What is the speed of light?

The highest attainable speed in the universe, the speed of light is enough to make you feel dizzy. Here are some things to be aware of.

Tell yourself that when you look up at the sky in the middle of the day and do you see the sunYou see it as it was 8 minutes ago. why ? Because It takes about that time for our starlight to reach us Thanks to the calculation of the speed of light.

Speed ​​of Light: Definition

According to the scientific definition, the speed of light is a fundamental constant in nature. It is the maximum speed at which any form of energy can spread Universe. First identified by Danish astronomer Ole Romer in 1676 Who measured the time it takes for a light signal to travel from one planet to another. He then estimated that the speed of light was 225,000 km/s. after two years, In 1678, Christian Huygens, Dutch astronomer He repeats the experiment and estimates that the speed of light is about 210,000 km/s. Two hundred years later, the calculations of Leon Foucault and Hippolyte Veseau made it possible for French physicists to get closer to the exact measurement of the speed of light with estimates of about 300,000 km/s.

Finally, it was not until 1983, three hundred years after Romer and Higgins, at the seventeenth General Conference on Weights and Measures (CGPM) The speed of light is defined as 299.792.458 km/s in a vacuum.

speed of light under water

The speed of light under water is not the same as in air. In fact, Light travels more slowly in very dense media such as water. Below the surface the speed of light is about 4/5 of the speed of light in a vacuum, i.e. About 225,000 km / sec.

The speed of light compared to others

It’s hard to imagine what the speed of light represents. It’s too highA particle of light can orbit the Earth about 7.5 times per second. To help you get an idea of ​​what it stands for, here are some comparison items:

• Usain Bolt flashed to 44.72 km/h over 100 m At the 2009 World Championships in Athletics.
• Cheetah Speed ​​can reach 110 km/h.
• The Bugatti Chiron Super Sport 300+ Speed ​​can reach 490 km / h.
• The speed of sound in air is 340 m/s or 1224 km/h.
• Earth turns on itself 1640 km / h.
• X-15 fighter planeUnited States Air Force Holds the aircraft speed record with 7273 km/h. Founded in 1967.
• Respondents travel 1 and 2 subordinate NASA away from the solar system at a specific speed of 61,000 and 54,000 km/h. It’s also the fastest human-built thing.

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