This river can be switched on and off 

I did try to find a cultural equivalent to my Crystal Maze reference for the French-Canadian subtitles, but sadly "turning the tiger's head" didn't quite fit...

I don’t know why but seeing ducks still swimming along on the simulated river made me happy.

Tom Scott is like a National Geographic host for non-natural phenomenon.

Tom, thank you so much for coming to Sherbrooke and filming our river! We're hoping to get some preliminary research published in 2023, if all goes well. (Oh, and with regards to floating on a tube: We've talked about floating down on one of those massive inflatable unicorns, but unfortunately we have sticks of rebar in the river to attach probes to, and that wouldn't end well...)

Can we talk about how Tom has gotten so powerful that he can just switch on a river by saying turn it on boys

0:41 "Pick out specific variables and play with them" That's how you know for absolute certain that this guy's a legit scientist

I'm French and fluent in English but the subtitles in my native language are warmly welcome and additionally seems very accurate ! Really appreciate the amount of work you and your team put in each of your videos

The most polite and Canadian way to say, “No, our river is not a joyride for inflatables.”

"I assumed simulating water was pretty much a solved problem" *Navier-Stokes has entered the chat*

I've always been fascinated with model waterways, ever since I was a little kid and there was a demonstration of erosion using a table of sand and a flow of water in class one day. I love that there's a near-full-size version of the same thing!

This is the university I went to and Jay Lacey was my teacher while I was there! He is a fantastic teacher and is the reason I love hydraulics and hydrology! Sadly, the river wasn't built when I was a student as I would have loved to work with it! Thanks Tom for coming to our small town of Sherbrooke!

Very cool to see you in Canada! As an engineer this is the kind of stuff we love. Computer simulations are great but a scale model (or if feasible, full size) can give you so much valuable data. This is especially true when fluid flow is involved as it's still very difficult to simulate, this is why wind tunnel testing is still so common. I work for the Canadian Coast Guard and many of the vessels we design and build are icebreakers (obligatory frozen Canada joke here) so we do a lot of ice tank testing on models as it's really hard to simulate all the loads on a vessel's hull as it transits trough an ice flow. Tom, I'd highly recommend recommend contacting the folks at the Nation Research Council of Canada regarding their ice tank in St. John's Newfoundland. It's a top notch facility and one of the largest ice tanks is the world. It's government owned and operated, and I'm sure they'd be happy to have you visit. The NRC also has over a dozen other facilities around the country doing interesting and important research in a vast array of fields, including a large 9m wind tunnel in Ottawa (actually a lot of their buildings are in Ottawa, given that it's the capital and all). Well worth checking out. If you're interested in ice tanks on the other side of the ocean, we've also worked with Aker Arctic in Finland, who operate a slightly smaller tank, and Aalto University, also in Finland, who has an even smaller but still substantial tank. We often use all the tanks as different groups have different methods of replicating sea ice and therefore models perform differently in each tank.

The look on the prof's face when asked about the tube is priceless

How Tom keeps finding material for his videos is beyond me. You'd think this guy has done it all by now

They even have ducks. So realistic.

Tech Support: _"Have you tried switching the river off and on again?"_

"Unaffected by wildlife" 2:58 - Quack

"I wouldn't advise it" is an incredibly polite way of saying "Are you mad? We can't possibly have that on our insurance."

To think Tom was only an hour away from me makes me happy. I'm glad you came to Quebec to see this. I'm sure there is plenty more that can be found around here.

The way Tom breaks down WHY the thing exists, is a real skill.

This video got me pumped up! You are an endless stream of information Tom, thanks as always!

Tom: This is an artificial river built for serious research. Also Tom: tries to go down it with an inflatable tube. Honestly be glad they didn't allow it or you might've ended up like the Go-Pro.😅

In New Zealand most tramping (hiking) deaths occur from drowning when people cross the rivers that can suddenly go from nothing to full flood because of our high rainfalls and mountainous terrain. The rule of thumb is to not cross if you can hear the rocks rumbling. There is enough power in a raging river to move surprisingly large rocks, so people have no chance! The rivers subside as quickly as they flood, so just walk back to the last hut and wait it out.

This reminded me, there's a full scale natural river called the Ocoee in Northern Georgia that was dammed off and now the river is redirected during the week to provide hydroelectric energy, and during the weekend they open the dam and the river becomes a huge natural white water center. It would be really neat to see a video of a system like that at full scale!

There are quite a few smaller (in terms of money and students) Canadian universities with absolutely massive amounts of land to play with. I wonder how many more cool things there are like this on their campuses

Over the course of two years in junior high, our school bus passed over a small creek. It was fascinating to watch how that creek moved about in its banks over time. With modern tech, it would be interesting to use a trail cam or something similar to capture an image or two every day, and compile that into a time lapse.

This is my Alma Mater, exactly. I did my bachelor's and Master's at UdeSherbrooke civil engineering faculty. (More on the building side tho) Very happy you could show some of what we do :)

Cool rainbow behind Prof. Lacey! Being from the Midwest, I'm legally required to point out each and ever rainbow I see.

Love that "Crystal Maze" nod at the start... i saw what you did there :)

I built a system just like that with a waterfall and a river, but a lot smaller in size. It’s nice to sit in the garden and listen to the water flow over the waterfall and watch Tom Scott videos on my phone.

Props to the audio editors for cutting out all the ums and ahs, you can tell by the finished interview that the professor didn't make their jobs easy

I live very close to the University of Sherbrooke and I have walked by this simulator many times in my life, however I had never realized it was such a special piece of infrastructure! I though it was a necessary tool that every university with civil engineering classes needed. Thanks for the discovery!

Another in a long line of excellent quality videos. Tom has a way of providing the spark that is needed to make the viewer interested in all things. Thank You, Sir.

this is my university! so glad you could cover this story 😊

This reminds me of my visit to Niagara Falls. We were joking about them turning them off at night - and off season they actually do. The machinery doing that would probably be an interesting subject for a future video

Imagine if Tom had a programme with the BBC. I could honestly watch these videos for hours

Tom, you always brighten my day with places I never knew existed. it is as if my education didn't stop with school, that was just the beginning. We keep learning, and that is thanks to people like you, and our own zest for understanding the world. Thanks!

Thanks for being the guy that sees something and says, "that looks interesting, let's pay some people to explain it to us professionally so I can share that information to everyone else". You're mind is like mine, but you have the means to act on your curiosity, and it's glorious! Thanks for letting us live vicariously through you sir!.

Your videos open up studies and new ideas that have not crossed my mind, thank you for all you've done over the years Tom.

There is now whay this is happening! I studie att l'Université de Sherbrooke and last week-ends i came across this new structure, and i was wondering what that was for, and juste after that, you make that vidéo, just wow, who could have think i would find out by one of your vidéo😆 very good work! (Sorry for my english no time to verify my traduction, only have 10 min break in my thermodynamique classe) 😂

Good to see you in Quebec! I hope you'll do more videos here, there's plenty of stuff to see that could be interesting, like Manicouagan for example

Absolutely the ice needs to be modeled. Realy great work! Love it.

0:31 love that Tom saw the perfect opportunity for a Crystal Maze reference 😂

This was truly fascinating! Thank you, Tom!

I worked at an amusement park for a summer and it reminds me of the water ride I worked at, we would pump insane ammounts of water from a lake into the ride, then turn on more pumps to pull that water vertical and then flow it downhill around course. Was really fun watching the ride turn on and off, It would fill up and drain in minutes.

I love when Tom starts a video with "you can't do X... unless you do." It lets me know that the video is going to be even more interesting than usual

Thank you and have a great week.

This is really cool! As a one-time geology student, I appreciate how much this is going to help in many studies. It could save lives!

What is really difficult is the fact that it's not just fluid flow, you've got a river bed of varying sized rocks; the water moves the rocks and the rocks influence the flow of the water. So computationally, you've got massive complications.

I liked (@ 3.35 ish) where the river flow on camera was also carrying debris, leaves, grass, small pebbles and sand etc ... A simple thing, but presumably very powerful as a model and test bed. 😜

" will you start the pumps please! " takes me back to the days when i used to watch, the crystal maze and the " will you start the fans please! "

a challenge for some problems in computational fluid dynamics is different time-scales for different space-scales of flow. if you want to model something small, you have to have a small timestep, but if your timestep is too small, long simulations take a looooooooong time to run, but if the simulation time is too short, then you won't capture the larger scale effects

I like how he casually mentions it's "very dangerous" to enter the river just after Tom says his cameraman waded in to retrieve a gopro

I like how the river model is so convincing even ducks are swimming in it @2:58

The best thing about these videos is hearing the expert discuss the thing Tom is showing off.

Thank you for the video Tom

During the summer I worked at a children’s museum, one of my jobs was to demonstrate & clean up the water table. I really want to have something like this in my yard :)

A research river. One of this thing my mind hadn't conceived that it would be a thing until Tom showed it to us!

I would have so much fun with that simulator. Took up river fishing this year and ended up wading a lot. I had never really waded before but realized it's one of the most relaxing experiences I've ever had. Then I became addicted. Was also looking at a career change and going back to school. Though I'm already almost 30 and still don't know what I wanna be when I grow up. After spending this season on the river, I can say I would love going to work everyday as long as I could do something to positively impact that system. Maybe a career path along the lines of Environmental Technology. Not sure yet. Super fascinating video, thanks for sharing Tom.

0:31 Tom saying “will you start the pumps please!” Immediately took me back to the old game show Crystal Maze where Richard O’Brien would yell “would you start the fans please!” In the crystal dome. Tom even said it in a similar manner

I remember feeling the same way as yourself when I found out we haven't modeled the full behavior of h2o. I remember someone saying, "so that's why the weather report is always wrong".

I swear that all of these science videos always relate to my environmental science class perfectly

Fascinating as always.

That's really cool! Having a playground for Civil Engineers to test and validate theories and data models regarding rivers and water flow is a great tool. Thanks for doing the video. I enjoyed it!

1:54 i thought he was gonna say "it does a very good job at washing away GoPros"

I study there! i never realized that the artificial river was made for that, quite a bit far from the main campus buildings too!

Enjoyed watching this video!

So glad to hear from Sherbrooke in your video!

You needed the crystal maze theme when the pumps started

0:32 haha Crystal Maze reference

that last little bit where the water is flowing into the river, youtube's compression totally jacked that up. i learned that from a different tom scott video

As a civil engineer this is so cool. My entire master thesis was on scour of bridge piers in rivers and involved complicate fluid dynamics modelling that I didn't quite work!

hey tom, i would really like to see a video of you diving into the topic of 2-wheeled vehicles like motorcycles. those things seem to simple but they are just dancing with physics to achieve what we witness and thats a very interesting topic imo. good video as always and cheers for your efforts

What a lucky coincidence that they happened to have a Go-Pro Rescue Operator on staff the day Tom was there.

the more i watch your work the more i admire you just a word thank you

Thx for the french subtitle! I usually use the english one since almost no one do them in french. Merci !

In addition to the Bay Model there was a huge scale model of the mississippi/missouri/Ohio system called Mississippi River Basin Model outside of Jackson MS built in the 50s or 60s. It's been shut down now. There's also a scale model of the mississippi at Mud Island in Memphis which you can walk along and splash in. Very cool

I used to draw little channels in the sand to drain large puddles as a kid. That small scale model would be my preferred version of a train model town 🤣

Glad to see you're in Canada, Tom!

this is one of the coolest things i have seen for a long time

I love that they even have ducks! I bet they are confused when the river turns on and off. 😆

Other benefit to this setup: you get to spend the day by a fake river outside instead of chaperoning a computer churning out your model.

Im super impressed how Tom explains without any cuts. He can make 20 min videos interesting in one go👏 . He would be a great teacher

It warms my heart every time I see Tom visit Canada.

My local river, Kajaaninjoki in Finland was turned off two weeks ago between two powerplants, it is natural river betwewn those powerplants at least. It was completely dried for that bit in the middle of Kajaani city. They did this a decade ago last time. It was filled up later that same day.

water

Once again another great informative video, thanks.

The Ducks very very good birbs. Much apreciated to have them in the Video.

If only I knew your passed by!!! I work in the research lab right by this artificial river, in a lab working on/designing/building drones for various applications. It would have been nice to show you around, even if it wasn't for a video!

You should go to the Wave Lab at Oregon State University and make a video on how tidal waves are made and studied. It’s such a genius and fascinating facility.

Tom always comes up with these fascinating stuff

Liked the Crystal Maze reference👍👍 "Start the fans, please!"

Tom Scott works so hard on these videos he definitely deserves a break from YT

3:23 Simulating water accurately is actually very far from being perfected. I don't think it'll be solved until we aolve the Navier-Stokes equations (I think that's what it's called?)

Very educating Tom 👍🏻

Excellent Crystal Maze reference from Tom.

One of the interesting things with your videos is that you cannot tell if it was recorded today or 10 years ago. The direction, recording techniques have evolved a lot but the consistency and red T-shirt gives off an illusion that they haven’t .

Today I read an article on the New York Times "Can Germans Save Their Beloved Rhine?". It is about droughts and the effect on transport on rivers, and to combat this the Germans actually did build a scale replica of the river and use appropriately selected sand to simulate the effect of erosion on their attemps to improve the depth of the river at an important section of the river.

Tom Scott is an international treasure.

Thanks Scott for pointing out the limitations of computer simulations in dynamic events like this.