Light, Heat and Wind


Image Source: (note: On weather maps, lines of constant pressure are drawn (as in the example, above) which are called “isobars”. These isobars are usually labeled with their pressure value in millibars (mb).)

1.  In 1643, an Italian scientist by the name of Evangelista Torricelli (1608 – 1647) invented the barometer

  • The barometer is a device that enables atmospheric pressure to be measured
  • “Atmospheric pressure is caused by the weight of the atmosphere pushing down on itself and on the surface below it. Pressure is defined as the force acting on an object divided by the area upon which the force is acting.” 1

2.  Torricelli was also the first scientist to provide an explanation for the cause of wind:

  • “Winds are produced by differences of air temperature, & hence density, between two regions of the earth” 2

3.  In short, wind is caused by air flowing from areas of high pressure to those of low pressure

  • Since the Earth rotates, the air doesn’t flow directly from those areas of high pressure to low ones
  • Instead, it is deflected: (1) a bit the right to the right in the Northern Hemisphere and (2) a bit to the left in the Southern Hemisphere
  • In essence, winds flow mostly around the high and low pressure areas 3













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4.  What causes changes in air pressure?

5.  In large part, temperature changes can bring about changes in air pressure (or atmospheric pressure)

6.  As sunlight heats the surface of the Earth, air becomes warmer

  • In warmer air, molecules move farther apart and the air becomes lighter

7.  Since warm air becomes lighter, it will rise

  • As this occurs, the warm air pushes down on the surface of the Earth with decreasing pressure
  • This causes a Low Pressure Area

8.  When the warm air rises, cooler air moves in to fill the vacuum and take its place

  • In cooler air, molecules move closer together (are more dense) and the air becomes heavier

9.  Cooler air sinks because it is heavier than warm air

  • As this occurs, the cold air pushes down on the surface of the Earth with increasing pressure
  • This causes a High Pressure Area 4


“By what way is light diffused, or the east wind scattered over the earth?”  – Job 38: 24


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10.  The Bible seems to associate light (or heat) with the movement of wind in this passage

  • The Hebrew transliteration for the word “light” here is “owr” – it means light of day, morning light or daylight 5
  • The Hebrew transliteration for the word “diffused” here is “chalaq”- it means to divide, distribute or apportion 6

11.  It could very well be that the Scripture is connecting light (and its associated heat) with the movement of wind

  • As the intensity of the heat changes (or is diffused), the result is a temperature change
  • If the temperature changes, wind will come about as a result


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