We wish to pursue the truth, no matter where it leads. But to find truth, we need imagination and skepticism both. We will not be afraid to speculate. But we will be careful to distinguish speculation from fact.
银河在上
This library was a citadel of human consciousness, a beacon on our journey to the stars. It was the first true research institute in the history of the world. And what did they study? They studied everything. The entire cosmos. “Cosmos” is a Greek word for the order of the universe. In a way, it’s the opposite of chaos. It implies a deep interconnectedness of all things. The intricate and subtle way that the universe is put together.
2000 年前的亚历山大图书馆（the Library of Alexandria）
Those are some of the things that molecules do, given 4 billion years of evolution. We sometimes represent evolution as the ever-branching ramifications of some original trunk, each branch pruned and clipped by natural selection. Every plant and animal alive today has a history as ancient and illustrious as ours. Humans stand on one branch. But now we affect the future of every branch of this 4-billion-year-old tree.
Human DNA is a coiled ladder, a billion nucleotides long. Many possible combinations of nucleotides are nonsense. That is they translate into proteins which serve no useful function whatever. Only a comparatively few nucleic acid molecules are any good for life forms as complicated as we are. But even so, the number of useful ways of assembling nucleic acids is stupefyingly large. It’s probably larger than the total number of atoms in the universe. This means that the number of possible kinds of human beings is vastly greater than the number of human beings that ever lived. This untapped potential of the human species is immense. There must be ways of putting nucleic acids together which will function far better by any criterion you wish to choose than the hereditary instructions of any human being who has ever lived. Fortunately, we do not know, or at least do not yet know how to assemble alternative sequences of nucleotides to make alternative kinds of human beings. But in the future, we might be able to put nucleotides together in any desired sequence to produce whatever human characteristics we think desirable. A disquieting and awesome prospect.