The physics of invisibility should be so simple. I have written articles on how light bends. Yes, light bends when time and space are bent. It has amazing applications. If you can manipulate gravity, you can bend light. For example, a person is walking on the street. If you can bend light and make a spectrum whereas from his right side, the spectrum bends light and then reaches the left side, he would have no shadow. The book in conclusion provides the story of an invisible planet. Can it be planet 9 of our solar system discussed in detail in Hindu Sciptures thousands of years ago.