Physics of Life

Event Date:
2024-07-11T16:00:00
2024-07-11T17:00:00
Event Location:
Hennings 201
Speaker:
William Bialek, Princeton University
Related Upcoming Events:
Public Events
Intended Audience:
Undergraduate
Local Contact:

Sabrina Leslie (sabrina.leslie@msl.ubc.ca) and Steve Plotkin (steve@phas.ubc.ca)

Event Information:

~this talk is hosted by Sabrina Leslie and Steve Plotkin as an event connected to the Frontiers in Biophysics Conference on July 12 2024 at the downtown SFU campus - all are welcome to attend!~

  • Wed 10 July:  Simon Fraser Physics Colloquium
  • Thu  11 July:  UBC Physics Colloquium

Physics of Life

Physicists have been interested in the phenomena of life for centuries.  During the twentieth century there were many dramatic successes at the interface of physics and biology, often changing the course of biology but leaving physics largely untouched.  Something changed circa 2000, and biological physics emerged fully as a part of physics itself.

In the first part of this talk I will review some of this history, drawing on the recent Decadal Survey of the field organized by the US National Academy of Sciences.  This survey led to the identification of four big questions that organize the physicists’ exploration of the living world. In the second part, I’ll describe work my colleagues and I have done addressing two of these questions. (1) How do macroscopic functions of life emerge from interactions among microscopic constituents?  Here we use ideas from statistical physics to uncover surprisingly precise scaling behaviors in the dynamics of neurons and behavior.  (2) How do living systems represent and process information? Here we use the early events in a developing fly embryo to show how maximizing information subject to physical limits generates successful predictions for system behavior, with no free parameters.  These ideas have a chance of being more general than the examples we have chosen.

Fri 12 July:  Frontiers in Biophysics

Ambitions for theory in the physics of life

Can we have a theoretical physicist’s understanding of life that has the generality we expect in physics yet engages with the myriad details that are characteristic of biology? The improved quality of data on these complex systems demands more ambitious theorizing.  I will provide a brief survey of different approaches, and then focus on the idea that living systems are characterized by the optimization of information flow subject to physical constraints.  This has a long history in the context of neural coding, and more recently my colleagues and I have explored the same idea in genetic networks, using the early events in the fly embryo as an example.  We have uncovered a surprising precision in this system, and shown how optimization principles provide parameter-free predictions for the architecture and dynamics of the relevant genetic networks.  These ideas could be more general, and I’ll speculate on unifying principles.

 

Bio:

I am interested in the interface between physics and biology, broadly interpreted.  A central theme in my research is an appreciation for how well things work in biological systems.  It is, after all, some notion of functional behavior that distinguishes life from inanimate matter, and it is a challenge to quantify this functionality in a language that parallels our characterization of other physical systems.  Strikingly, when we do this (and there are not so many cases where it has been done!), the performance of biological systems often approaches some limits set by basic physical principles. While it is popular to view biological mechanisms as an historical record of evolutionary and developmental compromises, these observations on functional performance point toward a very different view of life as having selected a set of near optimal mechanisms for its most crucial tasks. Even if this view is wrong, it suggests a theoretical physicist's idealization; the construction of this idealization and the attempt to calibrate the performance of real biological systems against this ideal provides a productive route for the interaction of theory and experiment, and in several cases this effort has led to the discovery of new phenomena.  The idea of performance near the physical limits crosses many levels of biological organization, from single molecules to cells to perception and learning in the brain, and I have tried to contribute to this whole range of problems.

 

Learn More:

Add to Calendar 2024-07-11T16:00:00 2024-07-11T17:00:00 Physics of Life Event Information: ~this talk is hosted by Sabrina Leslie and Steve Plotkin as an event connected to the Frontiers in Biophysics Conference on July 12 2024 at the downtown SFU campus - all are welcome to attend!~ Wed 10 July:  Simon Fraser Physics Colloquium Thu  11 July:  UBC Physics Colloquium Physics of Life Physicists have been interested in the phenomena of life for centuries.  During the twentieth century there were many dramatic successes at the interface of physics and biology, often changing the course of biology but leaving physics largely untouched.  Something changed circa 2000, and biological physics emerged fully as a part of physics itself. In the first part of this talk I will review some of this history, drawing on the recent Decadal Survey of the field organized by the US National Academy of Sciences.  This survey led to the identification of four big questions that organize the physicists’ exploration of the living world. In the second part, I’ll describe work my colleagues and I have done addressing two of these questions. (1) How do macroscopic functions of life emerge from interactions among microscopic constituents?  Here we use ideas from statistical physics to uncover surprisingly precise scaling behaviors in the dynamics of neurons and behavior.  (2) How do living systems represent and process information? Here we use the early events in a developing fly embryo to show how maximizing information subject to physical limits generates successful predictions for system behavior, with no free parameters.  These ideas have a chance of being more general than the examples we have chosen. Fri 12 July:  Frontiers in Biophysics Ambitions for theory in the physics of life Can we have a theoretical physicist’s understanding of life that has the generality we expect in physics yet engages with the myriad details that are characteristic of biology? The improved quality of data on these complex systems demands more ambitious theorizing.  I will provide a brief survey of different approaches, and then focus on the idea that living systems are characterized by the optimization of information flow subject to physical constraints.  This has a long history in the context of neural coding, and more recently my colleagues and I have explored the same idea in genetic networks, using the early events in the fly embryo as an example.  We have uncovered a surprising precision in this system, and shown how optimization principles provide parameter-free predictions for the architecture and dynamics of the relevant genetic networks.  These ideas could be more general, and I’ll speculate on unifying principles.   Bio: I am interested in the interface between physics and biology, broadly interpreted.  A central theme in my research is an appreciation for how well things work in biological systems.  It is, after all, some notion of functional behavior that distinguishes life from inanimate matter, and it is a challenge to quantify this functionality in a language that parallels our characterization of other physical systems.  Strikingly, when we do this (and there are not so many cases where it has been done!), the performance of biological systems often approaches some limits set by basic physical principles. While it is popular to view biological mechanisms as an historical record of evolutionary and developmental compromises, these observations on functional performance point toward a very different view of life as having selected a set of near optimal mechanisms for its most crucial tasks. Even if this view is wrong, it suggests a theoretical physicist's idealization; the construction of this idealization and the attempt to calibrate the performance of real biological systems against this ideal provides a productive route for the interaction of theory and experiment, and in several cases this effort has led to the discovery of new phenomena.  The idea of performance near the physical limits crosses many levels of biological organization, from single molecules to cells to perception and learning in the brain, and I have tried to contribute to this whole range of problems.   Learn More: Read his faculty webpage: http://www.princeton.edu/~wbialek/wbialek.html  Find out more about the Frontiers in Biophysics Conference at SFU this year: https://www.frontiers-biophysics.ca/  Event Location: Hennings 201