One of Carl Sagan's most pertinent messages for humanity

"Those worlds in space are as countless as all the grains of sand on all the beaches of the Earth. Each of those worlds is as real as ours. In every one of them, there's a sucsession of incidence, events, occurences which influence its future. Countless worlds, numberless moments, an immensity of space and time. And our small planet, at this moment, here we face a critical branch-point in the history. What we do with our world, right now, will propagate down through the centuries and powerfully affect the destiny of our descendants. It is well within our power to destroy our civilization, and perhaps our species as well. If we capitulate to superstition, or greed, or stupidty we can plunge our world into a darkness deeper than time between the collapse of classical civilization and the Italian Renaissaince. But, we are also capable of using our compassion and our intelligence, our technology and our wealth, to make an abundant and meaningful life for every inhabitant of this planet. To enhance enormously our understanding of the Universe, and to carry us to the stars." Carl Sagan explains the immensity of space and time. This clip is from Carl Sagan's Cosmos episode 8, "Journeys in Space and Time."