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Account of the life and works of francesco redi

There were actually two! Francesco Redi was the other. Francesco Redi is famous for his demonstration of the use of controlled experiments and his challenge to the theory of spontaneous generation. Controlled Experiments When a scientist designs an experiment it is important to eliminate as many unknowns as possible.

Francesco Redi and Controlled Experiments

For instance, if one were trying to assess the health effects of a drug on humans, there are many factors which may affect health.

We want to know how many got better or worse specifically from the drug. One solution might be to introduce a control to compare the drug-based tests against some standard case.

In these drug-tests one group is commonly given the drug and another group, the control group, is given a placebo commonly a sugar-pill with no known health effects. The subjects do not know which type of pill they have been given.

Spontaneous generation and Francesco Redi

The drug results from the test group can then be compared against those of the control group and we can get a better idea of which effects result from the drug. This important advance in scientific methods was introduced only 25 years after the death of Galileo and only a few kilometres away from where he lived.

The Francesco Redi Experiment Francesco Redi was able to disprove the theory that maggots could be spontaneously generated from meat using a controlled experiment. Spontaneous generation, the theory that life forms can be generated from inanimate objects, had been around since at least the time of Aristotle.

Francesco took eight jars, placed meat in all the jars, but covered four of the jars with muslin. Maggots developed in the open jars but did not develop in the muslin-covered jars. Today controlled experiments are commonly demanded by scientific journals and are sometimes legally required by regulatory bodies especially for pharmaceuticals.

The image below is taken from Esperienze intorno alla generazione degl' Insetti p. We are taught that Galileo introduced the scientific method while Francesco Redi introduced the controlled experiment. Both beliefs may be simplistic, however. Francesco Redi and Galileo Galilei demonstrated their methods using very simple experiments then explained their procedures in clear and compelling ways.

The Francesco Redi Experiment

This is why both are so important. But scientists before Redi and Galileo had recognized the need to control variables and had described the sequence of steps described in Galileo's experimental method. When Galileo was still a young boy, Giuseppe Moletti, a professor at the University of Padua, conducted a series of experiments on free fall account of the life and works of francesco redi dropping weights in different media see Timeline of Classical Mechanics.

His test with free fall in water and air specified that the balls must be of the same substance, weight and figure in order to remove doubt. Being careful to control for the known variables doesn't guarantee that you will get the correct results.

That is because "you don't know what you don't know". There might be variables that need to be controlled that you don't even know exist. This is why the famous Tower of Pisa experiment actually came up with incorrect results. Many consider the legend of the Tower of Pisa experiment to be a myth see Myth 1. The Tower of Pisa Myth. The experiment did occur. It was conducted by Vincenzio Renieri, a Catholic monk and another University of Pisa professor and not by Galileo as is commonly thought.

Vincenzio was a friend of Galileo's. Like Moletti before him, Renieri, controlled for size when he dropped two balls of the same size one of wood and one of lead. He came up with the wrong results. There was almost 2 metres difference between the heavier and lighter balls when they hit the ground. Galileo described similar results in some of his works. These scientists could not have known that they needed to control for human physiology as well.

This event is presented as evidence for the "the recurring clash between religion and science" see Galileo's Battle for the Heaven's. Francesco Redi's experiences counter this interpretation. Francesco Redi lived a comfortable life in Florence, walking the same streets and working for the same people that Galileo did the Medicis. He died without encountering any problems with the Church. Galileo's use of Italian instead of Latin was supposed to be a problem with the Church.

But with Francesco Redi, it wasn't. Any challenge to Aristotle was supposed to be a problem for the Church. It was Aristotle who proposed life-forms such as maggots spontaneously generated, and it was Redi who proved this false. The Galileo Affair was supposed to have caused the decline of science in Italy. Redi's important advances in the scientific method happened only a short time after the Galileo Affair in Galileo's adopted city.

The life and work of Francesco Redi provides cause to rethink the the Galileo Affair. The Galileo Affair is commonly presented as proof of the conflict between science and the church.

Francesco Redi was defending scientific ideas that were as radical as Galileo's. His experience with the church was completely different. Could Galileo's personality and his personal and professional disagreements with the other scientists of the day explain the difference? And leaving personality aside, Francesco Redi may have had a better argument against Aristotle because he used better methods. Francesco Redi and Controlled Experiments. In this book the protagonist describes an experiment where two balls of exactly the same weight, substance and shape are dropped through 100 paces of water and 100 paces of air.

When the passive participant in the dialogue asks why account of the life and works of francesco redi must be the same weight, substance and shape, the protagonist explains 'To remove causes of doubt'. Shortly after Moletti describes an experiment where two balls, one of twenty pounds of lead, and the other one pound are dropped from a tall tower, and that they both reach the ground at the same time.

He then mentioned that he controlled for size by conducting the experiment with balls of wood of different sizes. Moletti's book is dated at 1576. Donald Miklich who arranged for 51 students to perform repeated drops of balls with different weights then assessed the results.

In 88 percent of the trials the lighter ball preceded the heavier one. This experiment used very specific experimental conditions and since the experimental conditions of the early free fall experiments were not always well described, the experiment might not properly relate to all experiments of the time.