(CNN) Vera Rubin, a pioneering astrophysicist who proved the existence of dark matter, had a gift for overcoming daunting challenges. While there were indications going back to the 1930s that dark matter existed, her work confirmed it. If dark matter doesn`t fit that description, I don`t know what does. Her colleagues and those who admired her spirit remember her as someone who revolutionized our understanding of the cosmos by confirming the existence of dark matter, invisible material that comprises more than 90% of the universe. Others worked on the subject of dark matter, and it`s important to remember that in science, each person`s achievements are built on the backs of those who came before.

?The Palestinians wanted peace, without giving up their hatred of Israel. ?And he wanted a Palestinian state inside Israel that would be brought about by a return of Palestinian refugees and their soaring birthrate tomorrow. ?The Israelis wanted peace, while maintaining underlying control of the Palestinians,? he said in 2000. In 1986, Mr. Cohen was the catalyst for the first three clandestine sessions in Paris and Brussels between Israeli and Palestinian representatives, two from each side. Israel was ready to give him one Palestinian state, but not two.