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soffee
June 23rd, 2007, 10:20 AM
Ok, so i was revising for my physics exam on monday and i was just learning the whole theory of how a microphone works (with soundwaves making a diaphragm vibrate which then moves a coil through some magnetic field lines inducing an analogue current). And i came up with an idea. If sound can induce current the same way that steam can by turning magnet in a coil of wire, then why can't we use sound to make electricity?

You could put some kind of a giant super-sensitive microphone in a noisy city which could generate electicity with no fuel needed! Or everyone could have one in their house or in clubs or generally noisy areas?

I am pretty sure that there is a good reason nobody has ever thought of this, most probably because it wouldn't work for some reason or other. But the idea just came to my head and i was wondering if someone would like to explain to me why it wouldnt work or if i have come up with an engenious idea which will save the world from its fuel problems (which i doubt)

Alice Shade
June 23rd, 2007, 12:27 PM
Well...

The problem is exactly within the construction of microphone.

Putting it simply, such "sound powerplant" would produce jumbled electricity current, matching the noise.

Which is not really usable, as all devices are designed to use current of specific amplitude and modulation.

soffee
June 23rd, 2007, 12:45 PM
Damn, there i was thinking i'd saved the world!

Digs
June 23rd, 2007, 05:32 PM
Hm. Why not have a very stable speaker in a room designed for this purpose, pointed at an array of very stable mics? How much power would a sound plant, or rather an individual microphone, generate, soffee? More than the power paid to make the speaker in this scenario work?

Alice Shade
June 23rd, 2007, 10:30 PM
Digs, speaker is NOT a good source.

For sound powerstation, you`d need monotone hum. And that is generally created expending more energy then microphones would generate.

-AoG-Kero
June 24th, 2007, 02:37 AM
but you know, excluding the thought of microphones, Sound turning into energy could be a good thing if you could create a device suited to doing the job.

jon_hill987
June 24th, 2007, 09:11 AM
It would be nice, as it would make cities quieter, but have you seen the sort of current generated by a microphone? it is bugger all. That is why the signal has to be passed through an amp before being useful.

soffee
June 24th, 2007, 10:41 PM
Perhaps someone could invent some sort of a sound filter that only let in a sound wave of a specific frequency. No idea how that would work, but it could be doable i guess? Anyway, just a thought.

Alice Shade
June 24th, 2007, 11:34 PM
It is doable.

Problem is, that the filtering alone will consume more energy, then microphone can produce.

Digs
June 25th, 2007, 12:27 AM
Stupid law of conservation.

Alice Shade
June 25th, 2007, 03:05 AM
Purely theoretically, it might be possible to construct passive sound reverberator, that would turn all the noise directed at it into monotone hum in some point inside it.

Problem is, that I have absolutely no idea, just how big, complicated and sensitive it can be, if it`s possible at all.

Chances are, that areas needed to perform such modulation would be comparable to football fields, and will drown out all sound so much, that resulting hum will generate much less energy, then it`s needed to maintain the construction financially-wise. Cost of maintenance would definitely be bigger, then profit from sold electricity.

-AoG-Kero
June 25th, 2007, 03:37 AM
hmm, well screw that then lol, i saw we concentrate on hydrogen as fuel then!

Digs
June 25th, 2007, 03:24 PM
The "hydrogen-powered" cars we talk about right now actually use hydrogen as a sort of battery. The energy that they'd be using to power whatever they're powering would be produced somewhere else, perhaps a solar array or wind farm. Hydrogen doesn't really exist alone a lot on Earth, 'cause it can react a little strongly to a lot of stuff. We've got to expend energy to get hydrogen alone at all, generally via electrolysis though some metals react with water in ways that'll manufacture hydrogen. Sodium springs to mind.

There's no beating the law of conservation, in any event. I remember Heinlein said it "there's no such thing as a free lunch." Our planet isn't a closed system tho', so we've got the ability to catch Sol's stellar energy, and potentially a lot of sources. Don't worry about it too much.

-AoG-Kero
June 25th, 2007, 04:08 PM
The "hydrogen-powered" cars we talk about right now actually use hydrogen as a sort of battery. The energy that they'd be using to power whatever they're powering would be produced somewhere else, perhaps a solar array or wind farm. Hydrogen doesn't really exist alone a lot on Earth, 'cause it can react a little strongly to a lot of stuff. We've got to expend energy to get hydrogen alone at all, generally via electrolysis though some metals react with water in ways that'll manufacture hydrogen. Sodium springs to mind.

There's no beating the law of conservation, in any event. I remember Heinlein said it "there's no such thing as a free lunch." Our planet isn't a closed system tho', so we've got the ability to catch Sol's stellar energy, and potentially a lot of sources. Don't worry about it too much.


with the ever-rising price of gas, how can i not worry about it lol?

punkinside
June 25th, 2007, 11:33 PM
The only (theoretically) 100% efficient energy which potentially has even more energy output to energy input ratio than oil is anti-matter annihilation. Problem is, anti-matter is a bitch to store in "large" quantities. (A gram of anti matter could power NYC for a month!) A couple of thousand particles have been made in particle accelerators at CERN and in the US but they quickly annihilate with the matter left over from the collision.

Some scientists have been experimenting with wireless power transfer (pray for "witricity"), we could potentially put up a solar power plant in orbit and transfer the power back to earth, it would yield even more efficiency than on the surface of the earth. Others have been finding ways to make solar more efficient. The one that I think is completely useless (other than to make hippies feel warm and fuzzy inside) is wind power.

Alice Shade
June 26th, 2007, 01:00 AM
Wind power is not so bad where there are constant non-changing winds. Otherwise, maintenance costs more then energy made turns up.

Wireless transfer... Well, if that`s what I think misdirected transfer would be more then a bit nasty on the surface it misdirects on.

soffee
June 26th, 2007, 05:38 PM
hydrogen powered cars? Nope, I vote nitrogen powered. Then cars could run on air!

Alice Shade
June 26th, 2007, 07:55 PM
Nitrogen is largely inert.

Hydrogen us used because it can be combusted, and resulting "soot" would be just water.

Whereas nitrous oxydes are toxic, and even in small quantities, can induce delirium.

So, the only way to use nitrogen to power something would be nuclear reaction of some sort... And that`s more then a little tough with stable isotope.

punkinside
June 26th, 2007, 07:57 PM
Wind power is not so bad where there are constant non-changing winds. Otherwise, maintenance costs more then energy made turns up.

Wireless transfer... Well, if that`s what I think misdirected transfer would be more then a bit nasty on the surface it misdirects on.

Did you read the articles on witricity? Its something about resonating bodies which radiate the energy only towards each other, with minimal interaction with the rest of the environment.

The problem they're having is making the thingies transfer power over larger distances, at the same time miniaturizing the devices. Its primary intended use is to recharge things like laptops and cellphones wirelessly [sic] as soon as you step into a room set up with such devices.

Digs
June 27th, 2007, 02:50 PM
The wireless electrical energy transfer you guys seem to be talking about springs from the works of history's preeminent actually-mad scientists, Nikola Tesla. It works, confirmably, but last I heard you need to place a fairly big magnetron every so many feet to have it work with any kind of coverage. Maybe somebody is working on refining it for better range?

-AoG-Kero
June 28th, 2007, 03:33 AM
I'm telling you guys, the best way to get new energy is to use hydrogen. Its one of the most(if not most) abundant resources in the Universe. We dont have to worry about any known pollution, and we have more than we can ever need

punkinside
June 28th, 2007, 04:57 PM
Digs: search for witricty, its the old concept with new ideas, applied to something we've always known in a different way.

AOG: problem with hidrogen is that its not freely available on earth and has to be procured using up much more energy than it actually puts out. If you use a hydrogen powered car you actually pollute equally than other cars, just by the way the hydrogen has to be procured, which uses tons of "dirty" energy.

And it may be the most available element in the universe, but the universe is HUGE, getting it back here for our cars is sure to be a problem for another couple of hundred years.

-AoG-Kero
June 28th, 2007, 07:56 PM
AOG: problem with hidrogen is that its not freely available on earth and has to be procured using up much more energy than it actually puts out. If you use a hydrogen powered car you actually pollute equally than other cars, just by the way the hydrogen has to be procured, which uses tons of "dirty" energy.


um...you do know that water has hydrogen in it?

and there has been developmeants to use just water, with a engine that converts water to hydrogen and oxygen, and the exhaust would pretty much start to reverse global warming by adding oxygen

Digs
June 28th, 2007, 08:38 PM
Oh, that's pretty neat, actually. They worked past the need for a magnetron and used simple magnetic loop antennae instead.

I hope people appreciate everything Tesla gave them.

Kero, the hydrogen in water isn't free-standing. To be useful it needs to be alone. We can do this with electrolysis, but it takes energy.

punkinside
June 29th, 2007, 02:32 AM
Exactly, hydrogen doesn't appear alone in earth. Electrolysis is separating the hydrogen from the oxygen in water but the electrical energy (gotten from "traditional" polluting sources) needed is much higher than the final yield of the hydrogen.

-AoG-Kero
June 30th, 2007, 04:08 AM
ah, well if we could find a way around it it would be perfect...
surely there must be some otherway to do it

Digs
July 1st, 2007, 01:08 AM
Hee hee, sorry, Kero. "There ain't no such thing as a free lunch." There is no circumvention of the laws of thermodynamics.

Don't give up on hydrogen energy conversion, though - it has its own benefits, even after you consider the fact that you're losing energy converting it. Burning hydrogen is a much more viable fuel method for vehicles than just batteries, as it has some of the punch of combustion without the need for dinosaur soup. You can get the energy to make electrolysis happen effectively anywhere, in addition, which means Solar Farms = Viable Vehicle Energy Producers, which is a definite improvement. Batteries always suck compared to combustion, you see. Always. In addition, hydrogen cells produce a waste, water, but not really pollution per se.

You can get hydrogen alone through certain chemical processes, too. I know offhand that dumping pure sodium in water'll make it happen, but I imagine there are other materials that can do something similar.

-AoG-Kero
July 1st, 2007, 03:53 AM
You can get hydrogen alone through certain chemical processes, too. I know offhand that dumping pure sodium in water'll make it happen, but I imagine there are other materials that can do something similar.

well with solar power and the chemical processes im sure we could find some combination to make it worthwile

punkinside
July 2nd, 2007, 12:36 PM
Hee hee, sorry, Kero. "There ain't no such thing as a free lunch." There is no circumvention of the laws of thermodynamics.

Don't give up on hydrogen energy conversion, though - it has its own benefits, even after you consider the fact that you're losing energy converting it. Burning hydrogen is a much more viable fuel method for vehicles than just batteries, as it has some of the punch of combustion without the need for dinosaur soup. You can get the energy to make electrolysis happen effectively anywhere, in addition, which means Solar Farms = Viable Vehicle Energy Producers, which is a definite improvement. Batteries always suck compared to combustion, you see. Always. In addition, hydrogen cells produce a waste, water, but not really pollution per se.

You can get hydrogen alone through certain chemical processes, too. I know offhand that dumping pure sodium in water'll make it happen, but I imagine there are other materials that can do something similar.

It's pretty hard to get pure sodium on earth also. It's not like we could mine for it or anything because of its high reactivity. Now, I want to make sure you know I'm talking out of my ass, but I think the main way to get sodium is through salt (NaCl) and the process to separate those is an energy hog also.

As for solar, I think we're a few decades from making it a viable solution to the current fosil-fuel burning process.

I, for one, I'm a supporter of nuclear energy, alarmist dirty hippies have made the couple of insignificant (in the large scheme of things) accidents appear much more important than they are and given it a bad name. Nuclear energy has gotten many orders of magnitude safer than it already was in the last 20 years, and the waste disposal also. If we really want a viable solution to fossil fuels that doesn't fry the earth we should look no further.

Digs
July 2nd, 2007, 03:06 PM
No, nuclear power is cool, even if the waste it generates is problematic for a long time. It's the difference between having hideously concentrated bad stuff and widespread bad stuff resulting from the different fuels you're burning. If you keep nuclear waste in drums for a few decades, it becomes harmless, right? They build facilities for this sort of thing, I imagine. They're probably cheaper than the average, say, prison.

Don't discount solar power entirely, now. I remember reading a few months ago on digg/slashdot that some researchers in California can make solar panels that are 40+% efficient. Compare to the old standard of a low twenty-something percent. A few farms in the desert for those babies and you'll have a solution to power problems for a lot of people.

punkinside
July 3rd, 2007, 02:14 AM
I'm not saying we should abandon solar, I'm saying that the only reason we're not already curving our carbon emissions is because of the same dirty hippies that want us to live back in the stone age so we don't pollute.

And you're right, the waste of nuclear power plants could potentially be stored very safely. The one thing that's not right is that nuclear waste is not dangerous for decades, but for centuries. One of the things I would suggest is also taking a few hundred tons of that (possibly from various countries) and send that into space, crash it into the sun or something like that.

Digs
July 3rd, 2007, 02:34 PM
Well...shooting it into space might be irresponsible, but we could build a supergun and fire it up to Luna or perhaps into Jupiter with no noted chance of hitting something we shouldn't.

Googlist720
July 21st, 2007, 07:11 PM
Hahaha. Monotone hum. I can just imagine a group of people sitting there. "Ummmmmmmmm". Ah. :D

Alice Shade
July 21st, 2007, 07:32 PM
Buddhist monks as the source of power?

Might work... Somewhat. ^_^

Templar
July 23rd, 2007, 03:58 AM
I'm pro-nuclear as well, but I'm not sure if you can call Chernobyl insignifigant.

What about fusion? As opposed to hydrogen cells use the hydrogan in a much more energy producing way! Appart from the fact that is quite unstable at this stage of research, its worth looking at.