• Question: How long does it take for the light from the sun travel to Earth?

    Asked by itch to Allan, Diva, Nathan on 5 Jul 2012.
    • Photo: Allan Pang

      Allan Pang answered on 5 Jul 2012:

      The average distance of sun to earth is 150 million kilometers.

      The speed of light is about 300000 km per seconds

      So, the time for light to reach Earth is:

      Distance over speed of light

      = 150000000 kilometers / 300000 km/s

      = 500 seconds

      = 8 minutes 20 seconds

    • Photo: Diva Amon

      Diva Amon answered on 5 Jul 2012:

      Hey itch,

      Allan’s answer is perfect!
      Did you know though that the light that is currently reaching Earth was generated in the core of the Sun 100,000 years ago? Pretty amazing!
      The intense pressure at the core of the sun causes atoms of hydrogen to fuse and become helium emitting light. The individual particles of light take thousands of years to gradually work their way to the sun’s surface, as they keep being absorbed and re-emitted in random directions, and at slightly lower levels of energy. Once they finally do reach the surface, the light particles zoom away at 300000 km/sec, reaching Earth in about 8 minutes and 26 seconds.

    • Photo: Nathan Langford

      Nathan Langford answered on 5 Jul 2012:

      Do you want to know something wacky?

      From the perspective of the light itself, it takes absolutely no time to travel to the Earth! Einstein’s theory of relativity shows that the closer something travels to the speed of light, the slower time moves. And for something moving at the speed of light, time stands completely still! Of course, nothing is able to travel at the speed of light unless it has no mass, because objects that do have mass get heavier and heavier as you travel closer to the speed of light.

Comments