Friday, December 6, 2024

"COMIC: Using tools from fields like fluid dynamics to better understand how groups of people move around can improve flow and make large gatherings safer"

Fluid dynamics, very important.

From Knowable Magazine, November 5:

Bustling through the physics of crowds 

Text: We humans spend a lot of time moving in crowds.
Students move through a school hallway with lockers.Fans wearing baseball caps cheer from bleachers at a game. 
https://knowablemagazine.org/docserver/fulltext/human-crowd-dynamics-2-3.gifPanel 4: Many people heading the same direction exit through a wide doorway at a stadium. TEXT: Sometimes we share the same goals: leaving a stadium when the game ends, getting on the subway after work.

A person struggles to move in the opposite direction of everyone around him. TEXT: Sometimes we are at odds: trying to get to an airport gate just as a large group disembarks.Many people calming walking through a doorway with a big clear EXIT sign above it. TEXT: Sometimes it’s necessary to evacuate large groups quickly, without people getting hurt in the process. Good design of exit routes and doorways is literally life-saving.

People in a crowd in front of a stage press against each other and nearby barriers. TEXT: A lack of emergency exits at the 2021 Astroworld Festival in Houston may have led to 10 deaths and hundreds of injuries.People doing different things in a crowd: walking in various directions, standing and talking, rushing, carrying things, pushing strollers, walking dogs. TEXT: Designing safe spaces — that also allow people to move efficiently — is the focus of much of the research into crowd behavior. Social science is key to this work. By the late 20th century, physicists and engineers had developed many tools to understand how people move through public spaces.


A roughly rectangular space seen from above that has several exits and interior structures; five arrows come down from the top, each taking a different path to an exit. TEXT: People may be complicated as individuals, but crowds aren’t random. We move toward exits, avoid obstacles, and look for efficient paths determined by our goals.
Three different people thinking of different goals: an airport gate, a trash can, a bathroom, an exit. TEXT: While social science can reveal how we make decisions based on our own perception and circumstances, physics examines the universal features and collective behaviors, providing analogies from fluids, gases, and particles.

....MUCH MORE

If interested see also:

January 2020
The Trouble With Turbulence
In the introduction to a post on fish and the Little Ice Age last July I mentioned how mind-bendingly complex fluid dynamics can be.

September 2021
Fluid Dynamics (and the filth on your phone)

This is one of those fields of study that are so mind-bogglingly complex that, short of having a supercomputer close to hand, we can only approximate as to the details. See also weather, markets, and any other complex/chaotic system you can think of. So anyone who can get a handle on what is actually going on with this stuff gives a whole 'nother meaning to the concept of smart.

September 2021
Think You're Smart Don'tcha: Figure This Out And Make A Million Bucks

In last week's post "Fluid Dynamics (and the filth on your phone)" I made the assertion "This is one of those fields of study that are so mind-bogglingly complex that....", without supplying any supporting statements or facts.
(in these situations the reader can assume I am relying on the Charlie Munger all-purpose turnaround: "Think about it a little more and you will agree with me because you're smart and I'm right.")

June 2023
Figure This Out And Make A Million Bucks: Now With Penguins
First up, the penguins, from Chalkdust, (A Magazine For The Mathematically Curious)....

June 2023
Follow-up To "Figure This Out And Make A Million Bucks..."
There is a lot more money involved than just the million dollars from the Millennium Prize for understanding fluid dynamics and turbulence. In the climate arena the coupled climate models are still not all that skillful when trying to comprehend the interactions of the sea and the atmosphere, a huge and extraordinarily complex part of the whole picture and not that well understood.

On a much smaller scale, understanding turbulence can be worth hundreds of millions to billions of dollars when siting turbines on a wind farm.....

Figure This Out And Make A Million Bucks: Now With Penguins

...Turbulence, the oldest unsolved problem in physics

The flow of water through a pipe is still in many ways an unsolved problem.
Werner Heisenberg won the 1932 Nobel Prize for helping to found the field of quantum mechanics and developing foundational ideas like the Copenhagen interpretation and the uncertainty principle. The story goes that he once said that, if he were allowed to ask God two questions, they would be, “Why quantum mechanics? And why turbulence?” Supposedly, he was pretty sure God would be able to answer the first question.

The quote may be apocryphal, and there are different versions floating around. Nevertheless, it is true that Heisenberg banged his head against the turbulence problem for several years.

His thesis advisor, Arnold Sommerfeld, assigned the turbulence problem to Heisenberg simply because he thought none of his other students were up to the challenge—and this list of students included future luminaries like Wolfgang Pauli and Hans Bethe. But Heisenberg’s formidable math skills, which allowed him to make bold strides in quantum mechanics, only afforded him a partial and limited success with turbulence.

Some nearly 90 years later, the effort to understand and predict turbulence remains of immense practical importance. Turbulence factors into the design of much of our technology, from airplanes to pipelines, and it factors into predicting important natural phenomena such as the weather. But because our understanding of turbulence over time has stayed largely ad-hoc and limited, the development of technology that interacts significantly with fluid flows has long been forced to be conservative and incremental. If only we became masters of this ubiquitous phenomenon of nature, these technologies might be free to evolve in more imaginative directions.....

Joe Weisenthal and Tracy Alloway: "What Mathematical Models of Herding Cows Can Teach Us About Markets"

And much more seriously:

Before You Go In, Know How You're Getting Out

Which includes "The Fuzzy Logic Of Fleeing For Your Life"