What if you could understand Einstein’s theory of Special Relativity without needing a single equation? This book makes one of the most profound scientific ideas of all time accessible to everyone—no maths knowledge required. Using plain language, helpful illustrations, and clear examples, it reveals how time can slow down, lengths can shrink, and even the order in which events happen can depend on who’s watching. Given that time is variable, it shows that therefore mass and energy must be equivalent. When these concepts were published, the old certainties were overthrown and modern physics was born. If you have wished that you could understand what it actually means when you read that E=mc2 then this book is for you.