Paul Saffo: The Illusion of Scientific Progress

The breathtaking advance of scientific discovery has the unknown on the run. Not so long ago, the Creation was 8,000 years old and Heaven hovered a few thousand miles above our heads. Now Earth is 4.5 billion years old and the observable Universe spans 92 billion light years. Pick any scientific field and the story is the same, with new discoveries—and new life-touching wonders—arriving almost daily. Like Pope, we marvel at how hidden Nature is revealed in scientific light. Our growing c...

 Carl Sagan Summarizes Evolution of Life On Earth

Eventually, many billions of years ago, a molecule was formed that had a remarkable capability. It was able to produce, out of the molecular building blocks of the surrounding waters, a fairly accurate copy of itself. In such a molecular system there is a set of instructions, a molecular code, containing the sequence of building blocks from which the larger molecule is constructed. When, by accident, there is a change in the sequence, the copy is likewise changed. Such a molecular system – ...

 The Pioneer 10 Plaque

On the title page of this chapter is shown the message. It is etched on a 6-inch by 9-inch gold-anodized aluminum plate, attached to the antenna support struts of Pioneer 10. The expected erosion rate in interstellar space is sufficiently small that this message should remain intact for hundreds of millions of years, and probably for a much longer period of time. It is, thus, the artifact of mankind with the longest expected lifetime. The message itself intends to communicate the locale, ep...

 Overcoming Inherited Bias to Live In Peace

In our earliest history, so far as we can tell, individuals held an allegiance toward their immediate tribal group, which may have numbered no more than ten or twenty individuals, all of whom were related by consanguinity. As time went on, the need for cooperative behavior – in the hunting of large animals or large herds, in agriculture, and in the development of cities – forced human beings into larger and larger groups. The group that was identified with, the tribal unit, enlarged at ea...

 How Radiometric Dating Works

Briefly, a radioactive isotope is a kind of atom which decays into a different kind of atom: for example. one called uranium-238 turns into one called lead-206. Because we know how long this takes to happen, we can think of the isotope as a radioactive clock. Radioactive clocks are rather like the water clocks and candle clocks that people used in the days before pendulum clocks were invented. A tank of water with a hole in the bottom will drain at a measurable rate. If the tank was filled at...