You are observing the young moon through a telescope. Your friend covers the right (from you) half of the telescope

You are observing the young moon through a telescope. Your friend covers the right (from you) half of the telescope lens with a notebook. How will the appearance of the moon change for you?

The appearance of the moon will not change, but the brightness will be halved.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.