Paul Kriwaczek said this quote

Anyone who has ever watched children amuse themselves will recognize that the scientific and technological face of civilization is precisely the result of play in its purest form. Just as children are constantly exploring, experimenting, testing and trying things out, for no conscious purpose except the sheer enjoyment of the game itself, so pure science and applied technology play with ideas and toy with the principles and substance of the world; all the time wondering ‘just suppose…’ and asking ‘what happens if…?