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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

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.

echoangle 2y ago
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.
- _heimdall 2y ago
  Rereading your last comment and I think I just misunderstood it, sorry! I first read it as saying a study would be needed to know if something about the pool was anything them down, but you were still specifically talking about whether the depth is the issue.
  - echoangle 2y ago
    Yes, I think a lot of people misunderstood the point, I’m ESL so maybe i didn’t write it up properly. I was just talking about the effect of pool depth, not doubting that something is different this time.
    - _heimdall 2y ago
      For what it's worth, my misunderstanding wasn't actually due to your message at all. I simply focused on the first sentance and lost the next sentance that tied it back to pool depth. Your English is actually very, very good! I wouldn't have guessed that it is a second language for you.
- freejazz 2y ago
  So to be clear, you have no idea, you just insist on discounting the experiences of the swimmers because you can?
  - _heimdall 2y ago
    I misread the earlier posts here when I started dow this comment path, but I actually agree with them. There seems great evidence, including the swimmers', experience to say that something about the pool slows them down. It seems less clear that the depth is the issue, it could be something else or a combination of factors related to the pool that cause it.
- mmmrtl 2y ago
  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.
  - ff317 2y ago
    Yeah but it's not just "water", as in plain H2O. All water has different things dissolved or mixed into it. In pools there's commonly several chemicals added to that water: to correct the pH for humans, to sanitize, control corrosion of metal, avoid calcium deposits on other surfaces, etc. It's entirely possible that the additives in the water could be way off of normal and somehow affect things like viscosity or surface tension.
    - throwaheyy 2y ago
      No, it isn't.
  - echoangle 2y ago
    It’s not demineralized water though, have you ever added a tiny bit of soap to water and it immediately reduced the surface tension? I’m not saying there’s soap in the water in France obviously, but there’s a lot of other additives that could theoretically affect water properties even with a fixed temperature. Edit: for example, compare salt and fresh water properties here: https://ittc.info/media/4048/75-02-01-03.pdf#page2 https://ittc.info/media/4048/75-02-01-03.pdf#page2 At 25 degrees, fresh water has a Viscosity of 0.000890 Pa⋅s and sea water has 0.000959 Pa⋅s. That’s an 8% difference in viscosity by adding NaCl to water. Is it that strange that there could be a 1% difference in viscosity for example by having different additives in the pool water?
thaumasiotes 2y ago
> 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. This is a weird standard. Out of 200 people doing anything, how many do you expect to set a personal record? Say you drive to the grocery store. Are you setting a time record for the trip more than 0.5% of the time?
- Scarblac 2y ago
  These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day. Tbh I don't do much of that sort of thing for my grocery store trips at all.
  - thaumasiotes 2y ago
    > These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day. The only way this could actually happen is if they intentionally sandbag their performance starting several years in advance -- and continuing indefinitely -- which would prevent them from qualifying for the Olympics in the first place. It's not a possibility.
    - BoringTimesGang 2y ago
      Or it could happen that the training, diet and injury-avoidance regime for long term success is different from that for short term optimisation. As it is for many, many sports.
      - thaumasiotes 2y ago
        All right. The 2020 Olympics were canceled and a replacement event was held in 2021. According to this theory, there should have been a shocking drop in personal records set at the 2021 event. Was there?
        2y ago

echoangle 2y ago

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.

_heimdall 2y ago
Rereading your last comment and I think I just misunderstood it, sorry! I first read it as saying a study would be needed to know if something about the pool was anything them down, but you were still specifically talking about whether the depth is the issue.
- echoangle 2y ago
  Yes, I think a lot of people misunderstood the point, I’m ESL so maybe i didn’t write it up properly. I was just talking about the effect of pool depth, not doubting that something is different this time.
  - _heimdall 2y ago
    For what it's worth, my misunderstanding wasn't actually due to your message at all. I simply focused on the first sentance and lost the next sentance that tied it back to pool depth. Your English is actually very, very good! I wouldn't have guessed that it is a second language for you.
freejazz 2y ago
So to be clear, you have no idea, you just insist on discounting the experiences of the swimmers because you can?
- _heimdall 2y ago
  I misread the earlier posts here when I started dow this comment path, but I actually agree with them. There seems great evidence, including the swimmers', experience to say that something about the pool slows them down. It seems less clear that the depth is the issue, it could be something else or a combination of factors related to the pool that cause it.
mmmrtl 2y ago
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.
- ff317 2y ago
  Yeah but it's not just "water", as in plain H2O. All water has different things dissolved or mixed into it. In pools there's commonly several chemicals added to that water: to correct the pH for humans, to sanitize, control corrosion of metal, avoid calcium deposits on other surfaces, etc. It's entirely possible that the additives in the water could be way off of normal and somehow affect things like viscosity or surface tension.
  - throwaheyy 2y ago
    No, it isn't.
- echoangle 2y ago
  It’s not demineralized water though, have you ever added a tiny bit of soap to water and it immediately reduced the surface tension? I’m not saying there’s soap in the water in France obviously, but there’s a lot of other additives that could theoretically affect water properties even with a fixed temperature. Edit: for example, compare salt and fresh water properties here: https://ittc.info/media/4048/75-02-01-03.pdf#page2 https://ittc.info/media/4048/75-02-01-03.pdf#page2 At 25 degrees, fresh water has a Viscosity of 0.000890 Pa⋅s and sea water has 0.000959 Pa⋅s. That’s an 8% difference in viscosity by adding NaCl to water. Is it that strange that there could be a 1% difference in viscosity for example by having different additives in the pool water?

thaumasiotes 2y ago

> 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. This is a weird standard. Out of 200 people doing anything, how many do you expect to set a personal record? Say you drive to the grocery store. Are you setting a time record for the trip more than 0.5% of the time?

Scarblac 2y ago
These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day. Tbh I don't do much of that sort of thing for my grocery store trips at all.
- thaumasiotes 2y ago
  > These athletes plan their whole training and fitness regime for years so that they are at their absolute best at this particular day. The only way this could actually happen is if they intentionally sandbag their performance starting several years in advance -- and continuing indefinitely -- which would prevent them from qualifying for the Olympics in the first place. It's not a possibility.
  - BoringTimesGang 2y ago
    Or it could happen that the training, diet and injury-avoidance regime for long term success is different from that for short term optimisation. As it is for many, many sports.
    - thaumasiotes 2y ago
      All right. The 2020 Olympics were canceled and a replacement event was held in 2021. According to this theory, there should have been a shocking drop in personal records set at the 2021 event. Was there?
      - 2y ago