Why NASA kept using 100% oxygen after Apollo 1 ...
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- Опубликовано: 23 янв 2024
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My last video on Apollo oxygen supply received a lot of comments from people claiming NASA stopped using pure oxygen after the Apollo 1 accident , which is actually a common misconception
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#globe #science #flatearth #apollo 
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dave while everyone appreciates these videos they ironically seem to have no effect on flat earthers? it's like flat earthers come in here with a preconceived outcome in their head, they aren't going to listen to what you say no matter how many ways you tell them they're wrong about something. in all of these videos i just sort by newest comments and see a ton of flat earthers completely disregarding everything you said and calling you a shill even though it's just science proving them wrong. and ironically they all spout "do your own research" but they deny actual research, and the "research" that they actually want you to do is watching some BS flat earth video with all of their points having been debunked by actual research
it's like people have the high horse of thinking that they know some huge government coverup or that they "know the truth" and they don't want to embarrassingly accept that they're wrong so they lock themselves in flat earth echo chambers and convince themselves they're right
it's like people have the high horse of thinking that they know some huge coverup or that they "know the truth" and they don't want to embarrassingly accept that they're wrong so they lock themselves in flat earth echo chambers and convince themselves they're right
Well done!
Researching the data had to take a vast amount of time, and getting it organized to prove the data, had to be excessive.
I remember reading all those replies to and from HQ, and it requires careful reading so you do not misread data.
Much appreciated!
Also, the Apollo doors used to open inward, and cabin pressure kept them prisoner when the fire started.
Sad it always requires tragedy to fix problems.
They have no effect because they contain pure, unadulterated garbage created to produce money for the creator.
In this video, was it mentioned that Gus Grissom went home the night before this tragedy and said to his wife, " Honey, the CIA were all over the launch pad today, I've never seen them there before." ? This was days after Grissom, as Head astronaut for Apollo, called an impromptu, unofficial press conference in which he produced a model of Apollo with a lemon on top saying it was a hopeless task ? Or did Dave play the recording of Gus asking tower, "how are we going to get to the moon if we can't talk between two buildings"? He had to repeat that because nothing was working. Without watching, I know theses things aren't mentioned.
So why bring them up ? Because it puts into perspective, the lengths to which people will go to make money. This is a tragedy and needs to stop. This creator absolutely knows that man has never walked on the moon, but to admit that would cut off his grift. Shame on you Dave, its not what you say most of the time, its what you don't say. Your last video on bubbles should have included the reflection of a scuba diver in the astronaut's face visor and didn't, neither did you mention the Brevard Community and its hearings, I'm sure without watching that you didn't mention any of that or the footage of the bubbles behaving as if underwater.... because it was under water. I cannot wait until your video calling AI fake, when is that one coming ?
I was one person that commented about Apollo not using pure oxygen after Apollo 1.
I deleted the comment, however, within minutes because it only took about two of them on the Googles to realize my mistake.
It's sad and dissapointing that so many others didn't bother to check, but not surprising.
I was also in the Apollo 1 group, but did not comment. This latest video was great to clear up the misunderstanding
To be fair, you first commented and only then checked. So you're in a bag that's very near to the bag you put those people in
@@isais207
Yep.
I've replied without checking first.
But, I checked.
It also takes literally a few second to ask ChatGPT, which gives the correct answer.
@@isais207 Checking your ideas and amending them when they're wrong is what's important here.
I always knew they used pure O2, but never how it worked. Thanks for such a clear and concise explanation, as always.
I think Dave is now my favorite debunker. He designs his arguments very well. His graphics are very clear. His tone is respectful. His personality is engaging and trust-inspiring. Another great video, Dave!
Plus he has a gorgeous companion demanding his attention. 😼
I like him and SciManDan
@@BWA85 yes. I also like when Professor Dave does a beatdown, but McKeegan keeps it very positive, which, ultimately, is better. In the end, only kindness matters.
@@onegemini420 agreed. I was filming something Sunday. My cat is always underfoot. Thinking of Dave's example, I picked up Hobbes and held him for the intro. Might become a thing...
@@jeffmartin-g8r After Professor Dave started calling everone in the comments "homophobes / transphobes" (and trying to push some weird bs and woke stuff) for saying normal biologically accurate things, he was kinda a lost case to me 😅Maybe his whole video and then illogical attacks were just made on high or smth xD Idk.
Thank you Dave! As a chemist, after the prior video I was screaming at the screen "mention partial pressure!"
Scuba diver but same.
Haha. As a non chemist but having learned about this too before I also was like ok Dave when do you drop the term partial pressure. But yeah to be fair I think I learned about this when I learned diving.
Did you guys take a nitox diver class? That's here you really learn about partial pressure.
@@xidarian Yes. Though if you don't learn it in regular diving, you have a problem.
@@xidarian nitrox, but yes I did. But as someone above me mentioned you learn this in the basic diving course already.
Don’t worry Dave, I’m sure Ogxyen will forgive you for misspelling it’s name. 😉
Its
@@atticstatticoxagin will probably forgive grammar mistakes to
Oxygen has a hit team, they will arrange his molecules!
RESISTANCE IS FUTILE!
Speling is overrated. Though I’ve heard that commas save lives.
@@MichaelOninesSurely you meant “too”.
I will never understand why anyone would want to erase the combined worldwide effort of the hundreds, if not thousands, of scientists, mathematicians, engineers, mechanics, etc. that enabled space travel. The more I learn the more impressed I get.
They won’t achieve anything near it, so they don’t want anyone else to have done so
Millions
One fun fact is that NASA still uses pure oxygen environment but on its EVA suits. Although for that, pretty much everyone has to have it that way because the high pressure of the suit on a realistic Nitrogen/Oxygen atmosphere would mean the suit becomes too rigid to move. There's also an advantage that came from using pure oxygen environment on Gemini and Apollo and it is that they wouldn't need any conditioning needed prior to a spacewalk because both the cabin and the spacesuit were pure oxygen environments. For the Space Shuttle and now also on the ISS, astronauts needed to spend several hours or even up to half a day purging the nitrogen out of their bodies in order to be able to perform an EVA. This sort of problem becomes quite a pain in the back when it comes to emergency EVAs and the upcoming Artemis Human Landing System already introduces a scheduled pre-breathing period well before the landing occurs in case they need to perform an emergency EVA right after landing. It seems crazy now that they used pure oxygen environments on their cabins but when you look at all of this, it's a no brainer.
Excellent!
Aaaaargh
@@leonardgibney2997 WORT WORT WORT
Love that Skylab footage. There's a much longer version that has multiple astronauts running around the ring (for over 40 seconds), proving that it could not have been faked in a "vomit comet" (which can do a maximum of 20 seconds or so).
none of that stuff really "proves" anything since all the flat earth conspiracy arguments are ad hoc anyways. the word you mean is evidence, and even then, it's meaningless because the people who think space is fake are not considering evidence in the first place. it took me a long time to understand that there's no argument or logic that you can use in this community because it's not about that, it's about emotional needs and narcissism. evidence and proof have nothing to do with flat earth, they're just buzzwords lol
After the first crew NASA actually had to schedule a time for each astronaut to do that because the vibrations it caused would throw off the precision of Skylab's space telescope. The astronauts refused NASA's position of "Please don't", so that was the compromise
@@LordZaranoHmm...hadn't heard that. Makes sense though.
Off topic, but the Commander Wally Schirra judgement call goes to show why sometimes following the spirit of your orders is better than following the letter of them. Even though the later Apollo program, of which he was also a part of, were inundated with procedure after procedure should any single event go wrong (rightfully so), there is no replacement for having an experienced and intuitive leader in the room. He was initiated into the Naval Aviation Hall of Honor in 2000.
No facepalming, no degrading language, no making fun of people. No confrontational language. Just straight up facts.
As it should be if you genuinely want to educate someone.
In ftfe defense he's debated flat earthers live and seen first hand the dumb stuff they pull. He has to explain a concept over and over live in baby terms that if they dont get it they have to be dumb.
Also Dave does sneak in insults here and there but no where as blatant as ftfe.
BTW: A two-gas pressure control control system is very complicated. For just one thing, a highly accurate and reliable oxygen sensor is required. Maintaining the desired pressure of a 100% oxygen atmosphere only requires a 100% oxygen source with mechanical pressure regulators and relief valves with mechanical pressure gauges to verify the results.
On top of that multiple gases means a higher total pressure requiring a stronger spacecraft which means more weight
@@arachn01d You're right! I didn't think to add that.
🤣🤣🤣🤣 When the bleeding obvious is dressed up as authoritive expertise
This caused a problem during Voskhod 2.
Voskhod was a modified Vostok, and apparently did not have a partial pressure sensor. The crew would breathe oxygen, produce carbon dioxide, which would be sequestered by the scrubber, and the life support system released oxygen to replace the consumed oxygen. Fine and dandy.
Until you close a hatch after a spacewalk and can't quite seal it. Then you have a leak, losing oxygen and nitrogen. The life support system replaced that with pure oxygen, so pretty soon they had a dangerously oxygen-rich environment.
It's little things like this where after you hear it you're like "Duh, of course it works like that." and you feel a little silly for not realizing it sooner.🤣
FYI: EVA spacesuits continue to use 100% oxygen (at 4.3 PSI). Before going on an EVA (i.e. spacewalk), the astronauts have to do a "pre-breath" - the current NASA protocol is 2 hours peddling a stationary bike while wearing an oxygen mask. The purpose of the pre-breath is to purge the nitrogen from the astronaut's body (and therefore mitigate the chance of the bends). It's worth noting that Russia has tried using "zero pre-beath" suits; some versions of the Orlan suit have been designed to run at ~6-7 psi, however this is not quite high enough pressure to prevent the bends, so several cosmonauts have suffered the bends while doing spacewalks from the ISS.
I'm just genuinely curious, it seems a rather high level of specialized knowledge just for someone who is an enthusiast. did you/do you work in the field?
@@kylezo before retiring, I worked for the company that engineered and manufactured every EVA spacesuit for NASA for the past 55 years (i.e. EVA suits from Apollo through the current EMU used for spacewalks from the ISS). The company is currently working on next gen suits for the Artemis missions and commercial use.
I had not heard cosmonauts have gotten bent before; that's fascinating, but it makes sense.
@@JohnWilliamNowak Roscosmos (the Russian Space Agency) is not nearly as transparent as NASA, ESA, JAXA, or CSA so they have never publicized that some of their astronauts have suffered the bends. Also, cosmonauts are trained not to complain, so they are more likely to suffer in silence.
@@danielklopp7007 "cosmonauts are trained not to complain, so they are more likely to suffer in silence."
This is interesting information and it aligns with psychology and sociology.
Russia belongs to countries that have Shame Culture (as oppose to West that has Guilt Culture).
It means that people are ashamed for expressing feelings and opinions - and instead in Shame culture - people are taught and disciplined to believe that anything unusual is a personality disorder and any mistake or problem is observed as person's core value of who they are as person: an incompetent loser.
Needless to say - such shame mentality leads to organizational chaos which we see in Russia and eastern poor corrupt countries. Shame mentality leads to poverty and distrust in other people. The only exception to this Shame culture after-effect is Japan.
In the West - it is mostly southern parts of any country that have shame culture - like mafia-ridden Sicily in Italy or Texas and southern racist countries in USA. Shame is connected to crime and corruption - because people are trained since childhood to foster toxic shame deep inside - believing that they are abnormal and lacking as person - which they cover up through lies and overcompensations. There is simply inability to be truly honest and authentic - and instead building a fake image of narcissism and stoicism is perceived as being honest and authentic.
So that is what we have with Putin's country - people who are not honest about mistakes - never can learn from them - and they are stuck in hamster wheel of trying to be better and to compete - while as result always end up as being failure.
That is how USSR never succeed in anything - neither economy nor Moon landing - due to this shame culture.
I'm appalled that someone apparently commented asking how much Dave got paid to make that video. It's shocking that such an idea could go through someone's head, but then to post it online as some kind of a "gotcha" is utterly a very sad indictment.
Really? You haven't been accused of being a paid schill yet when providing supporting comments? Just wait..it will eventually happen.. they ALL think we are paid to promote science.. it's kinda weird, actually...
Excellent video! I followed the space program very closely back then and you are 100% accurate in what you said. Very thorough explanation except for one major reason why Mercury, Gemini, and Apollo required 5 PSI atmosphere. A 15 PSI cabin pressure would require a much heavier structure to handle all that pressure, making the spacecraft too heavy. So if the pressure is only 5 PSI, 100% oxygen is therefore required. The structural limitation led to everything else that you mentioned. The Space Shuttle was designed with a heavier structure around the pressure vessel (crew area) specifically to allow for normal 15 PSI air. It was a tradeoff between payload and safety and comfort. It was also much bigger than earlier spacecraft.
The structural limitation is not actually the issue.
A 15 PSI oxygen partial pressure is high enough to KILL you over time - you're body is designed for only a 3 PSI partial pressure, though it can handle SOME variation on that.
Sometimes I sympathize with the flerfs, the minds and skill behind the Apollo missions is staggering. Especially when broken down to details as small as a suit worn being pressurized 5psi higher. Great video!
Man, this content is simply amazing. As always. Please keep these videos coming.
6:56 it's not only the nitrogen, it's also the structural integrity of the spacecraft itself. at 3 or 5 psi internal pressure it doesn't have to be as strong as it would have to be at 14.7 psi, and therefore it can be built lighter. two birds, one stone.
Well it still needs to withstand 1 atm during launch, so that's not really an issue.
@@irrelevant_noob during the launch there is 1 atm inside and outside the craft.
@@lauriuusitalo764 16 psi inside and 14.7 psi outside would make a difference of 1.3 psi.
@@mrxmry3264 true, but not 1 atm. And it is much less than 5 (or 14.7) in space.
Thanks Dave. A very clear explanation and a much deeper dive than my knowledge could muster. I'm learning!
Great explanation. I had read about the Apollo 1 recommendations and thought that was a clever solution to avoid having to add a more complex (and heavy) gas mixture system. I liked how they switched over right at launch to simply start supplying pure O2 from onboard supply instead of the mixed gasses from the launch pad support system.
As a former submariner, we watched partial pressure of O2 constantly. But even without the instrument we knew when the partial-pressure was getting low by how well the cigarettes burned. lol Yes, it's all about Dalton's law and partial pressures.
The continued use of pure oxygen with Apollo also seems to be an example of "if it's not broken, don't fix it" and "let's not make things more complicated than they have to be". Pure oxygen worked, in space, at 5PSI. They had already done plenty of on the ground testing with people in 5PSI pure oxygen, and had practical experience of it during Mercury and Gemini, including for long durations during Gemini. A switch to a mixed system would have thrown in unknows and required extra testing, and possibly caused additional delays. They knew though that the Apollo 1 fire was as a result of atmospheric pressure pure oxygen, and that sort of fire wasn't possible at 5PSI.
I'm reading a book about the history of space stations, both American and Russian. In that book, the Apollo Soyuz program is described, and they had a challenge regarding atmospheres. Apollo used 5 PSI pure oxygen, Soyuz uses an oxygen/nitrogen atmosphere at sea level pressure. So if the cosmonauts entered the Apollo directly, they would get divers sickness. That's a kind of challenge we don't easily think about...
The big thing to remember is that, when going to the Moon, even with enormous Saturn rockets, the vehicle was horribly mass-limited. Anything that went all the way to lunar orbit took a very large amount of fuel to get there, moreso for things that went to the lunar surface and back. That's why, for example, Grumman was offering big rewards to its workers to come up with ways of reducing LM weights by OUNCES. Not even pounds. Now, add to that the much thicker and stronger pressure vessel walls the Command Module would have needed to maintain sea level pressure against vacuum without leaking somewhere, and all the extra plumbing and tankage needed to maintain a two-gas atmosphere in the vehicle. You now literally have a CSM that a Saturn V can get to the Moon, but not with a fully fueled LM. You'd have had to massively redesign the rocket and the spacecraft to change to a two-gas system in flight. Given the end-of-decade deadline and all of the other redesigns the Block II CSM would have to undergo to achieve it after the Fire, NASA's only option was to move ahead with the one-gas atmosphere in flight, and take as many measures as possible to ameliorate the risk of fire. To be honest, at 5psi of pure oxygen, the fire hazard wasn't nearly as bad as it was during the Block I pad tests, when the vehicle was filled with pure oxygen at at least 2psi above ambient air pressure, so things like replacing flammable nylon with inflammable Beta cloth, and reworking wiring insulation to be non-flammable, made the thing safe enough to fly. And yes, indeed, that one very risky testing regime was changed so that the cabin was oxygen-nitrogen when pressurized above ambient air pressure, but that air was bled out and replaced with pure oxygen as the vehicle rose to orbit.
Jeran is constantly talking about you. That shows you are doing really good work. Thanks!
This was a great explanation of partial pressure. I remember getting to this subject in Physics (or maybe Chemistry) and thinking it'd be a good idea to use pure O2 to cut the pressure on a manned spacecraft. Then I found out yes of course NASA had thought of that and implemented it long ago.
On a sidenote, the Russian space program discovered the danger of testing in a high-oxygen chamber at sea level many years before NASA did. On March 23, 1961, just less than three weeks before the first Vostok manned space flight, cosmonaut Valentin Bondarenko died in a sudden fire in a high-oxygen isolation chamber. The Soviet Union, however, concealed the accident, and NASA didn't know about until 1986. Anyway, the Apollo 1 high oxygen situation was easily fixed as you say. The astronauts weren't breathing the air in the space capsule at takeoff anyway, so it was just a matter of having a mixed atmosphere at takeoff (which the astronauts didn't breathe) and letting the tanks convert it during the mission.
I love your examples of terrestrial activities/industries that make use of the principles we use in space. It just goes to show the extremes one has to go to make the Globe Hoax consistent. It touches EVERYTHING. It seems like 100% of us have to be in this hoax - actively - to make it work. Kudos to absolutely everybody for your continued diligence and constant intense effort.
It also prevents people from using everyday jobs and occupations as some sort of debunking of the fact the Earth is a globe. Last video for example was made because people thought the existence of SCUBA divers disproved the Apollo missions, when in actuality the science behind them and modern technologies used in SCUBA only go to show the Apollo missions were good science.
yes, "Globe Hoax Science" is remarkably robust, comprehensive, and extensible. It's hard to believe it's all a sham to hide the dirt pizza and crystal dome. I can't wait to fully understand the flerf physics. @@billbill6094
What I want to know is... are you getting paid more than me?
All anaesthetists hollering in one voice - “hey, I know this stuff!!!!”
Great vid.
@8:32 The Apollo 1 Fire was Jan 27, 1967, not February as stated by you
@10:44 The Paragraph states that the LM Atmosphere was Maintained at 5 Psi, with Pure O2. However the LM was launched with Normal Air in it, but the Vent in the Tunnel Hatch was left Open, allowing all the Air to vent to Space. Once the CM had Docked to the LM, a Vent in the CM Tunnel Hatch was opened and O2 from the CM was used to fill the LM. A very simple way to make sure the LM didn't have any gas but O2 in it
On Gemini 6, Schirra certainly had Stones, not bailing on the Titan. He certainly Understood the Risks of using the Ejector Seat. I don't think any of the Astros really had much Confidence in the System. No Trials with a Human were ever done using the System. There were Doubts that an Ejection on the Pad would even be survivable
Fires also burn differently in Zero G, as Convection, which is needed to take the Hot lighter Products of Combustion away, and supply heavier fresh Oxygen, needs Gravity
Just curious, is your native language German? :-)
@@irrelevant_noob only Nouns would be capitalized then, I would say.
@@irrelevant_noob
Grandfather was a Kraut
I could never understand how Skylab stayed up as the rotor blades don't spin :)))) Apart from that a very enjoyable video and I learned something
It is just a trick of the camera. The stroboscopic effect, same as when it makes a wheel look like it is stationary when the vehicle is driving down the road at the right speed.
Excellent work as always, Dave. It might be useful to mention the EVA suits used on the Space Shuttle and the ISS still use 100% O2 at 5 psi. The soft suits would balloon out if filled to 15 psi. Prior to an EVA, the astronauts must breath pure oxygen for several hours prior to donning the suit to remove nitrogen from their systems and then slowly depressurize in the airlock before they disembark. They also have to re-pressurize when they return, though this doesn't take as long. Since the Apollo modules and suits used the same gas/psi, this step was unnecessary for them.
Always a great explanation. Thanks for all you do, Dave!
Rusty! Lets gooo! Thanks Dave and Rusty!
Yes🐾🍻😋
I too thought that NASA used normal air after Apollo 1. Wow! It took several decades to get this misconception cleared up by none other than you! Thank you very much.
This is a great follow up Dave. I appreciated your reply to my comment in the original video but this fleshes out the background very well. Cheers.
I consider myself pretty well educated on the Mercury, Gemini, & Apollo programs...and I also thought they switched to a 60/40 oxygen nitrogen mixture for Apollo after the incident.
Guess I'm about to learn something in this video.
Well, you're partially right. They did for pad activities, but purged as the craft gained altitude.
I watch to learn new, fun facts on topics I already have a good understanding of. Your videos are excellent. Flerfs and science deniers getting roasted and triggered is just the cherry on top
Oh i can just imagine having a heated verbal beatdown with one of your co-workers in that diver situation, breathing in Helium. I could not keep my poker face for a minute.
Thank you for clarifying. I hadn't researched the topic myself and fell prey to misconceptions. I think you addressed them very well in this video. Keep up the good work!
Reason, factual detail, and Rusty too! First rate.
Very good explanation. You can hear the crew mention that the cabin pressure is relieving during the boost phase of either the S-IC stage or S-II to the capcom during launch. There was also a call-out where they stated that the cabin had settled at 5 psi, shortly after (so the cabin held a pressure of 5 psi well before orbital insertion).
This method was also the main reason why the crews had to pre-breathe 100% oxygen, as well as having to wear their spacesuits for launch; they did not wear their spacesuits during re-entry.
Clear and educational - Everything we have come to love about your videos Sir... Keep. It. Up.... Brilliant. Your videos are defiantly loved all around the globe.
Does anyone else share my belief that the film 'Idiocracy' is a glimpse of the future for humanity?
It already is, at least in America😞
No. I have a foot in the grave 🐢
The kids are going to build good happy lives for themselfs
Also science says average IQ increasing 🤪
You know what a bell curve is and the science behind ir🤔
Bell curve is kommi 💩
America has been Idiocracy from 20 years now
Reality already blew past "Idiocracy" in several instances.
For example, consider the absolute worst president the screenwriters could imagine, Dwayne Elizondo Mountain Dew Herbert Camacho.
Yeah, he's a simpleton who likes to play macho, but:
1) He cares about the country he's supposed to be running: when a crisis strikes, he actually attempts to solve it
2) He did actual, real work in the past (porn star)
3) When presented with an expert, he recognizes he might not know everything, and puts the expert in charge of the crisis management effort
4) "I thought yo head would be bigger, it looks like a peanut" - he remarks, but does not allow this preconception of how a "smart person" should look like to color his attitude ; He allows the guy to stand or fall based on merit
5) Has actual charisma
6) Doesn't lie about his height or physical condition
7) Speaks in complete sentences and finishes his thoughts
8) Keeps his word, and rights wrongs: when he realizes he unjustly accused the expert of malicious intent, he compensates him for the moral injury and provides the reward he originally promised
That is literally the worst person that could be imagined running a dystopian future controlled by idiots. Now consider the real world :P
You need NASA merchendise in the background so they think you're a paid NASA shill.
I've been very close 😁
Beautifully explained, as always. Thanks Dave.
That was fantastic. Thank you. Misunderstood things like this regarding the Apollo missions are very interesting. Please do more!
It fascinates me how some people have taught themselves to be scientists or physcicts to prove flearthers wrong. Meanwhile all flearthers everywhere: "nope, you're wrong because i dont understand primary school science"
@@flatearth12 right on cue, thanks for proving my point 😂😂
@@flatearth12 get an education and grow up, go ahead I'm waiting
@@flatearth12 👏👏
@@flatearth12
1. When we measure the 3D position of a series of points on Earth's surface, we find that that surface is curved. All this requires science-wise is trigonometry.
2. You can watch a ship go over the horizon, and see it disappear behind the water from the bottom up. When you move to a higher elevation, the hidden part of the sip becomes visible again. This can only be explained by a physical obstacle between the observer and the ship. The only logical candidate for such an obstacle is Earth's curvature.
3. From high altitude, Earth's curvature is visible directly.
3 different proofs that are accessible to anyone without requiring more than knowledge of trigonometry and the scientific method.
@flatearth12 did you know you can learn the maths to derive the circumference of the Earth in primary school?
Thanks, after your last video I was wondering about fire in a pure O2 environment. excellent video as always!
Fire bad🦍
A very good and thorough explanation. Thanks Dave (and especially Rusty)
Excellent explainer Dave - I was one of the commenters who started the oxygen toxicity conversation on the last video.... I think you did a great job clearing up misconceptions a lot of people had. I would have enjoyed a quick bit on CNS vs pulmonary O2 toxicity, but nonetheless - great work.
The difference is this in the presence of 100% O2: Acute (meaning immediate) O2 toxicity causes CNS symptoms. Chronic (long term exposure) causes pulmonary symptoms. All of this is based on pressure. The higher the pressure the more "oxygen" you are intaking. All of the pressures and partial pressures that Dave is explaining is the base causation for O2 Toxicity. In medicine we are exquisitely aware of O2 when we are applying 100% O2 especially when done under "high flow" and pressure.
@kerwynbrat5771 I'm aware of that, I work in pulmonary medicine - I meant I would have liked to hear Dave's take on the differences as well as including it for other viewers who don't understand these things as well as we do. Good explanation though!
Those deep sea welders are crazy. You live deep underwater in the dark for a long time under the constant pressure.
It’s dangerous and has no escape and is even more dangerous than going to space.
It’s crazy.
Dave some people are so anal. The Moon landings were real .These people waste our time thinking it was not real! Your Vids are so informative and you do fantastic detailed research and explain it so well thanks!
To be fair it seems most of the people bringing this up don't question the landings happened, it was more that they were under the impression the landings were don't not using a pure oxygen atmosphere
@@flatearth12 Classic flat earth larper: 'I have no evidence whatsoever, can't explain anything at all, and rely solely on 'nuh-uh!' as an argument against any facts, hence earth = flat'.
@@flatearth12
Believe?
Wrong, we know, beyond any doubt, that the Erath is a sphere.
You seems to struggle with the meaning of the words "belief" and "knowledge".
@@flatearth12 Globers Dont believe they base reason and reality on Facts that can be proven with science over and over. Unlike Flat Earth, they just make things up!
@@flatearth12Seriously? 🤦♂️
Rusty being Pawsome as usual🐾
Oxigcen
Appreciate your efforts to explain it from a technical perspective.
Hi Dave. Just wanted to say that your channel is amazing. Your content is awesome. I'm really glad I found it. Keep up the amazing work!
MMM a fresh hot video from one of my favourite youtubers. Gonna enjoy watching it soon
RUSTY!!
o, hi dave
I really enjoy watching these debunking type videos because they really do emphasize just how insanely complicated these topics are, and just how smart the people who worked on these programs (and humans in general) are to overcome all the barriers they faced.
I do so enjoy your lessons. You are an awesome teacher. Keep up the good work.
Why can't flat Earthers and Apollo deniers do such in depth research?
Cuz then they wouldn't be Flerfs and Moon Truthers
@@flatearth12 NASA material on Apollo is supported by tons of third-party evidence.
The shape of Earth can be found by doing simple experiments.
@@flatearth12 You've convinced yourself that the earth isn't a globe using zero genuine research of any kind.
1. As mentioned, if they did, they would be flat earth/moon deniers (though plenty continue to pretend to be) -or-
2. They don't have the intellectual capacity to understand what they are finding. You could explain the science behind space travel all day to a squirrel, but they're never gonna understand it.
@flatearth12 how about research the fact that you yourself can bounce a laser off a mirroring device left on the moon by the Apollo missions for measuring the distance to the moon?
I forsee a lot of nuh-uh “arguments” in the comment section. 😂
There's already 1 person lol
flatearth12 took initiative on that
Hi Dave.
Again i've learned something, never to old to learn.
Love the way you attack and explain the items. Thanks
Excellent video. Good research. Thanks so much!
LOVE the explanation. Unfortunately, you will never convince those who hold to FE beliefs no matter how many times and how well you explain the details. They are spiritually blind to truth.
@@flatearth12 Watching RUclips indoctrination is not studying. You are being conned by your FE gurus.
Sorry, gotta go collecting my NASA payment for writing this.
@@flatearth12 What convinced you that the earth is flat when there's zero evidence to support it? How old are you lad?
@@leftpastsaturn67 see my other comment
@@flatearth12
I don't know about him, but I know, without any doubt, that the Earth is a sphere, due to decades of observations, experiments, and research, conducted on both hemispheres.
And you, what are you waiting before starting to do likewise and reach the exact same conclusion, instead of relying in your ignorant, and blind, beliefs and doing nothing to change this pathetic, and sad, reality?
@@flatearth12 A sunset alone shows that the earth is spherical. The sunset is geometrically impossible if the earth would be flat. If the earth would be flat the sun is always visible 24 hours a day.
Wait for flattened void (flatzoid) to challenge this and rip it apart with his immense knowledge...cant wait for the counter....
You’re playing fast and loose with the definition of _knowledge._ 😆
Lol I can't wait to see him misrepresent what Dave said and then change the subject
I was wondering about this. Thanks for sharing!
Not only the high pressure of the pure oxygen atmosphere, but also the innumerable amount of exposed flammable materials in the module, too. 16 psi 100% oxygen plus all that flammable material resulted in a deadly fire that consumed pretty much the entire capsule interior in only 90 seconds. That's why they completely changed all the interior fittings and wiring in addition to switching to a less flammable breathing environment on the Block II Command Module, which first flew with a crew on Apollo 7.
But Dave! The Earth HAS to be flat! Because God, an *OMNIPOTENT BEING,* is incapable of making round worlds!
Apropos of nothing, why am I getting anti-vape ads targeting younger people? Is everyone else here a 16-year-old vape user?
The algorithm is using you as a guinea pig it seems. Adds are targeted at users, not videos.
I get women's bras and Joe Biden ads.
@wasneeplus yes but they use wich videos you watch to pick your ads
thats based on your activity dude.
I'm not getting any. Instead, I just get the plain ol' "how to get rich in 60 seconds" ads. Might be a you problem
Excellent explanation video!
Love your explainers!
any news on jaxas moon cartoon? did we see the rover cruisin around on moon by now?
Oh hey, don't you get sick of abandoning threads and starting new ones?
@@Alysm-Aviation No, its fun. Its interessting we didnt get to see the moon car by now, isnt it?
@@waschbekenpinklerhave you at least finally worked out how GPS works?
Yup, we have.
Thanks, Dave. Always so thorough.
Excellent explanation! I was also confused in the last video, as I had also heard about them replacing the atmosphere with mixed gas. This made a lot of sense!
That was the smoothest sponsor segue I've ever seen
Thank you, Dave. I was a space buff when young (still am to an extent) and I, too, thought after Apollo 1 they switched to a mixed gas atmosphere.
What a great explanation of partial pressure. I got through A-Level chemistry and a pyhsics degree without thinking about it beyond the maths!
A very informative video❤ thanks!
Excellent presentation on a very interesting subject.
1:22 bruhhh that was a infuriatingly clean ad switch 😂
New to the topic. Very informative. Thanks!
Once again, an excellent explanation. Well done, sir!
I thoroughly enjoyed this, Dave. Partial Pressure makes so much sense, now.
Very good explanation! (good animated explanation of Dalton’s law of partial pressure ). Great presentation.
I learnt something today. Thank you!
Fascinating! Thank you!
Damned good explanation of a problem I had never thought of in full context, good job!
Another great video with perfect explanation and no trash talk😅Hope it'll never change 😊❤
Thanks again. I almost always learn something new in your videos.
Cheers Dave, very informative 👍
Brilliantly done. Thanks.
Oh, and not to mention that there is a website that contains EVERY. SINGLE. SECOND. of telemetry and radio chatter between mission control of Apollo IN REAL TIME. Me and my dad enjoyed listening to this website back in 2020 during the 50th anniversary of apollo 13. There's a lot of silence and boring science calculations in there. Not a lot of theatrics. It's widely available to anyone.
Great explanation thanks!
I would like to note that while not for spacecraft, pure oxygen is still used. For spacewalks it is much easier to make it deliver pure oxygen, it also allows for easier movement and less stresses on the spacesuit. But one effect of that is having to do pre-breathing of pure oxygen, which takes some time. Couldn't find much info on it but Russian and Chinese spacesuits are probably similar in that aspect.
The explanation of HOW a partial-pressure oxygen environment is safe for humans is very good, but I must have missed something. WHY did the Americans decide on reduced pressure? My understanding of this is that a reduced pressure atmosphere would allow the Americans to use thinner, and therefore lighter, containment structures. Also, less mass required for gas storage, valves, piping, etc.
It was all about saving weight. Even the mighty Saturn 5 could not boost enough mass to make it to the moon with a heavier structure. Much has been made of the thin skin of the LM. There was a real danger of puncturing it with an inadvertent drop of a tool on the Moon, or sticking it with a screwdriver. Saving weight was everything, so the decision was made to simplify and lighten the modules by reducing pressure. Brilliant.
It was basically all about weight - as you say, the capsule structure could be lighter when handling a smaller pressure differential between inside and out, but also they needed to carry pure oxygen for the fuel cells, so breathing that saved needing separate tanks of breathing air
People don't understand partial pressure. This is why you can't dive with a standard scuba tanks below a certain depth, because even at
FWIW, while the intended launch date for Apollo 1 was the 21st Feb 1967, the fire occurred on the 27th January.
Another great informative video.
The detail of this I'd never thought much about is that it's actually not toxic to breathe pure oxygen at full atmospheric pressure for a short time--where "short" could be several hours. I knew that Shuttle astronauts did a pre-breathing purge with pure oxygen before an EVA, never thought much about the biology of it.