Armchair Science is a Kindle ebook available at Amazon. It contains over 120 short mysteries of science that can be solved from a single observational clue, without the need for experimentation.
Science is not a collection of facts. Science is what facts teach us; what we can learn about our universe, and ourselves, by deductive thinking. From observations of the night sky, made without the aid of telescopes, we can deduce that the universe is expanding, that the universe is not infinitely old, and why black holes exist. Without resorting to experimentation or mathematical analysis, we can deduce that gravity is a curvature in space-time, that the particles that compose light have no mass, that there is a theoretical limit to the number of different elements in the universe, and that the earth is billions of years old. Likewise, simple observations on animals tell us much about the migration of continents, the evolutionary relationships among classes of animals, why the nuclei of cells contain our genetic material, why certain animals are long-lived, why the gestation period of humans is 9 months, and why some diseases are rare and other diseases are common. In “Armchair Science”, the reader is confronted with 129 scientific mysteries, in cosmology, particle physics, chemistry, biology, and medicine. Beginning with simple observations, step-by-step analyses guide the reader toward solutions that are sometimes startling, and always entertaining. “Armchair Science” is written for general readers who are curious about science, and who want to sharpen their deductive skills.
Here is an excerpt from the book:
Clue 49. There are more than a dozen extinct elements, elements that existed on earth, but were transformed into other elements through radioactive decay. The extinct element with the longest half-life is Samarium-146, which has a half-life of 103.5 million years.
Deduction. The earth is at least 4 billion years old.
Resolution. Elements, much like dinosaurs and dodos, can become extinct. They do so by transforming, over time, into other elements. The elements that transform into other elements are all unstable isotopes, capable of emitting alpha, beta, or gamma rays, and yielding so-called daughter isotopes, in the process. The daughter isotopes, which have an atomic weight or an atomic number that is different from the parent isotope, will also decay, until a stable isotope is produced. Every radioactive isotope is an intermediary element, on a transformational journey towards a stable and non-radioactive element.
Let us look at a list of some of the extinct radioactive elements that formerly resided on our planet, arranged in order of decreasing half-life.
Extinct elements Isotope Halflife (Millions of years)
Samarium-146 103.5
Niobium-92 34.7
Iodine-129 15.7
Curium-247 15.65
Lead-205 15.3
Hafnium-182 8.9
Palladium-107 6.5
Mn-53 3.7
Dysprosium-154 3.01
Caesium-135 2.33
Technetium-98 4.23
Iron-60 2.62
Technetium-97 2.6
Gadolinium-150 1.798
Zirconium-93 1.53
Al-26 0.7
Their half-lives fall into a range from about zero up to a little over 103 million years. There are many radioactive elements with half-lives much longer than 103 million years; half-lives of billions and trillions of years are not particularly unusual. The revealing finding is that none of the naturally occurring isotopes with half-lives greater than 103 million years are extinct. What is the significance of the 103 million year half-life cut-off that separates extinct elements from extant elements?
The explanation is simple. The earth formed from space debris that contained various elements, including the unstable elements that became extinct, over time. The earth is not old enough to provide sufficient decay time for radioactive elements that have a half-life exceeding 103 million years. Unstable elements less than 103 million years have slowly diminished to the point where they can no longer be detected. If we could compute the length of time for an element with a half-life of 103 million years to decay to the point that it can no longer be detected, then we would know the age of the earth. As it happens, it takes about 40 half-lives for an element to decay to the point that it can no longer be detected by current monitors. With each half-life being 103 million years, the age of the earth can be no shorter than 40 x 103 or 4.12 billion years.
At this point, the skeptical reader may ask, "If these elements, all having a half-life of less than 103 million years, cannot be found on earth, how could we possibly know that they existed at any time in earth's history?" The answer is simple. Extinct elements, as they decayed, produced characteristic daughter isotopes in the process, and these byproducts of decay are still present on earth. By observing the daughter isotopes, we safely infer the former presence of the extinct parent isotope.
I urge you to read more about this book. There's a good "look inside" of the book at the Amazon store.
- Jules J. Berman, Ph.D., M.D.
tags: deductive science, science mysteries, deductive reasoning, ebook, general science reading, general science book, science puzzles, scientific amusements
