Light

Radio waves

It is interesting to note that, for example, radio waves have a wavelength that can be compared to large buildings and can reach one kilometer in length. In radio waves, we distinguish between smaller and larger wavelengths, which we know from ordinary life, such as long, medium, short, very short waves (VHF, or Very High Frequency VHF) and ultra-short waves (Ultra High Frequency UHF). Very short radio waves have much smaller wavelengths than long radio waves, but only in comparison to the macro-wave (from kilometers to centimeters). For example, in comparison with light radiation, the difference between long and very short radio waves is negligible. It is also interesting to note that microwave radiation,such as that used in microwave ovens, has wave sizes in several millimeters (0.01m) and therefore does not affect materials at the molecular level.

All objects create shadows that capture at least part of the light. However, light must flow around the object, otherwise the shadow is not created. The shadow is therefore the place behind the object where there is less light than around. Shadows can also be colored if they are created behind an object that permits part of the light and is also colored. Light can vary in intensity. Some light sources provide very little light, others emit very intense light. The more light sources shine on a certain space, the more intense the light in the space is. For this reason, we can see lighter and darker shadows.

Reflection of light

One sees objects because light reflects of them. Since the light travels in a straight line , we cannot see objects that are behind the corner. We can only see an object on which the light is falling, and at the same time the light is reflected in our eye. As all objects on Earth reflect at least part of the light, they are visible to us. If the object were to absorb all the light, it would be invisible to the human eye. Invisible things become objects in the absence of light – in the dark. Even animals that are adapted to the nightlife and use sight for orientation in the environment cannot see anything in the complete absence of light (for example, a cat). However, with low light intensity, these animals can also see objects that no one can see. That is why we are talking about man as an animal adapted to the daily way of life. For this reason, man has a natural respect for darkness from birth.