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Gathering the Team
Published in Volker Knecht, AI for Physics, 2023
Lord Kelvin (1824–1907) and Rudolf Clausius (1822–88) formulated the law of conservation of energy. It is equivalent to the first law of thermodynamics stating the following: the change in the internal energy of a closed system is the heat supplied to the system minus the thermodynamic work done by the system on its surroundings. Kelvin and Clausius also stated the second law of thermodynamics implying that entropy (a measure of disorder) cannot decrease over time. Processes reversible in time (such as fluid flows in a well-designed turbine) are characterized by a constant entropy. In contrast, time-irreversible processes (such as the mixing of gases or fluids) occur along with an increase in entropy. The latter is often referred to as the concept of the arrow of time. Explaining this notion, as well as heat and in general the macroscopic behavior of nature (gases, fluids, or solids) from the behavior of large assemblies of microscopic entities (such as atoms or molecules), Ludwig Boltzmann (1844–1906) and Josiah Willard Gibbs (1839–1903) developed statistical mechanics, as a fundamentally new approach to science.10
Breaks?
Published in Jonathan P. Dowling, Schrödinger’s Web, 2020
It is a bit trickier to extract the second law from the atom point of view and attempts to do so drove Boltzmann mad. At the atomic scale, the equations of motion for ping-pong balls are invariant under time reversal. That is, the equations do not contain an arrow of time. Run a film of atoms moving forward in time, and it looks just as physical as a film of them running backward in time. But the second law contains an arrow of time – heat always flows from hot to cold but never the reverse. If you place a cup of boiling tea on your desk and wait a while, eventually, it becomes the same tepid temperature as your room. Never do you observe that when you place a cup of lukewarm tea on your desk, the tea heats up and starts to boil. That is the second law in a nutshell. Physicists still argue over this arrow of time business and write books about it, but we shall not take that detour here – for that is the road to perdition.13
Entropy
Published in Nicholas Stergiou, Nonlinear Analysis for Human Movement Variability, 2018
Entropy considerations are fundamental to our understanding of emergent properties in complex systems. The equations of classical mechanics, quantum mechanics, and relativity are time invariant, meaning that time could run forward or backward with no apparent consequences. For example, one could watch a video of a ball accelerating as it rolls down a hill, losing potential energy and gaining kinetic energy. If the video was played in reverse, the ball would have an initial high velocity and low potential energy, the ball would appear to slow down as it rolled up the hill, with the expected trade-off between kinetic and potential energy. Both the forward movie and the backward movie would make sense based on the laws of classical mechanics. However, processes that involve significant changes in entropy do not have this time-invariant quality. Mixing is an example of a process that increases the entropy of the system. Watch a video of milk mixing into a cup of coffee and then play the video in reverse. The reverse video does not make sense, because the milk would appear to separate out from the coffee. The second law of thermodynamics says that in an isolated system, the only allowable changes are ones that involve an increase in entropy. The separation of the milk back out of the coffee would involve a decrease in entropy and therefore would not make sense to someone watching the reversed video. Thus, it is entropy that determines the so-called “arrow of time” in physical systems (Kondepudi and Prigogine 1998).
Evaluation of structural formation of granular materials using anisotropy of magnetic susceptibility
Published in Marine Georesources & Geotechnology, 2023
Xueqian Ni, Yupeng Cao, Feng Zhang, Zhao Zhang
The five different sand materials were first dried completely by oven. To obtain uniform samples, the sand of pre-determined weight was divided equally into two parts for depositing in two layers. Then, the sand was dropped into the sample containers in an orderly way with the assistance of a long-necked funnel. The nozzle of the funnel was kept at a certain distance from the sand surface during the deposition process. After stuffing the cube containers, the initial structure was preserved by the impregnation of crystal epoxy resin, which has a low viscosity and disturbs the structure minimally. Finally, lids were placed on top and the tape was used to seal the containers to keep the structure. It is important to mark an arrow in time on the top surface to indicate the deposition direction.
Information exchange, meaning and redundancy generation in anticipatory systems: self-organization of expectations – the case of Covid-19
Published in International Journal of General Systems, 2022
Moving frame represent the arrow of time. Information obtained via informational exchange is processed with communication codes and expectations with respect to future time are generated at a system’s level. These expectations can be considered as redundancy density presenting non-realized but possible options, distributed along time interval, which can, not in all but in some cases, trigger subsequent actions. Here expectations are analytical events (options) and actions are historical events2 which can be observed after some time span with respect to expectations (as if expectations move against the arrow of time and turn into actions). In other words, there is a dynamic of the actions in historical events at the bottom and a dynamic of expectations at the upper level operating reflexively. Expectations are eventually transformed into actions representing new system state.3 The moments of time when expectations turn to actions correspond to the moments when the impulse returns to the origin.
Enhanced data narratives
Published in Journal of Management Analytics, 2021
Judd D. Bradbury, Rosanna E. Guadagno
For the present study, we constructed a Visual Data Narrative in the form of an interactive slide show with multiple frames of data visualization. The interactive slides are presented in a predefined sequence commonly referred to as a stepper in Tableau Storypoints. The categorization is derived from a navigation feature representing an arrow of time that allows the user to advance through data visualization frames, one step at a time. We selected this style of Visual Data Narrative as it is representative of a large cross-section of previous narrative visualization work used by the New York Times, The Guardian, and a number of other mass media publishers (New York Times, 2015; The guardian, 2015). The stepper approach allows the media publisher to check user attention through recorded clicks at particular steps. The interactive slide show with stepper navigation is also the designated style of storytelling represented in the Storypoints functionality in Tableau Software, as well as the Stories functionality in SAP Lumira Software (SAP, 2015; Tableau, 2015). The interactive slide show with stepper navigation is a leading archetype that is representative of Visual Data Narratives (Segel & Heer, 2010).