Broadcast 3970 Dr. Lee Cronin with Bill Gowan as co-host

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The Space Show thanks co-host Bill Gowan for his excellence in writing the summary for this program.

Guests: Dr. Lee Cronin, co-host Bill Gowan; Topics:  Dr. Cronin's work on searching for life in the solar system, the Assembly Theory, what does life do or not do, mathematics and his search, molecular weight, spectrometers, mapping the Tree of Life and more.

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We welcomed back to The Space Show Dr. Lee Cronin, Regius Professor of Chemistry at the University of Glasgow, Scotland.  Our co-host was friend of The Space Show, Bill Gowan.  On a recent show, Pete Worden mentioned the Breakthrough Initiative’s interest in using Lee’s work in molecular complexity and Assembly Theory to search for biomarkers and life on other worlds. Lee noted that since his Space Show visit a year ago, he and his team have advanced Assembly Theory by developing an underpinning theory that explains the properties of life. Lee explained that there is no consensus on the definition of life, but his lab asks the question, “What does life do that non-life does not do?” Life produces complicated objects that can’t arise by chance, and in “high copy numbers.” Then, you just need a “complex object detector.” These complex objects could range from proteins in a cell to smart phones.

Bill clarified that Lee was describing the use of Assembly Theory and that molecular weight as determined by mass spectrometers provide the input for calculating a molecule’s “Assembly Index,” a measure of how many steps it takes to create the molecule from its constituent parts. Lee noted that a recent development is the use of infrared (IR) spectroscopy to determine the best places to put a mass spectrometer.  David asked for an example of a complex molecule. Listen to Lee’s explanation of ATP’s role the cell, psilocybin, and Taxol as treasure troves of evolutionary information. All life on earth exploits such molecules.

Don’t miss the discussion about whether an industrial chemical discovered in the atmosphere of a planet would be evidence for life on that planet and the follow up question as to whether another civilization could have detected life on Earth based on its spectra before the Industrial Revolution. Also listen for Lee’s excitement about the Dragonfly mission to Titan.

Lee described advancements this year as being 1) updates to the theory of complexity and understanding what life is in an informational sense, 2) lab work that is showing the approach is robust despite contaminants and can detect life even better than PCR, and 3) expanding the number of ways they can detect the different number of parts. During this discussion, Lee mentioned the ability to map the tree of life using Assembly Theory vs. genetic or taxonomic approaches. A remarkable development because if we could sample life from another world we could map its tree of life very quickly. Expect a paper on this in 2023. There may well be medical applications from this as well.

Lee spoke briefly about his interactions with Breakthrough. He then responded to a question from David as to where he’d like to search for life in the solar system. Be sure to hear this interesting result. He also addressed whether Assembly Theory could be used to detect sentient life.

Lee explained some of the other work his lab is involved in, including possible commercial applications in medical and visual display fields. Interestingly, this discussion went into the possible need to rewrite some physical laws related to causality. Hear also the response to listener Todd’s question about why it’s so hard to detect these molecules. In response to a question from David, Lee described the kind of researchers that are hired in his lab. Fremont John asked for clarification that a physical sample is required to use the Assembly Index. Yes, and would have to be measured by a mass spectrometer, but Lee is working on a version that could measure the IR reflection from beaming a laser into the atmosphere.

Listen for the answer to Josh’s email question about the role of mathematics in Lee’s work and a discussion of whether “good” or “bad” is more complex. Also hear the answer to Bill’s question about how the Assembly Index was calculated for Scotch whisky. Bill pointed out some of the other work that Lee’s lab is doing in digital chemistry, chemical computers and the commercialization efforts through the company Chemify.

For more information about Lee Cronin’s work, visit the blog post by Dr.Space that provides the link to his site.  Posting it in the summary does not work with messages relating to Lee's site.  If the hyperlink does not work on the blog post, copy and past it into to your browser.     You can reach Lee through his university faculty page or The Space Show.  You can reach Bill through The Space Show.






Lee updates us on his work to detect life different than we know it to be.

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23 Dec 2022 Dr. Lee Cronin, Bill Gowan
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