Why is the shadow under the filament lamp very clear, and the shadow under the tube lamp is not clear?
Under the sun or light, people or other objects can leave their shadows. The shadow is a relatively dark area due to the trajectory of the blocked light.
If you look closely at the shadow’s direction, you will find that, in general, usually the middle part of the shadow is particularly dark, the four sides are slightly gray. The particularly dark in the center of their shadows is called a black shadow, while the gray shaded part around it is called ghosting. Why form shadows and shadows? Black Shadow is a shadow formed by all-filled rays of light, while partially filled light rays form ghosting.
A human is standing under a filament lamp because the light emits a single point. Still, the person’s body obscures a curled filament, the light from the extracted point, but the light from another point is not completely obscured. Thus, the person under the filament lamp’s light immediately produces shadows formed by shadows and shadows. On the other hand, because the filament of the filament lamp can also be considered relatively concentrated, the shadow formed is mainly black. The outline of a gray translucent rim around the black shadow is a shadow. Looking at even the shadow is relatively clear.
If standing under a tube light, the person’s shadow is not as obvious as standing under a filament lamp, looking faint. Because a tube lamp is a long crystal tube or a ring-shaped tube, its luminous area is very large, often that of a filament. Thus, although partially obscuring the ray of light, the body of a person cannot conceal as much light from another part as being reflected. So the resulting shadow is, basically, a shadow, a half dark, a half-light, and seeing a cloud of darkness, even the outline, is difficult to discern.
Based on black and shadow principles, people invented lamps without darkness for surgeons to use when performing surgery, called surgical lamps.
The structure of the operating lamp is not complicated. It has a very large circular lampshade; there are about ten lamp balls arranged in a ring or interlocking shape in the lampshade. There was a mirror-faced bulb in each bulb; on the inside corner of the lower half of the bulb was spread an aluminum layer, which evenly reflected light to soften the entire eye. Thus, all the light balls can light from different angles on the operating table, ensuring adequate light in the surgeon’s field of vision while leaving no shadows. The lamp without shadow is thus named.