地球が平面で重力が存在しないなら？
Suppose the earth is flat and gravity does not exist, and other physical conditions can be set freely.
In this case, are there any real physical phenomena that cannot be reproduced?
If we assume that the Earth is flat and gravity does not exist, then we are essentially imagining a world that is drastically different from our own. In this hypothetical world, many physical phenomena that we take for granted in our world would not exist, such as the curvature of the Earth, the rotation of the Earth, the tides, and the motions of the planets.
However, there are still some physical phenomena that would exist in this hypothetical world, such as the behavior of light, sound waves, and the laws of thermodynamics. For example, light would still travel in straight lines, and the speed of light would still be constant.
That being said, there are some physical phenomena that may be difficult or impossible to reproduce in this hypothetical world without gravity. For example, the formation of planets and stars, which are largely driven by gravity, would not occur in the same way as they do in our world. Additionally, the behavior of fluids, which is heavily influenced by gravity, would also be quite different.
In summary, while there are still some physical phenomena that would exist in a hypothetical world where the Earth is flat and gravity does not exist, many physical phenomena that we observe in our own world would not be present or would be drastically different.
