What are some phenomena that were long considered paranormal but were eventually explained by science?

Please ask the moderator to explain the scientific rationale behind the phenomenon of walking in circles, thank you!

In ancient times, there were masters of the I Ching who could make people experience the actual effect of walking in circles within 81 steps, but modern people need to cover a greater distance to achieve the same result. This also creates a \"circular\" effect. I remember that a team spent a lot of money to hollow out a mountain (I can’t recall which one exactly) in order to achieve this effect; however, one has to walk a long distance inside it. Let’s analyze this by looking at the image below. This image shows the excavation work inside the mountain. The protrusion at the bottom represents the starting point; one moves upward along the steps in a clockwise direction. It seems as though one is always going uphill, and indeed that is the case ； Up to the corner in the upper left corner, one is truly going upward, but after passing that corner, there are fewer steps upward; instead, there is more flat ground. It should be noted, however, that this flat ground isn’t truly flat – it’s slightly sloping downward. In other words, the flat stretch is long with a very gentle slope, so it doesn’t feel like one is going downhill. After walking for a while, another upward step appears, so mentally one feels as though they are still moving upward. But due to the long length of the sloping section and the few upward steps later on, in reality one is going downhill, until after completing a circle, one returns to the starting point. Throughout the whole process, since one’s consciousness seems to be moving upward, it’s surprising to realize that one is still at the same level as before; one might even think that something supernatural is at work. The diagram above shows only the principle; in actual caves, it’s very difficult to determine direction. The darkness inside the caves makes it hard to find any references, with the ceiling being the only thing that can serve as a reference point. However, the ceiling itself is modified as well – the ceiling on the downward-sloping platforms also has a slope, and this slope is slightly steeper than that of the platform steps. As a result, even though one is moving downward, the feeling of getting closer to the ceiling creates an illusion that one is actually moving upward. The phenomenon of hitting a wall in our daily lives works on the same principle. Generally, those who experience the phenomenon of seeming to hit a wall are people who lose their ability to think clearly due to psychological issues; combined with poor visibility at night and uneven surfaces, these factors contribute to this \"encounter with a ghost\" scenario. I hope my explanation is clear enough.

“\"Wall-running ghosts\" is the supernatural phenomenon that appears most often in folk legends. By providing scientific explanations for it, it is possible to dispel people’s superstitious beliefs, which helps to spread scientific knowledge and foster a scientific mindset among people. Thank you to the moderator for sharing!

Flying saucer, UFO. During World War II, Germany already possessed the technology to build disc-shaped flying vehicles; I guess what the witnesses saw were German masterpieces