Remains of an ancient branch of the Nile River hint at why Egyptians chose to build at Giza. Plus, how a ‘tactical sacrifice’ can save a building from collapse the our pick of the five best science books to read this week. Remains of an ancient branch of the Nile River hint at why Egyptians chose to build at Giza. Plus, how a ‘tactical sacrifice’ can save a building from collapse the our pick of the five best science books to read this week.