In the history of scientific instruments, who is credited with inventing the mercury barometer used to measure atmospheric pressure?

Introduction / Context:
A barometer is an instrument used to measure atmospheric pressure, which is important in weather forecasting, physics and aviation. The classic mercury barometer is a simple but powerful device that demonstrates the weight of the air. This question asks which scientist is credited with inventing this instrument and giving the first clear experimental proof of atmospheric pressure.

Given Data / Assumptions:

• The question is about the barometer that measures atmospheric pressure.
• We focus on the original mercury column barometer.
• The options list scientists and inventors from different fields.
• We assume basic awareness of early physics history.

Concept / Approach:
Evangelista Torricelli, an Italian physicist and mathematician, invented the mercury barometer in the seventeenth century. He filled a glass tube with mercury, inverted it in a dish and observed that the column height changed with atmospheric pressure. This experiment provided strong evidence for the existence of air pressure and is considered the birth of barometric measurement. Therefore, Torricelli is the correct answer.

Step-by-Step Solution:
Step 1: Recognise that the barometer is associated with early experimental physics and the study of air pressure. Step 2: Recall that Evangelista Torricelli performed the famous mercury column experiment, giving his name to the unit torr. Step 3: Compare with Edward Teller, known for work on nuclear weapons, and Gustav Tauschek, associated with computing devices, which clearly do not match the barometer story. Step 4: Conclude that Evangelista Torricelli is the scientist who invented the mercury barometer.

Verification / Alternative check:
A useful memory tip is that the pressure unit torr comes from Torricelli name, directly linking him with barometric pressure. Another link is that many physics textbooks describe Torricelli experiment as one of the earliest demonstrations of atmospheric pressure. These consistent references verify that he is the correct answer among the given options.

Why Other Options Are Wrong:

• Charles Xavier Thomas: Known for early mechanical calculating machines, not for inventing the barometer.
• Edward Teller: A physicist associated with thermonuclear weapons research, not atmospheric pressure instruments.
• Gustav Tauschek: Worked on early computing and storage devices, unrelated to barometers.
• Blaise Pascal: Conducted important experiments on pressure and supported Torricelli ideas, but did not invent the barometer itself.

Common Pitfalls:
Students sometimes confuse Pascal and Torricelli because both are linked to pressure. Pascal is famous for Pascal law and the Pascal unit, while Torricelli is directly linked to the barometer and the torr unit. To avoid confusion, keep a clear mental pairing: Torricelli and barometer, Pascal and pressure laws and units.

Final Answer:
The mercury barometer used to measure atmospheric pressure was invented by Evangelista Torricelli.