Nuestro planeta y nuestro sistema solar se hallan rodeados por un nuevo mundo oceánico, las profundidades del espacio. Y no es más infranqueable que … - Carl Sagan

Vigorous criticism is more constructive in science than in some other areas of human endeavor because in science there are adequate standards of validity that can be agreed upon by competent practitioners the world over. The objective of such criticism is not to suppress but rather to encourage the advance of new ideas: those that survive a firm skeptical scrutiny have a fighting chance of being right, or at least useful.

Es peligroso y temerario que el ciudadano medio mantenga su ignorancia sobre el calentamiento global, la reducción del ozono, la contaminación del aire, los residuos tóxicos y radiactivos, la lluvia ácida, la erosión del suelo, la deforestación tropical, el crecimiento exponencial de la población.

The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explorations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe our future depends on how well we know this Cosmos in which we float like a mote of dust in the morning sky.