Egyptian mourners carry the coffin of Nobel prize-winning Egyptian-American chemist Ahmed Zewail during the last part of his funeral procession at a cemetery on August 7, 2016 in Cairo's Sixth of October suburb. Zewail, who served as a science and technology advisor to US President Barack Obama, died on August 2, 2016 in the United States at the age of 70. / AFP PHOTO / STRSTR/AFP/Getty Images

Egyptians take pictures with their phones as the coffin of Nobel prize-winning Egyptian-American chemist Ahmed Zewail is carried out of an ambulance at the Sixth of October cemetery for the last part of his funeral procession on August 7, 2016 in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died on August 2, 2016 in the United States at the age of 70. / AFP PHOTO / STRSTR/AFP/Getty Images

A handout picture released on August 7, 2016 by the Egyptian Presidency shows a soldier carriying Egyptian-American chemist Ahmed Zewail's "Order of the Nile" award medal, Egypt's highest state honor, during his official funeral procession in Cairo. Nobel prize-winning chemist Ahmed Zewail received a funeral with military honours attended by Egypt's president and top state officials Sunday in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died Tuesday in the United States. He was 70. / AFP PHOTO / EGYPTIAN PRESIDENCY / HO / = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/HO/ EGYPTIAN PRESIDENCY" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS == HO/AFP/Getty Images

A handout picture released on August 7, 2016 by the Egyptian Presidency shows Egyptian President Abdel Fattah al-Sisi (C) walking with officials and relatives of prize-winning Egyptian-American chemist Ahmed Zewail, during his official funeral procession in Cairo. Nobel prize-winning chemist Ahmed Zewail received a funeral with military honours attended by Egypt's president and top state officials Sunday in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died Tuesday in the United States. He was 70. / AFP PHOTO / EGYPTIAN PRESIDENCY / HO / = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/HO/ EGYPTIAN PRESIDENCY" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS == HO/AFP/Getty Images

A handout picture released by the Egyptian Presidency on August 7, 2016 shows the coffin of nobel prize-winning Egyptian-American chemist Ahmed Zewail draped in an Egyptian flag on a carriage during his military funeral at al-Musher mosque in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died on August 2, 2016 in the United States at the age of 70. / AFP PHOTO / EGYPTIAN PRESIDENCY / HO / === RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / HO / EGYPTIAN PRESIDENCY' - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS ==HO/AFP/Getty Images

A handout picture released by the Egyptian Presidency on August 7, 2016 shows the coffin of nobel prize-winning Egyptian-American chemist Ahmed Zewail draped in an Egyptian flag on a carriage during his military funeral at al-Musher mosque in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died on August 2, 2016 in the United States at the age of 70. / AFP PHOTO / EGYPTIAN PRESIDENCY / HO / === RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / HO / EGYPTIAN PRESIDENCY' - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS ==HO/AFP/Getty Images

A handout picture released on August 7, 2016 by the Egyptian Presidency shows Egyptian President Abdel Fattah al-Sisi (R) paying his condolences to the relatives of prize-winning Egyptian-American chemist Ahmed Zewail, during his official funeral held at al-Musher mosque in Cairo. Nobel prize-winning chemist Ahmed Zewail received a funeral with military honours attended by Egypt's president and top state officials Sunday in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died Tuesday in the United States. He was 70. / AFP PHOTO / EGYPTIAN PRESIDENCY / HO / = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/HO/ EGYPTIAN PRESIDENCY" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS == HO/AFP/Getty Images

A handout picture released on August 7, 2016 by the Egyptian Presidency shows Egyptian President Abdel Fattah al-Sisi (R) paying his condolences to Nabil Zewail, the son of nobel prize-winning Egyptian-American chemist Ahmed Zewail, during his father's official funeral at held al-Musher mosque in Cairo. Nobel prize-winning chemist Ahmed Zewail received a funeral with military honours attended by Egypt's president and top state officials Sunday in Cairo. Zewail, who served as a science and technology advisor to US President Barack Obama, died Tuesday in the United States. He was 70. / AFP PHOTO / EGYPTIAN PRESIDENCY / HO / = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/HO/ EGYPTIAN PRESIDENCY" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS == HO/AFP/Getty Images