Brandon Carter

Brandon Carter is an Australian theoretical physicist who worked at Cambridge and later as a CNRS researcher at Meudon near Paris. Known in physics for his work on black holes in general relativity, he introduced the term 'anthropic principle' in a 1973 lecture, arguing that what we can expect to observe is restricted by the conditions needed for observers to exist. The idea became central to debates over cosmic fine-tuning and observation selection.

Key ideas

• Our location in the universe is privileged to the extent that it must be compatible with our existence as observers.
• The weak anthropic principle treats apparent coincidences in physical constants as selection effects rather than evidence of design.
• A stronger version concerns which universes could contain observers at all.
• Observer self-selection reasoning also underlies the doomsday argument associated with his name.

Major works

• "Global Structure of the Kerr Family of Gravitational Fields" (1968)
• "Large Number Coincidences and the Anthropic Principle in Cosmology" (1974)

In the conversation

• Question What is the anthropic principle, and is it an explanation or a polite way of not explaining? Serkan Aydoğdu · 4 replies