The discussion centers on identifying the greatest scientist of the 21st century, with a focus on scientific contributions, public education, and relevance in research. Participants debate the merits of various figures, notably Stephen Hawking and the Mythbusters team. While Hawking is recognized for his significant research contributions, some argue he is less effective at engaging the general public compared to the Mythbusters, who are praised for popularizing scientific concepts through entertainment. However, critics of the Mythbusters emphasize that their work lacks the rigor of true scientific research. The conversation also touches on the importance of defining what constitutes a "great physicist," suggesting that contributions to scientific knowledge should be prioritized over popularity or media presence. Overall, the thread highlights the complexity of measuring scientific greatness and the differing values placed on education versus research in the scientific community.