If you lived on Easter Island, would you really cut down the last mighty tree knowing that would be it? It seems either foolhardy or desperate to knowingly cut down the last of a kind and your last source of timber. So how could it happen?

Jared Diamond, in his book Collapse and article Easter’s End, explains how this situation could happen through a gradual, hardly noticeable decline over many years. Those who remembered the great trees which they used to make rafts, canoes and ships were old or had long since died. The trees seen today may be nothing like the forests and towering trunks of tens or hundreds of years ago.

Gradually trees became fewer, smaller, and less important. By the time the last fruit-bearing adult palm tree was cut, palms had long since ceased to be of economic significance. That left only smaller and smaller palm saplings to clear each year, along with other bushes and treelets. No one would have noticed the felling of the last small palm.

For another perspective, Seth Godin asks who cut down the second-to-last-tree?

Who cut down the last tree?

Apophenia is finding meaning and connections in unrelated things.

This might be faces in pieces of toast, or the man in the moon, or clouds making incredible shapes. Seeking patterns and meaning in random data is something we seem naturally inclined to do.

Also see: narrative bias — how stories feel better than randomness.

Apophenia

The Doppler effect is the change in frequency of a wave as its source moves relative to the observer. The same effect that causes the change in pitch of a siren as it drives past is also used to estimate blood flow with ultrasound, measure the speed of a passing car, and even determine the motion of the stars. Doppler shift-based satellite navigation was also the first operational use of a system that eventually led to GPS.

When a siren or similar approaches I try to imagine the crunching up of the sound waves — the vehicle seemingly chasing after its own sound — and the stretching out of the waves as it heads past and into the distance. At least it makes it less painful on the ears.

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The Doppler Effect