Secretary of State Hillary Clinton flew to Cairo yesterday for the first official U.S. visit to Egypt since Hosni Mubarak stepped down from power. During the visit, she emphasized the continued support being offered by the Obama administration to the people of Egypt as they transition into a new government. “To the people of Egypt, this moment belongs to you,” Clinton said. “You broke barriers and overcame obstacles to pursue the dream of democracy.” With a controversial constitutional referendum scheduled for this weekend, it is a tumultuous moment for Egyptians who are looking for change. But historian and author of “The Rise and Fall of Ancient Egypt,” Toby Wilkinson says that the ancient history of this North African country might help us understand its future.