Poll: Perpetual Motion. Will we obtain this technology in this century?

[tahrey]

OP: lrn2/laws_of_thermodynamics

However, if what you're actually meaning is some reasonably unlimited form of "clean" energy, then we've got a pretty good chance. My personal belief is that increased, early investment in renewables, and re-investment of revenues from such into more of them, could really pay off. It's a matter of gaining critical mass where can be creaming off enough payback from your steadily growing solar/wind/wave/tidal/hydro/etc portfolio that a total power grid conversion can be then rapidly and realistically achieved, and with enough excess to then transfer the great many energy sinks that run off other power sources onto distributable electricity instead.

'course, it won't happen overnight, or without a fair bit of external money being sunk into it at the start (neither did our existing generation/energy source resources) - unless a pioneeering renewable power firm pledges to sink all its post-tax/overhead profits into buying up more generation - and you'll probably still need a few nuclear pebble-bed reactors ticking over to pick up any slack on low-generation/high-demand days, microgeneration on a household-by-household basis, plus a(n intercontinental) "smart grid" to enable non-instant-demand devices (overnight chargers, washers, storage heaters etc) to work better with and better spread what's available, and probably a step reduction in everyone's personal consumption (thru lots of little individual changes) but I can see it being doable in my lifetime. As Donald Fagen said, we'll play in the city - powered by the sun. Clean air, no fossil fuel (and even what nuclear is used will be far cleaner both in extraction and in disposal thanks to the former now being sun-powered not diesel, and the latter a byproduct of the pebblebed design).

If I project back the same amount of time I've realistically got left (65 years at least, probably 70-75), that's 1945 or even '35. A massive amount of change has occurred in that time in all manner of areas. It's foolish to assume it won't again (just as it is foolish to assume it will). Never mind reaching the end of the century. What state were we in back in 1920? Precious few people even had a car, mains electricity/water/gas or decent sanitation for cryin' out loud. My house was built after that but still has numerous wood/coal-fire chimneys getting in the way and venting all our hot air and has had to be extensively rewired (how the heck it got built with a garage is anyone's guess, maybe it was meant for storing bicycles and/or ponies). It's also the year of my grandmother's birth, and she'll happily tell anyone who'll listen her tales of fetching water from a pump, coal grate fires/stoves, waiting to use an outside toilet, the excitement of seeing an actual motorcar come up her street, etc. We are as far from that as we are from 2100... in fact, 2100 is further away, given that you don't really form proper long term memories until you're about 5.

Heck, my little cheapo motorbike is a step back in time just 25 or so years, around the time that new vehicles started commonly running on unleaded fuel and being fitted with catalysers in the UK. Have any of the younger boardmembers ever been near an uncatalysed engine's exhaust? It stinks, and is slightly cloudier. You can tell it a mile off once you've been exposed (I chased down a mint condition '89 VW GTi the other day... it looked great, but the whole atmosphere around it hummed with the stench of waste hydrocarbons). EVERYTHING on the road used to do that. Hence smog, acid rain, various pollution-causing illnesses. In just a decade and a half after that, the air was pretty much cleaned up, as most of the old bangers were either scrapped or converted. Even the fairly rotten banger I got as my first car in '02 had a cat on it, and once serviced ran "clean". A bit more CO2, if Clarkson is to be believed, but well worth it for all the other benefits, and we're doing good at tackling that other problem now. It'll be a non issue if our power comes from non-CO2 producing sources... Give us six of those 15-year periods (or for my own curiosity's sake, 4 or 5), and we'll have it sorted.

 

[vxicepickxv]

True perpetual motion, no. We can build machines that can appear to have perpetual motion, but have other external factors that power them.

I have a feeling that this century we will have technology that will be called perpetual motion machines, even as they produce more power than it takes to run them, they won't be actual perpetual motion machines.

 

[PurePareidolia]

It's kind of impossible so no. Obviously.

 

[Wicky_42]

Lets get fusion working first, k? Then we can work n breaking the laws of physics. Hey, maybe crack that ol' speed of light barrier first...

 

[tahrey]

By the way, what are the prices like in australia right now? More or less than whatever your equivalent of GBP 1.25~1.30 per litre would be?

 

[Fumbleumble]

I'm just loving how everyone is quoting entropy and thermodynamics as gospel....

It may be for this time in our development, but it's by no means the be all and end all.... given some time (be it a decade or a century) those laws will be smashed all to hell, or at the very least found to be wildly inaccurate.

An terms of our development at the moment, compared to the knowledge we will have when we've evolved past what we are now... we are all still BABOONS scratching in the dirt.

Jeez people.. grow some perspective.

 

[DanDeFool]

the laws of thermodynamics and entropy are greatly overrated. they are by no means absoloutes.
perpetual motion is a misnomer, it already exists, but in a different sense. I mean, it is impossible if you believe in the big bang or gravity, but only by current definitions.
gah, a simple example of a perpetual motion 'machine' would be a waterfall as part of a river as part of a weather system, I know, I know, not in the strictest sense true, but more as a metaphor.

I don't think it has anything to do with efficiancy so much as the ways in which we see and understand the universe. both thermodynamics and entropy are based on our limited observation of the world and universe. I'm not saying they are wrong, just very limited. most of the processes behind what we see is still hidden and our current scientific understanding amounts to presumption of how things work.

In other words, science needs to progress, but we are on the right path. I hope. I think.

gah, what do I know, I'm just a crab.

Crab, this may be true, but is extremely unlikely.

First off, there's a reason why the laws of thermodynamics are called laws; they have been validated by every single experiment conducted since they were postulated. If there were even a single exception, they would be called the theoretical principles of thermodynamics (or something like that).

But there hasn't been, so they're laws.

Second, even if we do begin to understand the machinery of the cosmos at a deeper level, perpetual motion (at the macroscopic scale, at least) will still probably be impossible. It's like time travel, or going faster than the speed of light. The mathematical theories concocted by theoretical physicists, like Einstein, can be solved in ways that allow these things, but they only happen in truly exceptional circumstances, like inside black holes (maybe).

Third, there's no reason to build a true perpetual motion machine, other than that it looks cool. You couldn't use it for energy generation, because harvesting energy from the motion of the device would cause it to slow down and eventually stop. And if the device subsequently speeds back up again, it's probably getting its energy from something else that you're not immediately aware of. That would be cool and potentially useful, but then it's not a perpetual motion machine, it's just an engine.

Still, there's no reason to reach for those crab-crackers and put them around your chitinous little head; it took some of the greatest human minds decades to come to grips with these principles, and some of the greatest human science fiction authors have spent decades breaking all their diligently-constructed rules. It's natural to think that there are exceptions to these rules somewhere out there, but even if those exceptions are found, it's still no guarantee that we can make use of the exceptions in a way that is useful to us.

being useful or not does not really matter. I mean, that fact that it can exist and that it is an exception to the rule, kinda rules the rule moot. -- if there is an execption to the law, isn't the law wrong?

I am not trying to be faectious, but you're right about the greatest minds and sci fi authors, the thing is, they ain't stopped yet; we still have decades and decades of squishy great minds to lob at the mountian of the unknowing and scratch off a little more debris of understanding each time.

my understanding of a perpetual motion machine is something that creates energy, but I never thought it would be energy from nowhere. it's got more to do with the cyclic nature of everything - energy, when used just doesn't disapear. it ain't a matter of efficency, however thats spelt, it's more a way of changing how we see things.

thank you for not cracking my head open just yet, I keep important people in there!

No problem.

Having an exception to a law doesn't make the law wrong; it just makes it not a law anymore. Only the principles which apply everywhere are laws; principles which do not apply everywhere are just principles. It's a purely semantic distinction, but an important one.

An object at rest will stay at rest unless acted upon by an outside force.

No object with a nonzero mass can ever travel as fast as light.

Those are laws, because they apply to every situation without exception.

The second law of thermodynamics relates (in part) to the entropy of a system, stating that the entropy of a closed system never decreases. This might be explained by considering a rock on top of a hill. When you roll the rock to the bottom of the hill, that rock has lost a certain amount of its gravitational potential energy.

You could roll the rock back up the hill, but that requires that you expend energy from somewhere else. There's no way to get back the energy the rock initially had when it was first at the top of the hill; that energy is lost to the environment as an increase in entropy.

Perpetual motion is when the rock reaches the bottom of the hill and then spontaneously rolls back up the slope on its own without anything else acting on it.

This is a very basic example, but it illustrates the problem with perpetual motion; a perpetual motion machine derives its energy, figuratively speaking, form a bunch of rocks spontaneously rolling up hill. It just can't happen.

The fact that energy, once used, is basically lost forever, has shaped our human experience.

"You can't get blood from a stone."

"There's no such thing as a free lunch."

"All good things must come to an end."

"We are all going to die."

I had a little black humor chuckle at that last one. Maybe it's just because it's late.

Perpetual motion is like the Elixir of Life, the Philosopher's Stone, faster-than-light travel, time travel, and scientific proof of the existence of God. The ability to reuse expended energy is a scientific unicorn; it would be really cool if it were possible, must most of us agree that it's probably just a fantasy.

If the universe truly is finite, then at its beginning it had a certain amount of energy in it; a certain number of rocks at different heights on different hills. No more than that.

In a million, trillion, trillion years, if it turns out there's no way to get our energy back, the universe will end with all the rocks at the bottom of the deepest possible hill. All that energy will still be there, but if everything in the universe has the same amount of energy, nothing ever changes because the rocks can only roll downhill.

Eventually, even humans will end up at the bottom of that hill.

This is why we believe in souls, and spirits. We want there to be a part of us that isn't subject to the laws of the universe. We want there to be a part of us that lasts forever, and some way for us to transcend the end not only of the self, but of existence. However, science tells us that even forever has to end sometime. Humanity may expand to cover this entire galaxy, and even many galaxies. Perhaps human beings will come to cover the entire universe, but in the end this thing we call 'humanity' is only by-product of our surroundings. When our surroundings finally go, 'humanity' will no longer mean anything, because the very context which defines it will cease to exist.

When I think about the future, these are the things that come to mind, and I'm not a believer, so I find no comfort in the existence of an immortal soul, or the possibility of perpetual motion. Of course, some people do believe in those things, and are hopeful that something in the universe really does last forever; who am I to tell them that they're wrong?

What's saddest of all, perhaps, is that I wrote this entire goddamn article of a post, arguing a bunch of points that I do not have absolute confidence in. Looking into 2011, maybe what I'm really not looking forward to is living another year of my life without any idea of why I'm alive at all.

Oh well. At least there's video games to pass the time, and other people to keep me company. That's what we're all here for, right?

 

[Wintermoot]

troll science already achieved it: http://trollscience.com/troll/view/852 I dont realy see how this wont work

 

[Redingold]

Perpetual motion is impossible as a means of producing energy.

This isn't just based on observation, this is a direct mathematical consequence of the laws of physics being invariant.

http://en.wikipedia.org/wiki/Noether's_theorem

 

[octafish]

I think Michael Jackson said it best...

 

[Karma168]

Hey everyone!

Driving home from work today I was thinking to myself about the rising petrol prices in Australia (land I call home. Love the beaches!!! We need an R18+ rating for video games :-( grrr). Sorry. Anyway.

I was thinking about perpetual motion and if we will ever find a way to invent this technology in this century. If so, what do you think it might be based around? I think that in this day and age, we should be able to invent this technology. I mean, come on, if some regular, ordinary people can invent a motor that runs off old vegetables, grass, beer (although why would you want to use beer I don't know); surely our smart, intelligent scientists can come up with a motor that is run by, say a magnetic motor or something right?

So as you can see I think we will have a magnetic perpetual motor. I leave it up to my fellow escapists to see if they agree or disagree with me and to see what crazy inventions they might add to the table.

Nope sorry, never going to happen. the 2nd law of thermodynamics pretty much destroys the idea as all thing produce heat and heat cannot be used at 100% efficiency, so perpetual motion is impossible due to these little losses in energy from the system.

 

[Altorin]

Just had to search through my bookmarks, but you might find this interesting > http://www.infoniac.com/hi-tech/latest-invention-perpetual-motion-device-that-produces-power-from-gravity.html

these sorts of "harness the power of gravity" perpetual motion machines aren't new, and they can't work.

because even in a frictionless system, the energy needed to bring an item up out of gravity, is the same as the energy you get from dropping that same item. And that's not even accounting for the gravity acting on the second object. There is no amount of scaling that can get past this fundamental problem with gravity powered perpetual motion machines, and shows the problem with all perpetual motion machines.

Also, don't believe anyone that tells you that "Zero-point energy" powers their machine, because it's a lie. Zero-Point energy is a real thing, and theoretically it COULD do it, but there has been absolutely no scientifically backed up example of how zero-point energy can be harnessed - it's just a mathematical quirk of the universe.

Perpetual motion is impossible as a means of producing energy.

This isn't just based on observation, this is a direct mathematical consequence of the laws of physics being invariant.

http://en.wikipedia.org/wiki/Noether's_theorem

that all went over my head - I did give it the college try though. Theoretically, in a frictionless system, you could technically have perpetual motion. I don't think gravity would do it, and you'd have to account for gravity's effect on the system (In the world of perpetual motion, gravity will always cause more drag then it gives back)

However, as soon as you tried to add any sort of generator to it, no matter how big the machine was, even the smallest generator it would grind to a halt.

 

[Daverson]

Also

Perpetual motion is impossible due to the 3 laws of thermodynamics, which, in laymans terms state:

1. You can't put energy into an enclosed system, and get more out than you put in (so, you couldn't use a perpetual motion device to power another system)
2. You can't put energy into an enclosed system, and get an equal amount of energy out of the system, unless the system is at absolute zero (0 Kelvin, about -273 degree Celsius, or -460 degrees Fahrenheit).
3. By definition, you can't have a system operating at absolute zero.

You forgot the zeroth law, which states that when two objects are put beside each other, there will be an overall change of heat between them until they are the same temperature.

To be frank, I don't trust the "zeroth law". It showed up after a good few years of us having 3 laws, and tries to act like it's better than the other laws.

Besides, that's not what the zeroth law says, the zeroth law says that if two objects are in thermal equilibrium with a third object, then they're in thermal equilibrium with each other.

 

[King Crab]

just stumbled onto this page and started reading, thought I'd post it here -- I cannot vouch for the validity of what he writes, but he has summed up perpetual motion much better then I could;

What's that you say - perpetual motion is impossible? My, you're a difficult one to please. The electrons in the molecules of rock formations have been orbiting steadily for millions of years without stopping - at what point will you agree that they are in perpetual motion?

http://www.free-energy-info.co.uk/

 

[Nalgas D. Lemur]

http://en.wikipedia.org/wiki/Laws_of_thermodynamics

Obviously haven't learned about this in physics class yet. Essentially, it makes perpetual motion absolutely impossible under the laws of physics in our universe. You can't create energy out of nowhere, and there will always be friction or heat or something that takes energy away from the system.

1. Learn what entropy is.
2. Stop being silly
3.

Glad that didn't take very long. Thanks, guys, for restoring a little of my hope that the educational system isn't completely worthless. Heh.

 

[Kill100577]

No problem.

Having an exception to a law doesn't make the law wrong; it just makes it not a law anymore. Only the principles which apply everywhere are laws; principles which do not apply everywhere are just principles. It's a purely semantic distinction, but an important one.

An object at rest will stay at rest unless acted upon by an outside force.

No object with a nonzero mass can ever travel as fast as light.

Those are laws, because they apply to every situation without exception.

The second law of thermodynamics relates (in part) to the entropy of a system, stating that the entropy of a closed system never decreases. This might be explained by considering a rock on top of a hill. When you roll the rock to the bottom of the hill, that rock has lost a certain amount of its gravitational potential energy.

You could roll the rock back up the hill, but that requires that you expend energy from somewhere else. There's no way to get back the energy the rock initially had when it was first at the top of the hill; that energy is lost to the environment as an increase in entropy.

Perpetual motion is when the rock reaches the bottom of the hill and then spontaneously rolls back up the slope on its own without anything else acting on it.

This is a very basic example, but it illustrates the problem with perpetual motion; a perpetual motion machine derives its energy, figuratively speaking, form a bunch of rocks spontaneously rolling up hill. It just can't happen.

The fact that energy, once used, is basically lost forever, has shaped our human experience.

"You can't get blood from a stone."

"There's no such thing as a free lunch."

"All good things must come to an end."

"We are all going to die."

I had a little black humor chuckle at that last one. Maybe it's just because it's late.

Perpetual motion is like the Elixir of Life, the Philosopher's Stone, faster-than-light travel, time travel, and scientific proof of the existence of God. The ability to reuse expended energy is a scientific unicorn; it would be really cool if it were possible, must most of us agree that it's probably just a fantasy.

If the universe truly is finite...

Do you mean in terms of space or time because if it was infinate in time then every line of sight would end on a star, so we can tell its not. However the universe is infinate in terms of space in that is is constantly expanding (i think )

 

[Veleste]

No - it will never happen? Why? Because to create a perpetual motion machine you need to break the first and second laws of thermodynamics. YOU CANNAE BREAK THE LAWS OF PHYSICS!

http://www.projectrho.com/rocket/respectscience.php

This is a great site for explaining complex scientific issues in clear English for people interested in Science or science fiction.