In an alternate version of the universe, the earth rotates around its axis at the same speed with which it revolves around the sun (ie. 365 of our days for one rotation/r). Think about what this means for the time period of day and night in "alter-Earth". What would be the approximate value of the period of the rhythm that would evolve in most species in this world? a. 365 days b. 182.5 days c. 730 days d. There will be no rhythms based on the light cycle
Answered on
In this alternate universe, if Earth rotates around its axis at the same speed at which it revolves around the Sun, one side of the Earth would constantly face the Sun, while the other side would remain in darkness, similar to how the Moon behaves with respect to the Earth. This means that one rotation is equal to one year. Therefore, any given spot on the planet would experience daylight for about half of the year and nighttime for the other half of the year.
So, the period of day and night would each be approximately half of the Earth's orbital period around the Sun, which is 365 days. This makes the day length and night length 182.5 days each. Given this, most species on "alter-Earth" would likely evolve to have rhythms based on a period of:
b. 182.5 days
These rhythms would correspond to the long periods of daylight and darkness, unlike the 24-hour circadian rhythms found in most species on Earth.