For my degree in MA Education, I am doing a dissertation on the common misconceptions about science in society.
Here are the correct answers to my survey:
- An astronaut inside a space station is not in zero gravity, though the term is very
common in science fiction and documentaries. If there was no gravity, the space station itself would not be able to stay in orbit. The correct term for the gravity inside the space station is “microgravity.”
The station orbits the Earth because its centripetal force balances the gravitational pull of Earth. As a result, the astronauts inside also do not feel a net force, and appear to be weightless. Even then, the astronauts and the space station are under the force of gravity, still falling towards the Earth at a controlled rate.
2. The Moon is tidally locked to the Earth, which means that we see only one side of the Moon. This is called the “near side” of the Moon. However, the Moon receives light from the Sun, so as it revolves around the Earth and rotates, its entire surface gets light at different times.
3. Plants produce oxygen during photosynthesis, which takes place only during the day. They respire throughout the day and night. Since we learn that plants take in carbon dioxide during the day and oxygen during the night, it is a common assumption that they take in no oxygen during the day. However, the oxygen produced during photosynthesis is of much greater quantity that the oxygen used up for respiration.
4. If the seasons were due to the distance, then the whole Earth should experience winter when the Earth is farthest from the Sun. However, when the Northern hemisphere has its winter, the Southern hemisphere experiences summer. Seasonal changes are due to the tilt of the Earth’s axis. When the Northern hemisphere is tilted towards the Sun, the intensity of solar radiation is high, resulting in summer. At the same time, the Southern hemisphere is tilted away from the Sun.
5. Evolution is not a directed process which results in more advanced organisms. It merely ensures that only the fittest species survive. This means that every species on Earth is currently as adapted to its environment as humans. It is also a misconception that humans are a descendant of monkeys. Humans and other primates (old world monkeys) have a common ancestor. The closest relative to humans are chimpanzees.
6. A bullet shot from a gun is a projectile - it is released with a certain amount of kinetic energy, after which it slows down due to the action of gravity and the drag force (friction between the air and the bullet.
7. Moon phases are because of the angle between the Earth, Sun and Moon, as seen in this picture:
8. A solar eclipse is harmful because of one reason - Sunlight can damage the retina of our eyes. The darkness during an eclipse means that it is possible to look at the Sun without difficulty. This, combined with the fact that the darkness dilates our pupils, means that a lot of light can enter the eyes quickly, damaging the retina.
Sunlight can hamper bacterial growth, but the darkness during a solar eclipse does not lead to any growth other than what occurs in the shade or during the night. There is no additional radiation from the Sun, and our body cannot absorb any more of the radiation than it usually does.
9. The planets in the Solar System all revolve around the Sun at differing rates, so that it is very uncommon for all of them to be in a straight line. This common misconception is a result of Solar System diagrams that show all the planets in a straight line for convenience.
10. Plants are producers, but not all of them produce their own food. For example, Monotropa Uniflora or the ghost plant and Cryptothallus.
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