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Sunday 17 January 2016

Light

According to current theory, light did not exist until between 240,000 and 300,000 years after the Big Bang. Since Dark Matter probably existed already, you could say we had dark before light. This confirms the Genesis account. ("And God said, "Let there be light", and there was light.")

Until the 17th century, light was thought to travel instantaneously. Galileo, in 1638, was the first to show otherwise and try to measure its speed.

In 1665, Isaac Newton conducted experiments on the spectrum of light using a glass prism in his room, leading to his discovery of the phenomenon. He also performed self-experiments by placing a blunt needle, known as a bodkin, between his eye and the bone to observe the impact on his vision. These experiments contributed to Newton's understanding of optics and the nature of light.

On November 21, 1676, the Danish astronomer Ole Rømer announced to the Academy of Sciences in Paris the first quantitative measurements of the speed of light. Romer used Io’s eclipse of Jupiter. to calculate it The eclipse occurred ten minutes after the expectation, allowing the speed of light to be estimated at 220,000km/s.

Rømer's view that the velocity of light was finite was not fully accepted until measurements of the so-called aberration of light were made by James Bradley in 1727.

American experimental physicist Robert Millikan disliked Einstein's results about light consisting of particles (photons) and carefully designed experiments to disprove them. He ended up confirming the particle nature of light, earning the 1923 Nobel Prize for Physics for that.

The people of Perth in Australia all turned their lights on at the same time on February 20, 1962 to greet astronaut John Glenn who was orbiting above them in Friendship 7.

Light's speed in a vacuum is about 186,282 miles a second.

Rays of light shine through metal patterns into a railway station

Light doesn't necessarily travel at the speed of light. When travelling through glass its speed slows down to about 124,000 miles a second.

In 1999, Harvard physicist Lene Hau was able to slow down light to 38 miles per hour.

It takes 8 minutes for light to travel from the sun to the earth.

Sunlight can reach a depth of 80 metres in the ocean.

Around 1670 Sir Isaac Newton identified five colors in the light spectrum: red, yellow, green, blue and violet. He added orange and indigo later.

There is no red light 30 feet underwater, so blood appears green.

When light is refracted in raindrops, a rainbow is made. The raindrop acts like a prism and refracts the light until we can see the colors of the spectrum.


Some creatures produce their own lights - bioluminescence. The Brazilian railroad worm has a red light on its head and green ones on its side.

The human body literally emits light (like fireflies do), but 1/1000 times the sensitivity of naked eyes.The light emission is rhythmatic and peaks at 4 pm.

There is a Right to Light law in England. The owner of a building with windows that have received natural daylight for 20 years or more is entitled to forbid any construction or other obstruction that would deprive him or her of that illumination.

The light we currently see from the North Star was actually emitted in the year 1583.

Source Daily Express

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