I’m being extremely pedantic now, but you could classify it as a problem of converting rotational energy to forward motion. Everything in physics is about energy in one way or another.
I may have worded things badly, but I still think energy is key. More like overall energy efficiency maybe. If a car seems to be losing power, it could be the engine not producing as much power as it should, but it could also be as you suggest a flat tyre absorbing far more energy than it should, or the brakes binding and doing similar. It could even be an ECU fault, with the computer refusing to honour the driver's request for power from the accelerator. No matter if it's energy not being converted as efficiently as it should on the input side, and/or energy being dissipated inefficiently on the output side, and/or energy control mechanism's going awry, it all comes down to a system-wide energy issue one way or another. So a battery can go flat quickly if the battery is faulty, but it can also go flat quickly if the battery is fine but the device itself is consuming energy from it much more rapidly than it is supposed to, or a power controller messed up. As you say, far too little is understood yet about the mechanism with ME, but it is nonetheless going to come down to energy processing one way or another.
Just for fun, I'll try to be pedantic back: in the conversion from rotational to translational motion, no conversion of energy (under the conventional definition) takes place if we ignore friction losses. Both forms of motion give rise to kinetic energy. Where a conversion does take place is from the chemical energy in the battery or fuel to the kinetic energy the motor outputs, which is then transmitted, not converted.
Since we're on the topic of carefully choosing our words: "sickness behaviour" doesn't sit well with me either. Makes it sound like our chosen behaviour is the issue, not our symptoms.
Reduction in grooming is the only behaviour I see in that list. The others all describe some internal state of the subject that an observer can only guess at. For example 'eating less' is a behaviour that could imply 'loss of appetite', but 'loss of appetite' is not a behaviour in my dictionary.
But if some form of energy controller or interlock blocks or limits energy flow, then it still comes down to energy limitation. The person's problem ultimately down to energy limitation, no matter what is causing it, surely?
Hi Barry, I hope I didn't give you the impression I want to doubt your or your wife's experience of this illness. I can't even imagine what twenty years of living with the illness, or caring for someone that suffers from it, is like.
Did you mean to write "Nothing" instead of "Everything"? Otherwise I don't understand how that aligns with the three sentences after that.
Understood, and in my second corrected post I clarified that what I really meant was an overall system-wide energy limitation of some kind, be it energy input, or wasteful energy dissipation, or faulty energy control mechanisms.
This I find hard to accept. Energy is physics no matter what. But what I do think people confuse very much with ME is using the word "energy" in its generally meant usage, which is confusing and misleading because what they really mean is power, which is energy per unit time - but people just speak of energy. A key issue for my wife, and other people with ME from what I read here, is things taking them so much longer than it used to. So getting to the bathroom for instance is much harder and takes so much longer, which smacks strongly of the flow of energy being much reduced, and thereby taking much longer to do the same thing than before - reduced power. But I also agree it would get even more confusing if we tried getting people adopting "power" into normal conversation. But observing my wife, her real big issues are limited power, and delayed but major impact on power availability to do the things she normally would, if her pacing fails her.
I think you’re right about the language, that’s it’s a transfer and not a conversion. I got my translations messed up because of transfer vs transformation!
I was thinking more of less roundness and pressure for one wheel => more spinning freely => less energy put into the pavement to propell the car forward. I guess that the energy would primarily be lost to the friction within the system, resulting in heat and noise, so it would still be the same thing.
Actually it does. Energy used = applied force x distance moved. If you can only apply less force, then the energy used is less.
It’s not that easy. When you’re holding your arm straight out from the body you’re not moving at all but your muscle cells are still consuming energy and will fail eventually. Or do a plank.