What was the most important discovery?

Question: What was the most important discovery?
- Keywords:
  discovery,
  important
Asked by anon-244432 to Ondrej, Jordan, Eleanor, Ed, Christine, Alice on 11 Mar 2020. This question was also asked by anon-244771.
- Eleanor Jones answered on 11 Mar 2020:
  
  I’m sure if you talk to 100 different scientists, you would get 100 different answers and very valid arguments for each one. I suppose it depends on how you would define the importance of a discovery, whether it’s the impact a discovery has on the everyday lives of the population or whether it’s the impact a discovery has on furthering our understanding of something or whether even it’s the impact a discovery has at that point in time.
  
  I think the discovery of penicillin, albeit an accidental one, by Sir Alexander Fleming in 1928 was a huge discovery in the context of medicine. It’s the most commonly used antibiotic – imagine living without antibiotics today!
- Edward Banks answered on 11 Mar 2020:
  
  The discovery of electricity is one of the most important to modern life- although you could argue back to the discovery of fire being the start of it all!
- Ondrej Kovanda answered on 14 Mar 2020:
  
  A wheel – a long time ago. The further discoveries are more or less linked to this one. If we agree that new stuff in maths is a also discovery rather than invention (debate as old as mankind), the calculus discovered by Leibniz and Newton proved to be extremely useful.

Question: What was the most important discovery?