Homemade Binary Telescope Course Presentation
  A telescope is an optical instrument that uses lenses or mirrors and other optical devices to observe distant objects. It uses refracted light through a lens or reflected light by a concave mirror to enter a small hole and converge into an image, and then passes through an amplifying eyepiece to be seen. It is also known as a "telescope." The first function of a telescope is to amplify the angle of objects in the distance, allowing the human eye to see details with smaller angle distances. The second function of a telescope is to deliver a beam of light that is much thicker than the pupil diameter (up to 8 mm) into the human eye, allowing the observer to see dark and weak objects that they could not see before. In 1608, a Dutch eyeglass merchant named Hans Lippershey accidentally discovered that using two lenses could make it possible to see distant scenery clearly. Inspired by this, he invented the first telescope in human history. Over the past 400 years, the function of the telescope has become more powerful, and the observation distance has become longer. In 1609, the Florentine Galileo Galilei from Italy invented a 40-fold double-lens telescope, which was the first practical telescope to be used in scientific applications.

 A telescope is nothing more than a combination of two tubes, making it a telescope. At the front of the telescope is a lens, the objective lens, which collects light and combines it into a visible image, magnifying it, and then transmits it to the eyepiece, allowing it to enter the field of view. The magnification of the object or scene seen depends on the focal length of the eyepiece. For binocular telescopes, the magnification is generally between 5x and 10x.

The purpose of the experiment is to: 1. Understand the structure and principles of the telescope and the microscope.
 2. Recognize the importance of the application of convex lenses in imaging for human life and social development, and understand the continuous development of technology.





















Experimental Cognition
Lens: A tool used to block external light.

Concave and convex mirrors: The imaging of concave and convex mirrors follows the laws of light reflection: the angle of incidence equals the angle of reflection, and the path of light that is incident along the normal to the reflection point is reflected back along the same path but in the opposite direction.

Experimental steps:
1. Experiment preparation: Recognizing the experimental equipment: condenser, concave and convex lenses.

Experiment Report:
The size of the "field of view" is caused by the size of the eyes. The field of view is not only related to the size of the object, but also related to the distance between the object and the objective lens. Just like a mountain looks very small from a distance, but looks very big when you get close. Although the image formed by the objective lens of the telescope is smaller than the original object, it is very close to our eyes, plus the magnifying effect of the eyepiece, the field of view can become very large.