Daisyworld's sun begins it life with a diminished luminosity (like all suns) and grows steadily hotter and hotter, producing more and more energy. At the beginning of Daisyworld time, its sun provides 550 W/m2 and by the end of Daisyworld time, its sun gives off 1650 W/m2. A star like our Sun will take something like 10 billion years to run through its life cycle, but we have compressed things a bit in the model so that Daisyworld's sun goes through its life cycle in just 2 billion years -- a real flash in the pan! In the model, the solar luminosity is defined by means of a simple equation for a line that begins at a luminosity of 0.6 and ends at 1.8 after 200 time units (our basic time unit here is 10 million years).

The albedo of Daisyworld is a function of how much of its area is covered by white and black daisies. The albedo of uncovered land is set to 0.5, the land covered by white daisies has an albedo of 0.75, and the land covered by black daisies has an albedo of 0.25. The planetary albedo is calculated in the following manner:

Aplanet = funAun + fwAw + fbAb

where A is the albedo and f is the fraction of the total area of the planet covered or uncovered by different materials. This brings us to the next question -- what controls the area covered by the different daisies.

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