- #1
yahastu
- 79
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Generic biomass such as leaves contain a large amount of total carbohydrates, mostly in the form of cellulose.
Some animals such as apes and can digest cellulose and that is how they can survive on leaves.
Humans cannot digest cellulose because we lack the enzymes necessary to decompose cellulose. In addition, some leaves may contain toxins that we need to avoid.
Because leaves are plentiful and contain large amounts of energy, I'm curious to explore the question of what it would take to make leaves digestable by humans. I'm particularly interested in how this could be accomplished without super advanced tools, for example in a survival situation or primitive society.
I can think of three possible ways off the top of my head that seem like they might be plausible.
1) Breed animals that do have the necessary enzymes, such as sloths. You could then feed the sloth leaves, let the sloths convert the biomass into meat, and then you can eat the meat.
2) Would it be possible to cultivate the enzymes that break down cellulose directly, thereby cutting the sloth out of the picture?
3) In a survival situation, the first two would not be an option. However, it is known that the crystalline structure of cellulose can be destroyed and turned into amorphous form when subjected to high pressure (25 MPa).
Questions:
1) If you subjected a bunch of leaves to pressures over 25 MPa, would you then be able to digest the resulting leaf paste, assuming that these particular leaves do not contain toxins?
2) If the leaves do contain toxins, such as tannins, perhaps you could first grind up the leaves, then leech out the tannins by leaving them in a stream, and then finally subject them to higher pressures in order to break down the remaining cellulose and make it edible?
3) Would it be possible to achieve the necessary 25 MPa (megapascal) using primitive tools?
25 MPa is equivalent to 3,625.94 pounds per square inch (psi).
A 20 lb sledgehammer, lifted to a height of about 9 ft and let fall by the force of gravity, will be traveling at about 8 m/s when it strikes.
Now we need to know how fast the sledgehammer comes to a stop. Not sure, maybe 0.1 seconds?
F = m*(v/t) = 9 kg * 8 m/s / 0.1 s = 720 Newton
Suppose we hit an area the size of a nail head (0.01 sq inch = 6.4516e-6 m^2 ) by fashioning a pointy tip onto the sledgehammer. Then we get:
720 Newton / 6.4516e-6 m^2 = 111.6 megapascals. Wow, we destroyed that cellulose!
I'm guessing that the amount of calories we get from the 0.01 sq inch bit of cellulose is probably less than what it takes to swing the sledgehammer...but we did it, we can successfully digest the cellulose, right?
Some animals such as apes and can digest cellulose and that is how they can survive on leaves.
Humans cannot digest cellulose because we lack the enzymes necessary to decompose cellulose. In addition, some leaves may contain toxins that we need to avoid.
Because leaves are plentiful and contain large amounts of energy, I'm curious to explore the question of what it would take to make leaves digestable by humans. I'm particularly interested in how this could be accomplished without super advanced tools, for example in a survival situation or primitive society.
I can think of three possible ways off the top of my head that seem like they might be plausible.
1) Breed animals that do have the necessary enzymes, such as sloths. You could then feed the sloth leaves, let the sloths convert the biomass into meat, and then you can eat the meat.
2) Would it be possible to cultivate the enzymes that break down cellulose directly, thereby cutting the sloth out of the picture?
3) In a survival situation, the first two would not be an option. However, it is known that the crystalline structure of cellulose can be destroyed and turned into amorphous form when subjected to high pressure (25 MPa).
Questions:
1) If you subjected a bunch of leaves to pressures over 25 MPa, would you then be able to digest the resulting leaf paste, assuming that these particular leaves do not contain toxins?
2) If the leaves do contain toxins, such as tannins, perhaps you could first grind up the leaves, then leech out the tannins by leaving them in a stream, and then finally subject them to higher pressures in order to break down the remaining cellulose and make it edible?
3) Would it be possible to achieve the necessary 25 MPa (megapascal) using primitive tools?
25 MPa is equivalent to 3,625.94 pounds per square inch (psi).
A 20 lb sledgehammer, lifted to a height of about 9 ft and let fall by the force of gravity, will be traveling at about 8 m/s when it strikes.
Now we need to know how fast the sledgehammer comes to a stop. Not sure, maybe 0.1 seconds?
F = m*(v/t) = 9 kg * 8 m/s / 0.1 s = 720 Newton
Suppose we hit an area the size of a nail head (0.01 sq inch = 6.4516e-6 m^2 ) by fashioning a pointy tip onto the sledgehammer. Then we get:
720 Newton / 6.4516e-6 m^2 = 111.6 megapascals. Wow, we destroyed that cellulose!
I'm guessing that the amount of calories we get from the 0.01 sq inch bit of cellulose is probably less than what it takes to swing the sledgehammer...but we did it, we can successfully digest the cellulose, right?
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