In the 80s the nature of the Latino Diaspora changes again. From Cuba a second wave of refugees to United States – the Mariel exodus – floods Miami . The same decade sees the sudden arrival of hundreds of thousands of Central Americans (Salvadorans, Guatemalans, and Nicaraguans) fleeing death squads and mass murders at home like activist, Carlos Vaquerano. By the early 1990s, a political debate over illegal immigration – has begun. Globalization, empowered by NAFTA, means that as U.S. manufacturers move south, Mexican workers head north in record numbers. A backlash ensues: tightened borders, anti-bilingualism, state laws to declare all illegal immigrants felons. But a sea change is underway: the coalescence of a new phenomenon called Latino American culture-as Latinos spread geographically and make their mark in music, sports, politics, business, and education.

This episode explores the wave theory of light as studied by mankind, noting that light has played an important role in scientific progress, with such early experiments from over 2000 years ago involving the camera obscura by the Chinese philosopher Mozi. Tyson describes the work of the 11th century Arabic scientist Ibn al-Haytham, considered to be one of the first to postulate on the nature of light and optics leading to the concept of the telescope, as well as one of the first researchers to use the scientific method. Tyson proceeds to discuss the nature of light as discovered by mankind. Work by Isaac Newton using diffraction through prisms demonstrated that light was composed of the visible spectrum, while findings of William Herschel in the 19th century showed that light also consisted of infrared rays. Joseph von Fraunhofer would later come to discover that by magnifying the spectrum of visible light, gaps in the spectrum would be observed. These Fraunhofer lines would later be determined to be caused by the absorption of light by electrons in moving between atomic orbitals when it passed through atoms, with each atom having a characteristic signature due to the quantum nature of these orbitals. This since has led to the core of astronomical spectroscopy, allowing astronomers to make observations about the composition of stars, planets, and other stellar features through the spectral lines, as well as observing the motion and expansion of the universe, and the existence of dark matter.

Audrey Hepburn was a film and fashion icon of the twentieth century and one of the most beloved actresses of all time. She enchanted the world with elegance and innocent charm, and portrayed some of the most memorable characters in film. Although she was one of the few actresses to win an Emmy, Tony, Grammy, and Academy Award, Audrey was modest about her talents, often claiming she had no acting technique. She redefined glamour with elfin features and a waif-like figure that inspired timeless designs by Hubert de Givenchy.Raised in the Netherlands during World War II, Audrey never forgot her own struggles during the German occupation and dedicated her later years to helping needy children around the world, becoming an International Goodwill Ambassador for UNICEF and traveling around the world to provide aid. Audrey Hepburn is remembered as a natural talent, a timeless beauty and a great humanitarian.

Michael crosses Iran towards the Caspian Sea. He meets nomads who tell of Alexander's tryst with an Amazon queen, and the living descendants of Alexander's Persian enemies, who have their own tales of `Alexander the Accursed'.

Wood travels through war-torn Afghanistan, crossing the Oxus River into Central Asia and the Silk Road city of Samarkand where, in a drunken brawl, Alexander killed the friend who had previously saved his life.

The final leg takes him from the Khyber Pass through Pakistan to the Punjab, where Alexander's army mutinied and he was forced to return across the Makran Desert to Babylon, where he died at only 32 years of age.