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Chemistry   >   Chemical Complexity as a Sign of Life

What Is Complexity?

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Chemical Complexity as a Sign of Life

In this course, Professor Lee Cronin (University of Glasgow) delves into the topics of complexity, life, the origin of life, detection of life, and the future of life on Earth and in the universe. To begin, we: (i) explore the concept of complexity in relation to the search for extraterrestrial life; and then (ii) discuss the challenges of defining life; (iii) the origin of natural life; and (iv) the detection of natural and artificial life; before finally (v) addressing the future of life on Earth.

What Is Complexity?

In this lecture, Professor Lee Cronin explores the concept of complexity in the search for aliens. He introduces a new understanding of complexity, which he stumbled upon while trying to find extraterrestrial life. Cronin explains that complexity is determined by the number of independent elements in an object. Complexity is not limited to mathematics but also exists in various fields such as language and imagery. Cronin discusses the significance of low symmetry and defects in identifying complexity, using the analogy of a snowflake. He emphasises the ability to compare complexity by identifying common elements in objects, such as counting the features of a cat and a dog in photographs. Complexity plays a crucial role in the search for aliens, as it can indicate the presence of intelligent life. Mathematical techniques such as compression algorithms, asymmetry, and the probability of chance creation are essential in this pursuit. By considering these factors, scientists hope to uncover the secrets of complexity and potentially discover extraterrestrial beings in the vast universe.

Cite this Lecture

APA style

Cronin, L. (2023, July 03). Chemical Complexity as a Sign of Life - What Is Complexity? [Video]. MASSOLIT.

MLA style

Cronin, L. "Chemical Complexity as a Sign of Life – What Is Complexity?." MASSOLIT, uploaded by MASSOLIT, 03 Jul 2023,

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Prof. Lee Cronin

Prof. Lee Cronin

Glasgow University