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Check out Jazz It's not (yet) a top-level (wm replacement) but the concept of a zoomable interface has real potential for improving the management of many aspects of computing. Jazz

but cool nonetheless.
meteor collision calculator! [janus.astro.umd.edu]
Exantrius

Can't happen. There's a reason it's called the Accelerated Graphics Port. It's a spec for a special port with priority access to memory and such. It was never designed as a "bus", just as a "port" to connect two points, and it's nearly impossible to put two into a system.

There's a reason why you've never seen a motherboard with two AGP slots. They can't exist, given the current spec.

Looks like around 2000UT, the CME hit our earth, pushing the veolicity up to around 800, and now it's about 750.. if it's clear out where you live, probably, above 55 degrees magnetic latitude will have a good chance of seeing some northern lights.. keep your eye on POES Auroral Activity or space.com's Aurora Cam. Plus, watch spaceweather.com for updates in the next day about the storm

This is true in general. It is rare to see a project open source or proprietary that is really innovative and different. That's because it's easy to copy existing ideas than to think up and implement new ones.

But remember that the Web (http, server, browser) were started as open source projects and today Apache is still one of the best web servers there is.

If you look around there are number really cool open source projects that are way ahead of anything the propriatary world is doing. Here are two I like:

Jazz - a Zooming user interface, as discussed in Jef Raskin's book The Humane Interface.

Squeak - a ground up implementation of Smalltalk-80 which is being used in all kinds of explorations. One of the leaders of this project is Alan Kay (you've heard of him, haven't you?).

Innovation can come from unexpected places. If more people get to play with the code, then it's more likely that someone will think of something really cool...

...richie

Here's another mirror, made from this comment's parent's mirror:
con
cvrml1
This is my third try posting it, the lameness filter is causing me real trouble, is it worth it? Can't we just mod -1 lame instead of asking a PERL script to do it?

Here's another mirror, made from this comment's parent's mirror:
con
cvrml1
This is my third try posting it, the lameness filter is causing me real trouble, is it worth it? Can't we just mod -1 lame instead of asking a PERL script to do it?

The real details are not too hard to find...30 seconds with a search
engine came up with quite a few references, including:

http://www.cs.umd.edu/~waa/wireless.pdf

That document contains a fair number of bibliographical references
which you might find interesting.

The principal problem I've found with wireless security is that lots
of people deploy it poorly - effectively allowing anyone nearby to
"plug" into their network. Most of the news articles about hacking
wireless networking are about this kind of insecurity. The implication
is that when you set up a wireless network you need to use WEP to
encrypt the connection.

Some of the more alarming articles suggest that WEP is weak, and so
can't really be relied upon. If this is correct, then it means one
must use encryption at a higher level - which is not a trivial
undertaking. If you can't deploy IPSEC thoughout your network, you'll
have to put your wireless access points outside of your firewall and
use VPNs to get in.

If you liked that, you might also want to check out the physics demonstration archive at my old school (UMD).

IIRC It's the largest in the country.

Oh yeah, the Question of the Week is also very good.

If you liked that, you might also want to check out the physics demonstration archive at my old school (UMD).

IIRC It's the largest in the country.

Oh yeah, the Question of the Week is also very good.

If you liked that, you might also want to check out the physics demonstration archive at my old school (UMD).

IIRC It's the largest in the country.

Oh yeah, the Question of the Week is also very good.

As just the "guy who can fix my computer" I even knew a certain Epson 740i mac driver that kept me going back to this girl's room. Torture to be just there when you're too introverted to make that first move :)

That's when you demand that ThinkGeek create a new shirt that says "I'm introverted. Please make the first move for me." and wear that when helping girls set up their computers.

Other than that, I'm heading off to college in a week and a half and be taking both my Mac (OSX soon) and my PC (win2000/OpenBSD) with me, and will undoubtedly help everyone else out of the goodness of my heart. As long as they give me caffiene.

- Joe

A correlation may be established between hardness and some other material property such as tensile strength. Then the other property (such as strength) may be estimated based on hardness test results, which are much simpler to obtain. This correlation depends upon specific test data and cannot be extrapolated to include other materials not tested.

The University of Maryland in College Park runs the "Terrapin Trader", which has everything you could ever want. You can see some of their stuff here (click on inventory, then Data Processing for the computer stuff). It wasn't so long ago that they were giving away Alphas! Looking at it now, I see a lot of Sparcstations and some older PCs. Worth a look.

Of course, if you're operating an ISP from about your person then you'll need your Dockers Mobile Pants.

Regards, Ralph.

(Slaps Forehead)

Your absolutely right. My bad.

In this setup plasma particles align themselves with the MAGNETIC field, which is threated through the magnetic rings (duh). The Electric field is generated in the center and radiated outward toward the edge of the bottle.

For more information on this containment theory please visit my professor's web page at: Centrifugally Confined Plasmas

You can also get a good scematic of the design at: This link

I apologize for the confusion.

(Slaps Forehead)

Your absolutely right. My bad.

In this setup plasma particles align themselves with the MAGNETIC field, which is threated through the magnetic rings (duh). The Electric field is generated in the center and radiated outward toward the edge of the bottle.

For more information on this containment theory please visit my professor's web page at: Centrifugally Confined Plasmas

You can also get a good scematic of the design at: This link

I apologize for the confusion.

...the task of proving optimality seems impossible. No, I take that back, it is impossible

Actually, you're wrong. It is possible to prove in some cases that a given algorithm is optimal, and that a given implementation is optimal. You can discover this from a mathematically-based analysis of optimality, so that you can't use better hardware or loop unrolling, etc., to get a better solution.

Optimality is multi-faceted, since optimal solutions may exist for time constraints, space constraints, or both. Optimality is tied to computational complexity theory, since for some problem domains you can show that any solution must have a given complexity bounds, especially a theta-bound since that is the tightest bounds of a problem. Then you can show for a given machine set (abstracted assembly), with certain types of operations, that an implementation of the algorithm is in some sense optimal.

For some examples of proven optimal solutions to computational problems, see the following: static dictionary membership queries; generating minimal perfect hash functions; monte carlo estimation; scanning spanning trees of undirected graphs; hyperplane depth; simultaneous buffer and wire sizing (with implementation); maximum independent set of a circular-arc graph. The list could go on, but this gives you some idea of the breadth of solutions available. Sometimes, as with the halting problem, you can show that no solution exists, optimal or not.

As a final note, however, optimal solutions exist in algorithmics for well-defined computational problems. It is an entirely different thing to solve most real-world problems, where many non-theoretical issues enter the fray, such as how quickly can the code be written, is the design easily understood, how well can your code be maintained, does it do what the user or customer wants, does it have a good human interface, etc. These issues, rather than theoretics, dominate most of the actually programming that goes on in the world (despite what your professors may have taught you! ;-). In that sense, the language/optimality/editor/UI/paradigm flame wars will still go on for as long as people are using computers.

But it is still fun, on the rare occasion, to point out to your boss that your implementation of merging accounting transactions is theoretically optimal. Not that they really care, they just want it done by Friday. ;-)

the first Quantum Mechanics Symposium is being held in Ann Arbor, Michigan

There are symposia on quantum mechanics all the time (here's a short list of some). This one is different in that it deals with the future of quantum mechanics as it applies to technology.

Check out Crusade for Crusade for nearly daily updates on new B5 movies/series/good stuff.

When I was in high school, I was 'taught' that electrons had no mass. It is commonly held today that they do. It was assumed, I assume, that they did not have mass because it couldn't be proven that they did, since there was no way at the time to measure it.

There is not an infinite amount of money in some other dimension where it magically appears on this planet whenever we want it. It comes from turning natural resources into products.

That is true to some extent. There are two caveats. First, every exchange in a free market is an increase in wealth to both the buyer and the seller. This is a basic rule of economics, buyers pay less than they value an item at, and sellers ask for more than they value an item at. So we could all become billionaires...

But more on your point, humanity increases the availability of natural resources through the use of human intelligence. Your comment about "hitting a brick wall" will not happen as long as humans are free to come up with new ideas to solve problems, and there is an existing free market to properly value resources.

I highly suggest a reading of Julian Simone's work The Ultimate Resource which discusses how natural resource "shortages" have always been predicted, yet never actually happen because increasing value of scarce resources motivate people to think of new ways of obtaining those resources.

Of course, there are market externalities, such as global atmospheric resources, that cannot be represented in our existing law as private resources. So this doesn't mean that all environmental laws are bad. But we should be very careful that the costs of an environmental law is not larger than the benefit (e.g., millions dead each year because of malaria due to DDT ban, etc.)

The economy may not be a zero sum game but nature is. What you are describing a money flowing around in a closed system. Somewhere down the line either somebody prints more money (leading to money being worth less) or somebody takes something out of the earth and sells it. Even some low impact product like a software license requires natural resources. Programmer has to eat, drink, clothe himself, live in a heated house, and perhap even an office. He need a computer and electricity which required mining and drilling. The economy only grows at the expense of natural resources. Maybe they did not teach you that in econ 101 but it's true nevertheless. There is no such thing as free lunch.

If you want to look at some interesting web sites, take a look at this book by the late Julian Simon, or John McCarthy's page on human progress.

For those of you having problems loading the animations from the NASA site like I was, here's a mirror:

http://deepimpact.umd.edu

I saw that too somewhere. This page is a NASA site that lists the various projects currently going on to detect and catalog NEOs (Near Earth Objects). I'm fairly certain that one or more of the links from that page will find the exact quote. It's like a few dozen people at the most IIRC.

For a pretty good wow factor, this site has an online calculator that gives you the destructive force for impacts of different sizes and compositions of asteroids/comets/other BNRs (Big Nasty Rocks).

ssystem is a cool linux app (using OpenGL) that performs a similar function to this. It isn't 100% accurate, but the planetary locations are within a decent range (like you'd know anyway, hehe). :) Check it out the homepage

Although I don't see why matter has to be "diamond-like" once it's been determined that it is not metallic. Why can't they just compare it to glass?
The Physical Review Letters article might be worth reading but the SciAm blurb is a badly misleading popularization. People are going to think neutron stars are made of ordinary carbon diamond- which is the worst possible impression to give. It's so bad it's not even wrong! Neutron stars are far more interesting than diamonds are. You would never find anything resembling ordinary matter (atoms, nuclei, shells, etc.) in a neutron star, or even in a white dwarf.

Well, at least the standardization part is addressed by the Semantic Web stuff, currently advocated by Tim Berners-Lee, the "inventor" of the WWW and current Director of the W3C. An article was posted on Slashdot on April 11 about it that addresses this very issue. A Personal Web Page at the University of Maryland shows off some of the latest advances in this direction.

This is from the Semantic Web Activity Statement. It seems to be a set of technologies aiming to address the service discovery problem more generally than UDDI.

Well, at least the standardization part is addressed by the Semantic Web stuff, currently advocated by Tim Berners-Lee, the "inventor" of the WWW and current Director of the W3C. An article was posted on Slashdot on April 11 about it that addresses this very issue. A Personal Web Page at the University of Maryland shows off some of the latest advances in this direction.

This is from the Semantic Web Activity Statement. It seems to be a set of technologies aiming to address the service discovery problem more generally than UDDI.

The future of the Internet is in what I call "rational programming" derived from a revival of Bertrand Russell's Relation Arithmetic. Rational programming is a classically applicable branch of relation arithmetic's sub theory of quantum software (as opposed to the hardware-oriented technology of quantum computing). By classically applicable I mean it is applies to conventional computing systems -- not just quantum information systems. Rational programming will subsume what Tim Berners Lee calls the semantic web. The basic problem Tim (and just about everyone back through Bertrand Russell) fails to perceive is that logic is irrational. John McCarthy's signature line says it all about this kind of approach: "He who refuses to do arithmetic is doomed to talk nonsense." More on this a bit later, but first some history, because he who fails to learn from history is doomed to repeat its nonsense:

When I invented the precursor to Postscript (an audacious claim that I can back up -- it started as a replacement for NAPLPS which I proposed while Manager of Interactive Architectures for Viewdata Corp of America back in November of 1981 -- the Xerox PARC guys found my approach of what they called a "tokenized Forth" communication protocol to be an intriguing way to encode text and graphics), I was interested in having a Forth virtual machine migrate into silicon (ala Novix) so it could evolve from mere graphics rendering into a distributed Smalltalk VM environment (ala Squeak) as videotex terminal/personal computer capacities increased. But I was _not_ interested in object-oriented programming as the long-term semantics of distributed programming environments. (I still have some of the hardcopy of the communiques with Xerox PARC and others from this period.)

Rather, relational semantics were what I saw as the ultimate direction for distributed programming. I had a bit of a go at Tony Hoare's "communicating sequential processes" paradigm and its Transputer realization because he was, at least, starting with the hard problem of parallelism rather than making like the drunk looking for his keys under the light post the way everyone else seemed to be doing (and still are, save for Mozart, since threads, etc. are always an afterthought). But, because there were other hard problems like abstraction, transactions and persistence that he ignored, I christened his approach "Occam's Chainsaw Massacre" in my communiques (in honor of his distributed programming language "Occam") and dropped it in favor of relational programming, which has inherent parallelism resulting from both dependency and indeterminacy. (BTW: Dr. Hoare seems to have finally come to his senses about this issue.)

Unfortunately, the only researcher doing hardcore work on relational programming (meaning, getting to the root of relational semantics in a way that Codd had failed to do) at the time was Bruce MacLennan, then, of The Naval Postgraduate School, and he just didn't have the glamour of Alan Kay at places like Xerox PARC to attract the attention of guys like Steve Jobs. Bruce had a bit of a blind-spot, too, when it came to transactions and persistence, which I attempted to remedy by bringing David P. Reed's work on distributed transactions for the ARPAnet to him, but although he wrote a white paper on a predicate calculus (close to a relational) implementation of Reed's thesis (MIT/LCS/TR-205), he didn't really "get it", IMHO. Reed and MacLennan abandoned their work for other pursuits (ironically, Reed was chief scientist at Lotus while Notes was being developed but did not contribute his ideas on distributed synchronization to that development despite the fact that we had a mutual acquaintance from my Plato days by the name of Ray Ozzie -- so, I share some of the blame for this failure) even as Steve Jobs botched the embryonic object oriented world by abandoning Smalltalk and giving us, instead, a lineage consisting of Object Pascal on the Lisa/Mac which begat Objective C on Jobs's NeXT which begat Java at Sun via Naughton and Gosling's experience with NeXT.

This brings us to the present -- a world in which Javascript-based technologies like Tibet promise to not only salvage the object oriented aspect of the Internet from the birth defects of Jobs's spawn, but actually provide an advance over Smalltalk in the same lineage as CLOS and Self. But it is also a world in which there is growing confusion over the proper role of "metadata" in the form of XML -- particularly when it comes to speech acts and distributed inference. I would call Tibet "the next major Internet advance" except for the fact that the basic idea for a Tibet-like system has been around and well understood since the early 1980's. When it is finally released, Tibet (or a system like it) will put the Internet back on track. I call that a "recovery", not an "advance".

We are now poised to move forward with type inference based on full blown inference engines, thereby dispensing with the nonterminating arguments over statically vs dynamically typed languages that allowed Steve Jobs's spawn to get its nose in the tent. If you want to declare a "type" in a declarative language, just make another declaration and let the inference engine figure out what it can do with that information prior to run time. See how easy that was? Well, there is more to it than that, but not that much: Assertions have implications and assertions made prior to run time have implications prior to run time. Live with it and don't repeat the mistakes of the past.

The confusion over semantic webs, and the reason Berners Lee et al will fail, is essentially the same as the confusion that has beleaguered all inferential systems such as logic programming and "artificial intelligence" over the years: logic is irrational and the real world demands rationality -- otherwise nothing makes sense. By "rationality" I mean that reasoning must literally incorporate "ratios" -- or, as John McCarthy would put it, doing arithmetic so things make sense. By making sense, I mean there is a sense in which one interprets the sea of assertions that clearly dominates for a particular purpose. With logic not only are you limited to 0 and 1 as effective quantities; you have no adequate theoretic basis from which to derive more accurate quantities with which to make sense by taking ratios and determining which inferences are dominant.

Fuzzy logic and expert systems incorporating probabilities have typically failed because they are not based in the first principles of probability and statistics. As Gauss, the premiere probability theorist put it, "Mathematics is the study of relations." He didn't say, "Mathematics is the study of multisets." There are good reasons that relational databases, and not set manipulation languages, have come to dominate business applications -- and Gauss was aware of these differences when he began to derive his laws of probability. Subsequent axiomatizations of mathematics based on set theory were similarly misguided and have led to the idea that "fuzzy sets" are the way to introduce rationality into programming. Rather than sets, relations are the foundation, not just of mathematics but of rationality in the same sense that Gauss realized when he derived his theory of probability from the study of relations.

Rationality allows for judgment which is recognized as inherently fallible -- but which allows one to procede without exponentiating all possible paths of inference. Judgment also allows various identities to limit sharing of information to that needed -- thereby creating speech acts and a basis for rational measures of credibility associated with those identities. Since credit-rating is a degeneration of credibility, it should come as no shock that the invention of negative numbers, originating as they did with the Arabic invention of double entry account keeping, has its analog in something that might be called "logical debt" with which negative probabilities are associated.

And now we have come to the "quantum" aspect of rational programming. It is precisely the "credibility debt" aspect of rational programming that corresponds, in mathematical detail, to the various equations of quantum mechanics and their negative probability amplitudes. (Von Neumann's quantum logic failed to properly incorporate logical debt which has led to much confusion.) Logical debt is important to distributed programming for the same reason debt is important to financial networks. Logical debt is a way of handling poor synchronization of information flow in the same way that financial debt is a way of handling poor synchronization of cash flow. As in any rational system, there are both limits to credit and limits to credibilty that influence one's judgments and actions, including speech acts.

The object oriented folks may, in a sense, have the last laugh here because when we divide up inference into identities that engage in speech acts, we are reintroducing the notion of objects that hide information via exchange of speech act messages that can be thought of as "setters" (assertions) and "getters" (queries). However, I believe it is only fair to recognize that the excellent intuitions of Johan Dahl and Kristen Nygaard did need the added insights and rigor of philosophers like J. L. Austin and T. Etter.

Macs Netware is perfectly doable if everyone is willing to work together. (Unfortunately for my PowerBook, the local IT group wasn't willing). Some helpful links I found while trying to solve the problem unilaterally:

• Netware FTP site
• Installation guide at UMass
• FAQ at WTVI
• Troubleshooting at UMD

some other sites of interest are the IEEE annals of the history of computing: http://computer.org
Virginia Tech and the NSF's history of computing: http://ei.cs.vt.edu/~history/index.html

to get another audience on this you may want to ask you question on or join http://aoir.org the association of internet researchers

My own work and teaching is centered more around the Internet, but it seems to me you want to look at the earliest foundation of computing, such as the origin of information theory, which is quite interesting in itself.

Jeremy
Center for Digital Discourse and Culture
http://www.cddc.vt.edu

Don't forget the WEB in semantic web. In my vision (and I've written about it in several places including here. ) users create their own term libraries (or, more precisely, ontologies) either from scratch or by extending existing ones. These can be networked together by including terms from other ontologies via explicit URI use, can include declaring equivalences between terms (i.e. xxx:foo :equiv yyy:bar), including ontologies in others, and similar such linking. This creates a wide, complex, ugly graph of inconsistent knowledge -- hey, that's what we have on the regular web!!

This can really work -- we've been playing with ontologies on the web for a while now, and if RDF terms get anchored in ontologies, and these get linked together, a powerful web of semantics can evolve.

Don't believe it can happen? DARPA (remember the ARPAnet? That was us) is supporting an effort, in close cooperation with the European Union Semantic Web effort, to bring this to fruition. To learn more about this effort, or to be able to try it yourself, check out the DARPA Agent Markup Language

Jim Hendler
Chief Scientist, Information Systems Office
DARPA
jhendler@darpa.mil

Capitalism is unsustainable, and the incredible growth of homo sapiens...is due to "spending" a bank account that was accumulated over billions of years: fossil fuels (source Thom Hartmann: The Last Hours of Ancient Sunlight). We have reached the maximum rate of extraction, and this rate will begin to decline, while demand and human population continues to grow *expontentially* (source: Jay Hanson)

There have been gloomy talk about running out of oil for a long time:

1885, U.S. Geological Survey: "Little or no chance for oil in California."

1891, U. S. Geological Survey: Same prophecy by USGS for Kansas and Texas as in 1885 for California.

1914, U. S. Bureau of Mines: Total future production limit of 5.7 billion barrels, perhaps 10 years supply.

1939, Department of the Interior: Reserves to last only 13 years.

1951, Department of the Oil and Gas Division: Reserves to last 13 years.

The truth is that as oil reserves are continuing to increase because new technology is applied to new areas.

We don't actually know 100% how oil was formed (no one has ever been able to produce the equivalent of crude oil, yet we can make man-made diamonds). One particular theory claims that the lower crust of the planet is bathed in hydrocarbons from the time of planet formation, and the oil we see is only the little bits that get caught in traps near surface. In that case we'd never run out of oil. Who knows?

Nobody knows. Nobody knows how much oil is left, until a well runs dry. You can guess about it, but you are often wrong, because we can't count the drops of oil in every crack and crevice thousands of feet below the ground/ocean. Then once it "runs dry," you begin pumping in water to displace more oil, and you don't know how much more will come out. Nor do we know how much natural gas might be present, nor oil in oil shales.

I suggest reading Julian Simon's When will we run out of oil? Never!.

Other interesting tidbits: The trends in energy costs and scarcity have been downward over the entire period for which we have data. These "high oil costs" Americans complain about today are, after adjusting for inflation, not much different than 20 years ago. Energy has become less and less important as measured by its share of GNP.

And let's say we do run out of oil. Well, we'll have to get by somehow, perhaps nuclear/fusion using batteries, hydrogen, or other chemical energy storage technique. Long before the oil really runs out, there will be an economic incentive to build these devices (well, there will be in capitalist countries anyway). Looking at the price of oil right now, I don't expect to see them much in the near future.

Capitalism encourages unsustainable population growth, depletion of natural resources, and the creation of waste products.

The first part of this is really wrong. Capitalism increases the supply and efficiency of use of mineral resources. It also increases the size of sustainable populations. You may also want to compare starvation rates of US versus Mao's farming policies that killed 30 million people by starvation.

Capitalism does increase the creation of waste products, but as you mentioned, it does produce a market incentive to deal with them in a halfway reasonable way. The greatest environmental problems exist in situations where there is not ownership (waterways and multipoint atmospheric pollution).

I mean, Hell, I was never any good at Joust and my railgun sucks in Quake 3, but I'll take on any of you in a game of Charades!

-the wunderhorn

Three Cheers for Paul's achievement. As the prepubescent third of the SlashDot readership hasn't realized yet, getting an ATA driver on the Newton is really an amazing feat.

First things first: I'm (Sean Luke) not just a Newton user, I'm a Newton developer. I'm the person little by little working on the MP3 player for the Newton, along with Paul Guyot and a few other diehards. :-) I'm also the author of (in my opinion) the second coolest thing to come out on the Newton recently since Paul's ATA driver, namely Waba (Java) for the Newton. I've also written Hemlock (a Sherlock-compatible internet search system for the Newton) and a bunch of chinese programs and other fun stuff.

Okay, so I'm a diehard, but the only reason I write Newton programs is, ultimately, for me. They're all open source. If other people find them useful, more power to 'em. And it's fun and relaxing -- the Newton's development environment is quite nice, especially compared to the Hideousness that is developing on Palms or WinCE boxes, ugh!

The Newton I use is a MessagePad 2000, the oldest Newton model that really, truly is still superior to pretty much anything out there. Which disturbs me. And the Ebay market has reacted accordingly -- the MP2K was introduced 6 years ago at $1100, and is still worth about $400 used. Newtons hold their value like no other computer I have ever seen. Which is a pain in the butt for me because I'd like to buy a Newton MessagePad 2100 to do some further development on, but they're still in the $700 range. :-(

The MP2K was an astounding machine for its time -- it's still an impressive machine. It has a 480x320 16-bit grayscale screen, a 162 MHZ StrongArm processor (and this was back in '94!), 1 Meg of static RAM, and 4 megs of internal Flash RAM for archival storage. It has a battery life easily as good as a Palm Pilot. It's got two PCMCIA card slots, presently filled with a 16-meg linear Flash RAM card and an AmbiCom 10Base-T Ethernet card. I also have a modem card.

Early Newtons suffered because Apple rushed them out the door before ParaGraph International (the makers of Apple's first handwriting system) had handwriting working very well at all. ParaGraph never really did much better, and eventually migrated to WinCE. This first handwriting system was bad enough that Palm Computing was born through selling Graffiti, an alternative input method for the Newton. In NewtOS 2.0 (circa 1993) Apple supplemented Paragraph's word-by-word recognition system with Rosetta, a letter-by-letter recognition system developed internally at Apple. Perfected in NewtOS 2.1, Rosetta is, bar none, the best handwriting system available for any PDA in existence. If you think Microsoft's recent attempts are any match, you haven't actually tried a Newton (OS 2.1) machine. It really is that good.

Newtons are very sophisticated little beasts, able to fax, print to inkjets or postscript, beam, email, ftp, surf the web, create and display fully-formatted ebooks (the Newton pioneered the notion), write in aribitrary foreign languages (Newtons were the first devices to use Unicode, which is used throughout the device). Equipped with Apple's MacInTalk voice synthesis, they can speak text in different voices. They can record and play long chunks of sound.

For as small a user community as the Newton community was, there was a very large number of developers, partially due to Apple's exceptional NewtonScript development environment (NewtonScript is a proto-based OOP language rather similar to Self. As such, Newtons have an amazing array of stuff available for them for free now. Besides the typical notepad-datebook-namecards-etc., Newtons sport web browsers, web servers (!), terminal emulators, word processors, spreadsheets, drawing programs, mod players, astronomy software, on-the Newton development software (although most Newton development is done on Macs or PCs, the Newton comes with a built-in compiler), and of course games, including a great chess program which beats the snot out of ones on other PDA platforms.

Why did the Newton never really take off? Because it was WAY ahead of its time, and because Apple hadn't figured out the price point. Apple was selling highly sophisticated Newtons for $800-1000, when it should have been stripping them of features and selling them at $300. It took Palm to finally realize that what people wanted was a glorified day planner that you could put in your pocket, for $300, and to heck with powerful features. The result: the Palm Pilot, a terribly primitive device with a grotesque UI, but it cost the right amount, had a great battery life, and fit in your pocket. And more power to 'em! Palm got the market right. It's taken Microsoft years to realize the same thing.

Just before Steve Jobs axed the Newton, the product was finally making a profit and Apple was preparing to spin off the company into a separate firm, Newton Inc. It had taken years, but the Newton was finally making money, and Apple was preparing a tiny one to compete head-on with the Palm Pilot. Why did the whole thing get Steved? Former Apple employees point to the fact that the Newton was the brainchild of John Sculley, the man who ousted Steve in the first place.

Oh, well.

• Copper was chosen because it will cause the least interference with the measurements that will be made during the impact, will not leave a residue that would confuse potential future measurements, and can be made into a structurally strong impactor. In particular, all the inner shells of electrons for copper are completely filled. This means that it reacts very slowly with other elements, such as with the oxygen in cometary water, and it will end up producing relatively few bright emission lines in the spectrum of the vaporized materials. Other materials such as aluminum would produce far more and stronger emission lines (mostly due to aluminum oxides). There are only a few materials that satisfy this criterion and copper is the least expensive of them that is structurally sound. The material used to make the impactor is actually a copper alloy with about 3% beryllium to make the copper more stiff.

From Uni Maryland's FAQ (they're working with NASA on this project):

• Q: If the impactor split the comet, would any debris head towards earth?

• The orbit of Tempel 1 is at least 0.5 AU (about 46 million miles) from Earth's orbit at their closest points. There is absolutely no possibility of Tempel 1, the Deep Impact comet, getting near the earth. When comets fragment, the pieces also stay in orbits very similar to the orbit of the parent comet. Danger to the earth is from asteroids and comets whose orbits cross the earth's orbit. Tempel 1 never crosses the earth's orbit. The two orbits are totally separate and never cross each other. Tempel 1 can never be pulled into the earth's gravitational field at any time.

  The Deep Impact impactor will just scratch the surface of the comet making a relatively small crater compared to the size of the comet. Even if the comet were to be extremely fragile and break apart, the pieces would still be in the same orbit and would never come close to the earth's orbit.

• Wired News article, Nov 1998
• NASA Discovery Program: Deep Impact page
• UMD.edu Deep Impact page
• Spacecraft Trajectory

The copper cylinder will weigh 500kg / 1,100 pounds, and will carry a camera and an infrared spectrometer. The targetted comet is Comet 9P/Tempel 1.
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• Wired News article, Nov 1998
• NASA Discovery Program: Deep Impact page
• UMD.edu Deep Impact page
• Spacecraft Trajectory

The copper cylinder will weigh 500kg / 1,100 pounds, and will carry a camera and an infrared spectrometer. The targetted comet is Comet 9P/Tempel 1.
--

• Wired News article, Nov 1998
• NASA Discovery Program: Deep Impact page
• UMD.edu Deep Impact page
• Spacecraft Trajectory

The copper cylinder will weigh 500kg / 1,100 pounds, and will carry a camera and an infrared spectrometer. The targetted comet is Comet 9P/Tempel 1.
--

I thought that one of the reasons for the launch was to create a controled collision with a comet-like object. This way, since one of the object's properties are known, the comet could be analyzed more thoroughly. Another reason for the experiment is that the comet could be similar to Shoemaker-Levy 9. If so, it would probably help sort through the data they collected from the Jupiter collision. For example, if they did a spectral analysis of Jupiter's plume and included the Deep Impact data, they could tell the difference with what in the plume was Jupiter and what was the comet. Also, if there was a lot of a specific element, they could estimate what percentage belonged to each object.

I took a class taught by A'Hearn in which he discussed his project and some of the others that were scheduled to go up (like the mission to Pluto to see if there is an atmosphere there when it is in perihelion). He was bummed out that Congress was cutting a lot of other projects that either had more experiments packed into them, that were testing new satellite technology or that were cheep. Here's the University of Maryland College Park web page about Deep Impact:

http://www.ss.astro.umd.edu/deepimpact

• call for observation
  
• 
  notes on tempel1 here and here
  
• 
  Interesting notes on deep impact
  
• 
  - Deep Impact FAQs
  
• 
  - paranoia link - suggests that the project's real, unpublished goal is to "miss" Tempel1 and intercept OX4, whose course with Earth in 2014, 2038, 2044 and 2046 is "possibly" an intercept.
  

• call for observation
  
• 
  notes on tempel1 here and here
  
• 
  Interesting notes on deep impact
  
• 
  - Deep Impact FAQs
  
• 
  - paranoia link - suggests that the project's real, unpublished goal is to "miss" Tempel1 and intercept OX4, whose course with Earth in 2014, 2038, 2044 and 2046 is "possibly" an intercept.
  

NASA has been quite publically planning Deep Impact for years. It's purpose is to reveal the presumably pristine, primordial layers of stuff underneath the heavily weathered top layers of the comet.

Comets get heavily damaged from outgassing every time they pass close to the sun, so it isn't like NASA's perpetrating some sort of crime here.

Sharing the cache is hard

Cache is the vast majority of chip area in a modern processor; as others have pionted out, it's obvious that multiple processors should share a cache. However, this is difficult. The problem is that every load/store unit from every processor must share the same cache bandwidth.

Thus, for a 2-way chip with only a shared cache, memory latency---to the cache, the best possible case---is cut in half.

We can work around this by using various tricks up to and including multiported caches---but most of these tricks increase latency (lowering maximum clock speed) or require much more circuitry in the caches (we were sharing the cache because it was so big, remember?).

It makes much more sense to share the circuitry that feeds into the cache.

Those are the superscalar execution units! Thus, SMT.

Utilization

Instead of keeping half the execution units busy, we attempt to keep them all busy. Extrapolating very roughly from Figure 2 we can expect to issue about half as many instructions as we have issue slots (actually less if we have a lot of execution units). The basic idea is we can cut the number of empty issue slots in half each time we add a new thread. Further, instructions from separate threads do not need to be checked for resource overlaps---this circuitry is the main source of complexity in a modern processor.

What's happening now has been predicted for a long time. The extra resources (a bigger register set, TLB, extra fetch units) required for multithreading are now cheaper than the extra resources you'd need (mostly pipeline overlap logic) to get a similar increase in single-threaded performance.

SMT easier than SMP?

Moving thread parallelism into the processor is actually easier for the compiler and programmer; the weak memory models implied by cache coherence models aren't an issue when threads share exactly the same memory subsystem.

To get an idea for how hard it is to really understand weak memory models, consider Java (which actually tries to explain the problem to programmers---in every other language you're on your own). Numerous examples of code in the JDK and elsewhere contain an idiom---double-checked locking---which is wrong on weakly-ordered architectures. What's this mean? Your "portable" Java code will break mysteriously when you move it to a fast SMP. Alternatively, you will need to run your code in a special "cripple mode" which is extremely slow.

From a programmer's perspective, SMT (as opposed to SMP) architectures will be a godsend.

In any event (and this is not my specialty, so take this with the standard grain o' salt), the reason that a collapsar is expected to stop collapsing at neutron-star stage is that the neutron degeneracy pressure (basically, the Pauli Exclusion Principle in action) is able to resist the mutual gravitational forces up to some limit -- by calculation, 1.4 to 1.8 solar masses, although it appears that a value of 2.3 solar masses has been observed. Clearly, though, greater densities can exist, because if the limiting mass is exceeded the collapse continues -- to form a black hole, if you accept the present standard formulations of the problem. It's just that we don't know of a stronger force than neutron degeneracy, which will be able to resist the gravitational collapse. During the formation event (typically a supernova), if the collaspe forces (gravitation, implosion) exceed the neutron degeneracy forces, there's nothing to stop the continued collapse (through higher densities) to a black hole. Our lack of knowledge doesn't mean there's not a further stable state, though -- only that we don't know about it. Some scientists have speculated that a further point might exist in a quark star, which would consist (at least in its core) of free strange quarks. But some models of quark stars end up with lower densities than neutron stars... the problem is that we just don't know enough, yet.

(BTW, there's good info here on neutron stars, from a specialist.)

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"As part of the effort to encourage the participation of intellectuals in the new regime, in mid-1956 there began an official effort to liberalize the political climate. Cultural and intellectual figures were encouraged to speak their minds on the state of CCP rule and programs. Mao personally took the lead in the movement, which was launched under the classical slogan 'Let a hundred flowers bloom, let the hundred schools of thought contend'. At first the party's repeated invitation to air constructive views freely and openly was met with caution. By mid-1957, however, the movement unexpectedly mounted, bringing denunciation and criticism against the party in general and the excesses of its cadres in particular. Startled and embarrassed, leaders turned on the critics as 'bourgeois rightists' and launched the Anti-Rightist Campaign. The Hundred Flowers Campaign, sometimes called the Double Hundred Campaign, apparently had a sobering effect on the CCP leadership."

A recent e-mail forward to me read:

"Please sign this petition so we don't lose an irreplaceable resource....NPR On NPR's Morning Edition last week, Nina Tottenberg said that if the Supreme Court supports Congress, it is in effect the end of the National Public Radio (NPR), NEA & the Public Broadcasting System(PBS). PBS, NPR and the arts are facing major cutbacks in funding. In spite of the efforts of each station to reduce spending costs and stream line their services, some government officials believe that the funding currently going to these programs is too large a portion of funding for something which is seen as not worthwhile."

My response? NPR is not an irreplacable resource.

Twenty one years ago, National Public Radio petitioned the FCC to stop accepting applications for the low-power Educational License class. WMUC in College Park was one of the last stations to get a ten watt FM radio license under this plan, but this was a year before the UMBC campus (my school) even established a radio station.

Because of these rules that NPR brought about, UMBC cannot get a license under 1000 watts, and due to the large amount of high-power corporate radio saturation in this area, no higher-powered licenses are available.

National Public Radio has only their own interests in mind, not the interests of smaller communities and people who still want localized, non-corporate free radio.

Forget about NPR. Support your local communities and your universities by advocating for LPFM.

For more information, see the following sites:
Pirate/Free Radio on About.Com
Prometheus Radio Project
Media Democracy Now

And my own letters to the Senators, here and here.

PS: In the interests of full disclosure, this is a revised version of something I posted earlier to my my own web page.

--

A recent e-mail forward to me read:

"Please sign this petition so we don't lose an irreplaceable resource....NPR On NPR's Morning Edition last week, Nina Tottenberg said that if the Supreme Court supports Congress, it is in effect the end of the National Public Radio (NPR), NEA & the Public Broadcasting System(PBS). PBS, NPR and the arts are facing major cutbacks in funding. In spite of the efforts of each station to reduce spending costs and stream line their services, some government officials believe that the funding currently going to these programs is too large a portion of funding for something which is seen as not worthwhile."

My response? NPR is not an irreplacable resource.

Twenty one years ago, National Public Radio petitioned the FCC to stop accepting applications for the low-power Educational License class. WMUC in College Park was one of the last stations to get a ten watt FM radio license under this plan, but this was a year before the UMBC campus (my school) even established a radio station.

Because of these rules that NPR brought about, UMBC cannot get a license under 1000 watts, and due to the large amount of high-power corporate radio saturation in this area, no higher-powered licenses are available.

National Public Radio has only their own interests in mind, not the interests of smaller communities and people who still want localized, non-corporate free radio.

Forget about NPR. Support your local communities and your universities by advocating for LPFM.

For more information, see the following sites:
Pirate/Free Radio on About.Com
Prometheus Radio Project
Media Democracy Now

And my own letters to the Senators, here and here.

PS: In the interests of full disclosure, this is a revised version of something I posted earlier to my my own web page.

--