The Universe — Did It Come About by Chance? |
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"EVERY object in the Universe, even the most distant star, is made of atoms," explains The Encyclopedia of Stars & Atoms. Individual atoms are too small to see, but packed together they make up familiar chemical elements. Some of these elements are solids that we can see; others are invisible gases. Can the existence of all such chemical elements be explained by chance? Elements 1 to 92Though hydrogen is the simplest of all atoms, it fuels stars like our sun and is vital for life. An atom of hydrogen has one proton in its nucleus and one electron moving around that nucleus. Other chemical elements, such as carbon, oxygen, gold, and mercury, are made of atoms with many electrons moving around a nucleus of many protons and neutrons. Some 450 years ago, only 12 chemical elements were known. As more were discovered, scientists noticed a natural order to them. And when the elements were placed on a chart in rows and columns, scientists discovered that elements sharing a column had similar characteristics. But there were also gaps in the chart, representing unknown elements. This led Russian scientist Dmitry Mendeleyev to predict the existence of the element with the atomic number 32, germanium, as well as its color, weight, density, and melting point. Mendeleyev's "prediction about other missing elements—gallium and scandium—also turned out to be very accurate," notes the 1995 science textbook Chemistry. In time, scientists predicted the existence of other unknown elements and some of their characteristics. Eventually all the missing elements were discovered. There are no longer any gaps on the chart. The natural order of elements is based on the number of protons in the nucleus of their atoms, starting with element number 1, hydrogen, and continuing to the last element that generally occurs naturally on earth, number 92, uranium. Is this just a coincidence? Consider, too, the rich variety of chemical elements. Gold and mercury are elements with distinctive shining colors. One is a solid, and the other a liquid. Yet, they follow each other as elements 79 and 80. An atom of gold has 79 electrons, 79 protons, and 118 neutrons. An atom of mercury has just one more electron, one more proton, and more or less the same number of neutrons.
Is it just chance that a slight change in the arrangement of atomic particles yields such a rich variety of elements? And what about the forces that hold the atomic particles together? "From its smallest particle to its largest galaxy, everything in the Universe follows rules that are described by the laws of physics," explains The Encyclopedia of Stars & Atoms. Imagine what would happen if one of those rules were to change. For instance, what if an adjustment were made to the force that keeps electrons moving around the nucleus of an atom?
Finely Tuned Physical ForcesConsider the consequences if the electromagnetic force were weakened. "Electrons would no longer be bound to atoms," observes Dr. David Block in his book Star Watch. Just what would that mean? "We would have a universe where no chemical reactions were possible!" he adds. How thankful we can be for the fixed laws that make chemical reactions possible! For example, two atoms of hydrogen combine with one atom of oxygen to form a molecule of precious water. The electromagnetic force is about 100 times weaker than the strong nuclear force that holds together the nucleus of atoms. What would happen if this ratio were changed? "If the relative strengths of the nuclear and electromagnetic forces were to be slightly different then carbon atoms could not exist," explain scientists John Barrow and Frank Tipler. Without carbon, there would be no life. Carbon atoms represent 20 percent of the weight of all living organisms. Also crucial is the strength of the electromagnetic force compared with the force of gravity. "The most minute change in the relative strengths of gravitational and electromagnetic forces," explains New Scientist magazine, "would turn stars like the Sun into blue giants [far too hot for life] or red dwarfs [not hot enough to sustain life]." Another force, the weak nuclear force, controls the speed of nuclear reactions in the sun. "It is just weak enough so that the hydrogen in the sun burns at a slow and steady rate," explains physicist Freeman Dyson. Many other examples could be given to show how our life depends on the delicately balanced laws and conditions found in the universe. Science writer Professor Paul Davies compared these universal laws and conditions to a set of knobs and stated: "It seems as if the different knobs have to be fine-tuned to enormous precision if the universe is to be such that life will flourish." Long before Sir Isaac Newton discovered the law of gravity, the Bible referred to such fixed rules or laws. The man Job was asked: "Did you proclaim the rules that govern the heavens, or determine the laws of nature on earth?" (Job 38:33, The New English Bible) Other humbling questions were, "Where did you happen to be when I founded the earth?" and, "Who set its measurements, in case you know?" (Job 38:4, 5) The following article addresses these questions. |
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What accounts for the fine-tuning of the four physical forces? |
Appeared in Awake! October 8, 2000 |