191–200 of 205 posts
My first, brief, dive to 135 feet (41m) was in 1976 off the coast of Cozumel. I was in a group led by a dive master and we quickly descended, swam through a large ring shaped coral structure at around 135ft, and started our ascent. More accurately, all but one of use started our ascent. Back then, of course, we had to rely on the Navy dive tables for maximum safe bottom time (just 10 min from entry at the surface to…
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As far as I understand, historically, alcoholic beverages were primarily invented and used as a water disinfectant. Rum was used in British navy to disinfect fresh water in barrels. Wine was used to dilute it in water till the 20th century. Fun fact, in ancient Greece people who drank pure wine (not diluting it in water) were considered alcoholics and could be publicly denounced. Beer was used as a typical beverage a…
I'm not sure I buy your claim that rum was ever used to 'disinfect' fresh water on British Navy ships. The 'grog' mix they used was not of sufficient ABV to disinfect the water, as it was handed out at a 4:1 ratio of water:rum. It was moreso about making the daily rum ration difficult to hoard, and much more efficient to transport than beer or wine.
And it wasn't always rum. If a vessel was on foreign service and rum was unavailable then the crew would be issued an equivalent amount of other booze.
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Don't be ridiculous, no one is going to ban helium.
The delivery mechanisms for a nitrogen-free air – be they personal respiration devices or sealed environments – could be onerously regulated, or effectively banned for certain places/purposes. It can be hard to confine helium, and its presence can make some electronics malfunction: https://www.ifixit.com/News/11986/iphones-are-allergic-to-he... Occasional helium shortages, and the characterization of terrestrial heli…
Reminds me of Shadow Divers. IIRC they were instrumental in coming up with a breathing mix to counteract these effects https://www.amazon.com/Shadow-Divers-Adventure-Americans-Eve...
A 10% increase in reaction time could be fairly significant in many sports. Could we start seeing football players, sprinters, or baseball players breathing from masks between plays?
You already see this. Google "NFL oxygen masks". I'm sort of surprised I haven't heard about it in the context of shorter physical sports: I'd wonder what effect it would have on an 100m/200m/400m time or shotput distance to oxygen saturate like free divers do.
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Maybe it remains underexplored because if you find a significant effect and popularize it, then the substance gets banned. The people interested in using stuff like this have an incentive to avoid scientific research on the subject. Hell, even NAC almost got banned recently.
Don't be ridiculous, no one is going to ban helium.
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Don't be ridiculous, no one is going to ban helium.
They'll just make using it this way illegal and scrutinize purchases/suppliers as usual. NAC has been an over the counter supplement since the 70s and only an uproar from people a few years ago kept it unbanned by the FDA.
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You already see this. Google "NFL oxygen masks". I'm sort of surprised I haven't heard about it in the context of shorter physical sports: I'd wonder what effect it would have on an 100m/200m/400m time or shotput distance to oxygen saturate like free divers do.
You don't see NFL players using oxygen masks much anymore. Some people used to believe that it accelerated recovery from hard exertion but experiments have shown that it makes no significant difference. It's a placebo effect if anything.
> Some people believe it but experiments have shown that it makes no significant difference. It's a placebo effect.
I cannot count the amount of times I heard this on medicines and treatments. A too high percentage of them turn out to be not plasebo after a short amount of time. I believe “the experiments shown is plasebo” is the the first line of defense of the medical status quo against change.
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I've always wondered if fighter pilots ever had a system to pump different gases into their masks whenever they encounter a high-stakes situation.
Here comes the juice!
Just completed my deep (40m/120ft) diver certification. A significant amount of the course was focused on nitrogen narcosis, and how to handle/detect it. Apparently, some divers will start feeling the narcotic effect between 20-30m. Beyond 30m, a significant amount of divers can feel the effects. Beyond 40m is the realm of tech diving, with trimix (helium/nitrogen/oxygen) or even heliox (helium/oxygen). I know nothin…
Fun fact is the narcotic effect is very sudden for most people at a certain depth (30m for me) and also clears just as quickly. It's more pronounced if you are tired and/or the water is cold.
Helium is very expensive like you say. Normal air fills are like $10 AUD, a tank of Trimix can be hundreds. https://www.scubadoctor.com.au/trimix-requested-mix.htm. Normally you would need 3 or more 12L tanks filled with 240L of gas in each, depending on the dive.
Most people who use it a lot do rebreather diving, where you can recycle a few liters over and over. The rebreather costs $10k AUD + training though and has many more parts that can fail. One is the oxygen sensor, that has limited lifespan and if it fails and you don't catch it quick enough can kill you (you switch over to bailout which is a backup gas supply).