The eccentricity of the Earth's orbit about the Sun is 0.017 and the Earth is at perihelion when it is almost mid-winter in the northern hemisphere. Explain why summer, the time from the spring equinox to the autumnal equinox, is longer than winter, the time from the autumnal to the spring equinox. Estimate the difference between these two times and check your answer by consulting your diary.
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