13 KiB
[MK] [BST] Exploit "perfect" work (challenge)
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Author: u/6340 *
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URL: https://www.reddit.com/r/rational/comments/2ljonu/mk_bst_exploit_perfect_work_challenge/
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Score: 9
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Created: 2014-11-07T03:43:56
Post:
Say we could do perfect work. Thermodynamically perfect, the amount of energy we put in is exactly the amount of energy that is put out. So if we burn a pile of wood, we can retrieve the energy in the entirety of the heat that was expelled in the reaction, but nothing more: no extra energy is created.
Basically, we have ideal machines. They can do work "magically", so we're not limited to just moving things, but any sort of labor such as heating another thing up, charging a battery, and more.
How do you exploit this? Is there anything that breaks the universe/makes everything post-scarcity as soon as an intelligent person looks at it? Or do we have a stable world in which civilization progresses at a slightly faster rate than ours?
Comments:
u/ulyssessword [+4] (an hour later)
Assuming that they are versatile and powerful enough, it would almost instantly boost humanity to Kardashev Type II level abilities (i.e. able to harness the power output of a single star). Because of mass/energy equivalence, this is practically unlimited free energy.
Want some gold? Grab a lump of dirt and throw it into the machine. 100 kg of dirt has the same energy as 100 kg of gold so you don't need to add any external energy.
Want something accelerated? A 10 ton spaceship at rest has the same energy as a 9.999 ton spaceship moving very fast.
As soon as you can freely break down matter to do work, you're practically done climbing that branch of the tech tree.
u/6340 [+2] (an hour later)
We only have human levels of technology. Once the hypothetical civilization reaches the point where they can freely break down matter for energy, it hardly matters whether the work is 100% efficiency or not, you're going to be nigh-omnipotent anyway. I probably should have clarified that the "magical engine" can't break anything apart, except as the "output" of its reaction.
Is there any fast way to break down matter to energy using simpler rules? Maybe you could throw a baseball, and convert that baseball's kinetic energy to the kinetic energy of a hydrogen atom in a fusion chamber...
u/PeridexisErrant [+4] put aside fear for courage, and death for life (2 hours later)
It could however fuse anything up to Iron, or down, with net energy output.
u/6340 [+2] (2 hours later)
I see, once we start off a reaction, we could keep it going with the base energy retrieved from previous ones, while profiting the excess. Meanwhile, civilization advances from the free energy...
How much energy exactly will it take to start off a cascading fusion reaction?
u/PeridexisErrant [+3] put aside fear for courage, and death for life (2 hours later)
Enough to fuse exactly two atoms, since with perfect efficiency you don't have to worry about critical mass. If it's above zero Kelvin and composed of anything but pure Iron, you can get nuclear power out.
Meanwhile, all this energy can be used to power our other magical not-machinery...
u/6340 [+2] (2 hours later)
Don't we usually talk about critical mass with fission reactions? Though we would still need a constant supply of new fuel to put the output energy back into.
Moreover, what is the minimum atomic number past which fission is viable?
u/PeridexisErrant [+3] put aside fear for courage, and death for life (2 hours later)
Yep, usually you need critical mass to pass the problem of energy loss... which is instead bypassed by perfect efficiency.
Fusion is net energy-out up to iron (#26 protons), fission afterwards.
u/6340 [+1] (19 hours later)
I understand fission and fusion. I was wondering about the more practical aspects of the problem.
u/PeridexisErrant [+3] put aside fear for courage, and death for life (an hour later)
For micro-scale stuff, you can suddenly build microchips that use the fundamental minimum amount of energy to do a calculation. Heating is no longer an issue. Expect a revolution to bump computer performance a few orders of magnitude, in the short term.
Macro-scale, I think the 'magical completion of work' bit is equally useful. For example: (at perfect efficiency) something rising takes work, falling yields work, and hovering at constant altitude is work-less. Boom, everyone can fly horizontally without effort. And you basically just invented a space elevator everywhere, so expect a space revolution too!
u/6340 [+1] (an hour later)
Very interesting. I never thought of microchips, nanotech was what I was going with, but a tech boom of any sort can be expected, but that's only after civilization achieves that level of technology. I was also thinking production, as we now have a really precise tool that can use really tiny amounts of energy to get a complex task done. However, prior to that I don't think there are as many easy ways to abuse the system.
The horizontal hovering seems to be a problem... There has to be a force opposing F_g, right? Would it take energy to output that force of resistance or am I failing at basic physics?
Care to explain the space elevator? Just W = F*d?
u/PeridexisErrant [+2] put aside fear for courage, and death for life (an hour later)
Horizontal flying: by analogy to standing on rigid stilts, which exert a force but do no work.
Space elevator: basically you get to lift stuff anywhere with a perfectly efficient machine, instead of using a rocket (which also has to lift it's own structure and fuel, is horrible for other reasons including heat instead of kinetic energy, etc).
u/6340 [+1] (2 hours later)
I see... Perhaps then there exists similar "perpendicular to the relevant plane" munchinkery? And this makes me think that to use this in a novel I'd have to make it revolve around forces, not energy, which kicks a couple of my ideas offstage, but also makes new ones.
As far as the space elevator, I see the point. Making it based more on forces does resolve the issue a bit, but still leaves lots of opportunity for a space boom... And the problem is that, sans proper elevator, you still have to carry fuel, you just can use it to the maximum possible degree.
u/PeridexisErrant [+2] put aside fear for courage, and death for life (2 hours later)
Is our magical not-machinery limited by distance? If not... 'magical' pistons and ropes connected to celestial bodies makes space travel easy. Even if the action is simply "raise from earth" and "push away from horizon".
Yeah, if we're talking about work/energy (with 100% efficient conversion) that's utterly broken. Force might be a little better, but maybe not by as much as you expect.
u/6340 [+1] (22 hours later)
A distance limitation would make sense, probably a distance from the "input" energy.
In other words, once we reach the modern age, breaking thermodynamics breaks so much more.
u/None [+2] (6 hours later)
Dude, you basically just eliminated most energy-shortage problems.
u/6340 [+1] (19 hours later)
How so? We can't create new energy, but we can use existing energy more efficiently.
u/ajuc [+4] (21 hours later)
Why use and create(*) new energy when you can do work with the same energy over and over without loses to heat?
Fast trains going without energy loses in circles would solve all transport problems with only initial energy investment to get it moving (to allow people to board without stopping make the leaving passangers move to the last wagon, prepare new wagon with entering passangers to the front and switch them at each station (add balast to keep the momentum constant)).
AC, heating and refrigerators could be solved similary by moving the heat (without loses) to where it is needed at the moment.
I think such world could use very little energy to do the same things we do (orders of magnitude less).
(*) Yeah yeah energy conservation you know what I mean.
u/6340 [+1] (22 hours later)
Yeah, looking back at the responses, I'm seeing that 100% energy and work efficiency is definitely world-breaking. In talking with /u/PeridexisErrant, we raised the idea of simply considering ideal forces.
Forces have a bunch of useful definitions, and can be used in lots of different ways, can you see any way to abuse that?
u/Shadawn [+2] (14 hours later)
If i understand correctly, the only way you can "perfectly burn" a pile of wood is by violating Second Law of Thermodynamics somewhere. And if you can do this, it's unlimited energy from, for example, all the air this machines cool to 0 K and transform into useful work.
u/6340 [+1] (19 hours later)
That is basically what we are doing, violating the second law of thermodynamics up until a point.
And that is an interesting point, by "taking" energy from its surroundings, not only is it doing the rather hard work of supercooling everything around it, but also getting a LOT of energy with which to work...
u/Charlie___ [+2] (14 hours later)
Any time entropy is a problem, this is a solution. Electronics will look different and ridiculously better. Everything will run at 0 degrees Kelvin, because why not - cooling it down actually liberates energy. Quantum computing was a trivial engineering problem as soon as it was proposed.
u/6340 [+1] (19 hours later)
Yep, we've actually talked about this above. Almost anything that's used on a microscopic scale will grow extremely quickly. If you can use the ideal machine to do the tiny amounts of work to push the pieces of a self-replicating nanobot into place, bam, omnipotence. (or not, but considerably closer than we are now)
u/IX-103 [+2] (14 hours later)
Couldn't we use these machines as analog computers with infinite precision and accuracy? It seems possible that one such computers would have the same processing power as a cluster of infinitely many digital computers. With these things you could brute force any encryption with O(N) operations (as opposed to O(2^N)), breaking any encryption scheme but the one-time pad. This could also be applied to protein folding, climate modelling, finite element analysis, etc. This would basically allow you to perform most scientific computing calculations in days instead of years (with one computer instead of thousands). You could also use these computers to perform perfect correlation and combining of large data sets, allowing you to meet the information theoretic bounds of any system. This effectively allows you to pull any signal out of the noise given enough independent samples. Look for massive improvements in wireless communication speeds with significant reductions in power consumption (though the number of antennas on each device would sky-rocket). Look for imaging systems capable of taking 3D pictures with nearly perfect accuracy from almost arbitrarily far away (and do similar things when sensing with sound, magnetism, gravity, etc).
In short, humans would no longer need to guess anything. Everything would become observable, and we would be able to test theories against observations as fast as we could come up with them. Whether this would increase or decrease the rate of scientific progress is an open question. All the theories men have ever made are wrong (i.e. there some observation that they contradict), so I'm not sure how fast things would progress when the people setting forth theories know exactly in which ways those theories fail to match observations. It could be that all of the pure scientists would have nervous breakdowns from trying for perfection, and only the more practical, engineering-minded folks would continue.
u/6340 [+1] (19 hours later)
OK, I'm having a mind blank. How does perfect energy efficiency equate to infinitely fast calculations?
u/IX-103 [+2] (3 days later)
The calculations are not perfectly fast, but any linear operation becomes infinitely parallelizable. Effectively by allowing perfect thermodynamic work, you have removed the effects of noise on computation. Since the cardinality of the real numbers is unimaginably larger than the integers (to say nothing of the finite precision arithmetic we use in digital computers), we can encode an infinite number of these into a single real number (for example, we could represent a series of 64bit numbers as a_0+a_1/2^64 +a_2/2^128 +...). We can then perform linear operations on this real and extract the results. Things get a little more complicated with nonlinear operations since you need to avoid aliasing, but it is still theoretically possible.