Numbers are everywhere. You've probably described two equally appealing choices as "six of one, half a dozen of the other", or prayed for a seven on the dice, or celebrated a landmark age like 30 or 50. These integers, the natural counting numbers, may seem unimpressive when stacked up against the awe-inspiring quantities that span the Universe. A number like 3 is tiny compared with, say, 15 billion—the number of light years to the farthest cosmic objects. But it is huge compared with the number of metres it takes to span a proton, about 1 x 10~(-15). The counting numbers also lack the semi-mystical aura of quantities such as the irrational number π (3.14159...) with its infinite string of non-repeating digits, or the enigmatic imaginary number i, the square root of -1.
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机译：数字无处不在。您可能已经将两个同样吸引人的选择描述为“六个，另一个六个，或者在骰子上祈求七个”，或者庆祝具有里程碑意义的年龄（例如30或50）。这些整数（自然计数）当与横跨整个宇宙的令人敬畏的数量相提并论时，可能看起来并不令人印象深刻。与150亿（距离最远的宇宙物体的光年数）相比，像3这样的数字很小。但是，与跨越质子所需的米数相比，它是巨大的，约为1 x 10〜（-15）。计数数字还缺少半神秘的光环，例如无穷大的无重复数字字符串的无理数π（3.14159 ...），或神秘的虚数i，即-1的平方根。
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