Held as one of the most highly regarded facts of the scientific community, theories often change with the presentation of new evidence. However, the motivation behind obtaining this new evidence is often overlooked, wrought with political and personal motives guiding the work of scientists, as these scientists are able to make an impact on the rest of the world. Though separated by a century, Louis Pasteur and Rachel Carson offered evidence to solve some of the biggest questions of their time period, with Louis Pasteur effectively concluding the spontaneous generation debate and Rachel Carson promoting awareness of our careless use of DDT and the impact this had on future generations.
By the mid 1800’s, Louis Pasteur was caught up in the spontaneous generation debate after reviewing the contradictory experiments performed by Francesco Redi, John Needham, and Lazarro Spallanzani. Two centuries prior to Pasteur, Redi had argued that spontaneous generation could not occur, supported with experimental evidence. However, only one century prior to Pasteur, John Needham had shown that growth would occur in a flask of sterilized broth, which directly refuted Redi’s claim that spontaneous generation did not occur. Seeing a flaw in Needham’s experiment, Spallanzani repeated the experiment, this time sterilizing the broth and the air present in the flask. Without this source of contamination, the flask remained sterilized, while a similar flask of broth which he left open to the environment began to show signs of growth. In refute of Spallanzani, those who believed in spontaneous generation said that the air carried a necessary “life force” which life may directly come from. One hundred years later, Louis Pasteur joins the debate (1-9 Spontaneous, The Microbial World).
Pasteur set out to put an end to the debate once and for all. Hypothesizing that the air contained living organisms that were falling into the flasks and contaminating them, Pasteur sterilized swan-necked flasks full of broth. Although open to the air, and therefore “life force,” bacteria could not fall into the broth due to the shape of the flask. The resulting solution was free of growth, to which Pasteur proclaims, “I have removed life, for life is the germ and the germ is life” (Regis, 2008). Putting an end to spontaneous generation and giving rise to germ theory, Pasteur definitively refuted the theory of spontaneous generation.
In a similar challenge to widely accepted beliefs, Rachel Carson advocated for the restriction of DDT usage, as she foresaw the outfall of such widespread use of the chemical. An incredible insecticide, DDT became one of the most widely used chemicals in the United States due to its effectiveness as an insecticide. However, DDT had practically no history of usage and therefore the long term effects were unknown at the height of its popularity. In response to the national hype about the benefits of using DDT, Rachel Carson published Silent...