Is there really a space where excessive negative ions exist?
In fact, it is a common phenomena that charge can be unequal, i.e. excessive negative or positive ions can exist. Metal wire will be highly charged if it is stretched in air. This implies that charge in air is not neutralized perfectly. Thunder is generated because one type of charge is pooled on the bottom of some clouds, and the voltage between the cloud and the ground becomes so high that it finally discharges. Charge phenomena also occur when a bottle with liquid inside is twirled. If the liquid is water, the bottle is not charged because water is a conductive liquid and the charges are neutralized by the current between the bottle and the water. However, if the liquid is not conductive (e.g. oil), then the bottle is charged. This sometimes causes oil tankers to explode. Thus, it is important to prevent oil tanks from becoming charged. Charge phenomena tend to occur whenever substances are rubbed against one another. The claim that “there are many negative ions near waterfalls” is
