This month, for the first time in history, a probe built by humans left the confines of the solar system for the depths of interstellar space. NASA launched Voyager 1 in September 1977, when Jimmy Carter was president and I had just finished high school.
The era of interstellar travel, up to now the exclusive province of sci-fi, has officially begun.
As part of its labors, the sun, as any other star, pours huge quantities of electrically charged particles into space, most of them electrons and protons. This solar wind, as it is called, is confined to a huge bubble known as the heliosphere.
The outer edge of the bubble, the heliopause, marks the transition region beyond which the sun's influence in the interstellar medium becomes negligible. Voyager 1 just crossed this boundary, roughly 100 times more distant from the sun than we are. Even light takes some 14 hours to travel from there to here.
This remarkable technical feat is also a metaphor for science and for the human spirit.
As a human creation, science represents our effort to keep on pushing the limits of knowledge. With each discovery, we learn a bit more about the world and how we fit in. There is something heroic in this enterprise, which has both a practical value — as scientific discoveries are used in the most diverse ways — and a more mythic dimension.
We are searching together, as a species, for the answers to questions as old as our existence in this planet: questions of origins, of endings, of place and of meaning. We push boundaries so that we can learn more about who we are as a species and as individuals.
As wrote T.S. Eliot: "Only those who risk going too far can possibly find out how far one can go." It is hard to think of a more apt description of our effort to understand the cosmos through science.
This is how science moves, no doubt. But it is also how I try to live my life. It is a cry against conformism, against the sameness of everyday routine.
In science, the new is imperative: We need to invent a little bit more of the world every day, given that we don't know what's out there beyond what we know.
Of course, scientists don't have the same freedoms as a painter or a composer, given that we are bound to describe the world as it is, at least as we perceive it through our senses and the tools we use to augment them. We want to describe nature, figure out how it works. And nature always has the last word, even if it often forces us to toss away ideas we find beautiful.
It is in the stars out there, or better, in the planets and moons surrounding them, that other beings could exist, perhaps even thinking beings. Voyager 1 carries with it a gold-plated disk filled with sounds and images of our planet, our animals, our culture. The disk was Carl Sagan's idea; he wanted to announce to our potential neighbors that they are not alone in space.
Although the chances of an alien civilization finding the tiny probe are extremely remote at best (it will be more than 50,000 years before Voyager reaches the nearest star system), the gesture was essentially symbolic: It reflects our hope that we are not alone in the cosmos, that other thinking beings do exist, preferably lovers of life and creativity.