This is a book by Marcus Chown, a cosmology consultant for the New Scientist magazine. This is a "For Dummies" kind of book, trying to explain the concepts of quantum theory and the theory of general relativity without mathematics for the common people who did not study Science in college but who are curious to understand the universe we live in.
The title says it all - it is a gentle book without any hard theories and Marcus has a pleasant style of writing and so the book flows interestingly.
More importantly, you are armed to answer some of the toughest questions that children so effortlessly ask and you are left speechless and manage to mumble - "Oh, that is an interesting question. I don't know the answer too. Let us find out." Often I resist the urge to immediately google for the answer and force myself along with my daughter to instead search for it in the relevant book.
One such question is answered in the chapter 'Breathing in Einstein' in this book. If it would take 10 million atoms to span the width of a single full stop how did we ever discover that everything is made of atoms in the first place. A brief of that chapter then for your consumption.
The idea of 'atoms' was first conjured by the Greek philosopher Democritus in about 440 BC, who called the hypothetical building block of all matter atoms from the Greek a-tomos, meaning uncuttable. Since atoms were too smal finding evidence was very difficult. Bernoulli imagined a gas as a collection of billions of atoms in a frenzied motion like a swarm of angry bees. Boyle observed this too. However Robert Brown, a botanist observed in 1827 through a magnifying glass, pollen grains suspended in water, undergoing a curious zig zag motion through the liquid. But he could not solve the mystery which was solved eventually in 1905 by Albert Einstein. Einstein said that the reason for the crazy dance of the pollen grains was that they were under continual machine-gun bombardment by tiny water molecules and devised a mathematical theory to describe Brownian motion.
Then in 1981 the scanning tunnelling microscope - STM was invented by Binnig and Rohrer for which they won the Nobel Prize for Physics. The STM uses a stylus, more like a gramaphone needle charged with electricity, dragging it across the surface of a material and building a picture of the undulations in a computer.
The author says "Their STM images were some of the most remarkable in the history of science, ranking alongside that of Earth rising above the gray desolation of the moon or the sweeping spiral staircase of DNA. Atoms looked like tiny footballs ....."