David Blaine again!

[trux]

Originally Posted by Juan-John

Teach ME to be lazy and not go through the whole thread! :-)

Yes, sorry, I know, it is long and full of redundant posts, so it's not funny reading through it. Try reading this one, it describes the main differences: http://forums.deeperblue.net/710157-post62.html (post #62)

[blaiz]

Ive got a question... In the last forum about David Blaines record breaking attempt it was noted that the "samba" he displayed at the end of the dive was very violent and could have been attributed to O2 poisoning. So during this attempt, how was he so calm and collected after his dive?

He literaly came out of the ball, grabbed the micraphone and talked about how good he felt. You could tell that he was trembling a bit but I would have thought that he would have been all out convulsing.

[trux]

There are many factors playing a role at oxygen toxicity. Especially the length of exposure to O2, and the partial pressure (it means also depth) are the most important factors. Fatigue, nitrogen saturation, CO2 saturation, physical effort, etc will play a role too. It was not quite clear how long Blaine ventilated under oxygen at the previous attempt, or whether he breathed nitrox during some periods or the entire UW stay, but one is clear: he could not have surfaced without desaturzing nitrogen with O2 after a week under water in depth up to 2.8m (I believe that was the maximal depth). And since he spent most of the time sitting or laying on the bottom, he certainly was pretty well charged with N2. So either he's overdone it with the O2 exposure, or the other factors hit him.

[trux]

Originally Posted by trux

I do not know what information exactly you are looking for, but your listeners may want to know that air contains 21% of oxygen (it is ~20% once you start inhaling it, because of the added water vapor). It means 5 times less oxygen than if you inhale pure oxygen.

I just want to correct my statement: the five time ratio is valid for comparing air with oxygen outside the lungs. When in lungs, the the hypothetical maximal partial pressure of O2 in air is 160 mmHg (21% from the atmospheric pressure of 760 mmHg). In reality it is significantly less: typically around 100 mmHg, in rest little bit more, and with hyperventilation it can raise to some 130 - 140 mmHg (possibly slightly more with very strong hyperventilation).

The difference in the PAO2 is due to water vapor and CO2 content in the alveoli. It would be about the same difference when breathing O2: 760 mmHg - 60 mmHg = 700 mmHg, or up to ~740 mmHg at hyperventilation (or possibly even little bit more at long and profound hyperventilation, which is needed for O2 apnea).

Additionally, the partial alveolar pressure of oxygen cannot drop below some 50 mmHg (the value may differ depending on conditions). At O2 apnea the minimum may be higher if the pre-apnea hyperventilation was not sufficient and the CO2 grows over the level at normal apnea, but let's assume the same level.

So at air apnea with moderate hyperventilation, we can use approximately 130 mmHg - 50 mmHg = 80 mmHg of oxygen. At O2 apnea, with strong hyperventilation, you can hypothetically use 740 mmHg - 50 mmHg = 690 mmHg of oxygen. The ratio of oxygen to plain-air capacity would be then 690 / 80 = 8.6 and not 5 as I previously stated. That would hypothetically allow an apnea of almost an hour and half at the best breath holders!

Of course, as I already mentioned in the post #62, there are many other factors playing a role, and also the consumption will be higher, so the real maximum certainly cannot reach that theoretical level, and will be much lower. The basic problem, as already mentioned, will be the CO2 level. However, the currently achieved ratio of just about 2 (even less at Tom Sietas), still seems to be quite far from the possibilities O2 offers.

[BennyB]

Don't you people have jobs??

[Erik]

Hahahahaha!

[Bill]

Not me Benny. I started working my first job (part time, six days a week) in the summer of '48. In the summer of '99 I decided that I really didn't like working. Been a freedive rope-rat ever since.

[hteas]

Hi Bill
And a good one at that!
Howard

[tbgsub]

Im glad I dont have a TV! I didnt miss it, and I am goinng freediving this weeekend on ROTA in the CNMI islands where I live. I try to be in the ocean freediving or spearfishing two days out of the week, static apnea (especially O2 assisted) Records mean little to me really, but Ill be sure to tell the fish that a human held his breath for 17 minutes, I doubt they will be impressed. I am impressed by practical dynamic records, like the constant weight, and no fins records, because they are bodies in motion; atheletes who are refined for activity on a breath hold. I revere a 3 minute dynamic as much more of an accomplishment than a 5 min static anyday!!

I am curious how long that record will last. How long till someone who allready has a 10minute air hold decides to look into breaking the O2 record by serious times? I wonder...

anyone else wonder with me??........

it cant be too long can it?

at any rate I dont think any O2 record is very practical in a real world sense.

best of luck to you all.

TBGSUB

I'm going fishing! later!

[efattah]

Pure oxygen breath-holding does in fact have a very practical application, primarily as a way to replace commercial scuba divers with freedivers. There is a complicated method to freedive on pure oxygen without getting oxygen toxicity. This could allow extremely deep freedives up to 300m deep without any requirement for decompression. I have been working on this concept for a while, and I hope to get some data soon.

Disclaimer: Please don't try pure oxygen stunts at home or in the ocean!

[trux]

Originally Posted by efattah

... primarily as a way to replace commercial scuba divers with freedivers.

Yes, that's a great idea (although I am not sure if possible). It is true that it would allow extremely quick operations, so it would be especially interesting for emergencies. Just dropping the diver with a fast sled, scooter, or an open minisub to the spot, and then pulling him quick back to the surface again. Where a tech diver would need for such extreme dive + deco probably a full day + long planning and preparation + complex and expensive technical backing, with a freediver it could be done within a few minutes, and with negligible material costs.

That assumes though that with the method you work on, the diver could stay a couple of minutes at the bottom to perform some work (possibly physically and/or mentally demanding). If you count on emptying the lungs during the descent (similarly as Herbert does), minimizing so the gaseous oxygen volume, and avoiding the creation of free oxygen radicals and their toxicity in that depth, then do you think the diver would be really able to work down for more than a very short moment?

I also wonder if, besides the toxicity, also the narcotic effect of oxygen would not play a role. But if the volume of gaseous oxygen (and that dissolved in liquids) was really low, then perhaps it would not matter either (I assume that O2 bound to hemoglobin poses no toxic or narcotic risk, but am not entirely sure if it is really true for both). Did you find some studies about similar or related experiments (oxygen under great PP), Eric?

[Whopperhead]

For those who haven't seen it yet- and want to:

YouTube - DAVID BLAINE Breaks World Record on...

YouTube - DAVID BLAINE Breaks World Record on...

YouTube - DAVID BLAINE Breaks World Record on...

[trux]

Thanks for the links. Whopperhead!

I am rather surprised Blaine was allowed by Guinness judges making the breath-up and the final breath + packing under water. Well, the depth was not big (the lungs just in about 1m below the surface), but it already means he could inhale around 10% more oxygen. Now, I did not see the last record of Peter Colat, but at all the O2 records of Tom Sietas, he started on the surface and not below it. It does not seem to be very fair, but then again Guinness is no authority, and they have no clue, so I doubt they care whether their records are done in equal and fair conditions.

[efattah]

The old 1950's record of 13 minutes and some seconds (Guinness) was done at the bottom of the deep end of a swimming pool, with the diver breathing 100% O2 at the bottom of the pool, and taking the last breath down there as well. That would give much more advantage than what Blaine did.

[SEDATE]

it is very good illusion
He leave out something ..There is no jelly which can stand 23min+17min=40min in water ..When you use hardest one..the water will solve after 3 or 5 min ..xea water will start immediatly
after he sit on tube(before he start speaking) .it is easy to see shining jelly consist of brillantine on his head
There was a smillar trick on tv before.he stayed in tube 20 min here.. My idea there was another tube in tube. i smiled too much.. at the end he shaked his hand like blaine.. he is not good at david copirfield but not bad
Blain looks clever he is not acting quickly but not acting slowly, too. he is jumping on side of the tube using his hand after xxx min breathold : D
meanwhile there should be 4 camera front-side-up and very close one to blain face(i mean head shot cam) ..anyway.. it is so-so good trick