We all intuitively understand what is alive and what is not. Equally intuitively we know that time flows forward and the past is distinct from the future. Yet casting these ideas into a predictive mathematical framework and applying it to understand the unique science of living things has been extraordinarily challenging. We now know that the appropriate language for exploring these questions is the mathematics of chance. In other contexts, such as investment strategies which account for fluctuating stock values, we have had success in using the rules of chance to make profitable predictions. Can we do the same to better understand the laws of life and time?
Key message: In this talk, SFI External Professor Srividya Iyer-Biswas presents different ways that physicists have discovered time over the centuries and demonstrates her group's new research on a cellular clock that could serve as a universal time-keeping mechanism.
Highlights:
1:52 Introduction
5:23 How scientific enterprise has helped achieve progress by predicting and controlling inanimate systems
6:30 How living systems in motion capture our imagination
7:05 What are the laws of life and what is life?
7:30 How a physicist wrote a book on laws of life in 1944 through quantum mechanics
8:16 Galileo, Newton, and the geometry of motion
10:23 Using scaling laws to identifying universal truths
11:30 Indigenous cultures have considered nature of time as a cyclic and arrow-like quality with seasons and phases of the moon.
12:30 Perceptual leaps were influential on how we shape our environment and history.
14:00 Concept of repeatability in experiments vs. statistical experiments that get different results each time
18:03 How nature performs its own statistical experiments and the challenge of using Newton's laws to track the trajectory of individual molecules
19:50 How emergent properties are more than the sum of their parts
20:50 We can build effective theories of probabilities associated with predicted trajectories
23:00 What universal truth could we find from the random process of radioactive decay of the nucleus?
24:58 Can the events of space and time taking place in the boundaries of a living organism be counted with physics and chemistry?
25:25 Laws of life and the laws of time are inextricably linked
27:03 Understanding life as an emergent phenomenon
29:48 The work of Michael Ziller and the high-precision measurements of cellular dynamics, and introducing SChemostat: a new technology between life, time, and chance
32:55 Scaling laws governing stochastic growth and division of cells
34:27 Re-scaling size and time appropriately to reveal the emergence of a cellular unit of time.
36:25 Aging dynamics of individual cells
37:37 How to tell a mother cell from a daughter cell
39:10 How can theory compliment experimentation?
42:04 How is the cellular unit of time slowing down with time?
44:41 Factors that change statistically predictive applying to simple biological mechanisms