… they require a more or less fixed amount of energy in order to move stuff around. In order to transport a person you need enough power to move his body the required distance. In order to build a building, you need enough power to lift the materials into place.
There’s no hard lower bound on the amount of energy needed to move something horizontally. Any expenditure in transportation is all friction, no work. Now, reducing friction turns out to be a harder engineering problem than making smaller transistors, but just saying “energy” doesn’t explain why.
And the gravitational potential energy in 1 ton of stuff lifted by 1 storey would cost all of .001$ if bought from the grid in the form of electricity. So clearly the energy requirement of lifting construction materials into place is not the primary cost of construction either.
So clearly the energy requirement of lifting construction materials into place is not the primary cost of construction either.
The cost of the fuel itself is not the only cost that increases when the amount of energy increases. When a large amount of energy is applied all at once, it becomes important to apply the energy correctly, because otherwise the results can be catastrophic. If you take the energy required to lift a ton one storey, and misapply it, then you could damage property or, worse, kill people.
We let children ride bikes but not drive cars. Why? One reason is that a typical moving car has a much larger amount of kinetic energy than a typical moving bicycle, so if the car is steered badly, the results can be much worse than if a bike is steered badly.
So the more more energy is applied, the more carefully it must be applied. And this extra care costs extra money.
In a controlled environment such as a factory, the application of energy can be automated, reducing costs. But in an uncontrolled environment such as we see in transportation or building, significant automation is not yet possible, which raises costs.
Other costs also rise with energy use. For instance, the machinery that employs the energy must be built to withstand the energy. A toy car can be built of cheap plastic, but a real car needs to be strong enough not to fly apart when you step on the gas. And the machine has to be built so that it doesn’t wear down quickly in reaction to the great stresses that it is being subjected to as it operates.
There’s no hard lower bound on the amount of energy needed to move something horizontally. Any expenditure in transportation is all friction, no work. Now, reducing friction turns out to be a harder engineering problem than making smaller transistors, but just saying “energy” doesn’t explain why.
And the gravitational potential energy in 1 ton of stuff lifted by 1 storey would cost all of .001$ if bought from the grid in the form of electricity. So clearly the energy requirement of lifting construction materials into place is not the primary cost of construction either.
The cost of the fuel itself is not the only cost that increases when the amount of energy increases. When a large amount of energy is applied all at once, it becomes important to apply the energy correctly, because otherwise the results can be catastrophic. If you take the energy required to lift a ton one storey, and misapply it, then you could damage property or, worse, kill people.
We let children ride bikes but not drive cars. Why? One reason is that a typical moving car has a much larger amount of kinetic energy than a typical moving bicycle, so if the car is steered badly, the results can be much worse than if a bike is steered badly.
So the more more energy is applied, the more carefully it must be applied. And this extra care costs extra money.
In a controlled environment such as a factory, the application of energy can be automated, reducing costs. But in an uncontrolled environment such as we see in transportation or building, significant automation is not yet possible, which raises costs.
Other costs also rise with energy use. For instance, the machinery that employs the energy must be built to withstand the energy. A toy car can be built of cheap plastic, but a real car needs to be strong enough not to fly apart when you step on the gas. And the machine has to be built so that it doesn’t wear down quickly in reaction to the great stresses that it is being subjected to as it operates.