section_path: Award process/Recognition time lag
section_name: Recognition time lag
paragraph_text: Recognition time lag
  
  Nobel's will provided for prizes to be awarded in recognition of discoveries made "during the preceding year". Early on, the awards usually recognised recent discoveries. However, some of those early discoveries were later discredited. For example, Johannes Fibiger was awarded the 1926 Prize in Physiology or Medicine for his purported discovery of a parasite that caused cancer. To avoid repeating this embarrassment, the awards increasingly recognised scientific discoveries that had withstood the test of time. According to Ralf Pettersson, former chairman of the Nobel Prize Committee for Physiology or Medicine, "the criterion 'the previous year' is interpreted by the Nobel Assembly as the year when the full impact of the discovery has become evident."
  
  The interval between the award and the accomplishment it recognises varies from discipline to discipline. The Literature Prize is typically awarded to recognise a cumulative lifetime body of work rather than a single achievement. The Peace Prize can also be awarded for a lifetime body of work. For example, 2008 laureate Martti Ahtisaari was awarded for his work to resolve international conflicts. However, they can also be awarded for specific recent events. For instance, Kofi Annan was awarded the 2001 Peace Prize just four years after becoming the Secretary-General of the United Nations. Similarly Yasser Arafat, Yitzhak Rabin, and Shimon Peres received the 1994 award, about a year after they successfully concluded the Oslo Accords. A controversy was caused by awarding the 2009 Nobel Peace Prize to Barack Obama during his first year as US president.
  
  Awards for physics, chemistry, and medicine are typically awarded once the achievement has been widely accepted. Sometimes, this takes decades – for example, Subrahmanyan Chandrasekhar shared the 1983 Physics Prize for his 1930s work on stellar structure and evolution. Not all scientists live long enough for their work to be recognised. Some discoveries can never be considered for a prize if their impact is realised after the discoverers have died.