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

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

#51

Post by echoangle » Tue, Jul 30, 2024, 12:32 PM UTC

MrPatan wrote: post #43

echoangle wrote: post #25

Earlier quoted context omitted.

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. B…

Intuition forms because it works. When it doesn't it's remarkable to the point of writing books and movies about it.

Intuition is a heuristic that lets you form decisions fast without a lot of effort. But I wouldn’t say having a wrong intuition is that uncommon that I would write a book every time I had a wrong intuition. I have intuitions all the time about stuff and when I check, it turns out I was wrong. That’s also why I wouldn’t make important decisions based purely on intuition. Intuitions form because sometimes, you need quick decisions and it’s better to do something wrong some of the time than take longer to make a better decision.

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

#52

Post by aziaziazi » Tue, Jul 30, 2024, 12:33 PM UTC

dp-hackernews wrote: post #9

loloquwowndueo wrote: post #3

Earlier quoted context omitted.

FUD. Vegan food also has protein.

All protein derived from veggies are considered incomplete when compared to animal derived protein, which also require substantially more volume to obtain the same nutritional content. You only need to look at the amount of waste (feces) between a veggie based diet and an animal based diet - the difference is staggeringly different. I.e. far less waste is produced, because far less is required when eating animal base…

> All protein derived from veggies are considered incomplete when compared to animal protein

You’ be interested to have a look at amino acid in quinoa, tempeh and most of the mushrooms

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

#53

Post by dsr_ » Tue, Jul 30, 2024, 12:40 PM UTC

viraptor wrote: post #27

lou1306 wrote: post #23

Earlier quoted context omitted.

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…

> they are the worldwide foremost experts on competitive swimming On swimming, sure. But not fluid dynamics. It's a bit like music listeners shouldn't be treated as experts on music quality, or you'll get the audiophile nuts who need gold connectors. Some combination of personal experience for comfort and objective measurements for performance would be much better.

It's strange that you would pick on gold connectors. Gold is an excellent conductor and does not corrode in air, so it makes a great plating material. In the quantities needed for plating, it's not too expensive, either.

Silver corrodes relatively quickly and is expensive; that's a bad tradeoff against copper, which is much cheaper and nearly as conductive. So: gold-plated connectors on copper wires are extremely common.

None of that makes an audible difference, as it turns out: humans can't tell the difference between silver, copper, gold, aluminum, or even iron wires at audio frequencies and realistic (sub-kilometer) lengths with comparable resistance. All the advantages are material costs vs longevity without maintenance.

Also, most music listeners are not experts on music quality or sound reproduction quality (two very different things). Many music listeners are experts on their own preferences. Everyone is entitled to their own preferences.

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

#54

Post by loloquwowndueo » Tue, Jul 30, 2024, 12:44 PM UTC

dp-hackernews wrote: post #9

loloquwowndueo wrote: post #3

Earlier quoted context omitted.

FUD. Vegan food also has protein.

All protein derived from veggies are considered incomplete when compared to animal derived protein, which also require substantially more volume to obtain the same nutritional content. You only need to look at the amount of waste (feces) between a veggie based diet and an animal based diet - the difference is staggeringly different. I.e. far less waste is produced, because far less is required when eating animal base…

Dunno man, I poop a lot more (and stinkier) when I eat more meat as compared to vegetarian dishes.

Considered incomplete by whom? References?

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

#55

Post by defrost » Tue, Jul 30, 2024, 1:03 PM UTC

sshine wrote: post #41

defrost wrote: post #18

Earlier quoted context omitted.

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.

> 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.

    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

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

#56

Post by haunter » Tue, Jul 30, 2024, 1:05 PM UTC

>Could we have seen a sub-4 minute 400 IM by Marchand

Marchand beat the rest by more than 5 seconds in the end but basically "gave up" after 300 meters. Shoulda coulda woulda but he didn't need to push himself at all for the gold (his last split was the 2nd worst against everyone else).

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

#57

Post by _heimdall » Tue, Jul 30, 2024, 1:51 PM UTC

echoangle wrote: post #47

_heimdall wrote: post #46

Earlier quoted context omitted.

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.

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.

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.

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

#58

Post by 5555624 » Tue, Jul 30, 2024, 2:04 PM UTC

candlemas wrote: post #50

The pool in Beijing was said to be fast (25 world records broken). But they were also using a now banned swimsuit. https://www.npr.org/2008/08/10/93478073/chinas-olympic-swimm...

But you don't need to compare these results to 2008. It's not the suit. There wasn't a banned swimsuit used by everyone in Tokyo three years ago. (The 2020 Olympics were postponed a year.) As the first sentence of the article says, the eight men in the men’s 100-meter breaststroke final would have finished no better than eighth in Tokyo. Mactinenghi won in 59.03 seconds, more than two seconds slower than the current world record (and slower than the then-world record set at the 2008 Olympics).

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

#59

Post by lou1306 » Tue, Jul 30, 2024, 2:07 PM UTC

echoangle wrote: post #25

lou1306 wrote: post #23

Earlier quoted context omitted.

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…

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. B…

Sure, it is not necessarily the pool depth. But that is almost surely the one factor that deviates the most from the "average". Paris is 50-100m above sea level which is pretty unremarkable gravity- and pressure- wise. Its water is unlikely to be macroscopically different from that of other French or Western European cities.

I am aware the above may be proportionality bias, but at the same time there is some kind of "reverse proportionality bias" at play here: the assumption that since the effect of a shallow pool are too small, they can't significantly affect the athletes. Human behaviours are very nonlinear, and even very small sensory inputs may very well "throw off" an experienced swimmer.

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

#60

Post by johnp314 » Tue, Jul 30, 2024, 2:17 PM UTC

mysterydip wrote: post #11

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…

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

It would be interesting to see a comparison of lane effect, say for instance, re-running a race after let's say a weeks rest with the top finishers now nearest the side walls and the lowest finishers in the center lanes. Oh and for incentive, let's say the average of their two times determines the winners.