxford University Press, 1995) looks "at the forces for order that lie at the edge of chaos" (from the card catalog description).
In his book Evolution of Complexity by Means of Natural Selection (Princeton, NJ: Princeton University Press, 1988), John Tyler Bonner asks the question: "How is it that an egg turns into an elaborate adult? How is it that a bacterium, given many millions of years, could have evolved into an elephant?"
John Holland is another leading thinker from the Sante Fe Institute in the emerging field of complexity. His book Hidden Order: How Adaptation Builds Complexity (Reading, MA: Addison-Wesley, 1996) presents a series of lectures that Holland presented at the Santa Fe Institute in 1994.
Also see John H. Holland, Emergence: From Chaos to Order (Reading, MA: Addison-Wesley, 1998) and M. Mitchell Waldrop, Complexity: The Emerging Science at the Edge of Order and Chaos (New York: Simon and Schuster, 1992).