A person in a dark room looking through a window can clearly see a person outside in the daylight, where as the person outside cannot see the person inside. Explain
To the person inside the room, reflected light from the dark room is negligible in intensity compared to the transmitted light from outside. From outside, the reflected outdoor scene dominates. There is very little light coming through the window to the outside, even though about 92% goes through in both directions.
This phenomenon can be explained by the concept of lighting and visual perception.
1. Lighting conditions: The room where the person is located is dark, while outside is daylight. Daylight provides a significant amount of light, which allows objects to be well-illuminated and visible.
2. Visual adaptation: Human eyes go through a process called visual adaptation, where they adjust to the prevailing lighting conditions. When the person is inside the dark room, their eyes adapt to low light levels. As a result, their eyes become more sensitive to light, allowing them to perceive objects even in low light.
3. Reflection and contrast: When the person inside the dark room looks through the window, they can see the person outside because of the contrast between the brighter outdoor lighting and the darker interior. The daylight outside reflects off the person's body, making them visible to the person inside.
4. One-way visibility: Windows are typically constructed with transparent glass, allowing light to pass through. This means that the person inside can see outside because of the incoming light, but the person outside, who is in a well-lit environment, cannot see inside due to the lack of light or contrast within the dark room.
In summary, the person inside the dark room can clearly see the person outside in the daylight because their eyes have adapted to the darkness, and the contrast between the bright outdoor lighting and dark indoor environment allows for clear visibility.
The reason the person in the dark room can see the person outside while remaining unseen is due to a concept known as contrast adaptation or the Purkinje effect. When a person is inside a dark room for an extended period, their eyes adapt to the low light levels, making them more sensitive to seeing objects in low light conditions.
In contrast, the person outside is exposed to the daylight, which provides a much higher level of illumination. Because the person's eyes have adapted to the bright outdoor light, they find it more difficult to perceive objects in darker areas, such as the interior of a dark room.
To explain this phenomenon further, we can look at the human eye's two types of photoreceptor cells: rods and cones. Rods are responsible for vision in low light conditions, while cones are responsible for color vision in bright light. The human eye has a higher density of rods than cones, particularly in the periphery.
When the person in the dark room looks through the window, their rod cells are primarily activated due to the low light levels inside the room. Rod cells are more sensitive to light but not to colors, which is why the person inside can see the person outside.
On the other hand, the person outside, being exposed to the daylight, relies on the cone cells in their eyes. Cone cells are responsible for color vision and work best in bright light conditions. Because the interior of the dark room appears very dark compared to the bright outdoor environment, the cone cells in the person's eyes struggle to adapt quickly enough to perceive the relatively dim interior.
In summary, the person inside the dark room can see the person outside because their eyes have adapted to the low light levels, making them more sensitive to the contrast between the inside and outside environments. Meanwhile, the person outside, adapted to the bright outdoor light, finds it difficult to perceive objects in the relatively dim interior.