Category Archives: Light Rays

The Digital Camera: The Pinhole Camera

Over a period of several months in 2005 and 2006, a half-dozen artists converted a shuttered F-18 aircraft hanger into the largest camera ever made. To darken the hanger the artists used 24,000 square feet of viscuine, 1,300 gallons of foam gap filler, one and a half miles of gorilla tape, and 40 cans of […]

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The Digital Camera: Total Internal Reflection

Snell’s Law enables us to predict the way a light ray will refract — or bend — when it enters a new surrounding with a different refractive index. If the new surrounding has a larger refractive index the ray will bend toward the surface normal; if the new surrounding has a smaller refractive index the ray […]

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The Digital Camera: Snell’s Law of Refraction

In about 140 AD the Greek scientist Claudius Ptolemy compared the direction light traveled in air with the direction it traveled after passing into water, and he recorded his observations in a table that looked something like this: Although Ptolemy presented his results as measurements, historians of science believe he used a mathematical rule to […]

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The Digital Camera: The Principle of Least Time

Imagine you need to move from your current location to a site that is 3 miles to the south and 4 miles to the east. As all crows and most people know, the shortest path between those two locations is a straight line. To determine the length of that straight line, though, we need to […]

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The Digital Camera: Reflection

According to Greek mythology, the goddess Nemesis tricked the handsome hunter Narcissus into falling in love with the beauty of his own reflection. Narcissus did not recognize that his reflection was simply an image, and so he gazed at his own likeness until he died. Carvaggio’s depiction of Narcissus’s fatal gaze at his own reflection. […]

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The Digital Camera: Shadows

In Mark Twain’s Connecticut Yankee in King Arthur’s Court, King Arthur would have burned Hank Morgan to death on a stake if light rays did not travel in straight lines. But when the moon blocked the sun’s rays from reaching Camelot, Hank was spared from the fire and, instead, christened the principal minister to the […]

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The Digital Camera: Light Rays

At around 300 BC the great Greek mathematician Euclid of Alexandria published what we now understand to be an outlandish theory about the geometry of vision. Euclid believed that the eye projected several tiny rays outward in the shape of a cone and used those rays to sense – or “see” – the objects in […]

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