Urban75 Home About Offline BrixtonBuzz Contact

Can two substances combined increase in overall weight?

It's just the implication that this "explains" ingested calories leading to a greater weight increase than allowed by the laws of thermodynamics.
 
It's just the implication that this "explains" ingested calories leading to a greater weight increase than allowed by the laws of thermodynamics.
I think it was a humorously technical explanation, not an explanation of the subjective phenomenon :)

The real answer is that it might feel like the extra pounds are out of all proportion to the 200g of chocolate, but they're themselves the product of the consumption of the equivalent amount of food - quite a lot more, given the <100% efficiencies of the digestive and conversion-to-fat processes.

I remember reading somewhere that a pound of body fat was the result of the consumption of somewhere around 3500 calories. So, essentially, every 3500 calories you eat over and above your body's immediate needs will result in a pound gained. And, conversely, every 3500 calories you expend over and above your consumption will lose you a pound. There's 1100 calories in a 200 gramme bar, so that's about a third of a pound going to be gained from that. The cunning mathematicians amongst you will note that the weight gain is greater than the weight of the chocolate bar - that's because a pound of body fat doesn't just contain the calories, but all the cellular structures, water, etc., needed to store the energy.

ETA: actually, it's not. A third of a pound is about 150g. Although the bit about the cellular structures is still true.
 
The further you walk with the rucksack the more you sweat, which is absorbed by the rucksack and it gets heavier. :)
 
I think it was a humorously technical explanation, not an explanation of the subjective phenomenon :)

The real answer is that it might feel like the extra pounds are out of all proportion to the 200g of chocolate, but they're themselves the product of the consumption of the equivalent amount of food - quite a lot more, given the <100% efficiencies of the digestive and conversion-to-fat processes.

I remember reading somewhere that a pound of body fat was the result of the consumption of somewhere around 3500 calories. So, essentially, every 3500 calories you eat over and above your body's immediate needs will result in a pound gained. And, conversely, every 3500 calories you expend over and above your consumption will lose you a pound. There's 1100 calories in a 200 gramme bar, so that's about a third of a pound going to be gained from that. The cunning mathematicians amongst you will note that the weight gain is greater than the weight of the chocolate bar - that's because a pound of body fat doesn't just contain the calories, but all the cellular structures, water, etc., needed to store the energy.

ETA: actually, it's not. A third of a pound is about 150g. Although the bit about the cellular structures is still true.
The body doesn't actually work like that though. If you eat 50 calories a day above your "correct" level, you will not be morbidly obese by the end of the year. Likewise if you have 50 calories under, you won't starve to death. Your body manages how much it turns to fat. It's not a case of calories in, calories out.
 
The body doesn't actually work like that though. If you eat 50 calories a day above your "correct" level, you will not be morbidly obese by the end of the year. Likewise if you have 50 calories under, you won't starve to death. Your body manages how much it turns to fat. It's not a case of calories in, calories out.
The explanation was getting complicated enough as it was, so I didn't want to get into all that! I did make a vague reference to "<100% efficiencies", though.
 
Negative usually.

I'm in a boozer and a fella was telling a story about his rucksack getting heavier and heavier during the day. He checked his tote and found that the water was leaking from a bottle in his bag into, err ... his bag, which was causing him some weight discomfort. :facepalm:

This is very clearly ludicrous but it eventually produced a chemistry/physics discussion with someone else saying that it was possible with some chemicals. I've called massive bollocks but the second guy is adamant that it can happen with certain substances. I'm asking "where does the extra weight come from?"

I'm a bit pissed too at the moment, so just wanted to double check with you lot that I'm not just about to get pwned on some weird science that I'm unaware of.
The distribution of the weight could have changed in the backpack making it feel heavier.

A backpack closer to my back (tightly strapped) feels heavier to me than a lightly strapped one (weight further from body).
 
Clearly I think there can be a perception change about (and this is a great example) the weight of a backpack during a hike - because towards the end you are fatigued, it is going to seem heavier at that point - if you are operating at a lower energy level later on, hungry, tired, possibly dehydrated, then the backpack will seem more of a burden at that time than when you set off. It's also more than simply perception though, because if you hike for 40 miles with a heavy backpack, there is a scientific reason (and probably an equation for it!) involving how many calories you burn, and how much more (relatively speaking, compared to your energy level, calorie intake and expenditure, muscle fatigue etc) effort the backpack requires after 10 hours of hiking.

No, nothing is actually adding to its mass, but the effort put in by you that is required to keep it held up and moving increases in relative terms as your energy reserves become depleted, I am sure someone who knew more about physiology could add something about lactic acid in the muscles after a long period of effort also.
 
Clearly I think there can be a perception change about (and this is a great example) the weight of a backpack during a hike - because towards the end you are fatigued, it is going to seem heavier at that point - if you are operating at a lower energy level later on, hungry, tired, possibly dehydrated, then the backpack will seem more of a burden at that time than when you set off. It's also more than simply perception though, because if you hike for 40 miles with a heavy backpack, there is a scientific reason (and probably an equation for it!) involving how many calories you burn, and how much more (relatively speaking, compared to your energy level, calorie intake and expenditure, muscle fatigue etc) effort the backpack requires after 10 hours of hiking.

No, nothing is actually adding to its mass, but the effort put in by you that is required to keep it held up and moving increases in relative terms as your energy reserves become depleted, I am sure someone who knew more about physiology could add something about lactic acid in the muscles after a long period of effort also.
The greater distance you travel the greater number of leprechauns you walk past.
Leprechauns have a habit of slipping extra stuff unnoticed into your backpack so that you carry it for them and then removing them quickly before you take your pack off. Pass by a large number of leprechauns and it will just get heavier and heavier.
 
Threads like this are the reason I love urban. Not only does the thread exist but that I have read to the end, and, having posted, will see its inevitable serendipitous bump in years to come And also an example of why it is impossible to explain urban to other people
 
I've been thinking hard about this problem, and aside from altering the gravitational pull, I think I have another solution.

You add the first substance, let's say 100g. You add the second substance, let's say 100g as well. Then, and this is the clever bit, you add what I call 'The Great Mysterio', a hitherto unknown third substance, of let's say 500g, and when you measure the resultant product, you may be surprised to find that it has more than doubled in weight.

It's difficult to consistently reproduce this method at home, because some manifestations of The Great Mysterio do not necessarily 'react' or 'bond' well with the other substances, like balloons or wild cats, but generally I have found that in a controlled lab environment, you can expect an overall increase in weight at least 15% of the time.
 
Back
Top Bottom