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I was a college swimmer, qualified for Olympic Trials in 2012 and 2016. There are absolutely slow and fast pools. It basically comes down to two things: 1. The

I was a college swimmer, qualified for Olympic Trials in 2012 and 2016. There are absolutely slow and fast pools. It basically comes down to two things: 1. The depth - which is only 7ft in Paris, unusually shallow for a competition pool. 2. The sides. Does the water spill over the sides into the gutters, or smash into a wall and bounce back, creating more chop. A trained eye can see all the swimmers in Paris struggling in their last 10-20 meters (heck, an untrained eye can spot some of these). Bummer that it makes the meet feel slow but at least it generally affects all the swimmers equally

davidmurdoch 2y ago
To a lesser effect, there's also the surface tension of the water, which can be adjusted with salt and borates.
- HPsquared 2y ago
  Density and viscosity must also play a role, or are those managed via temperature control?
  - davidmurdoch 2y ago
    Seems very plausible. I haven't noticed a speed difference in my own pool with temperature changes, but that might just be because the temperature itself can be so distracting. But I do feel like a salty pool makes me faster (maybe from buoyancy), and borates makes the water feel smoother and less "sticky" (something about surface tension changes with borates, it even makes the surface look different).
    - HPsquared 2y ago
      Oh and of course the cooling effect. That's a factor for long distances especially if the water is too warm.
mysterydip 2y ago
Would the swimmers in the center lanes have any advantage by being furthest away from the wall-induced chop?
- hgomersall 2y ago
  Supposedly, that's why the fastest qualifiers get the middle lanes.
  - dist-epoch 2y ago
    [flagged]
    - chatmasta 2y ago
      If you put them in the slow lanes then there would be an incentive to place poorly in qualifying rounds.
      - esperent 2y ago
        Don't the qualifying rounds determine whether you get to compete or not? So if someone intentionally slowed down, even a fraction of a second, there's a chance they wouldn't get to compete at all.
        chatmasta 2y ago
        Yeah, but it would create weird incentives where e.g. if two people are way ahead of the pack, one of them wants to finish after the other. So do they just wait until the rest of the field catches up and then try to trick the other guy into hitting the wall first? Better to just avoid it by keeping incentives aligned with winning your qualifying heat.
        drdeca 2y ago
        Or they could randomize the order?
School-Cotton 2y ago
Why does it matter how deep the pool is? Edit: the article addresses this, so if anyone else is curious like I was, I suggest clicking.
- HPsquared 2y ago
  Edge effects affecting the flow field around the swimmer. I suppose the floor might trap turbulence near the surface rather than dissipating into the depths.
- defrost 2y ago
  If it's too shallow the swimmers arms hit the bottom ... Slightly deeper and there's drag from the floor as their arms barely miss it. That effect persists until it doesn't .. now it's deep enough. It needs to be deep enough that vortex's created by swimmers have disapated by the time they reach bottom and reflect back to the surface so as to not interfere with following swimmers or swimmers returning.
  - sshine 2y ago
    > If it's too shallow the swimmers arms hit the bottom Is it’s deep enough, the gravitational mass of the water will form a black hole and squash the swimmer to death.
    - defrost 2y ago
      Big whorls have little whorls Which feed on their velocity, And little whorls have lesser whorls And so on to viscosity. ~ Lewis Fry Richardson and then to an event horizon. ~ sshine
    - expression1sh 2y ago
      Well before that the hydrogen atoms would fuse into helium and release vast amounts of energy, killing all the swimmers, spectators, and many people in Paris.
- creshal 2y ago
croes 2y ago
>A lot of this is perception vs. reality,” he said. “If you were to talk to many very accomplished coaches, they would say the pool has to be a minimum 3 meters deep. Most of our research shows that anything over 2 meters is frivolous. … Obviously, some depth is very important. But after a certain point, it's diminishing return. Maybe it's just the swimmers and not the pool as such
- lou1306 2y ago
  But a lot of the swimmers themselves are not able to go anywhere near their personal bests: this is a sharp reversal from past Olympics, where many athletes reached new personal records. Plus, they are the worldwide foremost experts on competitive swimming. Definitely I would be more interested in their evaluation of a swimming pool rather than trust "research results" from the company that built the pool in question.
  - echoangle 2y ago
    Being good at swimming doesn’t mean you can evaluate the pool performance better than everyone else. I trust someone running a CFD analysis of a pool more than a competitive Olympic swimmer when it comes to the effect of pool depth. It’s very hard to make accurate statistical assessments from intuition. Edit: maybe I’m not making myself clear: I don’t doubt they are slower in the current pool than they were before. But I doubt they can accurately tell you that it’s because of the pool depth. There are other factors that could also influence the performance, and I’m not sure the swimmers can accurately determine which factor is the primary difference.
    - CoastalCoder 2y ago
      Even CFD analysis is a model though, with all that implies. Would a large, blind empirical study be more trustworthy?
      - echoangle 2y ago
        Only if the depth is the only variable that’s changed. You can’t just use two entirely different pools at different times and locations and conclude that the depth is the reason for different performance.
tweetle_beetle 2y ago
I'm no expert, buy there also seems to be loads more stuff lying on the bottom of the shallow floor than I remember from previous Olympics. Not even sure exactly what it is - large white panels and other equipment that the swimmers don't look that far off touching when underwater (not the robot cameras which are relatively unobtrusive).
- ranie93 2y ago
  digital lap counters to help the swimmers keep track
  - creaghpatr 2y ago
    Thats pretty nice, when I swam the 500 I would have to lift my head to see the lap counter dropping the sign in the pool which messes with your head position
- jonhohle 2y ago
  Wouldn’t the underwater camera on a track cause currents?
  - bhandziuk 2y ago
    I could be fully enclosed for the full length and just have a glass top
croes 2y ago
So now that two swimming worlds records have fallen, we can't blame the pools anymore, can we?
Scoundreller 2y ago
Dumb question I never thought about: do the circulation/filtration pumps get turned off during races? And for what minimum time before hand to let things settle? If so, I guess this would be a serious competition only thing because you wouldn’t want them off for hours.
- sandworm101 2y ago
  They do, but circulation cannot be totally stopped. This is a greater problem in outdoor pools but any pool will have some sort of temperature gradient that will inevitably result in circulation. Any water movement means slower times, at least in those events longer than 50m (1 length).
  - OJFord 2y ago
    Surely that has far less effect than that of all the other swimmers? Naïvely I would think we should be running time trials of a single swimmer at a time before caring about any of this?
- dredmorbius 2y ago
  FINA competition pool standards have recirculation minimum standards, and pumps run continuously. Further, "water distribution has to be such that no appreciable current or turbulence is created. 'Appreciable current' is defined as water movement that can move a floating basketball (filled with 6 litres of water to obtain the right buoyancy) in one direction for more than 1,25m in 60 seconds." <https://resources.fina.org/fina/document/2022/02/08/77c3058d-b549-4543-8524-ad51a857864e/210805-Facilities-Rules_clean.pdf https://resources.fina.org/fina/document/2022/02/08/77c3058d...> (PDF) Most competitive swimming pools have a large number of inlets with diffusers on them, laid out every 2m or so across the pool floor. Those are circular disks about 10cm in diameter, looking vaguely like this: __________ \________/ | | ^^^^^^ The carets indicate inlet water flow beneath the diffusers. The effect is that water entering the pool largely moves perpendicular to the pool floor, and slowly diffuses upwards. Water return is through the (large, wide, deep) gutters. Because the gutters are continuously removing water from the pool, circulation needs to be on to maintain a consistent fill level.
madaxe_again 2y ago
I actually did a fairly lengthy research project on pretty much exactly this as a physics undergraduate - I wasn’t looking at swimming specifically, but rather boundary separation and Reynolds number in an open channel of varying depth. The setup was simple - a constant head vessel to provide a constant but adjustable flow of water in from one end, and a little plastic boat sat in the middle of the channel, attached to a force gauge at one end of the channel. The outflow of the channel had a gate with an adjustable height in order to vary the depth. Also, a couple of dye injectors at different heights in the channel in order to see turbulent vs laminar flow. The key finding was that at shallower depths, turbulent flow began much more rapidly and resulted in erratic but overall higher resistive forces on the boat. Deep water remained laminar for much longer, and could flow much faster before turning turbulent near the surface. This was the expected result, but it was nice to experimentally prove it. So in short, the pool depth almost certainly impacts the point at which turbulence kicks in, and therefore athletic performance. It’s probably the dive/entry that is being most impeded, as that’s when the swimmer will largely be experiencing laminar flow.
- bjoli 2y ago
  Does it manifest directly? The water has had some time to settle when they start.
  - madaxe_again 2y ago
    Yes. An object moving through water is more or less equivalent to water moving around an object, and the moment you cross a boundary condition, be it depth, velocity, viscosity, the phase transition is instantaneous to all intents and purposes. I’d have entire days of experiments screwed up just by the water being slightly too warm or cold, or there being dust, or not enough dust, or sunshine, or… fluid dynamics are finicky.
    - LorenzoGood 2y ago
      Yes, but there will be no turbulence at the start of a swimming race.
manojlds 2y ago
Why doesn't it affect more the people closer to the sides?
- notatoad 2y ago
  this is the reason that the leftmost and rightmost lanes of the pool aren't used for competition.
- mb7733 2y ago
  It does. This is why the fastest qualifiers get to swim in the middle lanes.
conductr 2y ago
My untrained eye has noticed. But I also think it's not really a big deal. There are so few events where the conditions are exactly the same every 4 years. Just kinda the luck of the draw if you happen to be competing in the most ideal conditions for WR setting in any event
- kergonath 2y ago
  Also, the important bit is fairness for all competitors. As the OP said, the same conditions affect everybody. I have little sympathy for the (few) swimmers complaining. They are not owed a world record and if they’re that good, they’re going to get one anyway.
  - teractiveodular 2y ago
    Wouldn't the sides affect swimmers on the edge lanes next to them more? And is this one reason why the strongest swimmers are usually placed in the center lanes?
    - killingtime74 2y ago
      From the races I saw they specifically had the edge lanes (left most, right most) empty probably for this reason. I.e. 8 out of 10 lanes are used. I think one of them did have someone in one of those lanes because one of the qualifying heats was a dead heat.
    - lupusreal 2y ago
      Correct.
    - jseutter 2y ago
      Swimmers on edge lanes get affected more, and they leave the outside lanes unoccupied except for the first stage of qualifying.
    - aqfamnzc 2y ago
      Given the other comments I must be missing something, but wouldn't it be pretty much fair? The end swimmer gets one real neighbor and one simulated (reflection) neighbor from the wall. The middle folks have two real neighbors creating chop.
deleted 2y ago
[deleted]
ClassyJacket 2y ago
This is yet another reason on the huge list of reasons to keep the Olympics in Athens and just use the same facilities each time.
will1am 2y ago
[dead]
rightbyte 2y ago
> Bummer that it makes the meet feel slow but at least it generally affects all the swimmers equally Shouldn't the middle swimmer be worse off with "fast" pools? There would be less waves on the side lanes, compared to a "slow" pool where there are reflections.
myworkinisgood 2y ago
All swimmers are affected equally so I don't see a problem.
dredmorbius 2y ago
The one aspect which isn't equal at least amongst Olympic and other competitions is that a slower (or faster) pool will generate fewer (or more) records overall. One measure of the current games' bias would be the number of new Olympic and world records set as compared with other events --- prior or subsequent Olympics, and other world-level competitions within the current year, say. I expect the quants at sites such as 538 would be looking at this.
- alistairSH 2y ago
  Are records generally evenly distributed over time? Or do we see massive spikes due to single generational talents?
  - lostlogin 2y ago
    > Or do we see massive spikes due to single generational talents? Various types of doping could cause this too. More positively, tech, diet and science changes could too in some sports too.
  - dredmorbius 2y ago
    The more general tendency that I've seen and which has been noted in articles/studies I'm familiar with is generally technique and technology. Two examples of technique I'm aware of are the Fosbury Flop (1968) in the high jump, in which the jumper goes backwards over the bar (previously jumpers had gone forwards and feet-first, by 1968 with a sissors step), and heads-down technique in Australian Crawl "freestyle" swimming. Both dramatically improved results. The Fosbury Flop was enabled by the technological introduction of foam mats on the landing side of the high-jump. Without mats, landing on your back after clearing a 2m+ bar position was somewhat undesirable. Heads-down stroke in freestyle was in conjunction with freshwater (rather than salt) in swimming pools. Swimming heads-down without goggles in a salt-water pool burns the eyes quite strongly. With freshwater, and acrylic plastic goggles (acrylic being invented in the Great Plastics Boom of the 1930s). I'm not entirely sure when plastic swim goggles became widespread, though it may not have been until the 1970s, and the Montreal Olympics (1976) were the first to permit goggles. Track generally has also seen tremendous improvements in the track composition (loose cinders to rubberised surface). Swimming pools have hugely reduced wave action through wave-absorbing lane lines, deep gutters, inlet diffusers, and laser-guided construction ensuring accurate and consistent distance. That's on top of vast improvements in training, other equipment, doping (which has a very long history), professionalisation of sport (including the Olympics), and other factors. Talent is a component, but the overall phenomenon is highly multidimensional.
ldng 2y ago
Supposedly, all the Paris 2024 new accommodation were designed with re-usability for the general public after the Olympics. Is it possible that had an impact the swimming pool on design choices ? Put differently, are performance design at odd with more general/accessible design in the case of a swimming pool ?
- physicsguy 2y ago
  Given the abandonment of olympic venues all the way round the world, I don't think this is a bad thing. There's a lot in the book Soccernomics about how the economic value promised by politicians lobbying for hosting things like this rarely pan out.
  - wildzzz 2y ago
    There's definitely economic value but it really only goes to the companies building facilities, the suppliers, and the hospitality industry immediately surrounding the events. In an already well-developed city, they aren't going to be building many new permanent structures. Many will be temporary that will eventually be torn down or just converted back to what they were originally. The money is spent, distributed to the companies that directly participated in the build up and run of the Olympics but there's little gain made after. A more interesting way of doing the Olympics would be to only allow for developing countries to participate in the selection process. Each country would be required to meet a certain level of funding to guarantee they can support the entire Olympics. Foreign investment would be encouraged. There would be a requirement for some aspects to be permanent construction, you couldn't just build a tent city for the athlete village. Then a name is picked randomly. The host country then receives major foreign investment, not just in sporting arenas, but in many areas of its economy. The Olympic committee could also collect dues from participating countries based on GDP that would go to the host country for economic development. It would basically create a lottery system for the economy of developing countries. The build up to the Olympics would create the infrastructure needed for future investment. This would likely require host cities to be selected much further out in advance. An oversight committee would observe the development and if milestones are not met, a host city from a developed country that does have the infrastructure necessary would instead be chosen.
jmalicki 2y ago
For point 2, wouldn't the reflections off the sidewalls create more issue with chop on the outer lanes than the middle?
- palijer 2y ago
  The outer lanes are where the slower swimmers are placed already anyways, so if they were having more chop, it wouldn't likely impact a medal contender and cause a big upset... Not saying that outer lanes haven't come out on top in the last, but less likely.
pdpi 2y ago
> at least it generally affects all the swimmers equally > 2. The sides. Does the water spill over the sides into the gutters, or smash into a wall and bounce back, creating more chop. My only experience with competitive swimming is playing some water polo some 25 years ago, but wouldn't that effect disproportionately affect the swimmers on the outermost lanes?
adolph 2y ago
Why aren't swimming lanes stadium shaped like running tracks or speed skating? Floor mounted LED indicators could advise competitors of the relative distance ahead and behind of nearest adversaries.
Yawrehto 2y ago
Off-topic but congratulations for qualifying for trials!
sschueller 2y ago
Shouldn't that be part of the standard "Olympic Pool" definition? Depth, water height on side and overflow etc. seem to be as important as the nittting of a football goal net.

davidmurdoch 2y ago

To a lesser effect, there's also the surface tension of the water, which can be adjusted with salt and borates.

HPsquared 2y ago
Density and viscosity must also play a role, or are those managed via temperature control?
- davidmurdoch 2y ago
  Seems very plausible. I haven't noticed a speed difference in my own pool with temperature changes, but that might just be because the temperature itself can be so distracting. But I do feel like a salty pool makes me faster (maybe from buoyancy), and borates makes the water feel smoother and less "sticky" (something about surface tension changes with borates, it even makes the surface look different).
  - HPsquared 2y ago
    Oh and of course the cooling effect. That's a factor for long distances especially if the water is too warm.

mysterydip 2y ago

Would the swimmers in the center lanes have any advantage by being furthest away from the wall-induced chop?

hgomersall 2y ago
Supposedly, that's why the fastest qualifiers get the middle lanes.
- dist-epoch 2y ago
  [flagged]
  - chatmasta 2y ago
    If you put them in the slow lanes then there would be an incentive to place poorly in qualifying rounds.
    - esperent 2y ago
      Don't the qualifying rounds determine whether you get to compete or not? So if someone intentionally slowed down, even a fraction of a second, there's a chance they wouldn't get to compete at all.
      - chatmasta 2y ago
        Yeah, but it would create weird incentives where e.g. if two people are way ahead of the pack, one of them wants to finish after the other. So do they just wait until the rest of the field catches up and then try to trick the other guy into hitting the wall first? Better to just avoid it by keeping incentives aligned with winning your qualifying heat.
        drdeca 2y ago
        Or they could randomize the order?

School-Cotton 2y ago

Why does it matter how deep the pool is? Edit: the article addresses this, so if anyone else is curious like I was, I suggest clicking.

HPsquared 2y ago
Edge effects affecting the flow field around the swimmer. I suppose the floor might trap turbulence near the surface rather than dissipating into the depths.
defrost 2y ago
If it's too shallow the swimmers arms hit the bottom ... Slightly deeper and there's drag from the floor as their arms barely miss it. That effect persists until it doesn't .. now it's deep enough. It needs to be deep enough that vortex's created by swimmers have disapated by the time they reach bottom and reflect back to the surface so as to not interfere with following swimmers or swimmers returning.
- sshine 2y ago
  > If it's too shallow the swimmers arms hit the bottom Is it’s deep enough, the gravitational mass of the water will form a black hole and squash the swimmer to death.
  - defrost 2y ago
    Big whorls have little whorls Which feed on their velocity, And little whorls have lesser whorls And so on to viscosity. ~ Lewis Fry Richardson and then to an event horizon. ~ sshine
  - expression1sh 2y ago
    Well before that the hydrogen atoms would fuse into helium and release vast amounts of energy, killing all the swimmers, spectators, and many people in Paris.
creshal 2y ago

croes 2y ago

>A lot of this is perception vs. reality,” he said. “If you were to talk to many very accomplished coaches, they would say the pool has to be a minimum 3 meters deep. Most of our research shows that anything over 2 meters is frivolous. … Obviously, some depth is very important. But after a certain point, it's diminishing return. Maybe it's just the swimmers and not the pool as such

lou1306 2y ago
But a lot of the swimmers themselves are not able to go anywhere near their personal bests: this is a sharp reversal from past Olympics, where many athletes reached new personal records. Plus, they are the worldwide foremost experts on competitive swimming. Definitely I would be more interested in their evaluation of a swimming pool rather than trust "research results" from the company that built the pool in question.
- echoangle 2y ago
  Being good at swimming doesn’t mean you can evaluate the pool performance better than everyone else. I trust someone running a CFD analysis of a pool more than a competitive Olympic swimmer when it comes to the effect of pool depth. It’s very hard to make accurate statistical assessments from intuition. Edit: maybe I’m not making myself clear: I don’t doubt they are slower in the current pool than they were before. But I doubt they can accurately tell you that it’s because of the pool depth. There are other factors that could also influence the performance, and I’m not sure the swimmers can accurately determine which factor is the primary difference.
  - CoastalCoder 2y ago
    Even CFD analysis is a model though, with all that implies. Would a large, blind empirical study be more trustworthy?
    - echoangle 2y ago
      Only if the depth is the only variable that’s changed. You can’t just use two entirely different pools at different times and locations and conclude that the depth is the reason for different performance.

tweetle_beetle 2y ago

I'm no expert, buy there also seems to be loads more stuff lying on the bottom of the shallow floor than I remember from previous Olympics. Not even sure exactly what it is - large white panels and other equipment that the swimmers don't look that far off touching when underwater (not the robot cameras which are relatively unobtrusive).

ranie93 2y ago
digital lap counters to help the swimmers keep track
- creaghpatr 2y ago
  Thats pretty nice, when I swam the 500 I would have to lift my head to see the lap counter dropping the sign in the pool which messes with your head position
jonhohle 2y ago
Wouldn’t the underwater camera on a track cause currents?
- bhandziuk 2y ago
  I could be fully enclosed for the full length and just have a glass top

croes 2y ago

So now that two swimming worlds records have fallen, we can't blame the pools anymore, can we?

Scoundreller 2y ago

Dumb question I never thought about: do the circulation/filtration pumps get turned off during races? And for what minimum time before hand to let things settle? If so, I guess this would be a serious competition only thing because you wouldn’t want them off for hours.

sandworm101 2y ago
They do, but circulation cannot be totally stopped. This is a greater problem in outdoor pools but any pool will have some sort of temperature gradient that will inevitably result in circulation. Any water movement means slower times, at least in those events longer than 50m (1 length).
- OJFord 2y ago
  Surely that has far less effect than that of all the other swimmers? Naïvely I would think we should be running time trials of a single swimmer at a time before caring about any of this?
dredmorbius 2y ago
FINA competition pool standards have recirculation minimum standards, and pumps run continuously. Further, "water distribution has to be such that no appreciable current or turbulence is created. 'Appreciable current' is defined as water movement that can move a floating basketball (filled with 6 litres of water to obtain the right buoyancy) in one direction for more than 1,25m in 60 seconds." <https://resources.fina.org/fina/document/2022/02/08/77c3058d-b549-4543-8524-ad51a857864e/210805-Facilities-Rules_clean.pdf https://resources.fina.org/fina/document/2022/02/08/77c3058d...> (PDF) Most competitive swimming pools have a large number of inlets with diffusers on them, laid out every 2m or so across the pool floor. Those are circular disks about 10cm in diameter, looking vaguely like this: __________ \________/ | | ^^^^^^ The carets indicate inlet water flow beneath the diffusers. The effect is that water entering the pool largely moves perpendicular to the pool floor, and slowly diffuses upwards. Water return is through the (large, wide, deep) gutters. Because the gutters are continuously removing water from the pool, circulation needs to be on to maintain a consistent fill level.

madaxe_again 2y ago

I actually did a fairly lengthy research project on pretty much exactly this as a physics undergraduate - I wasn’t looking at swimming specifically, but rather boundary separation and Reynolds number in an open channel of varying depth. The setup was simple - a constant head vessel to provide a constant but adjustable flow of water in from one end, and a little plastic boat sat in the middle of the channel, attached to a force gauge at one end of the channel. The outflow of the channel had a gate with an adjustable height in order to vary the depth. Also, a couple of dye injectors at different heights in the channel in order to see turbulent vs laminar flow. The key finding was that at shallower depths, turbulent flow began much more rapidly and resulted in erratic but overall higher resistive forces on the boat. Deep water remained laminar for much longer, and could flow much faster before turning turbulent near the surface. This was the expected result, but it was nice to experimentally prove it. So in short, the pool depth almost certainly impacts the point at which turbulence kicks in, and therefore athletic performance. It’s probably the dive/entry that is being most impeded, as that’s when the swimmer will largely be experiencing laminar flow.

bjoli 2y ago
Does it manifest directly? The water has had some time to settle when they start.
- madaxe_again 2y ago
  Yes. An object moving through water is more or less equivalent to water moving around an object, and the moment you cross a boundary condition, be it depth, velocity, viscosity, the phase transition is instantaneous to all intents and purposes. I’d have entire days of experiments screwed up just by the water being slightly too warm or cold, or there being dust, or not enough dust, or sunshine, or… fluid dynamics are finicky.
  - LorenzoGood 2y ago
    Yes, but there will be no turbulence at the start of a swimming race.

manojlds 2y ago

Why doesn't it affect more the people closer to the sides?

notatoad 2y ago
this is the reason that the leftmost and rightmost lanes of the pool aren't used for competition.
mb7733 2y ago
It does. This is why the fastest qualifiers get to swim in the middle lanes.

conductr 2y ago

My untrained eye has noticed. But I also think it's not really a big deal. There are so few events where the conditions are exactly the same every 4 years. Just kinda the luck of the draw if you happen to be competing in the most ideal conditions for WR setting in any event

kergonath 2y ago
Also, the important bit is fairness for all competitors. As the OP said, the same conditions affect everybody. I have little sympathy for the (few) swimmers complaining. They are not owed a world record and if they’re that good, they’re going to get one anyway.
- teractiveodular 2y ago
  Wouldn't the sides affect swimmers on the edge lanes next to them more? And is this one reason why the strongest swimmers are usually placed in the center lanes?
  - killingtime74 2y ago
    From the races I saw they specifically had the edge lanes (left most, right most) empty probably for this reason. I.e. 8 out of 10 lanes are used. I think one of them did have someone in one of those lanes because one of the qualifying heats was a dead heat.
  - lupusreal 2y ago
    Correct.
  - jseutter 2y ago
    Swimmers on edge lanes get affected more, and they leave the outside lanes unoccupied except for the first stage of qualifying.
  - aqfamnzc 2y ago
    Given the other comments I must be missing something, but wouldn't it be pretty much fair? The end swimmer gets one real neighbor and one simulated (reflection) neighbor from the wall. The middle folks have two real neighbors creating chop.

deleted 2y ago

[deleted]

ClassyJacket 2y ago

This is yet another reason on the huge list of reasons to keep the Olympics in Athens and just use the same facilities each time.

will1am 2y ago

[dead]

rightbyte 2y ago

> Bummer that it makes the meet feel slow but at least it generally affects all the swimmers equally Shouldn't the middle swimmer be worse off with "fast" pools? There would be less waves on the side lanes, compared to a "slow" pool where there are reflections.

myworkinisgood 2y ago

All swimmers are affected equally so I don't see a problem.

dredmorbius 2y ago

The one aspect which isn't equal at least amongst Olympic and other competitions is that a slower (or faster) pool will generate fewer (or more) records overall. One measure of the current games' bias would be the number of new Olympic and world records set as compared with other events --- prior or subsequent Olympics, and other world-level competitions within the current year, say. I expect the quants at sites such as 538 would be looking at this.

alistairSH 2y ago
Are records generally evenly distributed over time? Or do we see massive spikes due to single generational talents?
- lostlogin 2y ago
  > Or do we see massive spikes due to single generational talents? Various types of doping could cause this too. More positively, tech, diet and science changes could too in some sports too.
- dredmorbius 2y ago
  The more general tendency that I've seen and which has been noted in articles/studies I'm familiar with is generally technique and technology. Two examples of technique I'm aware of are the Fosbury Flop (1968) in the high jump, in which the jumper goes backwards over the bar (previously jumpers had gone forwards and feet-first, by 1968 with a sissors step), and heads-down technique in Australian Crawl "freestyle" swimming. Both dramatically improved results. The Fosbury Flop was enabled by the technological introduction of foam mats on the landing side of the high-jump. Without mats, landing on your back after clearing a 2m+ bar position was somewhat undesirable. Heads-down stroke in freestyle was in conjunction with freshwater (rather than salt) in swimming pools. Swimming heads-down without goggles in a salt-water pool burns the eyes quite strongly. With freshwater, and acrylic plastic goggles (acrylic being invented in the Great Plastics Boom of the 1930s). I'm not entirely sure when plastic swim goggles became widespread, though it may not have been until the 1970s, and the Montreal Olympics (1976) were the first to permit goggles. Track generally has also seen tremendous improvements in the track composition (loose cinders to rubberised surface). Swimming pools have hugely reduced wave action through wave-absorbing lane lines, deep gutters, inlet diffusers, and laser-guided construction ensuring accurate and consistent distance. That's on top of vast improvements in training, other equipment, doping (which has a very long history), professionalisation of sport (including the Olympics), and other factors. Talent is a component, but the overall phenomenon is highly multidimensional.

ldng 2y ago

Supposedly, all the Paris 2024 new accommodation were designed with re-usability for the general public after the Olympics. Is it possible that had an impact the swimming pool on design choices ? Put differently, are performance design at odd with more general/accessible design in the case of a swimming pool ?

physicsguy 2y ago
Given the abandonment of olympic venues all the way round the world, I don't think this is a bad thing. There's a lot in the book Soccernomics about how the economic value promised by politicians lobbying for hosting things like this rarely pan out.
- wildzzz 2y ago
  There's definitely economic value but it really only goes to the companies building facilities, the suppliers, and the hospitality industry immediately surrounding the events. In an already well-developed city, they aren't going to be building many new permanent structures. Many will be temporary that will eventually be torn down or just converted back to what they were originally. The money is spent, distributed to the companies that directly participated in the build up and run of the Olympics but there's little gain made after. A more interesting way of doing the Olympics would be to only allow for developing countries to participate in the selection process. Each country would be required to meet a certain level of funding to guarantee they can support the entire Olympics. Foreign investment would be encouraged. There would be a requirement for some aspects to be permanent construction, you couldn't just build a tent city for the athlete village. Then a name is picked randomly. The host country then receives major foreign investment, not just in sporting arenas, but in many areas of its economy. The Olympic committee could also collect dues from participating countries based on GDP that would go to the host country for economic development. It would basically create a lottery system for the economy of developing countries. The build up to the Olympics would create the infrastructure needed for future investment. This would likely require host cities to be selected much further out in advance. An oversight committee would observe the development and if milestones are not met, a host city from a developed country that does have the infrastructure necessary would instead be chosen.

jmalicki 2y ago

For point 2, wouldn't the reflections off the sidewalls create more issue with chop on the outer lanes than the middle?

palijer 2y ago
The outer lanes are where the slower swimmers are placed already anyways, so if they were having more chop, it wouldn't likely impact a medal contender and cause a big upset... Not saying that outer lanes haven't come out on top in the last, but less likely.

pdpi 2y ago

> at least it generally affects all the swimmers equally > 2. The sides. Does the water spill over the sides into the gutters, or smash into a wall and bounce back, creating more chop. My only experience with competitive swimming is playing some water polo some 25 years ago, but wouldn't that effect disproportionately affect the swimmers on the outermost lanes?

adolph 2y ago

Why aren't swimming lanes stadium shaped like running tracks or speed skating? Floor mounted LED indicators could advise competitors of the relative distance ahead and behind of nearest adversaries.

Yawrehto 2y ago

Off-topic but congratulations for qualifying for trials!

sschueller 2y ago

Shouldn't that be part of the standard "Olympic Pool" definition? Depth, water height on side and overflow etc. seem to be as important as the nittting of a football goal net.