!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rule 1- All posts must be legitimate questions. All post titles must include a question.
All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.
Rule 2- Your question subject cannot be illegal or NSFW material.
Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding META posts and joke questions.
Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.
On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.
If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.
Rule 7- You can't intentionally annoy, mock, or harass other members.
If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.
Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- Majority of bots aren't allowed to participate here.
Our breathtaking icon was bestowed upon us by @Cevilia!
The greatest banner of all time: by @TheOneWithTheHair!
Well, "gas" is a pretty vague term but if you're referring specifically to farts, they're not necessarily heavier than air because they don't just consist of methane and hydrogen, but other poo-particles too that are heavier than air.
The realistic answer is: The change in weight is pretty negligible, but you probably still become ever so slightly lighter.
According to this site the average fart weighs between 0.0371-0.0464 grams.
That's not weight, it's mass. The difference in this case is the original question: Buoyancy. That article doesn't say if a fart is (on average) lighter than regular air, heavier, or about the same.
Ignoring stuff like breathing and eating and whatever, as gas builds up from microbes metabolizing shit in your gut, your mass stays the same but you become less dense (and therefore must take up more volume, and be physically bloated by the gas). The boyant force of air trying to get under your volume and push you up is a battle between volume and mass, so since you take up more volume for the same mass, boyancy will technically reduce your weight, but probably not by much.
When you fart, the gas is released and your volume and mass decrease by the same volume and mass of the gas. Because the density of this gas is much lower that your average density, your density increases while farting, removing any extra boyancy created by holding the gas in. Depending on the density of the gas, the weight of mass you lost is more than or less than the boyancy lost
If the gas is lighter than air, the mass weight lost from farting is less than the mass weight of air for an equivalent amount of volume lost. Just like deflating a helium balloon, this results in a net loss of boyancy, making you heavier.
The opposite is true for gas heavier than air. The mass weight lost from farting is more than the mass weight of air for an equivalent volume. Just like dropping sandbags from a hot air balloon, your boyancy increases (but seriously not a lot)
As for the density of farts? They are almost certainly lighter than air because we are usually hotter than our environment (else were uncomfortable) and methane is about half as dense as typical air. Apparently it's complicated but my impression is that farts are usually less dense.
Does this make any sense? Are we really experiencing a boyant force even when our average density is much greater than air? I dont think so, I think boyancy in air is irrelevant for humans. Here's an interesting bit of science that helped me understand why the way we are taught about boyancy isn't always the whole story
I'd imagine your farts would get compressed a bit increasing the air density. This would lead to expelling a larger volume of gas at whatever atmospheric pressure you're at, than what was inside your body under pressure. Maybe this is negligible, by maybe not. Just food for thought.
Agreed, I was trying to work out if that matters and decided to assume that it is negligible. Partly this was because it would change as the fart moves around, and as part of the farting process the air must be compressed to some degree. All of the quantities in this problem are basically negligible though so maybe it is important.
Since we've all participated so far, what not ask the more important question of how much thrust could a standard fart be expected to generate and how best to optimize for thrust?
Great comment, thank you!
You say buoyancy is irrelevant to humans, but would it be measurable?
I don't think so, but it is definitely possible. We have incredibly precise measuring devices, and although it would be complicated by all the other things our bodies do it may be possible to measure.
I used this calculator with density of 1.225 for air and 375ml for the volume of a large fart and it reports a force of about .0045 N. This is about .45 grams, which is about .001 lbs, which is what this company claims their sensitivity is... So since the boyant force excludes the gravitational force on the fart itself the measured force would be much smaller. you would need a scale much more sensitive to measure it. If you farted pure methane the force would be about half. A good measurement should probably have about 10 times the accuracy (.045 grams). Since you can buy a scale for a couple thousand dollars that almost gets there I'm going to guess that this would be measurable, but there may be some hidden gotcha I'm not aware of.
When you fart the expelled gas isn't immediately replaced. So you just become lighter by the mass of the flatulence. (Which will be a rounding error to the mass of your body)
While it is in your body, it would likely be compressed to a higher density than air
Somebody get Adam Savage, Jamie Hyneman and a very sensitive set of scales…
Wouldn't your volume reduce? Rather than you getting heavier...