Artificial Intelligence 101 - part 3

History of AI - from Golems to Dartmouth

It has been way too long (two years!) since I started this series, and I figure it's time to get back into it. For a refresher, here's part 1 : What is intelligence? and part 2: Why Artificial Intelligence?

What follows is by no means a definitive history of artificial intelligence. In fact, Wikipedia already has a very good entry on the history of artificial intelligence. Instead, this is a fairly brief history, with large gaps. I'm a bit more free to editorialize than Wikipedia.

distant past

Humanity has long searched for ways to get the benefits of human intelligence, without the requirements for actual humans. For most of human history, the solution was slavery - treating other human beings as if they were machines, and desiring only a small fraction of their mental potential.

Not only is slavery evil, it is also inefficient - slaves still require water, food, shelter, clothing, none of which is free. Automation of even the simplest sort is so vastly more efficient, along any metric one uses for comparison, that as soon as a task could be automated, it was.

The desire for intelligence in the inanimate has persisted through recorded history. The Golem is a fairly early example, and a cautionary tale as well. From Wikipedia:

The most famous golem narrative involves Judah Loew ben Bezalel, the late 16th century chief rabbi of Prague, also known as the Maharal, who reportedly created a golem to defend the Prague ghetto from anti-Semitic attacks and pogroms. Depending on the version of the legend, the Jews in Prague were to be either expelled or killed under the rule of Rudolf II, the Holy Roman Emperor. To protect the Jewish community, the rabbi constructed the Golem out of clay from the banks of the Vltava river, and brought it to life through rituals and Hebrew incantations. As this golem grew, it became increasingly violent, killing gentiles and spreading fear. A different story tells of a golem that fell in love, and when rejected, became the violent monster seen in most accounts. Some versions have the golem eventually turning on its creator or attacking other Jews.

The Zombie - no, not the Night of the Living Dead type, the Haitian voodoo kind - is a similar cultural expression of this desire for (partial) human intelligence animating human bodies. In both the cases of the Golem (an artificial creature) and the Haitian Zombie (a person enslaved through artificial chemical means and cultural expectations) the desire for control of a portion of human-like intelligence to perform tasks is evident.

Mary Shelley's Frankenstein is another example - a not-human (because he's dead) is re-animated under the belief that the mind could still function. Once again this fictional creation of artificial intelligence is a cautionary tale, as the creature turns on his creator. As an aside, it is also the inspiration for the subtitle to this blog.

In the late 18th century, the Turk chess-playing machine was a fraud that played off the desire for automated intelligence. A skilled chess player was hidden inside an elaborately constructed table with attached mechanical "opponent", operated by the player inside via levers and gears. So clever was the mechanism for hiding the chess master inside, and so great the desire (on the part of the audience) to believe that it was possible to automate intelligence with levers and gears, that the fraud persisted for decades.

the 1800s

In 1837, Charles Babbage developed the idea of a programmable computer, and a partial first sample of the Analytical Engine, which would have been the first Turing-complete computer had it been finished. Lady Ada Byron became the first computer programmer by writing a program to compute Bernoulli numbers on the Analytical engine. This was an important step, as it proved that some tasks which were once thought to be purely mental in nature could in fact be performed by machines - that calculation could be automated.

Then in 1854, George Boole developed a variation on elementary algebra called Boolean Algebra, operating solely on "truth values" of 0 or 1 rather than on all numbers. This Boolean algebra is the basis for all digital logic.

the 1930s

In 1937, Claude Shannon published his groundbreaking master's thesis, A Symbolic Analysis of Relay and Switching Circuits (available here). In that paper he showed that it was possible to use electromechanical relays to solve Boolean Algebra problems. In 1948 he introduced the idea of the "bit" as the smallest unit of information (among other ideas like information entropy) in the paper A Mathematical Theory of Communication (available here), which is itself the foundation of what we today call Information Theory. He showed that electronic circuits could perform logical operations, and that extraordinarily complex computations could be performed with electronics. Once again, what once had required the intelligence of a human could now be automated.

In 1936, Alan Turing described a thought experiment representing an automatic computing machine; this thought experiment has since become known as the "Turing Machine". In 1948 Turing described the idea as:

...an infinite memory capacity obtained in the form of an infinite tape marked out into squares, on each of which a symbol could be printed. At any moment there is one symbol in the machine; it is called the scanned symbol. The machine can alter the scanned symbol and its behavior is in part determined by that symbol, but the symbols on the tape elsewhere do not affect the behavior of the machine. However, the tape can be moved back and forth through the machine, this being one of the elementary operations of the machine. Any symbol on the tape may therefore eventually have an innings.

Although the physical details are different, the description is identical to the operation of any computer today. Instead of a physical tape being fed through the machine, a memory address is polled and the resulting "symbol" consists of a pattern of low and high voltages on wires, what we think of as the Zeros and Ones in a byte.

If a Turing machine is capable of emulating any other Turing machine, then it is considered a Universal Turing Machine. This led to the idea of a stored-program computer - the stored program being the translation software operating in the background. Indeed, most computers today can emulate pretty much any other computer, and the process usually only requires the appropriate software.

We're not done with Alan Turing yet. Besides groundbreaking work in computational theory, he also turned his attention to artificial intelligence. He devised a thought experiment to determine whether an artificial device was actually intelligent. The Turing Test consists of a human, an AI, and a human judge. The judge has a conversation with both the AI and the human through a teletype arrangement - what we would recognize today as a chat window - and tries to decide which one is the human. If the judge can't figure it out solely from the conversation in chat, then the AI is considered intelligent, according to the Turing Test. It isn't a perfect test, but at least it was a first attempt to evaluate the quality of our efforts towards developing artificial intelligence.

So to recap: there is a historical desire for at least (or only) a portion of human intelligence to perform tasks; it was shown that the task of calculation can be automated, mechanically; calculation and complex logical operations can also be automated with electronics; calculating machines with stored programs can emulate (or simulate) other calculating machines; and it is possible to test a machine for intelligence, at least to a first-order approximation.

the birth of AI as a field of study

The 1956 Dartmouth Conference is generally regarded as the birth of AI. Indeed, the term "artificial intelligence" was coined for the conference and came to be accepted as the name for the new field of study at that conference. The Dartmouth Conference led to an explosion of work in the field that continued until about 1974.

The Dartmouth Conference is a pretty good place to stop this section. The next three parts of this series will look at three approaches to artificial intelligence: neural networks, fuzzy cognitive maps, and genetic algorithms.

Nautilus-X update

I sent an email to Mark L. Holderman of NASA-JSC, asking him to respond to my last post about the Nautilus-X. Here is his response:

Hello Ed,
Thank-you for taking the time to look at Nautilus and to post the presentation on your site. [I have attached a slightly updated version; there has been some file corruption from multiple downloads]

I apologize for not responding sooner, but for some I/T reason a great many emails have been directed to the Server SPAM file; I now check it regularly.

A great deal of "detail" information is not contained in the presentation. This was by design; it was crafted to be an oral presentation with much of the technical content addressed by the speaker, who directly answers audience questions and can therefore better engage the particular interest(s) of various groups. What you have viewed is the Concept "Sales" package - it attempts to paint a picture that folks might want to find out more about. So questions, observations, critiques, no matter on what subject - and as long as they are more-or-less civil in tone, are all welcomed. If a dialog results, well then --- yahoo!

Your questions about thermal considerations are spot on. While in LEO [construction phase],the classic basting roll maneuver would likely be employed. But transit to L1, and at L1 require a different solution. Most folks don't notice the lack of thermal rejection capability in the Concept images; they are usually taken aback at the general (size) and odd structural manifestation that good engineering details are not usually assessed. Thermal load/rejection and management at L1 will be different than at LEO, will be different than during a CIS-Lunar route [repeated], and definitely different than for an inner Solar System junket[trek...I wanted to avoid that term]. So yes, Thermal management is a major technical consideration that has a couple of nifty solutions that are being pursued. One of the inflatables will have a decidedly green element associated with it....[think Silent Running w/ Bruce Dern]. It is a partial thermal shunt, not the complete solution. Radiators will still be required, along with some new Variable Conducting Heat-Pipes that the old Hughes Aircraft Corporation had utilized.

The "Winnebago" section is new-think applied to the design success of the Apollo LEM. The Lunar Excursion Module is THE most successful spacecraft ever built. Purely and completely a space-craft that journeys in the Space environment. I purposefully exclude ISS, as it is essentially a static platform. Many of its design factors were constrained by the method of its construction --- Orbiter delivery with on-orbit assembly. The OV payload bay is incredible, but it does have both constraints and strong limitations [I am from the SSP]. With that understood, Nautilus design knowingly departed from ortho/iso-grid cylinder construction to embrace the lessons learned from the Grumman "flat-panel" LEM. Load path negotiation was a nightmare back then, and early NASTRAN was an indication of a trend, not even remotely considered an absolute.

The addition of what is called the "exo-truss" to the entire vehicle, for managing and transmitting the Propulsion Pod(s) thrust(and Isp), will give Nautilus sufficient structural integrity. We also hope for hefty a natural frequency so that the Centrifuge can become a positive input into the overall GN&C design.

I hope this helps answer of few of your questions. If nothing else, it is hoped that Nautilus-X is utilized as a development tool/mechanism for good System(s) engineering design and produces some decent axioms for large, long-duration spacecraft design. But it is something of a nifty Concept....

Warm regards,
--- mark

First of all, thanks to Mark for shedding a little more light on this concept. The updated powerpoint (linked above) contains a few more pictures of the Nautilus-X from different angles.

Slide 32 is particularly interesting - an orthogonal view of the "underside" of the craft. It is clear from this slide that the single biggest section is that "Winnebago" at the nose. No other segment even comes close in size - everything else could probably be launched on currently- or near-term-available rockets, but that Winnebago would need something much bigger than we have right now.

I understand they are eager to use the flat panels, drawing from the Lunar Excursion Modules as an inspiration. The slide-out concept might even work just fine. That heavy lift requirement for just that one element is the problem.

If one were to imaginarily slide that command deck back and the big airlock forward, it is easy to see that this one piece could be broken up into three pieces with no slide-outs, each of which could fit on existing rockets.

I agree completely with doing the ISS demo of the centrifuge. We might get lucky with that size centrifuge and find the right amount of spin to reduce or eliminate bone loss without making astronauts dizzy. If it turns out we need a bigger centrifuge, then we've found that out early on. If not, then that's a big hurdle out of the way.

I agree with the external truss framework. It makes lots of sense. The one weak point is at the centrifuge. All thrust loads have to be transmitted through those bearings. I could see having a central truss through the centrifuge taking the load off the bearings, but having that centrifuge located coaxial with the main thrust axis in between the Winnebago and the rest of the ship gives me the willies. It might be better located right at the nose of the craft. Having two centrifuges rotating perpendicular to the centerline might even be better. It isn't clear whether the centrifuge is rotating during any boosting operations; if not, that might simplify the loading during boost.

"Silent Running w/ Bruce Dern" - oh, boy. Bruce Dern also gives me the willies. Kidding aside, I think that having lots of plants and hydroponic food and so forth will go a long way towards improving the life support system of space vessels. Hydroponic gardens are already extensively used by submarine crews around the world, and will surely be useful in long-duration space flight. Just having green growing things around will provide a psychological boost to the astronauts, but their primary use would be to help replenish the oxygen supply and to provide food. I'm all for it.

The more I look at the solar panel arrangement, the more convinced I am that the booms should be longer, and that there should be Canfield joints between the booms and the solar panels. The mechanism is far less complicated than the SARJ used on the ISS, and would allow a full hemisphere of aiming for each solar panel.

NASA designs an actual spaceship

The Nautilus-X MMSEV is the closest NASA has come to a design for an honest-to-goodness spaceship in decades. There has already been extensive discussion over at Selenian Boondocks and Hobbyspace, and this is probably a couple weeks late on the subject. However, this is an idea that has considerable merit and deserves further study. So, I uploaded the Holderman powerpoint to Google Docs, and here it is:



If you click on the "open in new window" button, then you can view it in full screen.

There is a lot that I like about this design - in fact, much of it looks like items on my list of technological stepping stones to space. For one thing, it is modular. Yes yes absolutely yes. Several launches are required to put it together, all of which could be done with existing vehicles (with one exception which I'll get to later). It includes a centrifuge, which might mitigate some of the bone loss effects of microgravity. It includes inflatable modules. Above all it is a spaceship - its environment is space, it has no landing gear or reentry heat shield.

Now, there are some things I don't like about the Nautilus-X.

That big core section would require a single launch, probably on something heavier than anything in stock today. It has RV-style slide-outs for the command deck and a large airlock. Worst of all, it has flat walls - probably due to the slide-outs. The flat walls and slide-outs are brand-new technology that introduce unnecessary failure modes and complexity. This could be redone as two pieces with curved walls: the radiation mitigation chamber is one piece, the airlock and command deck are another, set "sideways" to make a T shape. These two smaller pieces could then probably be launched on existing launch vehicles.

The centrifuge radius is an educated guess. We don't know the minimum gee required to reduce or eliminate bone loss. That particular centrifuge would produce no more than a few percent of a gee (i.e. about lunar gravity at 4RPM by my estimate) before problems due to high angular velocity start to occur. If a few percent gee is enough to slow or stop bone loss, great! If not, then this centrifuge would be an added layer of complexity for limited benefit. There would be benefits, no doubt, particularly for things like eating and ablutions, but the primarily-intended benefit would be missing. The bearings on the centrifuge - allowing nearly frictionless rotation while not allowing atmosphere to escape - are going to be a novel engineering challenge.

The MMSEV is intended for very long duration missions, up to two years. Unlike satellites in low earth orbit, which spend half their time in Earth's shadow, the MMSEV would be out in cislunar space or interplanetary space constantly being exposed to the sun. The entire craft would have to do a slow "barbecue roll" to avoid overheating one side, most likely along its long axis in the opposite direction of the centrifuge. Canfield joints at the end of the beams holding the big solar panels would allow them to continuously track the sun during the barbecue roll.

It's a good start.

Update Mark Holderman responds.

demolishing global warming

The theory of anthropogenic global warming (AGW) is based upon the following principles:

• the global climate is changing
• carbon dioxide content of the atmosphere is increasing due to human industrial activity
• the increase in CO2 concentration increases the amount of heat trapped in the atmosphere
• this could cause a runaway effect making the earth uninhabitable

This is all presented as though it is established fact, and that the obvious conclusion is that we must greatly decrease the amount of industry worldwide -- achieved through regulation, internationalism, and so-called "green" activity.

But what if one of those principles above is wrong? What if CO2 concentration is not correlated to average global temperature? What if the current variation is in fact insignificant?

The glaciers of Greenland have yielded thousands of ice core samples to scientific survey. Significantly, the Oxygen-18 isotope concentration in the ice is a good proxy for average global temperature over a long timescale. A water molecule containing O-18 is 11% heavier than the O-16 water molecule, so it takes more energy to get a water molecule containing O-18 to evaporate into the atmosphere than it does for O-16. This heavier isotope is more abundant in the snow when the temperatures are warmer, and less abundant when it is colder globally. The ratio of O-18 to O-16 in the ice corresponds to a temperature at ancient glaciers in Greenland - a yearly average high-resolution record going back over 100000 years.

Dr. Don J. Easterbrook has an analysis of these ice core samples, analyzing the rates of change of temperature:

Temperature changes recorded in the GISP2 ice core from the Greenland Ice Sheet show that the magnitude of global warming experienced during the past century is insignificant compared to the magnitude of the profound natural climate reversals over the past 25,000 years, which preceded any significant rise of atmospheric CO2. If so many much more intense periods of warming occurred naturally in the past without increase in CO2, why should the mere coincidence of a small period of low magnitude warming this century be blamed on CO2?

So that about does it for anthropogenic global warming.

Update: Here's another view, looking at ocean sediments, providing a temperature reading dating back 65 million years. And here is the GISP2 data; see for yourself.

civility in politics?

Ya gotta be kidding me. After eight years of reading about Chimpy mcBushitlerburton? After seing how the Left conducts demonstrations (oh yeah, all those balaclava-garbed idiots throwing firebombs at G20 meetings are "anarchists"), Obama's frequent threatening tone ("... so we know whose ass to kick"), and an incident where Sara Palin was hung in effigy ("For weeks the life-size mannequin of Republican vice presidential nominee Sarah Palin that hung from a noose around its neck in front of Morrisette's West Hollywood home caused little controversy.")- now you want civility?

Lemme tell ya something, princess. Politics ain't ever been civil:



update the next day: remember this from just a few months ago? I could probably dig up a hundred more examples if I wanted to.



I'm with Don Surber. Bite me.

Messing with the template. Again.

Longtime readers (yes, there are a few) will notice something different today; I've changed the blog template again. This is an old tradition here at Robot Guy, going back to the very first days of this blog; the stable template of the last few years has been the anomaly.

The change was forced on me by Blogrolling.com; while I had displayed rather a lot of blogrolls, many relied upon blogrolling.com to supply their innards. Alas, blogrolling.com has performed rather flakily for a while, and I just can't use it anymore. This is unfortunate, as the Space Blogroll was ensconced in blogrolling.com, and hundred of blogs out there were showing up as a big blank.

Well, Google Reader to the rescue. I had already entered as many blogs for which I could find an RSS feed as I possibly could over the course of the last several years. Now it turns out that Google Reader can produce a blogroll from the spaceblogs feed; the new Space Blogroll now resides on the left sidebar. I will probably be adding quite a few feeds to the blogroll over the next few months. I have also added the latest posts from space blogs and space news sites over on the right sidebar, also courtesy Google Reader.

Merry Christmas