An example of a common alternative conception:
The following question was posed on the website 'brainly.com':
"The eccentricity of a perfect circle is zero. Which of these effects would be observed if the eccentricity of Earth's orbit around the Sun were to become zero?"
The site offers a 'community answer' and a version of the answer supposedly 'textbook and expert verified'.
"Community Answer
This answer helped 6035 people
Final answer:
If the eccentricity of Earth's orbit around the sun were to become zero, the orbit would become a perfect circle and there would be no seasons. The distance between the Earth and the Sun would be constant throughout the year.
Explanation:
The eccentricity of a perfect circle is zero. If the eccentricity of Earth's orbit around the sun were to become zero, it would mean that the orbit would become a perfect circle. Currently, Earth's orbit has an eccentricity of approximately 0.017, which means it is slightly elliptical.
With a zero eccentricity, the distance between the Earth and the Sun would be constant throughout the year. This would result in no seasons because the Earth would receive an equal amount of sunlight in all regions. [This seems to ignore the curvature of the Earth if it means the radiation density is constant everywhere.]
Additionally, the orbital speed of Earth would become constant as well, as there would be no variation in the distance traveled. The time taken for the Earth to complete one orbit around the Sun would remain the same." [This seems to imply the time take for one orbit is not constant in an elliptical orbit.]
The main cause of the seasons is the Earth's rotational axis being tilted compared with the plane of its orbit: the Northern hemisphere is tilted towards the Sun during part its Summer, and the Southern hemisphere during its Summer. (If seasons were due to the orbital eccentricity then it would be Summer everywhere at once. The Earth is nearest the Sun in January – when it is Winter in the Norther Hemisphere.)
"Textbook and expert verified
If Earth's orbit were perfectly circular (eccentricity zero), there would be no seasons due to constant distance from the Sun. This would lead to a stable climate and constant orbital speed. Overall, life on Earth would face significant changes without seasonal variations.
If the eccentricity of Earth's orbit around the Sun were to become zero, the shape of the orbit would transform into a perfect circle. This means that the distance between Earth and the Sun would remain constant throughout the year, leading to several notable effects:
- No Seasons: Currently, Earth's slightly elliptical orbit causes differences in distance from the Sun, contributing to seasonal changes. A perfect circular orbit would prevent these variations, resulting in uniform temperatures across the year, eliminating seasonal contrasts.
- Constant Orbital Speed: In a circular orbit, Earth would travel at a constant speed. The variations in speed that occur currently–where Earth moves faster when closer to the Sun (near perihelion) and slower when farther away (near aphelion)–would no longer occur.
- Stable Amount of Solar Energy: With no variation in distance, the amount of solar energy received would be stable. This would have profound implications for climate systems and ecosystems on Earth.
In summary, a zero eccentricity would significantly alter the natural cycles of Earth, impacting not only geology and weather patterns but also the biological rhythms of ecosystems and agriculture."
Again, because the eccentricity is small, there are no major variations in the total solar energy incident on the Earth (except in the rare case of an eclipse). The Earth's tilt is responsible for the variations over the year in a particular place. It is not clear what impact the lack of variations in Solar radiation would have on geology?
It is disappointing seeing such misinformation appearing on a site which claims its answers are verified by textbooks and experts, and which encourages uses to subscribe.
Read about the nature of alternative conceptions
Read about some examples of science misconceptions
Read about historical scientific conceptions
