Convert Earth polar radius to caliber Online | Free Length Converter

Earth Polar Radius

The Earth's polar radius is the distance from the center of the Earth to the North or South Pole. It measures the Earth’s radius along its rotational axis.

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  Its value is approximately 6,356.8 kilometers (about 3,949.9 miles).

  
  
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  The Earth is an oblate spheroid, so the polar radius is slightly shorter than the equatorial radius due to the planet's flattening at the poles.

  
  
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  This measurement is crucial for geodesy, understanding Earth’s shape, and satellite navigation.

  
  

Key facts:

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  Polar radius ≈ 6,356.8 km

  
  
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  Smaller than equatorial radius by about 21.3 km

  
  
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  Important for precise Earth modeling and mapping

  
  

The difference between the polar and equatorial radius reflects the Earth’s rotation and its effect on the planet’s shape.

Caliber

Caliber is a term used to describe the internal diameter of a cylindrical object, most commonly the inside diameter of a gun barrel or firearm bore. It is typically measured in inches or millimeters.

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  In firearms, caliber indicates the diameter of the bullet or projectile that can be fired from the barrel (e.g., a .45 caliber means the barrel’s internal diameter is 0.45 inches).

  
  
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  In other contexts, such as engineering or piping, caliber can refer more generally to the diameter or thickness of tubes or cylindrical objects.

  
  

Key points:

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  Caliber = internal diameter of a barrel or tube

  
  
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  Measured in inches or millimeters

  
  
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  Important for firearm specifications and ammunition compatibility

  
  
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  Also used in engineering and manufacturing

  
  

Caliber is crucial for matching ammunition to firearms and for defining performance characteristics like velocity and accuracy.