What life lessons can we learn from Braess's paradox?

it always makes me chuckle when solutions to traffic problems basically end up reinventing some form of public transportation

That spring+string demo blew my mind.

I teach this paradox as an introduction to game theory-on the first day of class, I get the students to recreate it (letting them discover the paradox for themselves, arising out of their own decisions!). It works really well, and it's also a nice way to introduce students to one of the fundamental ideas of game theory, namely, making choices in an environment where other people's choices affect you.

So many hours that I spent on that Chyung-gye highway in my dad’s car when I was a kid due to the everyday route from my school to his work places and home. After the highway gone, the traffic indeed improved. And thanks to this video now I know why!

"No one in New York drove, there was too much traffic" - Fry.

This is probably the most underrated channel. Every video is thought provoking and super well explained.

Your example with the strings and springs and the analogy with the roads was utterly fascinating, such an excellent way to explain the concept.

8:05 Assuming a linear spring constant and perfectly inelastic ropes with equal amounts of slack, the weight will rise if the system satisfies this equation: s < 4.9 * m / k where s is the slack in each rope, m is the mass of the bottle (in kg), and k is the sprint constant

16:26 "your natural state often isn't your most efficient state" with visual lmao. Nice work miss Up and Atom.

For those that might not be convinced this video is about an actual paradox, Braess yourself.

Very good explanation/illustration of Braess’ . (i had not know about the Korean highway) - The practical issue for traffic engineers is that the initial west-east road network made things very arduous for the people traveling north-south. That connector made things very nice for people living at midpoint south the get to midpoint north. Also mention that the illustrated road network was simplex (one-way at any given time - often done on bridges tollways). Kudos to you and roborace for raising awareness!

I absolutely love, love, love your videos!!! Science can sometimes be very confusing to me, but you break it down in easy to digest steps, keep up the wonderful work.

Using the spring/string model is an ingenious way to model this phenomenon! Great work on this vid

The animation is so good! You explain more complicated concepts than any other channel I watch regularly but you do it so well & clearly. I had never heard of Braess. I couldn't tell if the magician's hands were you or a professional, such expert mysterious movements ;p

Educational/informative way to present scientific principles and paradoxes. Plus, you made it fun to watch with graphics, demonstrations, and thought provoking questions. Great channel. Will definitely keep watching more.

I wish I had discovered your channel sooner. Your video's are very brilliant, and you have blown my mind several times. Thank you, and please keep up the good work.

I knew about the phenomenon in traffic but I've never seen a physical example! Very cool!

Kudos for the spring-string anology !

Man, I thought the bottle would stay in place, as the strings and springs compensate for each other. Figured the height of the bottle was immutable equilibrium itself. Fascinating twist! I was never great at STEM but I just found your channel and you make it so digestible. Subbed :3

Smarter every day tweeted your traffic video and now I'm subbed.

The string + spring experiment made me click the notification bell.

Dude! That spring string demo was fascinating!

Fantastic video in so many ways! including great progression from introducing a new concept to demonstrating to current implications! You're terrific. Thanks!

That kind of reminds me of how, in electronics, putting two resistances in parallel gives you an overall resistance that is lower than the lowest of those resistances which sounds counter-intuitive.

"catastrophically terrible consequences" switching to happy face was great

One important thing that we can learn is that one choice that gives us a very small gain, such as saving 2-3 minutes on an hour drive can have a larger impact on more people, such as causing 50 people to lose 5 minutes. Also, even before we are in fully autonomous cars, apps like Waze already use collective intelligence to improve the entire system. Even with a small percentage of driver's acting as a sensor network, Waze is pretty good at predicting slowdown and mitigating it by redirecting drivers to alternate routes. It regularly chooses different routes home from work that have similar times and distances. I've noticed that when I ignore the chosen route and choose the more commonly used high efficiency route, I fairly regularly end up in congestion with all of the other drivers who are also choosing the route that is more efficient at times that there are less travelers. Thank you for this video (and all of your videos!) It is very insightful and you always present things in a very interesting and engaging way!

Found this channel recently and being enjoying content. But gotta admit wasmore excited for a second with this one as read it as the Braless Paradox.

When the video got to the point of disconnecting the two springs you got a new subscriber :) Excellent job (the whole video, not just the springs) of explaining Braess's paradox. It is very subtle and it will take me time to begin seeing its impact on my daily world. As for traffic, I live near Washington DC. One of the worst traffic areas in the US.

@ 10:30 the analogy was amazing and very clear.

Absolutely everything I’ve seen on this channel is absolutely amazing! Keep up the great work!

As always awesome graphics and excellent explanations!

I love your video's! They are so well explained and thought out. Really awesome!

For me, a visceral understanding of this paradox came from looking at the center of the string/spring setup at 9:03 and imagining what would happen if a force pulling the two visible center spring ends towards each other were applied. Once I realized that the lower end of the left spring would have to move down, I could see that the weight at the bottom would be free to move down as well (since the left string would be moving down and, because the situation is symmetrical, the right spring would be stretching as much as the left spring).

That moment when your sponsor promotion is as interesting as the rest of the video

What a beautiful example of strings and springs. Loved it!!! Thank you

Brilliant stuff! Thank you. So nice to come across things like this that you weren't aware of. I've subbed.

Honestly though this Paradox makes me anxious about my life choices lol

Thank you for all the effort you put into your videos!! This was amazing, I learnt so much! 💕

Well that was just brilliant. I loved every moment of this fascinating presentation.

Basically, when you're driving on a road, you become a fluid particle

I think linking the 2 lanes would make sense with ever growing traffic load. After 4500 cars, the equilibrium switches since the fastest route is to take the highway but it's only after 9000 cars that the linked configuration is more interesting than the 2 separate lanes.

I came here from Steve Mould’s very short video on the same subject (made in 2021) and found a great video and new channel to subscribe to. Great vid and I really like the cheery yet quite dark not at the end. Brilliant! 😁

I love your string-spring setup. That is very cool. Right - the non-stretching string is analogous to the fixed-time number-of-car-independent half of the route from A to B, while the stretchy spring is analogous to the time-varies-with-#-cars half of each route. A+!

This is an exceptional educational video-probably the best I've seen on this channel so far! Keep up the great work!

The springs and strings system was amazing. WE ALL LOVE YOU A LITTLE MORE NOW. THanks !!

Well well, good job. Your videos are getting better and better. This was very interesting for a topic I would have never considered as such.

Awesome explanation and practical example! Loved it!

Your videos continue to be some of the best science content on KZfaq. Thank you for sharing your talent for explanations with us.

I come for the science, I stay for the quirky animations.

love love love the video. The sping demo was mind-blowing

omg i love your analogies,brilliant!

Your natural state :DD That was priceless

This was so didatic and well researched (and interesting)! Great job Jade 😉

Fascinating! I didn't want the video to end ... bravissima!

Absolutely love it! Brilliant Video!

That's monkey was so lit. Also such an novel and awesome video. Also the idea of using network theory to road is so compelling and those happen now.

Thank you for the awesome video, 17 minutes well spent. Looking forward to the next video.

really well done, this channel is so underrated

This was so good. Thank you!

Brilliant analogies in the second half, very insightful, I was super impressed 😊

Beautiful filmography and storytelling. You make difficult ideas so interesting and digestible.

Really fun and cool videos. Thanks so much for doing these!

I'm here from Steve Mould's channel.

This video was amazing! Very high quality content, I'm really impressed! Thank you for explaining this to me in a way that made it easy to understand. 😁

Impressive modeling with the strings/springs example, thx.

Honestly I love how interesting you make your videos...Anybody can watch your videos

Great production and interesting topic

Lovely explanation. Cool illustrations; Even cooler demo. Wish I could give you more than one thumbs up.

I think grannies shouldn't drive when they high on coke.

This is an awesome explanation. Thanks a lot.

I do love that Braess' Monkey. The spring-string demo thing was a great way to explain it too! Also the terrifying yet endearing confrontation of life's catastrophic ineptitudes! :D

The spring+string Analogy was pretty cool!

On top of everything else to be thankful for in your great vids, thanks for the metric love.

Lovely explanation of a truly fascinating topic!

Amazing videos, i love this channel!

Fascinating but I think this is where theory and reality divide. In reality, it wouldn't be that everybody @5:00 would take upper road and then switch to lower road. What would actually happen is 70-80% would start on lower road and switch to upper road where there is maximum throughput at all times. The remaining 20-30% would equalize the upper-to-lower route due to lack of traffic. A theorist might be tempted to say “Let's assume Braess Rd is a one way.” but again, this isn't theory. In reality you'd be a fool to build a one way road in this configuration. Theory is nice but short of going to some extreme like a Tesla Valve (AKA, valvular conduit) I'm struggling to imagine a real-world situation where one could reduce flow by adding more paths for the cars/water/electrons to flow through. I'd be interested in seeing you collaborate with either Physics Girl, Smarter Every Day or King of Random to test a functioning model of this. Say, start with a tub of water with connecting pipes of different diameters. Then throw a valve and see what happens.

I was watching your video of quantum tunneling again and you just upload a video. Yayyy!

Been a fan for a while.. always need reminding, thanks.

I've been recently starting to champion the implementation of Game Theory in my corporation, for HR and some other areas. I'll use this video to do so, as I think it would be relatively simple to translate a lot of corporate stuff, like organization, procedures and personal management into networks and network assembly. Overall this has been an excellent channel, good work!

Wow, I really like those animations and graphics! :D

I love your animation style!

Beautifully executed demo!

New favorite youtube explainer of things. Thank you

well, nice video. I really enjoyed it, as usual I do when I watch your videos:) however, I think the question you asked in the video is not a well-defined question with an exact answer. the mechanical system shown in the video has some parameters which are unknown for us viewers. actually all three proposed answers could be the right answer depending on the exact parameters. most importantly (and in idealistic case) there are 4 parameters which determine the right answer: constant length of the strings (K), constant length of the unloaded springs (S), the spring constant (k) and the weight of the load (m). using the laws of classical physics (Newton): m*g=k*x, where “x” is the spring’s deviation from its original length. so: x=g/k*m=α*m (g and k are constants, so g/k is also a constant, which is now α). so the length of a loaded spring is S+α*m. using these variables we can figure out in which cases will be the “parallel” (i.e. uncoupled) system the shorter one, longer one or exactly equal to the “serial” (i.e. coupled) system. before this we can also deduct some basic conditions from your system by looking at it: K>S (unloaded case), K>S+α*m (loaded case). actually the former is a weaker condition and the latter is a stronger condition. the stronger condition’s alternative form is: (K-S)/m*α > 1. the “parallel” system has a length of: K+S+1/2m*α [the weight of the load on each spring: 1/2m] the “serial” system has a length of: 2*(S+1m*α) [the weight of the load on each spring: 1m] equating these two terms we can determine the configuration of parameters when the two system has the same length. it turns out that the 4 parameters determine this in the following way: - “parallel” system is the shorter, if: 1 < (K-S)/m*α < 1.5 [the lower limit is from the condition mentioned above] - the lengths of the two systems equal, if: (K-S)/m*α = 1.5 - “serial” system is the shorter, if: 1.5 < (K-S)/m*α so, actually it would have been possible that uncoupling your system its length increases, if the configuration of the above-mentioned 4 parameters had been such that. this means that the question asked in the video cannot really be answered due to the lack of enough information:) so those, who had correct answer, either guessed, or simply picked the most counterintuitive answer considering that this video is about a paradox:D ps: do you think this paradox is somehow related to the Simpson’s paradox? I do think this, even if they are related only on a very deep level. I am curious if you can confirm me:)

Great episode! I enjoyed the various animations and experiments, and I thought they added clarity as well as entertainment, as well as regulating the flow rate of information so that it was easier to follow along as the audience. I think it would be more accurate to say not that people are acting selfishly, but to say they are acting in accordance with their own experience. As an emergence of this, if everyone got where they are going sooner, there would be fewer cars on the road altogether at any time, and so everyone's travel time and conditions would get better. This is how raising the speed limit on interstate highways in the USA actually reduced accidents and fatalities. The 55 mph "safety" speed limit that was imposed for many years was actually killing more people every day. What has already started providing collective intelligence in driving is the cars and cell phones getting traffic updates to inform drivers to take alternate routes before they get snarled in traffic in the first place. It's a good example of how a person can "think with the system" without requiring additional regulatory machinery to be in place. By hooking them into the hive mind, their experience reaches into the potential futures and far from direct view. Many plants engage in this kind of widespread communication naturally.

Learning new stuff and eye candy. Earned my subscription!

great vid Jade, i work in manual therapy and I use a network of questions for diagnosis and treatment (destination). In this network of Q's many answers provided by clients provide shortcuts to more advanced questioning and getting to the destination quicker as certain answers cuts out swathes of Q's. This is called pattern recognition. Biological systems and manual therapeutics are inherently complicated. For instance roughly every second day I will encounter something new amongst 1 of 16 clients in clinic- effectively growing my Q's network whilst the other 15 clients provide an opportunity to eliminate or tailor existing networks.

Reminds me of the maximum flow problems in computer science.

Super interesting! Another way for people to cooperate and reduce overall traffic is to use public transport. Centrally controlled and more efficient!

That happens in Maximum Flow Problems too (finding a feaseble flow in a flow network that is maximum), where not all the blocking flows that you may find have the maximum flow value for the net (Dinitz algorithm). :)

Brilliant explanation, brilliant video! 👍🏽

I knew the load on springs were going to contract but the strings threw me off I thought it was gonna stay the same at the same time I thought it was going to go up but I voted for stay in the same I keep learning things from your Chanel keep it up this is very educational, key words here are ‘learning’ and ‘educational’, don’t stop for the love of everything good in this mundane existence keep teaching, please and thank you.

Blanch is awesome 4:10

Great explanation, the experiment with the water bottle connected to the spring was really clever!

Thank you for this eye-opener!

Here from Steve Mould who has also made a video on this and he pointed out you did yours first so thought only fair to check it out.

Great video, i love it when i actually have to think a little while watching things :)

Awesome storytelling of deep concepts!

And people thought it was about Fullerene :P. Great video btw.