Artificial Intelligence

Maybe I've said it before, but the idea that any intelligence can somehow be artificial feels misleading. If you separate the element of humanity from intelligence, it is easy to see that all intelligences are real, not artificial. On the other hand, the concept of artificial doesn't make any sense to me to begin with. Regardless, consider the mechanical structure of the mammalian nervous network: it is indeed a network of trillions of cells, little nodes, communication points. When you touch something, a change in net potential electrical charge of ions over neural cell membranes travels from your fingertips through nerves (made of neurons) to your brain. When it enters your brain, it traverses a number of distinct pathways en route to the mammalian cerebral cortex, which is a recent development in Life; mammals specifically have this part of the central nervous system, whereas lizards and other less evolved creatures do not. This construct of many individual nodes networked into some meta entity with whatever emergent properties is not a unique one though. Perhaps the greatest example I can think of other than the brain is this thing called the internet--it too is composed of many networked nodes, and in several senses of the word. For one, the internet works thanks to a tremendous amount of electronic switching nodes, which are in many ways similar to the neurons of our own brains. Alternatively, perhaps people are nodes in this "higher" mind called the Internet, each mind some small part of a more complicated implementation of consciousness. It is difficult to say with any certainty if the systems of switches and wires performing our rote requests is experiencing some kind of consciousness--after all, how could we tell? We can't even measure or readily define our own conscious experience, how are we to begin to hope to communicate with this higher mind!? Even then, it is certain that the construction of this higher mind is very different from the mammalian brain, and doesn't this seem to strongly suggest that its experience or manifestation of consciousness would likewise be very different? I'm reminded of higher dimensions: when you think about one, two, or three dimensions, things make a reasonable amount of sense. But when you get into higher dimensions, even just four, things cease to make hardly any sense at all. So imagine it from a different perspective, one conscious dimension lower than the one we're used to: if you were a cell, one among trillions, could you even begin to imagine the everyday human experience? And yet cells are stupendously sophisticated machines, sophisticated enough to prevent us from answering many questions about human health, answers they have to reveal.

It goes without saying that the value of science is very real, which is another way of saying that our intuition frequently misleads us--if thinking alone were enough we'd have faster than light zero-energy transportation and the galaxy would be colonized by now because the easiest way to do those things would be obvious, as obvious as the Earth revolving around the Sun nearer the edge of the Milky Way galaxy among hundreds of billions of others. Once it is seen that our rough draft perception of things is generally wrong, the confidence in human intelligence erodes, and I think makes a stronger case for "intelligence" being something not anthropospecific.

Note it is institutionally correct to capitalize Internet; it is a proper noun. Even if all this somewhat ambiguous babbling about higher minds is patently false, there's no loss in the magnitude of the Internet. For certain it has become something fairly hard to define on all levels, and regardless a boon to our lifestyle to an inconceivable degree. Imagine, if some great mind were born a few decades ago just a bit too lazy, they might never flourish for lack of access to information. Now however, an inconceivable amount of information is literally available at our fingertips (I was just getting a refresher on the mesencephalon, and earlier I was playing with Wolfram Alpha which can show you how to solve even ambiguous equations like 2x3 - 6.543x = x2, among many other things). If there were any aspiring minds starved of information before, there are definitely a lot fewer now.

Tacit assumptions

How much of the strife that arises in our daily lives is attributable to the assumption that we understand what we are experiencing? How much can a person recognize their own assumptions? How much do we assume?

Probably just about everything.

This isn't necessarily an insurmountable flaw, given the remarkable success of humanity, but at the same time I doubt anybody is unwilling to abandon whatever flaws they can. Recognizing assumptions is very difficult because they are by nature not questioned. Take for example the thought experiment that led Einstein to his celebrated theories; it isn't extremely technical, but rather something that had just never been considered. Mr. X explains better than I ever could, so, from episode 8 of Cosmos (feat. a song familiar to this blog already, coincidentally) (also on Netflix on demand):

The next part is equally engaging and descriptive, visualizing the surprising effects of traveling at C, the speed of light.

Matter and Electromagnetism

With precisely 20 minutes of focus anybody can come to know a very significant portion of the foundation of our physical reality.

Garrett Lisi: Unification Theorist

Garrett Lisi is a particle/theoretic physicist who has come up with a very intriguing theory, one that mathematically unifies the quantum and relativistic branches of physics. The theory is fascinating and attractive, despite being essentially beyond comprehension. I had read about his theory at some point a while back and found it of general interest and know I've brought it up in discussion many times. Those times though my recollection was poor and didn't communicate the very important bit that is the author's name, but now I don't think I'll forget.

Unification is of course the holy grail of modern physics, an achievement similar in magnitude to curing cancer. A great thing about Lisi's theory is that it makes predictions which should be answered when the LHC makes it to full power. I have mentioned already that the theory is naturally appealing, and I wasn't lying: his paper is the most downloaded of all on arXiv.org, which is probably the largest online collection of pre-print scientific articles.

At the 2008 TED Lisi gave a presentation, his attempt at a lay explanation of the theory. You might want to take a moment to breathe deep and clear your mind before you watch...

The Secret to Weight Loss

This is a "common misconceptions" post that I've been meaning to do for a long time, and thanks to a recent article in The New York Times I finally have a good reason. More on that later.

Everybody knows weight loss is a big deal, the fact is obvious from the astounding range of products/services with weighty promises (lose 30 pounds in 30 days!!!); the advertisements assault us constantly, from every possible angle. Given that the majority of US Americans are considered overweight in a culture with highest regards only for the exact opposite build, it's really no surprise that weight loss is big business. The real surprise is just how successful such ventures are when practically all of them make explicitly outrageous claims and just as many (if not more) are wholly ineffective. The truth is that with few exceptions commercial weight loss products are simply fraudulent--they are designed to take your money, not to help you lose weight.

I know the secret to losing weight, and I'm willing to share it... for free! It is very simple, and not simple in the subtly very complicated way, just simple. Ready?

How to lose weight:  Eat less.

 It's a matter of physics. Imagine an extreme case where a person doesn't eat or drink anything; by the very laws of nature and obvious from elementary intuition, it is impossible for that person to gain weight. This would be just like setting a scale in a sealed room: it would be very silly to think that the scale might at any point suddenly measure any more weight than it has all along. Humans are magnificently, extraordinarily, incomprehensibly complex systems, but that doesn't exempt us from the laws of physics. Unless more stuff is added to a body, that body will either maintain or lose weight. In case it isn't obvious, let me remind you that abstaining from all consumption for longer than a little while is a bad idea--remember, the rule is to eat less, not to eat nothing.

Let's explore the physics in slightly more detail. The main reason we eat is to supply our body with energy; our bodies need fuel to keep the magic alive, just like a car needs gas to move. Clearly it would be a bad setup if the energy we consume couldn't be stored, like a car without a gas tank we wouldn't get very far. There are a variety of ways the human body can store energy, but the presently relevant one is best known as fat. Call me crazy, but next time you see that extra bit of flab, try being grateful--if it weren't for that "unsightly" bit of excess, a few missed meals would result in death. I don't know about you, but I'd rather have a less than optimal social image than be dead.

So fat is stored energy, but what's this energy? Is there any way to quantify it so that its consumption might be regulated? In fact, yes, there is! The energy in food is also known as Calories, which is actually a kilocalorie or 1,000 calories. A calorie is a unit of energy, just like an hour is a unit of time. If you eat 2,000 Calories in a day and only use half of them, the rest will be stored, with some portion of them being stored as fat, it's as simple as that! If you are gaining weight and it's not because you're building muscle mass, you are eating more energy than you're using. Here's the Eureka moment!

How to lose weight (revised): Eat fewer calories than you use.

But wait, what about fatty foods, exercise, and metabolism, don't these play a major role in weight loss? Lets look at each of them.

Fatty Foods
One of the strongest diet related misconceptions around is that eating foods with excess fat, saturated, unsaturated, or otherwise will lead to increased body fat. This isn't true, food fat doesn't automatically turn into body fat. Perhaps this misconception arose because lipid nutrients and adipose tissue are both known colloquially as fat, but the notion that consumed lipids will transform into adipose tissue is as silly as the notion that eating brain will make a person smarter. Anybody can eat pure fat every day and lose weight, because the amount of fat in a food doesn't matter for weight management, what matters is the amount of Calories in the food and how much food (ergo how many Calories) is consumed. It's true that fat, with 9 Calories per gram, has a higher energy density than protein and carbohydrates, which have 4 Calories per gram, but for the purposes of weight loss this is moot--all Calories in a food, regardless of the source, are accounted for by the "Calories" figure on every nutritional label. Predictably there's a fair degree of complexity in how effectively food energy is captured, but the given number of Calories represents the maximum; if you closely regulate energy intake, you will realize there are no magical foods that cause body fat. Often, however, energy intake is far from regulated, far even from monitored, and it is very easy to underestimate how many Calories are eaten in a day. One case deserves special mention: high-fructose corn syrup (HFCS), the modern sweetener du jour, has been shown in a recent Princeton study to lead to more weight gain in mice than equal amounts of cane sugar. The theory I've heard is that HFCS is far more easily digested than cane sugar, and since digestion requires energy, HFCS results in more energy than an equal amount of sugar.

Exercise
When people think weight loss, they usually think exercise. It's always a point of contention when I say it, but exercise does very little to hasten weight loss. The reason is that the body burns a lot of energy no matter what its doing; for most people exercise causes only a marginal increase in energy consumption from the already high baseline. Remember the NYTimes article I mentioned? Here's a quote from it:

“In general, exercise by itself is pretty useless for weight loss,” says Eric Ravussin, a professor at the Pennington Biomedical Research Center in Baton Rouge, La., and an expert on weight loss.

The exception here is athletes, whom require many more calories than everybody else. This is because athletes have bodies that are especially efficient in utilizing energy--in other words, they have a higher basal metabolic rate. For those of us who aren't professionally physically fit, the connection between exercise and weight loss isn't anywhere near as clear cut. For more information on this topic I recommend reading the aforementioned NYTimes article: "Weighing the Evidence on Exercise." Beyond weight loss, keep in mind that frequent aerobic exercise is universally acknowledged as a critical component in the maintenance of cardiovascular health.

Metabolism
One of my pet-peeves, if you can call it that, is when people disseminate false information. We live in an age when almost the full knowledge of Earth is accessible on demand, so the reasoning goes that it's time we stop defaulting to wild speculation and just google it. Of course I have nothing wrong with wild speculation, my displeasure arises when the speculation is presented as fact. I'm bringing this up because it's relevant to the topic at hand, metabolism. Everybody has heard the word, it's used all the time, especially in regard to weight management, but what does it mean? What is metabolism? For all the mention it gets, I'd think everyone would be familiar with what exactly was being referred to. If you visit the Wikipedia page for metabolism, you might find that the subject is rather complicated; the summary refers to cellular respiration, metabolic pathways, and the carboxylic acids that are part of the citric acid cycle. That doesn't sound like weight loss! Metabolism is something of a shotgun term that refers to the chemistry of life. The basal metabolic rate is a bit more specific, as it refers to the amount of energy an organism expends while at rest and in a post-absorptive state. Since basal metabolic rate is roughly energy expenditure, it must be able to indicate how many Calories are needed to manage weight, and indeed it does. Interestingly enough, metabolic rate is strongly correlated with lean muscle mass and the same figure has been arrived at for all people: 16 Calories per pound of lean mass per day. This means an estimate for how many Calories you need each day can be found by multiplying your lean mass by 16. This also indicates what has been shown in other studies as well: the best known way to increase the basal metabolic rate is by increasing lean muscle mass.

Just one final note: losing more than a pound or two a week is neither healthy nor permanent.

Nexus One, an Android

I've had an iPhone since shortly after they were first released, nearly three years now. For the most part, I've enjoyed it. These days, particularly when it comes to electronic devices, three years is a really long time; as such, it's almost difficult to recall why the iPhone had the hype it had. One thing to recall is that the app store, which is now probably the most attractive and well known feature of the phone, didn't exist when the phone first came out. The reason the iPhone was viewed as revolutionary (and that it was) was because it was the first cell phone to give what could be called functional access to the Internet, where most all websites were available to a mobile phone without any modifications. Clearly the Internet has revolutionized society; the movement from being available only on home computers to being available almost anywhere with cell reception is undoubtedly a movement that has been similarly transformative.

The availability of the whole content of the Internet, many Terabytes of information, on a diminutive device feeling like a polished stone, is practically inconceivable to me. But the notion is one conceived many times over in the science fiction canon. The most obvious example I know of is the device which shares the name of the book in which it resides: The Hitchhiker's Guide to the Galaxy. In his remarkable series Cosmos, Carl Sagan repeatedly fantasizes about perusing the fundamentally similar, fictional Encyclopaedia Galactica, a compendium of all the knowledge gathered throughout the existence of an intergalactic species. Both of these bits of media originate around 1978, a time in which something like the iPhone and the Internet must have been considered far out by any reasoning; it is apparent that at least two foraward thinking people saw such a device as a product of civilizations living on a galactic scale.

From 1978 the iPhone must have been a long way away, considering the primitive original Apple Macintosh didn't even hit the market until January of 1984, though development started in 1979. The Macintosh had an 8 MHz processor, 128 KB of RAM, and a 9" 512x342 monochrome display. Fast forward 23.5 years, and though our progress in intergalactic exploration hadn't much changed from naught, our computers had made unexpected advances! The original iPhone runs at 412 MHz, 128 MB of RAM, and a 3.5" 320x480 18-bit color display--it's roughly 52 times faster, has 1,000 times more memory, and a far superior display. It fits in a pocket and can run all day without needing a charge, it can replace books, newspapers, televisions, and the list goes on beyond any reasonable expectations.

Three years later, the revolution of Internet on a phone has taken place, and giant leap taken all that remains is incremental improvements: the Nexus One. This past December there was a buzz about the web as rumors of a Google phone spread. The buzz persisted for a little while and then mysteriously subsisted. The Google phone arrived almost as if it were secret all along, almost as if it remained a secret--from what I've read, the sales of the device aren't remotely as impressive as those for the iPhone. But for what it lacks in popular perception, it makes up for in spec: 1 GHz processor, 512 MB RAM, 3.7" 800x480 display, or about twice an iPhone. Having just recently mentioned that GHz isn't a very important measure, I'd be foolish to regard that as a concrete measure of performance; it isn't, but the Nexus One noticeably outperforms the iPhone in every respect. Interestingly enough, the Nexus One matches or exceeds the recently released iPad in almost every spec except for screen resolution--it's truly a remarkable device.

One of the things about today's cell phones, also called smart phones or super phones, is that they're actually powerful little computers masquerading as phones. The iPhone does a very good job at hiding the power under it's hood, and this is very much one of the reasons I chose to go with a Nexus One over another iPhone; the Nexus One has only a thin veil to hide the fact that it's a computer running a version of Linux. In order to write an application for the iPhone, one needs to pay Apple about $100 to apply for the opportunity. If they choose to accept you, there are a number of steps to follow, including authorizing a particular device, associating it with a particular machine, writing particular code, and accepting a very hefty agreement which includes conditions such as not displaying your device in public and the right of Apple to take ownership of your code without notification or recompense. The $100 only covers one year--every year requires another $100 to continue participation. I did go through this process at some point, but I didn't get as far as getting code onto a device before my membership expired; after that, I gave up. The Nexus One is a different story: anyone can write anything and put it on their phone at any time, for free. The first day I had my new phone I had a custom application uploaded to it. The second day I gained root access, installed a custom bootloader and a modified version of the Android operating system known as CyanogenMod; in other words, I now own my phone.

The subject of science fiction is relevant for one last note: the name Nexus One comes from the most advanced android in a story called "Do Androids Dream of Electric Sheep?" better known as "Blade Runner," by Philip K. Dick.

Nothing says "I'm a geek and I know what I'm doing" like a command line:

One thing that really stands out about the Nexus One versus the iPhone is the much higher resolution display (click to see a version large enough to tell the difference, also note that some aliasing in the form of red, blue, and green banding may appear depending on your monitor):

Here's a side by side comparison:

There are still a few things I like about one more than the other, but the power of the Nexus One is that I can change nearly everything as I see fit--the same most certainly cannot be said for the iPhone.

Computer Graphics

As part of my course on computer graphics this semester the class has been writing a ray tracer. The details of ray tracing aren't really worth going into, instead I'd rather share a picture (more technically a rendering) that is the result of my work.

If you are particularly learned, you'll recognize this figure as the Mandelbrot set. In case you didn't recognize it, at least you will in the future! This version in particular is really an abuse of the ray tracing engine we've developed; typically other much more efficient means are used to generate an image. However in using the ray tracer I'm able to generate images that simply couldn't be done with the more traditional methods. For instance, this rendering uses a reflection model to add an additional layer of the delicious recursiveness that characterizes fractals. Though you could do the same given the more traditional code, simply having the code alone versus a ready-made rendering program allows me to color the actual Mandelbrot set, which is almost always left black:

For the sake of completeness, here's a more traditional ray traced image that specifically includes a good variety of capabilities a ray tracing engine made in a single undergraduate semester has:

As you can tell, my cylinder code still has some issues that need to be resolved.

Demonstration of feasibility

I'm a bit too busy to give the normal glyphic flood, but as proof following my plea for autonomous vehicles this demanded mention. The Center for Automotive Research at Stanford (CARS) is planning to send an autonomous Audi up Pikes Peak at race speeds. Pikes Peak is a mountain road used as a rally stage, with surfaces varying from packed dirt to loose gravel. Actually an autonomous car has finished the course previously, but "only" at an average 25 mph. There is some reason to suspect the Stanford team will succeed in their intent, as they won DARPAs Grand Challenge and took 2nd place in their Urban Challenge; the car can at least drive 120 mph across the salt flats. I cannot wait to hear the results!

Nissan Succumbs to Logic

Making the rounds on the web is a new Nissan Land Glider concept vehicle. My opinion is that this represents the first indication of a correct step towards a sustainable near-range vehicular platform from a major automobile manufacturer. Included with all the sites discussing it are a few pictures and the following video (which has a very interesting choice of music with what I'm quite certain is the avant-ambient work of Steve Roach):



Get more after the jump!

Telescopes in Space

At first the idea of a telescope floating around in space is absurd, but any marginally knowledgeable astronomer can profess that it's a fantastic idea. Astronomy at the most fundamental level is the study of space, everything and anything that's not Earth, and it's one of the oldest realms of intrigue known to humankind; it was popular long before the scientific method wandered onto the scene, despite being very much a scientific pursuit. On one hand, that space is an old interest isn't surprising--anyone that has turned their sight to the sky on a clear, dark night knows exactly why. A gaze into what might as well be the infinite unknown, the act itself as simple as a glance at our own hands, has a way of inspiring speechless profundity in even the most uninterested amongst us. On the other hand our primal fascination with space is surprising for its distance, simply far removed from our experience and altogether relatively bland to the naked eye for its expansive empty darkness excepting the occasional tiny point of light. I find it interesting that this practical void drew fascination more readily than the exceptionally vibrant and astonishing diversity of phenomenon on Earth which we can easily approach and examine. I suppose it's another case of obscene acclimation leading to an almost humorous misplacement of gratitude (or the frog in slowly heated water, though I'm not a fan of the literal part of the notion when put that way). Nonetheless, space is a fascinating place, especially when explored with our modern technologically augmented senses, the subject of this post.

As it turns out, Earth is a lousy place from which to explore everything that's not Earth. The telescope, primary instrument of astronomers, is often incapacitated by the humble cloud, and it is increasingly difficult to find a spot where light pollution (that light from the ground which obfuscates the much fainter light from billions of miles away) isn't a problem. But even on the highest, most remote mountain on the clearest night, a telescope on Earth is substantially limited by a variety of factors, and thus the idea for a telescope in space. Space telescopes were proposed by at least the 1920's; the first (Hubble) was funded in the '70s but took about twenty years to get into space, in 1990. Of course, 20 years from paper to space is ok by me, given that it's a hulking monstrosity, nearly 25,000 lbs of technical wizardry. It may have launched as early as 1986 if it weren't for the Challenger disaster, which put Hubble in cold storage but to the tune of $6 million a month, not your everyday storage unit. Nonetheless, the time investment seems to have paid off, as the Hubble is very near entering its 20th year of functionality.

Despite the near 20 years of development, shortly after launch the images Hubble was transmitting indicated a serious issue, with quality far less than expected to the extent that it performed similarly to ground telescopes. Before long it was discovered that the main mirror was shaped incorrectly. Telescopes depend almost wholly upon the precise shape of the main mirror, and the precision of the Hubble's is astounding--it was perhaps the most precisely manufactured mirror ever made, with a deviation from the intended curve never more than 10 nanometers. In other words, the shape was at most off by a length about 40 times shorter than the shortest wavelength of visible light (the color violet, at 400 nm). To give you some kind of perspective, nothing skinnier than about 400 nm can be seen with our eyes, no matter how powerful a microscope you can find: the problem is that for something under 400 nm, visible light can't hit it, which means it can't bounce back and into our eyes. So given a mirror so amazingly precise, how could it possibly have been so bad? Well, the mirror was very precisely manufactured to the wrong shape!

Here's a question: how do you fix a ~7ft diameter mirror that took 5 years to manufacture, stuck in the middle of a technological marvel which is hurtling through space at 17,000 mph?? There were two backup mirrors made, but replacement wasn't an option. Fortunately, the Hubble had a strength, a unique design choice: it was built so that it could be serviced by astronauts. After extensive analysis of the problem, a surprising solution was conceived--new sensor instruments, something like the chip in any digital camera, would be  specifically designed to be flawed in a way that would be the anti-flaw of the mirror, thus cancelling out the effects! It reminds me very much of doing the same thing to both sides of an equation in math; you can do whatever you want, as long as you do it to both sides (note that this isn't always true). This story is one that I find informative and inspiring, I hope you can find similar value in it. I also recommend taking a look at the Hubble Space Telescope page on wikipedia, as there's a lot more generally interesting stuff to know. Surprisingly, the Hubble is just one of around 100 space observatories past, present, and future. ~45 of them have been terminated, ~15 are planned for the future, and this year alone stands to see the launch of 8 new observatories!

Energy? Let's Keep it Real.

When I was in elementary school my dream was to make a perpetual motion machine, which are commonly referred to these days as "over-unity" devices. I'm all for other people trying to do it, but I no longer feel the need to waste my time with it. Of course, there are loads and loads of people lacking a strong scientific background trying to come up with these devices, and as such it is useful to know a bit of the scientific background so we aren't so easily deluded into believing their claims. Personally I'm a fan of innovative approaches and casting much doubt towards commonly held assumptions, but there are definite limits to this concept - at some point, you are just wasting time trying to come up with results that have already been long known (and which were discovered by geniuses who got lucky, something unlikely to happen again to any naive experimentalist).

Conservation of energy is the first law of thermodynamics and fundamental to every physical science, it's shown up in every one of millions of experiments and is about as established as a theory gets. Even more, the theory is one that makes a lot of sense and is descriptive to the extent that it has encapsulated and explained every single experimental observation yet made. Of course, science hinges on the precision of explanation, which implies that experimentation outside common conception--a theoretical dictum such as Thermodynamics--is not a threat but either 1. A chance of showing that common conception is accurate, or 2. A chance at showing it is incorrect and must be changed to accommodate new observations. Quality observation is very difficult to do, and it is easy to make mistakes in measurement that will lead to erroneous results, as was the case with the famed events surrounding cold fusion. Scientists as a community realize this difficulty and thus relies on an unofficial system called peer-review. In attempting to submit your results to a reputable source, a small group of individuals including some in the field of concern reviews the document for possible experimentation errors. Rather than publishing it outright, the expectation is that you receive your returned paper with questions and concerns to which you respond or preclude publication with that journal. This kind of process is often not enjoyed by scientists, but I'd say on the whole it is accepted as important when not disheartening. Thus, with proper background, it makes sense that there was some controversy over cold fusion, because the researchers went to the popular media which lacks peer-review or the knowledge to vet the material. As it became more clear that such technology would revolutionize the world, it was also with growing disappointment as other scrambling scientists failed to reproduce their results. Thus also we can see the importance of proper procedure with science, and the reason pseudosciences always have air-time on the local news but not space in reputable journals. This too is why anything related to emerging science in mass media should be taken with serious skepticism (though if I take my science pants off I'd also argue that all mass media content should be avoided at all cost).

Perpetual motion now acknowledged as very unlikely, the closest we're going to get to "free energy" in the real world/foreseeable future is going to be nuclear power. That's not to say nuclear power is anything less than enough; the process converts mass directly into energy, and there is an incredible amount of energy stored in mass. Einstein's famous and very proven equation shows this clearly: Energy = mass * speed of light^2 aka E=m*c^2 (the c is thought to stand for celeritas, Latin for speed or swiftness). Thus, even the slightest amount of mass stores an amount of energy proportional to the speed of light squared, which is an Incredible amount; the Fat Man dropped on Nagasaki was the result of just ~1 gram (the same mass as about half of a US dime) of mass being turned into energy.

This is actually really easy to calculate with the help of google's calculator, since google is just awesome like that. The wikipedia article says Fat Man released about 88 terajoules of energy. Since we know energy and c, rearrange to solve for mass:

E = m c^2
to
E / c^2 = m

and simply google "88 terajoules/(c^2)" (or clicky here).

So the whole bomb weighed over 4,000,000 grams... had all that mass been turned to energy there would probably no longer be a place called Earth. Likewise, my body mass (and I am a rather Skinny Man) converted directly into energy would be about 74,000 times more powerful than Fat Man. Thus, one could guess that the next greatest energy discovery be how to turn some "more stable" mass (as in not plutonium) into energy by nuclear fission, which is the idea behind cold fusion. Cold fusion is generally considered impossible, but some researchers continue to look into it.

Electromagnetism was discovered in the early 1800's, so it's pretty safe to say that any secret way to get free energy with magnets/electricity would've been figured out by now, particularly given that we have explored electromagnetism (EM) at the most fundamental (quantum) level; EM is one of four fundamental forces in physics: strong nuclear, weak nuclear, EM, and gravity. Since we're on a physics roll, connecting these four forces (referred to as unification) into a single theory is the holy grail of physics research today, and the person who figures it out will probably become the most famous scientist in history. String theory (actually theories) is an untestable proposal for the unified theory. Since they are untestable, they aren't considered scientific and thus not viable candidates until tests are developed.

Back to nuclear power: recently a story in the local paper had our new governor Gary Herbert saying much about the role of nuclear power in future infrastructure. This all stems from the current Energy Secretary, Steven Chu, pushing for nuclear reactors to be the future energy source for the USA. It has been suggested that the US has wasted the past 30 years by not developing energy infrastructure based on nuclear power, and this is true. Nuclear power is the cleanest, most sustainable and efficient way to get power. Likewise, there is a lot of opinion that the explosive growth seen in China over the past few decades has been fueled by nuclear power, and it isn't difficult to see that without this kind of powerful technology for power generation the rate growth couldn't have had such a pace.

There have been plans put forth for miniature reactors, termed "neighborhood nuclear reactors" or "nuclear batteries." Residing in a 10 foot cube of heavily reinforced concrete, the reactor can provide power for 20,000 homes for 10 years. Divided evenly between 10,000 households, the projected cost for a decade of electricity is $250. Backyard reactor sounds like a bad idea? Absolutely not. Even if a group were able to secretly reach the buried cube, they would need to penetrate several feet of reinforced concrete. Assuming they were able to do that, they would need to do it many times as each reactor contains a diminutive amount of nuclear material. They would be better off just buying some on the Internet, which anyone can do (I used to have a bookmark for an online store with plutonium available for purchase, but alas, no longer). Assuming these would-be idiot terrorists had secured enough nuclear material, they would then need the resources of a nation to refine it into something weapons-grade, not to mention the necessary detonation device. Thus, there is no risk of terrorism aided by nuclear batteries, QED.

What about catastrophic failure, as in Chernobyl or 3-mile island (which is when we stopped building reactors)? Not possible. First, nuclear power technology has come a Long way since the 1970's, just like Everything else. Second, the mini-reactors are closed systems with no moving parts, there is no way for them to catastrophically fail. Third, there isn't enough radioactive material in them to do much damage in the impossible case they were to fail.

Quick digression: radioactivity gets a bad rap because of a few common misconceptions, so it's re-education time! Everything you see is radioactive! Color is simply a form of electromagnetic radiation in the range of frequencies we happen to be able to see... in other words, light is radiation. Heat can also be radioactive, which is why something "glows red hot." In fact, there is a whole construct called the electromagnetic spectrum, on which all radioactive frequencies are described. On this spectrum resides color (light), micro waves, radio waves, gamma rays, X-rays, and so on. Thus there is an important distinction to be made with different types of radiation, and it's very simple: there is ionizing radiation, and there is non-ionizing radiation. Things like light and radio waves are non-ionizing, which means there is no risk of cellular damage. You can think of it in terms of light: light can't penetrate a piece of paper (otherwise it would be invisible) much less your skin, and neither can many other forms of radiation. On the other hand, there are very powerful forms of radiation that can ionize. These compact rays of energy are so powerful and concentrated that they literally knock atoms out of molecular bonds, and this is a bad thing for we cellular/molecular creatures. A small dose of ionizing radiation will probably not have major effects, which is why it is considered ok to have an X-ray done every once in a while. A large dose of ionizing radiation will completely disrupt the cellular processes that allow a living thing to live, thus able to cause extremely fast death. However it is not even necessarily to be considered a negative thing, ionizing radiation--Carl Sagan postulates in Cosmos that the occasional radioactive wave that manages to penetrate the ozone layer may have been critical in the role of evolution, by knocking apart random pieces of DNA with possibly beneficial side effects. By analogy, we might imagine a lucky hominid named Peter Parker getting hit by an interstellar wave in such a way that he gains super-human, spider like abilities, making him an exceptionally viable reproductive candidate (all the ladies know Spider Man is hawt). Thus evolution could depend on cosmic rays for random mutation, with similar albeit far more subtle results. Amazingly, simple forms of life have been found that can repair cellular damage due to radiation. For one, this opens the possibility of anti-radiation medications, but this also means that were humans to wipe out most life on Earth in a global nuclear war And the ozone completely wiped out, other forms of life would continue despite the heavily irradiated environment, ionizing and otherwise.

Nonetheless, nuclear power is the only viable energy source for the very near future. And it can't happen soon enough, when you consider the amount of pollution from coal and fossil-fuel power plants... which is so extensive that nearly every body of water is severely contaminated by mercury, a dangerous neurotoxin. In case you don't know the connection, coal fired power plants are by and far the greatest source of mercurial emissions, about 50 Tons released into the air each year according to EPA estimates from 2000. I would much rather have spent nuclear material buried in my literal backyard than be breathing mercury. Let's get the ball rolling, folks!