Big Questions: Nature of Scientific Inquiry
Mendeleev's Dream (#104)
The story of how Meneleev devised the periodic table of elements. Dmitri Mendeleev revolutionized our understanding of the properties of atoms and created a table that probably adorns every chemistry classroom in the world. The ancient Greeks had the idea that everything was made from one of four elements – fire, water, earth and air. Mendeleev studied everything that was known about the elements and and looked for patterns in their properties. He realized that there were some elements that had not yet been discovered, and that any pattern must allow for these gaps. This breakthrough enabled him to make predictions that turned out to be amazingly accurate and convinced scientists that his periodic table was one of the most powerful tools in modern science. [19 minutes]
This episode has not aired in the past few months on Iowa Public Television.
Series Description: It's a slow painstaking business unlocking the secrets of the universe. But occasionally an inspired individual makes sense out of confusion – and comes up with a theory or invention that changes the world and our understanding of how it works. This series, enthusiastically presented by Adam Hart David, focuses on the lives, works and struggles of scientists who have made these great intellectual leaps.
All Episodes
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Faraday's Famous Inventions (#101)
The story of how Michael Faraday, a self-educated, working-class boy became a world famous scientist. [19 minutes]
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Charles Darwin's Evolution (#102)
Charles Darwin put forward his theory of evolution in 1858, at a time when most people believed in the Creation. Central to the theory is the fact that species change, a notion that was completely contrary to the generally held belief – eloquently argued by William Paley – that all organisms were created by God and are unchangeable. During his famous voyage on the Beagle, Darwin found evidence that species do change over time. But how does this happen? Reading Malthus, Darwin saw how competition between individuals could lead to evolution through a process of natural selection. [19 minutes]
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Mendel and the Gene Splicers (#103)
Mendel's experiments on pea plants showed that characteristics are passed from one generation to the next by some sort of “particles”, which he called "factors” but we know as genes. This idea is in contrast to Darwin's belief that inheritance involved the blending of features with each other, like the mixing of paints. So what are Genes? They are made of DNA, an immensely long, but tightly packed, molecule containing a sequence of organic bases (the genome) for a number of organisms, including humans, has been worked out, and this has led to the possibility of rearranging them into new patterns. This is the basis for genetic engineering. [19 minutes]
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Mendeleev's Dream (#104)
The story of how Meneleev devised the periodic table of elements. Dmitri Mendeleev revolutionized our understanding of the properties of atoms and created a table that probably adorns every chemistry classroom in the world. The ancient Greeks had the idea that everything was made from one of four elements – fire, water, earth and air. Mendeleev studied everything that was known about the elements and and looked for patterns in their properties. He realized that there were some elements that had not yet been discovered, and that any pattern must allow for these gaps. This breakthrough enabled him to make predictions that turned out to be amazingly accurate and convinced scientists that his periodic table was one of the most powerful tools in modern science. [19 minutes]
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Hubble's Expanding Universe (#105)
Edwin Hubble is renowned for determining that there are other galaxies in the Universe beyond the Milky Way, and for observing that the Universe is expanding at a constant rate. He became famous for showing that there are different types of galaxies: spiral, elliptical and irregular. Hubble proved that the Universe was bigger than previously thought by using stars that change regularly in brightness – Cepheid variable stars. Hubble found variable stars in other galaxies much farther away than the Andromeda Galaxy which eventually led to the discovery that the universe is expanding. [19 minutes]