Im just a layman so someone can correct me if I’m wrong, but gravity has a stronger or weaker effect on different sized objects. For instance, if you enlarged an ant to our size, it would not be able to lift that much, let alone stand under its own weight. And if we were the size of an ant, we could lift much more in comparison to our weight than we can now.
The smaller you are, the more you can lift relative to your mass. muscle strength is based on how big the muscle’s cross-section is, but your weight is based on your volume.
Weight increases by a factor of 3 (cubed) while strength increases by a factor of 2 (squared). This applies for all animals. And most objects in general.
In essence it is more of a math problem than a biological wonder. If you understand how squares and cube relates you can understand why this may be the case.
In addition ants have certain skeletal and muscular properties which adds to this quality.
square cube law, basically. If you have a cube that is 1x1x1cm and double the size of it to 2x2x2 cm, you actually raise the volume, and therefore mass, of it 8 times.
The smaller a thing is, the less it has to hold the weight of its own body, and the stronger it gets in comparison to its size.
50x the weight of an ant is very little still, whereas 50x the weight of a person is a massive amount, from the point of view of material strength. Ants, and many other very small animals, can therefore support massive amounts of weight compared to their body size, because they can ignore this scaling issue.
They also don’t get damaged by falling, just as a bonus fun fact. Terminal velocity for many small creatures is not enough to cause damage to them.
Small objects scale better because of the number of dimensions.
If I double the length of your leg, that’s just 2x.
But if you double all dimensions, that means that 2x as long leg is supporting 8x the weight.
When you’re tiny that works to your advantage – it’s why spiders, ants, etc. can do incredible things (spiders can float on the wind, ants can lift huge amounts for their body weight), and why birds are generally small and have up an upper size limit.
And it’s why elephants struggle to walk or run fast, let alone jump or fly.
Because if you just double the sizes, the leg or wing is 2x as long but supporting 8x the weight… and after a while that leg will just collapse under its own weight.
its all a matter of scale, if humans were shrunk to the size of an ant, we would be able to lift 50x our small weight as well!
When a creature gets bigger, its muscles grow larger in area, but its weight (which depends on volume) grows even faster so its a LOT harder to lift your “weight” again.
Veritasium made a very simple explanation on human physics in a small scale like this 🙂Veritasium Vid
Strength is determined by the cross section of your bones and muscles while mass tends to be a factor of volume. Structural strength is N times N while Weight is N times N times N. Scale these things down to the size of an Ant and you realize that Weight has decreased a lot while the Strength has only decreased a little.
“If an animal were isometrically scaled up by a considerable amount, its relative muscular strength would be severely reduced, since the cross-section of its muscles would increase by the square of the scaling factor while its mass would increase by the cube of the scaling factor. As a result of this, cardiovascular and respiratory functions would be severely burdened.”
Comments
Essentially ants have an exoskeleton and humans have internal skeleton.
Im just a layman so someone can correct me if I’m wrong, but gravity has a stronger or weaker effect on different sized objects. For instance, if you enlarged an ant to our size, it would not be able to lift that much, let alone stand under its own weight. And if we were the size of an ant, we could lift much more in comparison to our weight than we can now.
The smaller you are, the more you can lift relative to your mass. muscle strength is based on how big the muscle’s cross-section is, but your weight is based on your volume.
Weight increases by a factor of 3 (cubed) while strength increases by a factor of 2 (squared). This applies for all animals. And most objects in general.
https://en.m.wikipedia.org/wiki/Square–cube_law
In essence it is more of a math problem than a biological wonder. If you understand how squares and cube relates you can understand why this may be the case.
In addition ants have certain skeletal and muscular properties which adds to this quality.
Because they’re incredibly small and have a strong exoskeleton
square cube law, basically. If you have a cube that is 1x1x1cm and double the size of it to 2x2x2 cm, you actually raise the volume, and therefore mass, of it 8 times.
The smaller a thing is, the less it has to hold the weight of its own body, and the stronger it gets in comparison to its size.
50x the weight of an ant is very little still, whereas 50x the weight of a person is a massive amount, from the point of view of material strength. Ants, and many other very small animals, can therefore support massive amounts of weight compared to their body size, because they can ignore this scaling issue.
They also don’t get damaged by falling, just as a bonus fun fact. Terminal velocity for many small creatures is not enough to cause damage to them.
Edit: wrong law, woops
Scaling.
Small objects scale better because of the number of dimensions.
If I double the length of your leg, that’s just 2x.
But if you double all dimensions, that means that 2x as long leg is supporting 8x the weight.
When you’re tiny that works to your advantage – it’s why spiders, ants, etc. can do incredible things (spiders can float on the wind, ants can lift huge amounts for their body weight), and why birds are generally small and have up an upper size limit.
And it’s why elephants struggle to walk or run fast, let alone jump or fly.
Because if you just double the sizes, the leg or wing is 2x as long but supporting 8x the weight… and after a while that leg will just collapse under its own weight.
This isn’t what this video is about but along the way they get into the answer to your question deeper then most.
https://youtu.be/dFVrncgIvos?si=vg2q3rs2zVYbVM6n
its all a matter of scale, if humans were shrunk to the size of an ant, we would be able to lift 50x our small weight as well!
When a creature gets bigger, its muscles grow larger in area, but its weight (which depends on volume) grows even faster so its a LOT harder to lift your “weight” again.
Veritasium made a very simple explanation on human physics in a small scale like this 🙂Veritasium Vid
Side effect of the Squared Cubed law.
Strength is determined by the cross section of your bones and muscles while mass tends to be a factor of volume. Structural strength is N times N while Weight is N times N times N. Scale these things down to the size of an Ant and you realize that Weight has decreased a lot while the Strength has only decreased a little.
https://en.m.wikipedia.org/wiki/Square%E2%80%93cube_law
“If an animal were isometrically scaled up by a considerable amount, its relative muscular strength would be severely reduced, since the cross-section of its muscles would increase by the square of the scaling factor while its mass would increase by the cube of the scaling factor. As a result of this, cardiovascular and respiratory functions would be severely burdened.”