L
Lincsbodger
Ive just had an interesting discussion i thought id share with you all.
It all started with the question 'are there any mammals that cant jump?'
It turns out there plenty, and theres a good reason. Elephants and Hippos cant jump, and neither can alligators and Tortoises, all for different reasons, but its the first ones that we talked about.
If you scale an animal up by doubling its linear dimensions, eg making everything twice as big, you scale up the mass of the animal by a cube law, but you only increase the cross section of the load bearing parts (ie the bones) by a square law, and by definition you only double the power of the muscle. So you can see theres an upper limit, since the mass rapidly outstrips the ability of the muscle and bone to transport it and support it. So elephants and hippos cant jump. If they did, they would break there legs. If you go the other way, very small mammals and rodent can stand being dropped from large heights - apparently you can drop a mouse such it reaches terminal velocity, and when it hits the ground it will bounce and walk away unharmed.
The same lesson was also was learned by man when building . In the early 1920's the highest you could build was about 10 storeys, because all building were made of bricks, and the higher you went, the thicker the ground floor walls had to be to support the weight above. At ten storeys, the walls at the bottom need to be about 4 feet thick, and putting doors and windows in a 4 foot wall is problematic. The way round the problem, as we all now know, is to build with a steel girder superstructure, that will get you up to about 50 storeys. After that, you have to start building in addition to a girder superstructure, a geodesic shell, ie a triangulated shell to help support it all.
Even higher and you get problems with the building swaying in the wind. The way round that one is to have big weights hanging down the middle of the buildings, this gives the building inertial mass, lowering the resonate frequency and helping it stay still even in earthquakes.
Giraffes are very high. We wondered how high you could grow a giraffe, but realised there probably already at the maximum height limited by there legs and neck. Obviously, we concluded, the solution is to breed hollow giraffes with internal anti-sway weights, and a geodesic shell like a tortoise...........wonder why nature hasnt thought of that one yet?
Thus are the conversations i have with my 20-something son...............
It all started with the question 'are there any mammals that cant jump?'
It turns out there plenty, and theres a good reason. Elephants and Hippos cant jump, and neither can alligators and Tortoises, all for different reasons, but its the first ones that we talked about.
If you scale an animal up by doubling its linear dimensions, eg making everything twice as big, you scale up the mass of the animal by a cube law, but you only increase the cross section of the load bearing parts (ie the bones) by a square law, and by definition you only double the power of the muscle. So you can see theres an upper limit, since the mass rapidly outstrips the ability of the muscle and bone to transport it and support it. So elephants and hippos cant jump. If they did, they would break there legs. If you go the other way, very small mammals and rodent can stand being dropped from large heights - apparently you can drop a mouse such it reaches terminal velocity, and when it hits the ground it will bounce and walk away unharmed.
The same lesson was also was learned by man when building . In the early 1920's the highest you could build was about 10 storeys, because all building were made of bricks, and the higher you went, the thicker the ground floor walls had to be to support the weight above. At ten storeys, the walls at the bottom need to be about 4 feet thick, and putting doors and windows in a 4 foot wall is problematic. The way round the problem, as we all now know, is to build with a steel girder superstructure, that will get you up to about 50 storeys. After that, you have to start building in addition to a girder superstructure, a geodesic shell, ie a triangulated shell to help support it all.
Even higher and you get problems with the building swaying in the wind. The way round that one is to have big weights hanging down the middle of the buildings, this gives the building inertial mass, lowering the resonate frequency and helping it stay still even in earthquakes.
Giraffes are very high. We wondered how high you could grow a giraffe, but realised there probably already at the maximum height limited by there legs and neck. Obviously, we concluded, the solution is to breed hollow giraffes with internal anti-sway weights, and a geodesic shell like a tortoise...........wonder why nature hasnt thought of that one yet?
Thus are the conversations i have with my 20-something son...............
