Osmosis is a process where a solvent will move, without any external energy input, towards an area with more solute, through a semi-permeable membrane. It is a fundamental process for life, as all of our cell walls are semi-permeable membranes, and it is osmosis that regulates what goes into and out of your cells.
It works like this. If you have a membrane material, say a thin sheet of polyimide, and use it to construct a barrier between two reservoirs of water, then fill one reservoir with salt water, and one reservoir with purified water, there will be a net flow of water from the pure water side over to the salty water side. This flow would continue until the salty water is so diluted by the pure water, that the residual osmotic pressure cannot overcome the drag of the membrane. Or until you run out of pure water.
This is exactly why pouring salt on a slug makes it shrivel up. Slugs are mostly water, have semi-permeable skin, and generate a lot of mucus to maintain their fluid balance (amongst other uses). If you pour salt on the slug, some of it dissolves in the mucus, making it salty. This causes osmotic pressure, which forces water out of the slug’s body to dilute the now-salty mucus, which causes more of the salt to dissolve, and so on until most of the water in the slug is pushed out of the slug, and the slug dries out while immersed in it’s own fluids. Nasty.
This also explains why most fish can only live in salt water or freshwater, and if they are transported from one to the other, they die. Most fish have complex osmosis regulation systems based on their need to keep from desiccating in the ocean (as the salty water is constantly drawing their body’s water out) or bloating up in freshwater (as their salty blood draws fresh water in). Fish like salmon that move from one to the other have to go through a complex metamorphosis, known as smoltification to survive the transition. Sharks have a unique system where they retain urea, the waste product mammals turn in to urine, in their blood to keep it osmotically in balance with the ocean. This is why shark meat tastes simply terrible unless it has been boiled long enough to boil the urea out. If you are offered a rare shark steak, don’t take it.
There is nothing magic about osmosis, it has a pretty simple explanation, and there are thousands of examples of it working in nature, and in man-made systems.
Which brings me back to the topic of the month. I was discussing the United boulevard Connector with a friend who is a keen observer of both science and politics. He remarked:
“The laws of membrane dynamics suggest that the net effect will be to bring more car molecules into New Westminster than are removed, since the partial pressures are much higher in Coquitlam”.
…brilliantly tying the flow of traffic to the concept of osmosis.
There is the impression, I think mistaken, that the UBE will somehow alleviate a couple of nagging traffic problems in New Westminster: “rat running” through Sapperton neighbourhoods, and traffic backups up the hill on Braid.
The second is a ridiculous claim. When this $170 Million is spent and gone, cars and trucks will still need to turn left at the bottom of Braid, and there will still need to be a traffic light there. The sight lines will still be crappy, the merging issues will still exist. Some of those left-turners will now turn right and go up the one-lane ramp to the “T” intersection (to the next light), but they will still have to wait at the light on Brunette, as the through traffic will still be there. So the same cars (well, likely more, but that is my next point) will need to pass through that intersection, and will still need to stop at the same lights. How will this reduce back-ups again?
The first claim is equally silly. When (soon-to-be) 10 lanes of Highway 1 traffic and 6 lanes of Lougheed Highway traffic hit 2 lanes of Brunette and 2 lanes of Braid, there are going to be backups, and people are going to bail out onto the side streets. Adding an additional three lanes to the Bailey Bridge is not going to relieve this problem, it is going to exacerbate it, by bringing more cars into the City.
A clever person might argue that by building this overpass we are also increasing capacity out of the City, and therefore there will be fewer cars! This is where osmosis comes back in.
New Westminster is a City with an enviable Alternative Mode Share . Because we are a compact City with very good transit infrastructure, people in New Westminster tend to drive less than most Cities in Metro Vancouver. Coquitlam is another story. It is spread out; with much more limited transit development other than bus. Its entire commercial land base is built to only be accessed by automobiles. The commercial area of Coquitlam on our eastern border is a good example, but perhaps even more telling is their “Town Centre”, a shopping mall separated from their only real transit hub (the West Coast Express Station) by no less than 9 lanes of Lougheed Highway and a half a kilometer of parking lots. The Proposed Fraser Mills development shows this is a trend Coquitlam is not looking at changing any time soon.
(click image to enhance pie-viewing experience)
Good for them. Coquitlam can continue to develop their City the way their elected officials and citizenry wish. If I don’t like it, I don’t have to live there. Fine.
However, because of their different planning, Coquitlam has lots of cars. They generate a lot of traffic. Cars, (in our now-finally-assembled allegory), are like water molecules. Open spaces between cars, and empty back streets and laneways in Sapperton and across the City (i.e. a lack of congestion) are like the salt dissolved between the water molecules and attracting them. The United Boulevard Extension is the semi-permeable barrier. The cars can pass across it, the empty spaces cannot. And since there are more cars on the Coquitlam side every day, the opening of the semi-permeable membrane means there will always be a flow into New Westminster that more than compensates for any flow out of New Westminster, until the osmotic pressure is relieved. And the worst part is that the more we do on our side to relieve congestion (say, riding our bikes, taking the Skytrain, or just walking to the store), the more empty space we create, and the more osmotic pressure that will be exerted across the membrane.
The UBE will not solve any traffic problems in New Westminster. It will only exacerbate them.