One of the greatest joys of childhood is imagining the mysterious worlds and happenings brought to children through books. We all remember the fairy tales and imaginary adventures planted in our minds by the readings of our loving parents, or our own forays into the mysteries of reading. Many grown children, maybe most, can recall in great detail the goings-on and dialog in books read to them, or in bedtime stories told by parents. These memories enrich their own sense of self, and sometimes give guidance in understanding the events in their lives, and in making major decisions about their future. Most childhood stories are fictional, and often are replete with amazing phenomena that don’t happen in real life. They are fun, to be sure, but not informative when it comes to what is possible. In these books, Dr. Williscroft attempts to enrich children through stories, fictional for now, but non-fiction some day, based on little-known wonders of the universe that ARE real and quite amazing. Children, and most adults, are unaware of many phenomena of the universe that we don’t sense in every-day life, yet are more and more important to us. For example, there is light in “colors” that our eyes can’t see. Everything in the universe is made of tiny, tiny invisible particles that make possible television, computers, nuclear energy, the light of the sun and stars – and, indeed, sometimes can even be hazardous to us and make us sick. Dr. Williscroft bases A Relativity Birthday Present on one of his son’s favorite stories when he was little, on an unseen yet major phenomenon – the Theory of Special Relativity. He hopes to plant the concepts of Special Relativity in your child’s mind, just like tales of fairies are planted by other children’s stories. He hopes that in the future, as your child encounters this and the other subjects of this series in school, the memory of these enchanting tales will bubble to the surface, and your child will readily understand and cherish concepts that otherwise would be perplexing. This is an ingenious experiment that worked for Dr. I genuinely hope that it works for your child, too, and that each new story in this series will enrich your child as much as they did his son. In fact, I sincerely hope that this experiment will prove to be very successful for all children! Dr. Frank Drake Carl Sagan Center for the Study of Life in the Universe SETI Institute, Mountain View, California