Humans are efficient, but not across the board. Trivial counterexample: walking is incredibly energy inefficient vs a bicycle or other wheeled conveyances whose primary dissipater is rolling resistance.
There might be more efficient ways to move but we are pretty well equipped by evolution.
Agreed, but it was gp that brought up the human vs. machine efficiency argument. Machines can have wheels.
It's not strange at all, I was responding to a specific, incorrect claim. I even quoted the wrong claim in my earlier comment , and I'll repeat it again, with added emphasis
>>> humans are incredibly efficient, from an energy perspective, in anything we do, compared to machines
I simply provided contrary evidence to a well-defined, falsifiable claim. How is that strange?
Then to boldly claim that humans are more efficient at anything compared to a machine, just does not follow.
But annoyingly pedantic.
Might this just be selection bias? I mean, if humans can't do a task efficiently, we're not going to do the comparison with a machine.
Some actions we do seem (to me) very inefficient when compared with machines. For example: grating carrots and brushing teeth.
Electrochemical reactions in your muscles combined with the mechanical advantage from the geometry of your joints and ligaments is simply more energy efficient than most mechanical or electromechanical systems. On top of that, our learned and evolved kinematic algorithms result in vastly more efficient control. Humans tend to be pretty good at using only exactly as much energy as required for a given action. Overshoot is quite limited compared to robots.
Your suggested actions seem inefficient, but if you look at the actual energy expenditure, mechanical means are much worse simply because mammalian muscle is so efficient.
I read efficiency as "Energy inputted to accomplish a task", in which case, biological systems are far more efficient than current-day mechanical ones. It's a tradeoff.
Humans cannot fly.
My own is ~250W @ 3.12W/kg. I can't even hit 700W yet, let alone for over a minute. My 5 second power is ~640W.
Crazy numbers.
Lost the opportunity to say "bread".
I would suspect my equivalency to be about 1/3rd a Robert [unit of measure from vidlink].
Thanks a lot. Unfortunately I can’t edit it anymore.
Even without a battery, I could easily imagine designing an efficient single slice toaster that could handily brown a pop tart on a 300W budget.
If you like then "golden," perhaps the entire box.
It’s also interesting that the industry has settled on using watts to mean rate of useful work whereas calories to mean the total work including inefficiencies, despite that calories is just a unit of energy. A rule of thumb for cyclists is that in addition to usual unit conversions, the “calories” figure should be multiplied by four to account for energy expended by the body but not used for rotating the pedals. I don’t use rowing machines but I’m sure they would have a similar conversion factor in order to calculate calories.
Imagine the work(out)station of the future.
</s> (or not)
However you can expect around only 3 watts of output at normal speeds and you will need to put in around 5-7 watts of power for the same speed. This is barely enough to trickle charge modern phones.
I will probably end up with no sound system and just expensive dynamo lights, using a USB speaker that doubles up as a power brick.
There is a nice USB battery kit for dynamo that fits in the steerer, so it is soldering iron time for that, so might as well learn how to do USB-C power things.
One day there will be structural solar panel batteries that can be 3D printed into lightweight bicycle frames, so maybe I will stick to throwaway lights until then!
please don't inflict your music on everyone around you.
Unfortunately even with the bike it seems like you really need to find one machine that can be repurposed, a rowing machine seems a bit of a stretch.
The Concept2 rowing machines can power itself using the power you generate by rowing, so we're partly there.
It's the only unit that makes sense tbh
For an average untrained male cyclist who is 175lb, they should be able to maintain 1.5-2 w/kg over an hour, or 120-160watts. A beginner cyclist who's been cycling recreationally over over a year should be able to attain 2-2.5w/kg which is 160-200 watts. A recreational cyclist who's be training for several years should be able to maintain 200 watts.
Trust me, I'm a cyclist, and I cycle with a power meter.
If you are not chasing watts, it’s much more sustainable to do 70 watts for two hours. You can probably do this every day.
Basically, you can probably charge your macbook at peek power for an hour every other day, or every day for a short while if you're okay with burning out eventually.
Expect to need to eat 400-600 calories and a lot of water each time you do this.
But that was 35 years ago and it was a high school physics experiment meant to be entertaining more than precise.
Considering the difficulty of sustaining 700 watts vs 350 watts, we could've had some very well-burnt toast if they uninstalled the heating coils for the 2nd piece of bread!
While watching the video, I was wondering how they modified the >1kW device to produce a toasted toast in that short amount of time (I guess you could substitute instantaneous power for time up to a point, but the video wasn't that long), thinking maybe they removed one of the sides' circuits. Now I'm disappointed as well. Thanks xD