Centuries ago, when Copernicus indicated the heliocentric theory, no one believed him, and think he became crazy. If one lived in that age, he might possibility say Copernicus’ theory seems unrealistic or a misleading image. However, as time goes by, more and more people prone to believe Copernicus is right and realistic.
Hundreds years ago, people thought fly in the sky seems impossible. No one could reach high enough to the moon. However, after Russian launched the first sputnik after WWII. Everyone began to realize that the idea they used to think unrealistic became wrong. People are able to get out of the earth and get in other planets. The possibility is extremely realistic. “Imagination is everything. It is the preview of life's coming attractions. (Einstein). However many people often wrongly regard imagination as “unrealistic”.
If ye seek, ye shall find. If one wants to do something, the first thing he needs to do is to believe in it. Imagination is the orientation of humans’ history. An age exists without the orientation will lose its way and become dead.
