[O]ur ability to handle and manipulate fire is… critically dependent on the basic design and dimensions of the human body being close to what they are. Our ability to handle fire is no trivial ability because it was only through the use of fire that technological advance was possible. Through fire came metallurgy and metal tools and eventually chemical knowledge. Because metals are the only natural conductors of electricity, the discovery of electromagnetism and electricity, even the development of computers, are all in the last analysis the result of our ancient conquest of fire.Michael Denton, Nature’s Destiny, p. 242. For more information about the unique properties of human beings to make and use fire, read the book Fire-Maker by Michael Read More ›
The physical design of the human larynx enables us to utilize a much broader range of vowels and consonants than any other mammal, facilitating sophisticated verbal communication of complex ideas. Human speech depends not only on our special cognitive abilities but also on our possessing the appropriate organs to generate complex sound patterns. In fact, modern man’s speech-producing apparatus is quite different from the comparable systems of living nonhuman primates. Nonhuman primates have supralaryngeal vocal tracts in which the larynx exits directly into the oral cavity. In the adult human the larynx exits directly into the pharynx. This confers on man the capacity to generate a far richer phonetic repertoire than that available to a chimpanzee. Many vowels and consonants Read More ›
On our planet, plants utilize the energy of sunlight to manufacture sugars and other essential organic compounds by a process known as photosynthesis. Photosynthesis converts radiant energy from the Sun into a form of stored chemical energy that plants can use. But along the way, photosynthesis also generates an important waste product: oxygen. In other words, the same process that supplies the energy plants need, just happens to also produce a waste product that supplies energy to humans and many other animals. For more information about photosynthesis, and how it makes human life and the life of other organisms possible, view The Privileged Species or read Chapter 6, “The Vital Gases” in Michael Denton’s book Nature’s Destiny.
Most liquids contract as they freeze, making their solid form denser than their liquid form. Unlike virtually every other liquid, however, water expands when it freezes, making frozen water less dense than liquid water. That’s why ice floats. This special property of water helps preserve it in its liquid state. If water acted like most other liquids, oceans and lakes would freeze from the bottom up until there was no liquid left. Most of the Earth would be permanently encased in ice, making life as we know it impossible. The unique way in which water freezes has a special relevance to the continuing existence of large organisms such as human beings. [T]he freezing of water from the top down rather Read More ›
Human beings live on a planet that seems optimized for scientific discovery. Our clear atmosphere and location in the galaxy enable many of the observations that have fueled modern science. [O]ur location within the Galactic Habitable Zone offers the best overall location to be a successful astronomer and cosmologist. Even though we’re near the mid-plane, there’s very little in the way of dust in our neighborhood to absorb light from nearby stars and distant galaxies. We’re far enough from the Galactic center and the disk is flat enough that it doesn’t excessively obscure our view of the distant universe. We have access to a striking diversity of nearby stars and other Galactic structures, as well as a clear view of Read More ›
Highly active organisms like ourselves need oxygen in copious quantities. Surprisingly, an adult human consumes about 250 ml of oxygen each minute at rest and 5,000 ml per minute during vigorous exercise. Such high consumption rates of oxygen can only be satisfied by directly absorbing oxygen from an oxygen-rich atmosphere, at concentrations high enough to allow its rapid and efficient uptake within our lungs… Our current atmosphere contains about 21% oxygen, generating a partial pressure of about 150 mm Hg. Oxygen is needed at this level in order to sustain active metabolism… On the other hand, if atmospheric levels of oxygen rise much above 21%, spontaneous combustion of carbon compounds becomes an increasing danger. The fact that oxygen levels sufficient Read More ›
Water’s “ability to form the basis of biochemistry may well be unique … no other liquid has even a fraction of the favorable attributes of water… life not only has an absolute requirement for a liquid solvent, but… water is by far the most ‘qualified’ solvent to fulfill that role.”— Kevin W. Plaxco and Michael Gross, Astrobiology: A Brief Introduction, pp. 14-17. Water is able to hold in solution an enormous, unequalled range of diverse chemical compounds. Its particularly high dielectric constant is responsible for its ability to dissolve virtually all charged molecules. Its power as a solvent, along with its relative chemical inactivity, confers on water ideal properties to serve as the matrix of living systems… By vital coincidence, Read More ›
Carbon is unique among the elements in the number and variety of the compounds which it can form… it is the basis of all forms of living matter. Moreover, it is the only element which could occupy such a position. We know enough now to be sure that the idea of a world in which silicon should take the place of carbon as the basis of life is impossible.British chemist Nevil Sidgwick, Chemical Elements and Their Compounds, vol. 1, p. 490. For more information about the unique properties of carbon, and how they make human life and the life of other organisms possible, view The Privileged Species or read Chapter 5, “The Fitness of Carbon” in Michael Denton’s book Nature’s Read More ›