the cosmos is incomparably small; our time in it is but a humming-bird’s beat. It would not be too surprising if there are aspects of reality for which we, like dwellers on a tiny desert island, have little knowledge.

One of the greatest learning tools at our disposal is human intuition. Given our peripheral position in the oceans of space, we can use the power of logical deduction to infer much about what lies on distant shores. An outstanding example of the use of human intuition to extend our knowledge far beyond Earth involves the mystery of why the sky is dark at night. By applying some thought to this riddle, there is much we can learn about the universe at large.

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