• Question: If light is shining onto something does it add more weight to that object? Even by a billionth of a gram?

    Asked by tosty55 to Aggelos, Andrew, Eileen, Naomi, Shane on 19 Nov 2012.
    • Photo: Shane Bergin

      Shane Bergin answered on 19 Nov 2012:

      light is made of photons – small elementary particles that are massless. so you could irradiate a sample with an infinite number of photons and it would not get heavier.

      Also, if photons had mass, they would not be able to travel at the speed of light (the fastest speed that anything can travel at : 3,000,000,00 meters/second) as they would violate Einstein’s theory of relativity

    • Photo: Andrew Jackson

      Andrew Jackson answered on 19 Nov 2012:

      i bow to shane’s far superior knowledge on this! nice answer shane, and a really really great question. I would have guessed it would, and i would have been wrong!

    • Photo: Eileen Diskin

      Eileen Diskin answered on 20 Nov 2012:

      SUCH a cool question! And I learned something too 🙂

    • Photo: Aggelos Zacharopoulos

      Aggelos Zacharopoulos answered on 21 Nov 2012:

      you would not be able to add weight to an object but how about powering a spaceship using something called “solar pressure” generated by the light and high speed ejected gases from star!

      So if you are in space you can use a “solar sail” which will capture the solar pressure and allow a spaceship inlimited travel similar to a sailing boat from planet to planet!

      Have a look: http://science.nasa.gov/science-news/science-at-nasa/2011/24jan_solarsail/