4 ms·

Steam engines are surprisingly complex too, but you can control them by ignoring everything except shaft rotation and a steam inlet valve. What kind of coal? D

Steam engines are surprisingly complex too, but you can control them by ignoring everything except shaft rotation and a steam inlet valve. What kind of coal? Doesn't matter. What's the hill gradient? Doesn't matter. Is the driver tired? Doesn't matter. Boiler size? Number of driving wheels? Who the engineers were dreaming of marrying when they designed the pistons? Track width? Hardness of the water? Doesn't matter. You can control the whole system by observing one output and using one input.

waterlesscloud 12y ago
What method do you suggest will measure calories in and calories out exactly? If these cannot be observed exactly, what's the point in being so insistent about them?
- jacques_chester 12y ago
  There's been a misunderstanding. I agree with you that direct caloric balance is unobservable on an individual basis, it can only be approximately estimated. I'm saying that weight and appearance are observable, and that diet is adjustable. Want to gain weight? Change your diet a bit, observe the results over the following weeks. Repeat until satisfied. Want to lose weight? Change your diet a bit, observe the results over the follow weeks. Repeat until satisfied. Some people do these with old-fashioned calorie counting. Some with specialised diets. Some but dropping sweet drinks. But unless you first internalise the locus of control, you won't get anywhere.
- revelation 12y ago
  My car can't even observe speed exactly, it's off by a few km/h. It doesn't matter because the cops measuring speed expect the error and subtract the margin for me. For "eating less to lose weight" you're looking at megajoules/week change. Theres plenty of room for impreciseness here.
DanBC 12y ago
But if tou have one engine going downhill and another engine going uphill they are going to be burning different amounts of energy. We know that some gut flora encourages obesity; we know other flora encourage thinness; so having a method to make sure obese people don't have the fat-encoiraging flora and do have the thin-encouraging flora at least gives people a fighting chance.
- jacques_chester 12y ago
  > But if tou have one engine going downhill and another engine going uphill they are going to be burning different amounts of energy. Yes. The goal is to maintain a particular speed. > so having a method to make sure obese people don't have the fat-encoiraging flora and do have the thin-encouraging flora at least gives people a fighting chance. Sure, I think that's a very promising line of research that may make it easier for many people to modify their appetites. But for any given gut flora, the basic logic still holds. Just as for any given steam engine, the Watt governor works on the same principle.
dllthomas 12y ago
That's proof there exist complex systems that can be usefully modelled simply. In no way does it demonstrate that all complex systems can be usefully modelled simply or give us any confidence that the human body is such a system.
- jacques_chester 12y ago
  Do you have proof that long term average weight requires any other variables?
  - dllthomas 12y ago
    No, which is one part of the reason why I make no particular claim whether or not that's the case.

waterlesscloud 12y ago

What method do you suggest will measure calories in and calories out exactly? If these cannot be observed exactly, what's the point in being so insistent about them?

jacques_chester 12y ago
There's been a misunderstanding. I agree with you that direct caloric balance is unobservable on an individual basis, it can only be approximately estimated. I'm saying that weight and appearance are observable, and that diet is adjustable. Want to gain weight? Change your diet a bit, observe the results over the following weeks. Repeat until satisfied. Want to lose weight? Change your diet a bit, observe the results over the follow weeks. Repeat until satisfied. Some people do these with old-fashioned calorie counting. Some with specialised diets. Some but dropping sweet drinks. But unless you first internalise the locus of control, you won't get anywhere.
revelation 12y ago
My car can't even observe speed exactly, it's off by a few km/h. It doesn't matter because the cops measuring speed expect the error and subtract the margin for me. For "eating less to lose weight" you're looking at megajoules/week change. Theres plenty of room for impreciseness here.

DanBC 12y ago

But if tou have one engine going downhill and another engine going uphill they are going to be burning different amounts of energy. We know that some gut flora encourages obesity; we know other flora encourage thinness; so having a method to make sure obese people don't have the fat-encoiraging flora and do have the thin-encouraging flora at least gives people a fighting chance.

jacques_chester 12y ago
> But if tou have one engine going downhill and another engine going uphill they are going to be burning different amounts of energy. Yes. The goal is to maintain a particular speed. > so having a method to make sure obese people don't have the fat-encoiraging flora and do have the thin-encouraging flora at least gives people a fighting chance. Sure, I think that's a very promising line of research that may make it easier for many people to modify their appetites. But for any given gut flora, the basic logic still holds. Just as for any given steam engine, the Watt governor works on the same principle.

dllthomas 12y ago

That's proof there exist complex systems that can be usefully modelled simply. In no way does it demonstrate that all complex systems can be usefully modelled simply or give us any confidence that the human body is such a system.

jacques_chester 12y ago
Do you have proof that long term average weight requires any other variables?
- dllthomas 12y ago
  No, which is one part of the reason why I make no particular claim whether or not that's the case.