2007-03-23 04:44:45 · 5 answers · asked by --Lost in this world-- 3 in Science & Mathematics ➔ Chemistry
As in creating the measurement of millimetres of mercury.
2007-03-23 04:48:23 · update #1
Well, actually, he has an alibi, and he didn't create mmHg.
The reason is that Evangelista Torricelli lived from 1608 to 1647, and the metric system (the system of measurement that includes millimeters) wasn't invented until 1790. So Torricelli didn't measure anything in millimeters of mercury, because millimeters hadn't been invented yet.
What Torricelli did do (and it's the reason that the unit of air pressure, the torr, is named after him) is to invent the barometer and create the first reasonably good sustained vacuum. He was struck by the fact that a reciprocating water pump (which, though he didn't at first know it, works by suction and partial vacuum) could lift water a distance of only 33 feet. He reasoned that the water wasn't rushing in to fill the vacuum, but was being pushed into the vacuum by some force. That force, he decided, was the pressure of the atmosphere pushing down on the exposed surface of the pond, which must have a force about equal to the weight of 33 vertical feet of water.
How to test this? He couldn't easily construct a 35- or 40- foot long tube in his laboratory, but he figured that mercury was much more dense than water and a short tube of mercury would weigh as much as a long tube of water. (Galileo gave him the idea to use mercury.) He got some mercury, filled a four-foot long tube that was sealed at one end, inverted it, and placed the open end in a bowl of mercury. The mercury in the tube fell, but not all the way out -- about 30 inches of mercury remained. He could readily weigh the 30 inches of mercury and thus calculate the pressure of the atmosphere.
2007-03-23 05:20:41 · answer #1 · answered by Isaac Laquedem 4 · 0⤊ 0⤋
Yes, Torrecelli was the first to measure atmospheric pressure in terms of mm of mercury.
2007-03-23 05:18:56 · answer #2 · answered by Taharqa 3 · 0⤊ 0⤋
No he did not use mm of mercury , but torr is named AFTER him not because of him. The unit is named after Evangelista Torricelli, Italian physicist and mathematician, for his discovery of the principle of the barometer in 1643.
2007-03-23 05:10:46 · answer #3 · answered by The exclamation mark 6 · 0⤊ 0⤋
Yes it's the Torr named after him. And it's Torricelli btw
2007-03-23 04:52:49 · answer #4 · answered by Del Piero 10 7 · 1⤊ 0⤋
Yes. The unit mm Hg is interchangable with the unit Torr, named in his honor.
2007-03-23 04:50:52 · answer #5 · answered by Brian L 7 · 1⤊ 0⤋