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Comment on If I stood on a precision scale and farted, would I get lighter or heavier?

PhilipTheBucket@piefed.social ⁨1⁩ ⁨week⁩ ago

Fart gas is warmer than the surrounding atmosphere, therefore less dense. Your digestive system is under very slight compression (10-20 mmHg gauge pressure according to the internet), which I would guess does not equate to enough pressure to be more significant than the temperature gradient. Fart gas is also less dense than air at a given pressure by a pretty significant margin (1.06 g/L compared with 1.20 g/L).

When you fart, you're releasing gas that is less dense than the atmosphere, which means you get slightly heavier. Think of yourself as a hot air balloon with a very tiny chamber, and when you release a 90 milliliter fart, you lose a little buoyancy and sink a little. You get heavier when you fart.

I haven't done the math, but I looked around on the internet at some numbers, and that's what I think. I also ignored this because it is clearly AI slop, which is a little upsetting.

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MalReynolds@piefed.social ⁨1⁩ ⁨week⁩ ago
You seem to be assuming that the volume is immediately replaced by the external atmosphere, which I doubt is valid, more likely that the volume of the person would decrease, at least temporarily. The weight of 1 Liter (assuming a massive fart) of air is 1.275g according to wolfram, so, using your density numbers above, 1.275 * 1.06/1.2 = 1.126g lighter. Measurable with a really good scale, if the 90ml fart volume is realistic (has to be more realistic I guess), that's ~.1g,

Think of yourself as a hot air balloon with a very tiny chamber, and when you release a 90 milliliter fart, you lose a little buoyancy and sink a little. You get heavier when you fart.

No, you get denser, but not heavier.

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- PhilipTheBucket@piefed.social ⁨1⁩ ⁨week⁩ ago
  
  You seem to be assuming that the volume is immediately replaced by the external atmosphere, which I doubt is valid
  
  No, I was assuming your volume decreases. I don't actually know that to be the case, but my assumption is that there isn't "extra" space inside a person, and so if you lose material from a part of your body that isn't encased in anything rigid your volume decreases slightly.
  
  So maybe I did have my terminology wrong. When a hot air balloon deflates, it falls. The density went up, but that's not what's directly relevant. The weight went down, I guess, but the "number on the scale", weight minus buoyant force, went way way up, because it lost some lower-density volume that was making the whole thing float. The weight (in a strict physics sense) went down, sure. But the number on the scale (which I was incorrectly calling "weight") went up. Same thing for a farting person.
  
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- magikmw@piefed.social ⁨1⁩ ⁨week⁩ ago
  I feel like like I get denser everyday no matter I do.
  
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aeternum@lemmy.blahaj.zone ⁨1⁩ ⁨week⁩ ago
so that’s why i can’t lose weight.

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Lost_My_Mind@lemmy.world ⁨1⁩ ⁨week⁩ ago
This is like what would happen if Bill Nye needed to worry about sweeps.

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jnod4@lemmy.ca ⁨1⁩ ⁨week⁩ ago
How many litters of gas I’d need to pass to lose a kilogram on the scale? Let’s consider I have indestructible guts that can be ever enlarging without rupture and we ignore the linear increase of pressure that would happen

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olafurp@lemmy.world ⁨1⁩ ⁨week⁩ ago
Couple of nuances with this that are not fully accounted for.

Farting in a vacuum will make the scale go down because the fart has a non-zero mass.

Direction of fart and speed of exiting will also affect the scale when farting against a base not connected to the scale such as a platform.
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prole@lemmy.blahaj.zone ⁨1⁩ ⁨week⁩ ago

When you fart, you’re releasing gas that is less dense than the atmosphere

Speak for yourself…

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