We cannot see objects directly by their beams of light because light itself is not directly visible to the human eye. In order for us to perceive an object, light must interact with the object and then be reflected, scattered, or emitted from its surface. This reflected or scattered light then enters our eyes and is detected by the light-sensitive cells in the retina, allowing us to perceive the object.
When light falls on an object, several processes occur. Some of the incident light is absorbed by the object, converting its energy into other forms such as heat. The remaining light interacts with the surface of the object, causing it to reflect or scatter in different directions. The reflected or scattered light then travels to our eyes or other optical devices, allowing us to see the object.
For example, when we see a book on a table, light from a light source (such as a lamp) illuminates the book, and some of that light is reflected off the book's surface. The reflected light enters our eyes, and the receptors in our retina detect the light, sending signals to our brain, which then interprets the signals as visual information, allowing us to see the book.
In summary, we cannot directly see objects by their beams of light because light itself is not directly visible. We perceive objects by the light they reflect or scatter, which then enters our eyes and is processed by our visual system.