Читать книгу Universe: The story of the Universe, from earliest times to our continuing discoveries - Peter Grego - Страница 10

Sunshine and starlight

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Without the stars, the night skies would lose much of their splendour; without the Sun, there would be nobody around to appreciate the stars. The Sun may not be the most important star in the cosmos, but it is critical to the existence of the Earth.

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Cosmic speed limit

Light travels at the staggering speed of around 300,000km per second. The Moon is 1.3 light seconds away and sunlight is around nine minutes old. Light from the nearest stars in our galaxy takes more than four years to reach us, and light from the most distant galaxies is billions of light years old. Nothing in the Universe can travel faster than light.

Universe: The story of the Universe, from earliest times to our continuing discoveries

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