Is a 'slow' swimming pool impeding world records? • Hacker News Board

Re: Is a 'slow' swimming pool impeding world records?

#101

Post by stingrae » Wed, Jul 31, 2024, 6:42 PM UTC

AtlasBarfed wrote: post #83

croes wrote: post #80

Earlier quoted context omitted.

Maybe they all change their behavior because they know the pool is less deep as they are used to. Some kind of placebo effect or fear of coming to close to the ground. Many athletes are superstitious.

There's Olympic gold medals on the line. People are going absolutely as hard as they can. There's no way an Olympic pool for the actual Olympics should be that shallow. If athletes prefer a deep pool, the pool should be deep. Swimming is one of the premier sports at Olympics. It's also a facility that has one of the most reuse if built properly. You don't think a Paris aquatic center wouldn't get tons of reuse in wor…

> It's also a facility that has one of the most reuse if built properly. You don't think a Paris aquatic center wouldn't get tons of reuse in world championships and other types of top end level events if they'd built a fast pool

They didn't build a dedicated aquatic center. "The pool here in suburban Paris — a temporary vessel plopped into a rugby stadium"

Re: Is a 'slow' swimming pool impeding world records?

#102

Post by MisterBastahrd » Wed, Jul 31, 2024, 6:43 PM UTC

Well, if this is the case, then wouldn't a person who gets out to an early start have a tremendous advantage over the rest of the group since she'd be swimming largely without interference for the first length of the race while the trailers would have more turbulance? Also, I've never understood why there aren't more standards for Olympic tracks / pools / gear. For example, everyone should be required to train in and wear identical apparel when in a timed event like swimming so that nobody gets a technological advantage.

Re: Is a 'slow' swimming pool impeding world records?

#103

Post by Scoundreller » Wed, Jul 31, 2024, 6:49 PM UTC

samldev wrote: post #5

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 struggli…

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.

Re: Is a 'slow' swimming pool impeding world records?

#104

Post by beAbU » Wed, Jul 31, 2024, 6:56 PM UTC

AtlasBarfed wrote: post #83

croes wrote: post #80

Earlier quoted context omitted.

Maybe they all change their behavior because they know the pool is less deep as they are used to. Some kind of placebo effect or fear of coming to close to the ground. Many athletes are superstitious.

There's Olympic gold medals on the line. People are going absolutely as hard as they can. There's no way an Olympic pool for the actual Olympics should be that shallow. If athletes prefer a deep pool, the pool should be deep. Swimming is one of the premier sports at Olympics. It's also a facility that has one of the most reuse if built properly. You don't think a Paris aquatic center wouldn't get tons of reuse in wor…

The pool is a temporary structure, La Defence is a multi purpose venue. The pool is literally a tub on top of a rugby field.

Perhaps this is why its shallower than normal.

Re: Is a 'slow' swimming pool impeding world records?

#105

Post by mmmrtl » Wed, Jul 31, 2024, 6:58 PM UTC

echoangle wrote: post #39

_heimdall wrote: post #29

Earlier quoted context omitted.

You don't necessarily need to do an in depth study of the pool when every Olympic swimmer in it fails to meet their own personal records. A study may be useful to understand why depth still matters beyond the 2m point, but a study isn't needed to show that swimmer performance is impacted.

Or maybe there’s something else going on? There are a lot of other variables in a pool except depth, no? Maybe water tension, density, viscosity? Someone else mentioned the walls of the pool also influencing the wave properties in the pool. Just noticing the pool being more shallow and people swimming slower doesn’t mean that’s the reason.

Explain to us how water "tension", density, and viscosity are variables that would change? It's just water, and temperature is set at ~25 C. The shape of the pool and gutter setup are the only major factors at play, assuming the filtration system isn't causing major currents.

Re: Is a 'slow' swimming pool impeding world records?

#106

Post by madaxe_again » Wed, Jul 31, 2024, 7:04 PM UTC

samldev wrote: post #5

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 struggli…

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.

Re: Is a 'slow' swimming pool impeding world records?

#107

Post by RaftPeople » Wed, Jul 31, 2024, 7:14 PM UTC

swores wrote: post #91

AtlasBarfed wrote: post #83

Earlier quoted context omitted.

There's Olympic gold medals on the line. People are going absolutely as hard as they can. There's no way an Olympic pool for the actual Olympics should be that shallow. If athletes prefer a deep pool, the pool should be deep. Swimming is one of the premier sports at Olympics. It's also a facility that has one of the most reuse if built properly. You don't think a Paris aquatic center wouldn't get tons of reuse in wor…

Placebo or fear can absolutely be a possibility regardless of how badly they want to do well because it's the Olympics. Firstly, if a swimmer were to wrongly worry about hitting the floor even if there is 0% that any of their races ever saw them go as low as this floor, it could be in the back of their mind that going as low as they usually do might cause them problems and therefore seem logical to avoid. Secondly, h…

> Placebo or fear can absolutely be a possibility regardless of how badly they want to do well because it's the Olympics.

But it seems unlikely all swimmers would be impacted equally by psychological effects. Some thrive some wither, lots of variation.

Re: Is a 'slow' swimming pool impeding world records?

#108

Post by ben7799 » Wed, Jul 31, 2024, 7:26 PM UTC

beAbU wrote: post #104

AtlasBarfed wrote: post #83

Earlier quoted context omitted.

There's Olympic gold medals on the line. People are going absolutely as hard as they can. There's no way an Olympic pool for the actual Olympics should be that shallow. If athletes prefer a deep pool, the pool should be deep. Swimming is one of the premier sports at Olympics. It's also a facility that has one of the most reuse if built properly. You don't think a Paris aquatic center wouldn't get tons of reuse in wor…

The pool is a temporary structure, La Defence is a multi purpose venue. The pool is literally a tub on top of a rugby field. Perhaps this is why its shallower than normal.

I had read in one of the other articles about this issue that you are correct, that is exactly why the pool is shallower than usual.

The building was going to need structural modifications to make the pool standard depth.

Re: Is a 'slow' swimming pool impeding world records?

#109

Post by AnthonBerg » Wed, Jul 31, 2024, 7:27 PM UTC

echoangle wrote: post #42

boringg wrote: post #30

Earlier quoted context omitted.

While part of it may be true. The athletes who spend 1000s of hours can probably intuit something being different.

The can maybe intuit being slower, but I doubt they can accurately tell you that it’s because of a different pools depth. There are a lot of other variables that could be the reason.

Do you have links available to any peer-reviewed scientific literature on which you base your theory that – just to make sure we’re on the same page — the theory that it is difficult to the point of impossibility for people to correctly ascertain that the depth and construction of the pool they swim in has no effect on their swimming dynamics, efficiency, and competitive performance?

Re: Is a 'slow' swimming pool impeding world records?

#110

Post by bobthepanda » Wed, Jul 31, 2024, 7:30 PM UTC

Someone wrote: post #89

AtlasBarfed wrote: post #83

Earlier quoted context omitted.

There's Olympic gold medals on the line. People are going absolutely as hard as they can. There's no way an Olympic pool for the actual Olympics should be that shallow. If athletes prefer a deep pool, the pool should be deep. Swimming is one of the premier sports at Olympics. It's also a facility that has one of the most reuse if built properly. You don't think a Paris aquatic center wouldn't get tons of reuse in wor…

> People are going absolutely as hard as they can. Not necessarily. If they think the pool is slower, they’ll think they will have to swim for a bit longer, and may (possibly subconsciously) adjust their power output to allow for having something left when they have swum for as long as they think it would take them in a fast pool.

In fact a lot of the upcoming olympics specifically don’t have as much new construction because of the white elephant criticisms of the Olympics leading to most developed host candidates declining and/or having hosting referenda rejected.

The Athens 2004 and Rio 2016 venues in particular are not doing very well post-Games.