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Workshop on the Physics of Fine-Tuning: Life in the Universe

REGISTRATION & CONTACT

 

The registration for the 1st Workshop on the Physics of Fine-Tuning: Life in the Universe is free. Click here to register.

For any enquiries regarding this please email Leanne O'Donnell.

 
ORGANISING COMMITTEE
 
Khalil Chamcham
Roger Davies
David Sloan
Joe Silk
Leanne O'Donnell
 
VENUE & DIRECTIONS
 
The workshop will take place in Trinity College on the 3rd of November. Directions can be found in the here.
 
SCHEDULE
14.00-14.10
Welcome
Roger Davies
(University of Oxford)

 

14.10-15.00
Assessing Fine-Tunings in Physics: How Many? How Fine? How Come? [abstract]  [slides]
Bernard Carr
(Queen Mary University of London)
chair:
Roger Davies
15.00-15.50
Contingency, Convergence and Hyper-astronomical Numbers in Biological Evolution [abstract]  [slides]
Ard Louis
(University of Oxford)
chair:
Joe Silk
15.50-16.20 Coffee Break    
16.20-17.10
Possibility Spaces as the Context for Existence of Life in the Universe [abstract]  [slides]
George Ellis
(University of Cape Town)
chair:
David Sloan
17.10-17.40 Round Table Discussion

 

 

 

ABSTRACTS

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Contingency, Convergence and Hyper-astronomical Numbers in Biological Evolution [pdf]
Ard Louis (University of Oxford)
 
Biological sequences scale exponentially with length, so that, for example, the set of all possible combinations of amino acids that make up proteins of the mean length in humans (about 476 amino acids) would weight 10^(500) times the mass of the visible universe. But in spite of the hyper-astronomically vast size of these genetic search spaces, we can observe many examples of convergent evolution, where the very similar solutions are found independently. How can this be? By applying concepts from algorithmic information theory, I will argue that the mapping from genotypes to phenotypes biases the arrival of variation to an exponentially small fraction of all possible phenotypes. Such intrinsic constraints explain many observed patterns in the structure of functional (non-coding) RNA [1], and may provide a novel mechanism for evolutionary convergence that does not rely on natural selection. More generally, basic geometrical properties of genotype-phenotype mappings such as bias and genetic correlations [2] greatly facilitate evolutionary search, in fact, it maybe that life is not possible without them.
 
[1] The structure of the genotype-phenotype map strongly constrains the evolution of non- coding RNA, Kamaludin Dingle, Steffen Schaper, Ard A. Louis http://arxiv.org/abs/1506.05352
[2] Genetic correlations greatly increase mutational robustness and can both reduce and enhance evolvability, Sam F. Greenbury, Steffen Schaper, Sebastian E. Ahnert, Ard A. Louis http://arxiv.org/abs/1505.07821
 
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Possibility Spaces as the Context for the Existence of Life in the Universe [pdf]
George Ellis (University of Cape Town)
 
The deep underlying structures for all that exist are eternal and unchanging possibility spaces. These exist in some abstract Platonic sense: they must be distinguished from our knowledge of them, which is culture bound and changes with time. This epistemic fact does not alter their ontological nature. They come in two major classes: possibility spaces for abstract entities, such as logic, mathematics, and algorithms, and possibility spaces for physical entities, such as electrons, quarks, photons, atoms, molecules, crystals, rocks, planets, stars, and galaxies, as well as for living beings and their components. It is the latter that relate to the anthropic issue. Underlying Waddington’s evolutionary landscapes, which are possibility spaces occurring in given ecological contexts, is a deeper structure of biomolecular possibilities that enable the problematic evolutionary timescale problem to be resolved, as explained by Andreas Wagner in his enlightening book Arrival of the Fittest. The foundational issues regarding the values of the constants of nature and the existence of life do not just involve creation of galaxies, stars, and planets where all the elements for life occur, as usually discussed: they involve why the values of these constants are such as to allow existence of the biological possibility spaces identified by Wagner.
 
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Assessing Fine-Tunings in Physics: How Many? How Fine? How Come? [pdf]
Bernard Carr (Queen Mary University of London)
 

It is often claimed that some fundamental physical constants or parameters associated with the initial conditions of the universe or even the laws of nature themselves are fine-tuned. There are different types of tuning but one is usually referring to prerequisites for some kind of observer. The evidence for this claim comes from a number of unexplained ‘coincidences’ between the constants which are necessary for observers but otherwise unexplained.  If one envisages the values of the relevant constants – or the form of the laws – as occupying some abstract mathematical space, this suggests that our universe must reside in a very small region of that space.  With this interpretation, the strength of the fine-tuning argument then depends on how small the filling factor is for observer-supporting regions. To determine this, we must consider how many parameters are involved in such tunings (the first how) and how precisely they are tuned (the second how). This must partly depend on what the constants are tuned for but this is uncertain since it is unclear what qualifies an observer. Are they tuned for life (in which case we need to fold in our knowledge of biology) or consciousness (in which case we may need to decide some threshold of intelligence) or just complexity of which life and consciousness are incidental features. Or are they tuned for some purely physical characteristic, such as the existence of black holes? Finally we address the scientific or philosophical interpretation of these tunings (the third how). In particular, to what extent do they require a multiverse scenario, in which the mathematical space of constants is associated with a physical space of universes?