Notes: Gregory Neil Derry: What Science Is And How It Works:

Heart of science is in its methods of investigation and ways of thinking, not in specific facts and results. Observations must be put in a general framework to be understood; science tries to provide a coherent understanding of the real world. Meringues should be beaten in a copper bowl, because of formation of stable conalbumen/copper complexes.

Types of discoveries:
1.) Serendipidy and Methodical Works: Serendipidy = discovering something that you are not looking for. Wilhelm Conrad Röntgen discovered X-rays by accident [1895]; also found that bones absorb the rays better than other tissues; --> medical applications; [However, Derry does not mention that Nicola Tesla had already lectured three years earlier, in 1892, about a 'very special radiation' that he used to create 'shadowgraph' pictures, before his lab was destroyed in a fire. See Margaret Cheney: Tesla: Master of Lightning, p. 75]

2.) Detailed Background and Dreamlike Vision: Friedrich August Kekulé claimed to have found the solution to the structue of benzene in a dream, after a prolonged period of apparently fruitless concentration on the problem.

3.) Idealized Models and Mathematical Calculations: Understanding semiconductor behavior, assuming energy bands separated by band gaps in solids; discovered by several people between 1928 and 1931. Attempting to explain how electrons can travel through metals. According to calculations before 1928, electrons should not get father than 1-2 positive ions, but experiments showed that they can pass hundreds of ions.
a.) Felix Bloch applied principles of quantum mechanics, where electron is a wave rather than a particle. Also assumed that ions are arranged in periodic lettice. The new calculations agreed with experiments (i.e., high conductivity); resistance was only due to vibrations of ions, and imperfections in the crystal.
b.) Then, Rudolph Peierls varied the strength of forces between ions and electrons. 'Flattening' of the energy curves of electrons, i.e., leads to energy zones where no electron states at all can exists (gaps), followed by another, higher band of 'allowed' energy states and so forth.
c.) Alan Wilson (1931): If a band is 'full' (all possible states occupied by electrons) then no electron can gain energy, because that would put the electron in a gap. Solids with full energy bands are insulators, solids with partly empty bands are metals (conductors). Semiconductors (e.g. silicon) become better conductors at higher temperatures instead of worse (like metals): they are solids with full bands, but with rather small band gaps; thermal activation allows transition to band above the gap.

4.) Exploration and Observation: Alexander von Humboldt [1769-1859]. Biogeography of ecosystems. Humboldt was a versatile 'natural scientist': astronomy, botany, geology, geophysics, meterology, oceanography etc. Climbed mountains and found dramatic changes in vegetation and animal life in different elevations; developed theory of biogeography, i.e. how physical conditions determine inhabitance of a place.

5.) Hypothetico-Deductive Method: Edward Jenner. Smallpox vaccine (1796). It was publicly known that infection with cowpox can protect from contracting the more severe smallpox. Almost one third of all children under age three in Britain succumbed to smallpox (the Red Death); disease sometimes raged in terrible epidemics; victims either died, or were left horribly disfigured, blinded and insane. Jenner extracted cowpox material from a pustle on the hands of a milk maid (particular type of the disease was necessary!), and administered it to a young boy, before infecting him with live small pox! The boy did not develop any smallpox symptoms.