9 ms·

Water and CO2? (And, of course, some other byproducts, but by and large.) I mean, I think this is a well-known answer, no? Sorry I don't mean to sound facetiou

Water and CO2? (And, of course, some other byproducts, but by and large.) I mean, I think this is a well-known answer, no? Sorry I don't mean to sound facetious, I haven't opened the article, so I may be surprised, but I thought this was standard knowledge (at least, it was taught in middle school and high school, even though that's been a while ago for me).

qz2 6y ago
Not that well known in some circles. I decided this year to lose some weight and only worked out the mechanics of it after researching throughly. It never factored into my education or general knowledge. It was demotivating to be honest knowing how much of me I had to breathe out. I will say that it was one of the best changes I ever made to my life.
- LolWolf 6y ago
  > I will say that it was one of the best changes I ever made to my life. Wohoo! That's awesome, congrats! :) It is rather surprising just how much air needs to be exchanged, which is crazy and definitely not intuitive. (And I could definitely see how it could be demotivating... but, hey, we do breathe out quite a bit!)
  - baby 6y ago
    Wow interesting. So I feel like I don’t breathe correctly. Could it be the reason why I can’t lose weight :D?
    - qz2 6y ago
      Just have to breathe a lot :)
watwut 6y ago
Our school did not taught that.
- LolWolf 6y ago
  Was this in the US? I went to a very large public middle school and high school in Texas, so our experiences may differ, but it was certainly standard there. (This, of course, varies even district to district, but perhaps my experience isn't as general as I imagined.)
  - wahern 6y ago
    I can't image that the mechanism isn't taught. I mean, this is basic biology that we probably all learned in middle school, and certainly had to learn in chemistry class. But I think we just fail to put 2-and-2 together, even the teachers. I think I was in my late 20s when it dawned on me that I was exhaling the food I ate. But I came to that realization in a matter of seconds based on first principles--principles learned in middle and high school. Economics is similar. Almost every undergraduate students take economics. And Economics 101 is a pretty simple topic. But very few people learn to "think like an economist", even many economists. I guess alot of subjects are like this--real life isn't like the examples in textbooks, but that doesn't mean the rules and principles don't apply just the same. They do apply. Things can quickly get more complicated than in the textbooks. Perhaps we translate "complicated" to "it doesn't apply" rather than what we should be thinking: it does apply just the same, but so do other dynamics, and the interactions can produce counter-intuitive results.
    - thaumasiotes 6y ago
      > I think I was in my late 20s when it dawned on me that I was exhaling the food I ate. But I came to that realization in a matter of seconds based on first principles--principles learned in middle and high school. But as noted elsewhere in the thread, you mostly aren't exhaling your food. Respiration is a reaction that takes in O2 and produces CO2. The only thing you can get rid of by breathing is carbon. But you need to excrete a mixture of carbon, hydrogen, oxygen, and nitrogen. (Plus trace elements.)
      - wahern 6y ago
        Sure, "it's more complicated". But the most basic, predominate mechanism is that you're literally burning carbon and exhaling CO2. Only from that realization can you start to identify and answer more sophisticated questions, including the exceptions. My point is that you can get an incredible amount of mileage from the most basic principles taught in school. Which is literally the point of a basic education. But people tend to emphasize "don't believe everything you learn in school" rather than "most of what you're taught in school are foundational truths to your environment that can have immense utility in your day-to-day life." If you focus on the former rather than the latter, you won't get into the habit of learning how to apply your knowledge. And if you're not well practiced at application--which is a life-long endeavor for even the most basic rules--then superficially that knowledge tends to seem useless. I never studied computer science in college--I was already writing Perl and JavaScript when I entered a 101 course which was teaching Pascal, and I dropped it the next week. But I did end up learning--and still learn--the theory and its application. I often hear computer science graduates lament that they never actually need to apply what they learned in school in their professional lives. Well, "need" and "can" are two different things and it's a choice you make. Failure to rigorously apply even basic principles is a big reason, IME, why so much software is utter crap. Do you need to consider algorithmic complexity for every little script you write? Yes! Not because it necessarily matters to the performance of the script, per se, but because the script will be part of a larger data processing system, and the way it fits into and shapes that system can and often will effect algorithmic efficiency down the line. It's a useful skill to apply first principles to everything you encounter in life. Not just scientific principles, but moral and emotional principles, too.
vowelless 6y ago
Hopefully by now you have opened the article and read it. Did it dazzle you?
- LolWolf 6y ago
  Shocked me to my core; flabbergasted me to no end. I never could have imagined! :)
habeebtc 6y ago
I recall from Chemistry: When hydrocarbons combust, the outputs generally are CO2 and Water. Driven home by living with a gearhead after college. At least some of the liquid dripping from tailpipes is water.
- mikepurvis 6y ago
  Also relevant if you've ever looked into what a modern "condensing" boiler/furnace is: https://www.ernstheating.com/blog/condensing-furnaces/ https://www.ernstheating.com/blog/condensing-furnaces/ A consequence of the secondary heat exchanger is that a bunch of the steam from the exhaust condenses back into water, and unfortunately it's water containing a bunch of heavy metals and other nasty stuff, which usually ends up flushed into the municipal sanitary sewer. Probably still better than it going up the chimney and into the atmosphere, but it would be nice if there was a way to capture and isolate those pollutants in that relatively concentrated state, before they end up mixed in with everyone's bathtub water.
  - Scoundreller 6y ago
    My hope is that this is highly dependent on fuel source. Really bad for coal, medium for kerosene and not a huge issue for natural gas.
    - mikepurvis 6y ago
      Me too, but the reason I have it on my mind is because I was reading the technical manual [1] for the fancy new NG boiler I'm having installed next week, and they specifically list the max concentrations of lead, chromium, cadmium, and other scary things in the condensate water after the neutralizing unit, with a recommendation to check with your my regulations to ensure that it's legal to dispose of this water down the drain. Possibly it's just an abundance-of-caution thing, but I assume the reason for the warning is that in some places it isn't, perhaps because of stricter environmental standards, or maybe a sewage treatment system which isn't set up for this. 1: https://www.viessmann.ca/content/dam/vi-brands/CA/pdfs/wall-mount/vitodens_100_tdm.pdf/_jcr_content/renditions/original.media_file.inline.file/vitodens_100_tdm.pdf https://www.viessmann.ca/content/dam/vi-brands/CA/pdfs/wall-...
cperciva 6y ago
I'd say water and CO2 and urea. Protein is roughly 16% Nitrogen by weight.
- thaumasiotes 6y ago
  I was about to say, excreting water and CO2 leaves you no way at all to get rid of nitrogen.
  - Retric 6y ago
    Body fat is just a mix of HCO https://en.wikipedia.org/wiki/Fat https://en.wikipedia.org/wiki/Fat With extreme weight loss blood, protean, and even bone mass is included. So it’s really Oxygen, Carbon Hydrogen, Nitrogen, Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, and Magnesium plus some trace elements. However, the body heavily favors removing water and fat with mild weight loss.
divbzero 6y ago
Yes, something like (CH2O)n + n O2 → n H2O + n CO2 for sugars and analogous for fats and proteins.
Fezzik 6y ago
This is a fantastic video that breaks down the process, including great visual aids: https://m.youtube.com/watch?v=vuIlsN32WaE https://m.youtube.com/watch?v=vuIlsN32WaE
TimSchumann 6y ago
It's actually like 85% to 90% CO2 by weight IIRC, can't remember the chemistry off the top of my head, but I remember being shocked by that. You literally breathe most of the weight off. Edit: Found a source, memory was about right. Per this info-graphic [0] and this paper [1], approximately 84% of fat loss by mass is exhaled as CO2. [0]https://www.bmj.com/content/bmj/349/bmj.g7257/F2.large.jpg https://www.bmj.com/content/bmj/349/bmj.g7257/F2.large.jpg [1]https://www.bmj.com/content/bmj/349/bmj.g7257.full.pdf https://www.bmj.com/content/bmj/349/bmj.g7257.full.pdf
Ayesh 6y ago
I learned this from a Ted talk, and surprised me quite a lot. The audience seemed surprised too.
SeriousM 6y ago
> I haven't opened the article Well done...

qz2 6y ago

Not that well known in some circles. I decided this year to lose some weight and only worked out the mechanics of it after researching throughly. It never factored into my education or general knowledge. It was demotivating to be honest knowing how much of me I had to breathe out. I will say that it was one of the best changes I ever made to my life.

LolWolf 6y ago
> I will say that it was one of the best changes I ever made to my life. Wohoo! That's awesome, congrats! :) It is rather surprising just how much air needs to be exchanged, which is crazy and definitely not intuitive. (And I could definitely see how it could be demotivating... but, hey, we do breathe out quite a bit!)
- baby 6y ago
  Wow interesting. So I feel like I don’t breathe correctly. Could it be the reason why I can’t lose weight :D?
  - qz2 6y ago
    Just have to breathe a lot :)

watwut 6y ago

Our school did not taught that.

LolWolf 6y ago
Was this in the US? I went to a very large public middle school and high school in Texas, so our experiences may differ, but it was certainly standard there. (This, of course, varies even district to district, but perhaps my experience isn't as general as I imagined.)
- wahern 6y ago
  I can't image that the mechanism isn't taught. I mean, this is basic biology that we probably all learned in middle school, and certainly had to learn in chemistry class. But I think we just fail to put 2-and-2 together, even the teachers. I think I was in my late 20s when it dawned on me that I was exhaling the food I ate. But I came to that realization in a matter of seconds based on first principles--principles learned in middle and high school. Economics is similar. Almost every undergraduate students take economics. And Economics 101 is a pretty simple topic. But very few people learn to "think like an economist", even many economists. I guess alot of subjects are like this--real life isn't like the examples in textbooks, but that doesn't mean the rules and principles don't apply just the same. They do apply. Things can quickly get more complicated than in the textbooks. Perhaps we translate "complicated" to "it doesn't apply" rather than what we should be thinking: it does apply just the same, but so do other dynamics, and the interactions can produce counter-intuitive results.
  - thaumasiotes 6y ago
    > I think I was in my late 20s when it dawned on me that I was exhaling the food I ate. But I came to that realization in a matter of seconds based on first principles--principles learned in middle and high school. But as noted elsewhere in the thread, you mostly aren't exhaling your food. Respiration is a reaction that takes in O2 and produces CO2. The only thing you can get rid of by breathing is carbon. But you need to excrete a mixture of carbon, hydrogen, oxygen, and nitrogen. (Plus trace elements.)
    - wahern 6y ago
      Sure, "it's more complicated". But the most basic, predominate mechanism is that you're literally burning carbon and exhaling CO2. Only from that realization can you start to identify and answer more sophisticated questions, including the exceptions. My point is that you can get an incredible amount of mileage from the most basic principles taught in school. Which is literally the point of a basic education. But people tend to emphasize "don't believe everything you learn in school" rather than "most of what you're taught in school are foundational truths to your environment that can have immense utility in your day-to-day life." If you focus on the former rather than the latter, you won't get into the habit of learning how to apply your knowledge. And if you're not well practiced at application--which is a life-long endeavor for even the most basic rules--then superficially that knowledge tends to seem useless. I never studied computer science in college--I was already writing Perl and JavaScript when I entered a 101 course which was teaching Pascal, and I dropped it the next week. But I did end up learning--and still learn--the theory and its application. I often hear computer science graduates lament that they never actually need to apply what they learned in school in their professional lives. Well, "need" and "can" are two different things and it's a choice you make. Failure to rigorously apply even basic principles is a big reason, IME, why so much software is utter crap. Do you need to consider algorithmic complexity for every little script you write? Yes! Not because it necessarily matters to the performance of the script, per se, but because the script will be part of a larger data processing system, and the way it fits into and shapes that system can and often will effect algorithmic efficiency down the line. It's a useful skill to apply first principles to everything you encounter in life. Not just scientific principles, but moral and emotional principles, too.

vowelless 6y ago

Hopefully by now you have opened the article and read it. Did it dazzle you?

LolWolf 6y ago
Shocked me to my core; flabbergasted me to no end. I never could have imagined! :)

habeebtc 6y ago

I recall from Chemistry: When hydrocarbons combust, the outputs generally are CO2 and Water. Driven home by living with a gearhead after college. At least some of the liquid dripping from tailpipes is water.

mikepurvis 6y ago
Also relevant if you've ever looked into what a modern "condensing" boiler/furnace is: https://www.ernstheating.com/blog/condensing-furnaces/ https://www.ernstheating.com/blog/condensing-furnaces/ A consequence of the secondary heat exchanger is that a bunch of the steam from the exhaust condenses back into water, and unfortunately it's water containing a bunch of heavy metals and other nasty stuff, which usually ends up flushed into the municipal sanitary sewer. Probably still better than it going up the chimney and into the atmosphere, but it would be nice if there was a way to capture and isolate those pollutants in that relatively concentrated state, before they end up mixed in with everyone's bathtub water.
- Scoundreller 6y ago
  My hope is that this is highly dependent on fuel source. Really bad for coal, medium for kerosene and not a huge issue for natural gas.
  - mikepurvis 6y ago
    Me too, but the reason I have it on my mind is because I was reading the technical manual [1] for the fancy new NG boiler I'm having installed next week, and they specifically list the max concentrations of lead, chromium, cadmium, and other scary things in the condensate water after the neutralizing unit, with a recommendation to check with your my regulations to ensure that it's legal to dispose of this water down the drain. Possibly it's just an abundance-of-caution thing, but I assume the reason for the warning is that in some places it isn't, perhaps because of stricter environmental standards, or maybe a sewage treatment system which isn't set up for this. 1: https://www.viessmann.ca/content/dam/vi-brands/CA/pdfs/wall-mount/vitodens_100_tdm.pdf/_jcr_content/renditions/original.media_file.inline.file/vitodens_100_tdm.pdf https://www.viessmann.ca/content/dam/vi-brands/CA/pdfs/wall-...

cperciva 6y ago

I'd say water and CO2 and urea. Protein is roughly 16% Nitrogen by weight.

thaumasiotes 6y ago
I was about to say, excreting water and CO2 leaves you no way at all to get rid of nitrogen.
- Retric 6y ago
  Body fat is just a mix of HCO https://en.wikipedia.org/wiki/Fat https://en.wikipedia.org/wiki/Fat With extreme weight loss blood, protean, and even bone mass is included. So it’s really Oxygen, Carbon Hydrogen, Nitrogen, Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, and Magnesium plus some trace elements. However, the body heavily favors removing water and fat with mild weight loss.

divbzero 6y ago

Yes, something like (CH2O)n + n O2 → n H2O + n CO2 for sugars and analogous for fats and proteins.

Fezzik 6y ago

This is a fantastic video that breaks down the process, including great visual aids: https://m.youtube.com/watch?v=vuIlsN32WaE https://m.youtube.com/watch?v=vuIlsN32WaE

TimSchumann 6y ago

It's actually like 85% to 90% CO2 by weight IIRC, can't remember the chemistry off the top of my head, but I remember being shocked by that. You literally breathe most of the weight off. Edit: Found a source, memory was about right. Per this info-graphic [0] and this paper [1], approximately 84% of fat loss by mass is exhaled as CO2. [0]https://www.bmj.com/content/bmj/349/bmj.g7257/F2.large.jpg https://www.bmj.com/content/bmj/349/bmj.g7257/F2.large.jpg [1]https://www.bmj.com/content/bmj/349/bmj.g7257.full.pdf https://www.bmj.com/content/bmj/349/bmj.g7257.full.pdf

Ayesh 6y ago

I learned this from a Ted talk, and surprised me quite a lot. The audience seemed surprised too.

SeriousM 6y ago

> I haven't opened the article Well done...