NEWSPEAK Blog

Better living through condensed matter physics: Thermoelectric edition!

A new thermoelectric (TE) material developed at Ohio State made modest headlines this week. It doubles the efficiency of TE devices that are best applied to obtaining electrical energy from otherwise wasted thermal energy in, say, internal combustion engines. It's kind of a big breakthrough in a field that is decades old. "Let me 'splain. No, there is too much. Let me sum up."

The TE effect itself is nothing new. In purely phenomenological terms, it is the relation between a temperature gradient across a material and a corresponding voltage drop. It can work either way: apply a voltage to get a temperature difference, or apply a thermal gradient to get a voltage. (Note we're talking about a thermal gradient. The normal heating you associate with current going through a wire is energy loss from scattered electrons, and it is essentially uniformly distributed.) Simple enough, right? How it works is only slightly complicated.

Imagine some container with water in it. If you make one side of the container hot and the other cold, your a priori thermodynamic intuition (which will turn out to be correct) is that water molecules on the hot side will heat up and start flowing to the cold side, and the ones on the cold side will flow to the hot side to fill in the gap left behind. This is oversimplified, of course, because really these suckers are bouncing off each other like crazy, but the basic idea is right: convection.

A metal is pretty much analogous, except instead of water molecules, you have conduction electrons, which behave like a fluid (albeit a fluid that carries electrical charge). So we put two ends of a metal at different temperatures and the electrons will convect. Great. But notice that there's no electric current - not yet at least. Remember the back-filling: there are just as many hot electrons going one way as cold electrons going the other.

So what's a condensed matter physicist to do? One trick is to employ a diode (see p-n junction), which is an everyday electrical circuit component that only allows electrons to flow in one direction. (OK, technically you want to split the diode in half and sandwich it with some metal, but the idea's still the same.) Just like that, you have a one-way valve for hot electrons. Want to pump heat across the device? Connect the TE device to a battery. Want to convert thermal energy to electricity? Replace that battery with your waffle maker, and heat one end of the TE while cooling the other.

So now that you have a sense of how this stuff works, what happened at Ohio State to bring about this breakthrough? Well, that's a long and technical explanation (band structure, density of states, Fermi energy, etc.) way beyond the scope of this already too-long post! Let it suffice to say that quantum mechanics works.

TE devices have found a lot of uses in the last couple decades, particularly for small cooling applications. They're great - cheap, low power consumption, no acoustical noise or vibrations, extremely long operating lifetime, and no coolants required (water, freon, etc.). High-sensitivity CCD cameras in astronomy and other fields use TE cooling to reduce camera noise due to thermal "dark" current (not at all related to dark matter/energy, BTW). Some high-power lasers use TE's for cooling as well. DIY computer builders, gamers, and home theater enthusiasts are beginning to catch on. I've even spotted TE camping/tailgate coolers that plug into your car's cigarette lighter.

Hopefully the future will see TE's in our homes in the form of refrigerators, A/C and heating units, and computer coolers. Unfortunately, it's my opinion that the success of the technology will rely heavily upon our willingness to restructure our electrical infrastructure. These are low-voltage, DC devices, while your home is mostly wired with 120 V at 60 Hz. Sure, you can step down the voltage and rectify it, but so far that's surprisingly inefficient - just put your hand on your AC adapter next time you use your laptop. That baby's putting out some heat, and as a corollary, wasting a lot of energy before any of it ever even gets to your processor. This is one of the reasons why a related technology, LED lighting (also in the press this week), is not in widespread use in buildings but is instead mostly limited to applications that use batteries, like the lights on your bike.

That's all nice Back to the Future II-type stuff, but what should really excite us, and what makes the Ohio State discovery an important milestone, is the potential to use the TE effect to help offset the inefficiencies in other devices. Anything - and I do mean anything - we ever build is inherently inefficient (see Laws of Thermodynamics, 2nd). And almost always, a significant portion of the wasted energy is lost in the form of heat. TE devices give us a way to easily convert some of this energy back into electricity. Considering that even the best combustion engines can't break about 20% efficiency (and even some small electric motors have room for improvement), the potential energy (and carbon) savings are enormous. Moreover, consider that a standard hybrid vehicle, in order to charge its batteries, uses a generator to actually steal energy that would otherwise go to the wheels. (Caveat: regenerative braking doesn't have this drawback.) So with the Prius, for example, you're actually making the combustion engine more inefficient in the short term in order to save gas over the long haul. TE devices, by contrast, aren't so parasitic - they get their energy from throw-away heat that would have been lost anyway, and, on top of that, they help cool the engine block, thereby allowing the engine run even more efficiently!

Keep the faith.

Another astronaut has come out as a believer in extraterrestrials. It's Edgar Mitchell, the sixth man to walk on the moon, which ranks him fame-wise somewhere between the "Where's the Beef?" lady and the guy who played Boner on Growing Pains. But Mitchell's claims that he was "privileged enough to be in on the fact that we’ve been visited on this planet and [that] the U.F.O. phenomena is real” have garnered quite a bit of press. Here's him talking about Roswell:

Now, John Glenn alluded to his belief in alien life, but Mitchell is a lot more overt. I've already given you my thoughts on the matter, but to me, it comes back to one central concept, the Fermi Paradox: if there is extraterrestrial life visiting Earth, if we are truly part of a galactic community, where the hell is everybody else? All we're given is grainy footage, like the stuff heralded in May, cultish evangelism and dubious books by people who feel the need to include their credentials on the cover (good rule of thumb: books by Dr. So-And-So, Ph. D. are full of shit. Sagan never needed to list his credentials. Nor did Stephen Jay Gould, Stephen Hawking, Niels Bohr or, you know, Einstein). Unless there is some sort of Star Trek Prime Directive at work, why is this rampant, active alien culture so shy? Why does the touted "conclusive proof" invariably evade conclusiveness?

I, like you, want to believe. But I think I'm a dumbass for doing so.

You know, I never thought about it this way.

Study: Most Children Strongly Opposed To Children�s Healthcare

The BS behind biofuels

Biofuels aren't all bad, I suppose. They may, after all, provide a stop-gap for our foreign oil dependence while our infrastructure makes the shift to actual green technology. In doing so, they could be a boon for our rural economies, and they might even make the world just a tiny bit more peaceful. Just one problem: much of the public thinks that biofuels will reduce greenhouse gas emissions sufficiently enough to thwart global warming. Many of us have known for some time that this is complete and utter bologna, but some new studies -- which take into account the effects of converting huge tracts of arable land for biofuel production -- are especially damning.

This just adds to the nausea I already feel when people put "green" and "biofuel" together in the same sentence.

Alternative Energy Technologies You Might Not Know About

There's so much great new alternative energy technology, but a lot of it's not getting any coverage from the MSM. Instead of relying on those worthless do-nothings, let's start our own compendium of lesser-know green solutions. Here we go...

Big Auto is nothing but lies, lies, lies. Working hard to reduce fuel consumption my ass. Here are two companies that have blown the mainstream auto industry's attempts at fuel efficiency out of the water:

Aptera - Their kick-ass three-wheel hybrid-electric gets 120 mpg on a bad day, as in after the batteries are totally dead and you're just running on gas. Under normal conditions, you should expect even better mileage. Way better.

Tesla Motors - Their all-electric roadster goes 0-60 in 4 seconds, can go 220 mi per charge, and costs less than $0.02/mi to charge.

While cruising the countryside in our green speed demons, why not turn our landfills into something useful? Check it:

Plasma gasification - Garbage goes in plasma torch. Resulting gas is a fuel to be used like natural gas to generate electricity. It's got some environmental downsides, but then again, so do landfills. Time will tell if it's a viable technology.

Garbage-to-oil - This one's been around, but I think most people still haven't heard about it. It's also controversial, both in its claims and its benefits. This gist is this: a company called Changing World Technologies has a method to convert your junk into Texas light crude. Garbage goes in, oil comes out, plus some other goodies like water and inorganics. The process is not unlike an accelerated version of what goes on under the earth to make oil. What sucks: The company markets this as a way to replace foreign oil for use in cars/industry, which doesn't do anything to help the greenhouse problem. What's cool: Someday the planet will be out of oil. Ready to give up plastic? How about any of the products of modern organic chemistry, i.e., drugs, solvents? These things owe their existence in large part to oil. The bi-products of the oil refining process are important basic chemicals (benzene, etc.) used to synthesize all sorts of useful stuff. If you want better living through chemistry, then to some degree, you want oil. I'm not saying burn it. I'm saying make some useful things and put the rest back in the ground.

Oh, and why are we sitting on our asses waiting for maximum-efficiency photovoltaics to reach the market? We already have a totally rockin' solar solution:

Solar troughs - It's so freaking simple. You get a real long parabolic mirror and put it in the desert. Anything you put at the focus of that parabola is going to get hot as shit. So... put something in there that can take a lot of heat. Water? Think hotter. Try salt. Heat that stuff until its molten. Now it's liquid so you can pipe it around. Send it circulating through a bunch of water, put a turbine over that stuff, and voila! Want to store your energy instead of spending it right away (after all, the sun don't shine at night!)? Screw fuel cells! Heat's easy to store! Run your pipes through some huge concrete blocks -- yes, concrete! -- they'll stay hot all night.

Got any other "underground" alternative technologies we should know about?

It's like aspirin, 'cept it makes you gay

John Tierney just put up a post related to a recent article in Nature Neuroscience. Apparently some researchers have engineered a way to switch fruit flies between hetero/homo by altering how they respond to certain pheromones. The treatment works within hours.

While we're nowhere near doing the same thing in humans, it does raise a ton of interesting questions. In classic Tierney style, John lists off a slew of them. This is probably old hat "what if?" thinking within the gay community, but this new research sort of gives it new legs...

So let the discussion begin. I don’t think of homosexuality or heterosexuality as an “illness” to be “cured,” but I wonder how people would use the ability to control sexual orientation — to have a designer libido. Would some people, gay or straight, who weren’t having luck attracting one gender decide to switch to the other? Would some people casually switch back and forth?

Would some social conservatives (like Leon Kass), who normally object to biologists “playing god” and pharmacologists altering “human nature,” change their minds and urge the use of biotechnology to promote heterosexuality? Would some social liberals try to restrict the use of this biotechnology? Would parents, gay or straight, want to regulate their children’s sexual orientation — and should they or their children be allowed to do so?

That last question is really interesting to me. If you're of the sort that would call homosexuality a disease, then it would seem imperative (in your eyes, at least) that you treat your children. If you're like most of us, though, then you view homosexuality as a trait more akin to a "harmless defect." Sure, in the eyes of natural selection, it may not be, well, the best way to spread your genes, but whom does it harm beyond your own non-existent lineage? But here's the catch: I can name tons of harmless physical traits that parents are free to alter in their kids. Suppose I have an imaginary kid and I notice he's got some run-of-the-mill wart on the back of his hand. It doesn't hurt him. It could be there the rest of his life and it wouldn't do a thing. But suppose every time he sits down at the dinner table, I end up staring at it. I can't explain why -- it just turns me off. Maybe the same thing happens at school. Maybe he gets teased a lot. I can say this is all irrational, and that no one should be teased for having a wart on the back of his hand, but that doesn't change the reality. Would it be wrong of me to put some Compound W on that sucker?

"But," you protest, "that's not a fair comparison. A wart is not a part of who someone is." Right. But if you want to proclaim nature over nurture -- if you want to say homosexuality is more genetic than cultural (and my hunch is it probably is) -- then aren't you arguing that sexual orientation is just like a harmless little wart, or birthmark, or whatever? Aren't you saying that homosexuality isn't an identity -- at least any more so than any other physical trait? Doesn't this imply that parents should be free to "treat" their children for this (albeit inconsequential) "condition?"

Another interesting question would be: when would you be deemed old enough to take the drug for yourself?

I'm just playing devil's advocate here. I don't know the answers to any of these questions. What questions would you guys ponder? What are your hunches as to the answers?

It all makes sense to me now....

All my life I've intuitively understood that humanity is a disease, but now there's definitive proof of our ignoble origins! Geneticists recently announced that 8% of the human genetic code originated from viruses 40 million years ago. Yes, that's right. Look in the mirror. You know it's true. 8% of your body is a virus, a distant cousin of the HIV virus, in fact. Combine that with 92% ape, and you can understand why we enjoy spending our tax dollars on oil subsidies and weapons of mass destruction. I feel as though a great burden has been lifted.

The best NOVA ever!

As was decided in Kitzmiller v. Dover, Intelligent Design (i.e. Creationism) is not science, and it has no place in public science education. We who understand the difference between science and religious conjecture must be ever vigilant against the forces of ignorance who want to dismantle a 400-year-old tradition of rational skepticism and replace it with untestable hypotheses. Part trial drama, part science education, Judgment Day: Intelligent Design on Trial exposes the Religious Right for the dangerous frauds they are and demonstrates that there might actually be hope for America. Imagine that!

G.B.O.T.

From the land of lovers and fighters and wild bull riders

Very important! Mario level plays itself!

Apparently you can pass the level unscathed by not touching the controller! Apparently "Mario" is a videogame of some sort! Jon Stewart is hosting the Oscars again!

The Only Mario Level That Plays Itself - Watch more free videos