Masuda N and Porter M (2021) The Waiting-Time Paradox. Front. Young Minds. 9:582433. doi: 10.3389/frym.2020.582433

Suppose that you are going to school and arrive at a bus stop. How long do you have to wait before the next bus arrives? Surprisingly, it is longer—possibly much longer—than what you might guess from looking at a bus schedule. This phenomenon, which is called the waiting-time paradox, has a purely mathematical origin. In this article, we explore the waiting-time paradox, explain why it occurs, and discuss some of its implications (beyond the possibility of being late for school).

Read the full article at: kids.frontiersin.org

Prieto Curiel R, Patino JE, Duque JC, O’Clery N (2021) The heartbeat of the city. PLoS ONE 16(2): e0246714. https://doi.org/10.1371/journal.pone.0246714 

Human activity is organised around daily and weekly cycles, which should, in turn, dominate all types of social interactions, such as transactions, communications, gatherings and so on. Yet, despite their strategic importance for policing and security, cyclical weekly patterns in crime and road incidents have been unexplored at the city and neighbourhood level. Here we construct a novel method to capture the weekly trace, or “heartbeat” of events and use geotagged data capturing the time and location of more than 200,000 violent crimes and nearly one million crashes in Mexico City. On aggregate, our findings show that the heartbeats of crime and crashes follow a similar pattern. We observe valleys during the night and peaks in the evening, where the intensity during a peak is 7.5 times the intensity of valleys in terms of crime and 12.3 times in terms of road accidents. Although distinct types of events, crimes and crashes reach their respective intensity peak on Friday night and valley on Tuesday morning, the result of a hyper-synchronised society. Next, heartbeats are computed for city neighbourhood ‘tiles’, a division of space within the city based on the distance to Metro and other public transport stations. We find that heartbeats are spatially heterogeneous with some diffusion, so that nearby tiles have similar heartbeats. Tiles are then clustered based on the shape of their heartbeat, e.g., tiles within groups suffer peaks and valleys of crime or crashes at similar times during the week. The clusters found are similar to those based on economic activities. This enables us to anticipate temporal traces of crime and crashes based on local amenities.

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Stephen Wolfram uses modern tools to explore Emil Post’s tag system. Possible states, cycle structure, random walks, number theory, other tag systems and ties to his own work.

Read the full article at: writings.stephenwolfram.com

Miguel García-Valdecasas

Adaptive Behavior

In recent decades, several theories have claimed to explain the teleological causality of organisms as a function of self-organising and self-producing processes. The most widely cited theories of this sort are variations of autopoiesis, originally introduced by Maturana and Varela. More recent modifications of autopoietic theory have focused on system organisation, closure of constraints and autonomy to account for organism teleology. This article argues that the treatment of teleology in autopoiesis and other organisation theories is inconclusive for three reasons: First, non-living self-organising processes like autocatalysis meet the defining features of autopoiesis without being teleological; second, organisational approaches, whether defined in terms of the closure of constraints, self-determination or autonomy, are unable to specify teleological normativity, that is, the individuation of an ultimate beneficiary; third, all self-organised systems produce local order by maximising the throughput of energy and/or material (obeying the maximum entropy production (MEP) principle) and thereby are specifically organised to undermine their own critical boundary conditions. Despite these inadequacies, an alternative approach called teleodynamics accounts for teleology. This theory shows how multiple self-organising processes can be collectively linked so that they counter each other’s MEP principle tendencies to become codependent. Teleodynamics embraces – not ignoring – the difficulties of self-organisation, but reinstates teleology as a radical phase transition distinguishing systems embodying an orientation towards their own beneficial ends from those that lack normative character.

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Experience shapes future foraging decisions in a brainless organism
Jules Smith-Ferguson, Terence C Burnham, Madeleine Beekman

Adaptive Behavior

The ability to change one’s behaviour based on past experience has obvious fitness benefits. Drawing from past experience requires some kind of information storage and retrieval. The acellular slime mould Physarum polycephalum has previously been shown to use stored information about negative stimuli. Here, we repeatedly exposed the slime mould to three stimuli with differing levels of potential risk: light, salt and lavender. We asked if the slime mould would change its foraging behaviour depending on the level of risk. In our experiment, taking risk yielded better food. We consistently selected individuals that made the same foraging decision (accepting risk or avoiding risk) over multiple trials. Hence, the same individuals were tested over a period of time, but only individuals that continued to make the same decision were allowed to continue. Regardless of selection regime, slime moulds in the light became more likely to select the food in the light over time, while those exposed to salt became more salt averse. Lavender had no effect. Our results can cautiously be interpreted as examples of non-associative learning, adding to a growing body of work showing that the absence of a central nervous system is no impediment to possessing sophisticated information processing.

Read the full article at: journals.sagepub.com