Blaise Pascal

Blaise Pascal (June 19, 1623–August 19,1662) was a French mathematician, physicist, and religious philosopher. Pascal was a child prodigy, who was educated by his father. Pascal's earliest work was in the natural and applied sciences, where he made important contributions to the construction of mechanical calculators and the study of fluids, and clarified the concepts of pressure and vacuum by expanding the work of Evangelista Torricelli. Pascal also wrote powerfully in defence of the scientific method.

Contributions to the physical sciences

Pascal's work in the fields of the study of fluids (hydrodynamics and hydrostatics) centered on the principles of hydraulic fluids. His inventions include the hydraulic press (using hydraulic pressure to multiply force) and the syringe. By 1646 Pascal had learned of Evangelista Torricelli's experimentation with barometers. Having replicated an experiment which involved placing a tube filled with mercury upside down in a bowl of mercury, Pascal questioned what force kept some mercury in the tube and what filled the space above the mercury in the tube. At the time, most scientists contended that some invisible matter was present there—not a vacuum.

Related Topics:
Hydrodynamics - Hydrostatics - Hydraulic fluids - Syringe - 1646 - Evangelista Torricelli - Barometer - Vacuum

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Following more experimentation in this vein, in 1647 Pascal produced Experiences nouvelles touchant le vide, which detailed basic rules describing to what degree various liquids could be supported by air pressure. It also provided reasons why it was indeed a vacuum above the column of liquid in a barometer tube.

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In 1648 Pascal continued his experiments by having his brother-in-law carry a barometer to higher elevation, confirming that the level of mercury would change, a result which Pascal replicated by carrying a barometer up and down a church tower in Paris. The experiment was hailed throughout Europe as finally establishing the principle and value of the barometer.

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In the face of criticism that some invisible matter existed in Pascal's empty space, Pascal delivered in his reply to Estienne Noel one of the seventeenth century's major statements on the scientific method: "In order to show that a hypothesis is evident, it does not suffice that all the phenomena follow from it; instead, if it leads to something contrary to a single one of the phenomena, that suffices to establish its falsity." His insistence on the existence of the vacuum also led to conflict with a number of other prominent scientists, including Descartes.

Related Topics:
Estienne Noel - Scientific method - Descartes

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