cab1729

math geek with no social life, Code Samples: Riemann-Siegel formula

2011-08-29T13:32:00.001-07:00

Java implementation of the Riemann-Siegel Formula used to find non-trivial zeros of the Riemann Zeta Function

import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; public class RiemannSiegel { private static final double twopi = 2.0 * StrictMath.PI; private RiemannSiegel () { // prevent instantiation } /** * Reimann-Siegel Z(t) function with additional parameter * for number of R terms to add * @param t * @param r * @return */ public static double Z (double t, int r) { // t/2pi^1/2 double t2 = StrictMath.sqrt(t/twopi); double N = functions.fabs(t2); double p = t2 - N; int k = 0; double R = 0.0; double tt = theta(t); double sum = 0.0; for (int n = 1; n <= N; n++) { sum += (StrictMath.pow(n, -0.5) * StrictMath.cos(tt - (t * StrictMath.log(n)))); } sum = 2.0 * sum; // add remainder R here double piot = StrictMath.PI/t; while (k <= r) { R = R + C(k,2.0*p-1.0) * StrictMath.pow(2.0 * piot, ((double) k)*0.5); ++k; /* */ } /* */ R = functions.even((int) N-1) * StrictMath.pow(2.0 * StrictMath.PI / t,0.25) * R; /* */ return sum + R; } /** * C terms for Riemann-Siegel * coefficients of remainder terms * @param n * @param z * @return */ public static double C (int n, double z) { if (n==0) return(.38268343236508977173 * StrictMath.pow(z, 0.0) +.43724046807752044936 * StrictMath.pow(z, 2.0) +.13237657548034352332 * StrictMath.pow(z, 4.0) -.01360502604767418865 * StrictMath.pow(z, 6.0) -.01356762197010358089 * StrictMath.pow(z, 8.0) -.00162372532314446528 * StrictMath.pow(z,10.0) +.00029705353733379691 * StrictMath.pow(z,12.0) +.00007943300879521470 * StrictMath.pow(z,14.0) +.00000046556124614505 * StrictMath.pow(z,16.0) -.00000143272516309551 * StrictMath.pow(z,18.0) -.00000010354847112313 * StrictMath.pow(z,20.0) +.00000001235792708386 * StrictMath.pow(z,22.0) +.00000000178810838580 * StrictMath.pow(z,24.0) -.00000000003391414390 * StrictMath.pow(z,26.0) -.00000000001632663390 * StrictMath.pow(z,28.0) -.00000000000037851093 * StrictMath.pow(z,30.0) +.00000000000009327423 * StrictMath.pow(z,32.0) +.00000000000000522184 * StrictMath.pow(z,34.0) -.00000000000000033507 * StrictMath.pow(z,36.0) -.00000000000000003412 * StrictMath.pow(z,38.0) +.00000000000000000058 * StrictMath.pow(z,40.0) +.00000000000000000015 * StrictMath.pow(z,42.0)); else if (n==1) return(-.02682510262837534703 * StrictMath.pow(z, 1.0) +.01378477342635185305 * StrictMath.pow(z, 3.0) +.03849125048223508223 * StrictMath.pow(z, 5.0) +.00987106629906207647 * StrictMath.pow(z, 7.0) -.00331075976085840433 * StrictMath.pow(z, 9.0) -.00146478085779541508 * StrictMath.pow(z,11.0) -.00001320794062487696 * StrictMath.pow(z,13.0) +.00005922748701847141 * StrictMath.pow(z,15.0) +.00000598024258537345 * StrictMath.pow(z,17.0) -.00000096413224561698 * StrictMath.pow(z,19.0) -.00000018334733722714 * StrictMath.pow(z,21.0) +.00000000446708756272 * StrictMath.pow(z,23.0) +.00000000270963508218 * StrictMath.pow(z,25.0) +.00000000007785288654 * StrictMath.pow(z,27.0) -.00000000002343762601 * StrictMath.pow(z,29.0) -.00000000000158301728 * StrictMath.pow(z,31.0) +.00000000000012119942 * StrictMath.pow(z,33.0) +.00000000000001458378 * StrictMath.pow(z,35.0) -.00000000000000028786 * StrictMath.pow(z,37.0) -.00000000000000008663 * StrictMath.pow(z,39.0) -.00000000000000000084 * StrictMath.pow(z,41.0) +.00000000000000000036 * StrictMath.pow(z,43.0) +.00000000000000000001 * StrictMath.pow(z,45.0)); else if (n==2) return(+.00518854283029316849 * StrictMath.pow(z, 0.0) +.00030946583880634746 * StrictMath.pow(z, 2.0) -.01133594107822937338 * StrictMath.pow(z, 4.0) +.00223304574195814477 * StrictMath.pow(z, 6.0) +.00519663740886233021 * StrictMath.pow(z, 8.0) +.00034399144076208337 * StrictMath.pow(z,10.0) -.00059106484274705828 * StrictMath.pow(z,12.0) -.00010229972547935857 * StrictMath.pow(z,14.0) +.00002088839221699276 * StrictMath.pow(z,16.0) +.00000592766549309654 * StrictMath.pow(z,18.0) -.00000016423838362436 * StrictMath.pow(z,20.0) -.00000015161199700941 * StrictMath.pow(z,22.0) -.00000000590780369821 * StrictMath.pow(z,24.0) +.00000000209115148595 * StrictMath.pow(z,26.0) +.00000000017815649583 * StrictMath.pow(z,28.0) -.00000000001616407246 * StrictMath.pow(z,30.0) -.00000000000238069625 * StrictMath.pow(z,32.0) +.00000000000005398265 * StrictMath.pow(z,34.0) +.00000000000001975014 * StrictMath.pow(z,36.0) +.00000000000000023333 * StrictMath.pow(z,38.0) -.00000000000000011188 * StrictMath.pow(z,40.0) -.00000000000000000416 * StrictMath.pow(z,42.0) +.00000000000000000044 * StrictMath.pow(z,44.0) +.00000000000000000003 * StrictMath.pow(z,46.0)); else if (n==3) return(-.00133971609071945690 * StrictMath.pow(z, 1.0) +.00374421513637939370 * StrictMath.pow(z, 3.0) -.00133031789193214681 * StrictMath.pow(z, 5.0) -.00226546607654717871 * StrictMath.pow(z, 7.0) +.00095484999985067304 * StrictMath.pow(z, 9.0) +.00060100384589636039 * StrictMath.pow(z,11.0) -.00010128858286776622 * StrictMath.pow(z,13.0) -.00006865733449299826 * StrictMath.pow(z,15.0) +.00000059853667915386 * StrictMath.pow(z,17.0) +.00000333165985123995 * StrictMath.pow(z,19.0) +.00000021919289102435 * StrictMath.pow(z,21.0) -.00000007890884245681 * StrictMath.pow(z,23.0) -.00000000941468508130 * StrictMath.pow(z,25.0) +.00000000095701162109 * StrictMath.pow(z,27.0) +.00000000018763137453 * StrictMath.pow(z,29.0) -.00000000000443783768 * StrictMath.pow(z,31.0) -.00000000000224267385 * StrictMath.pow(z,33.0) -.00000000000003627687 * StrictMath.pow(z,35.0) +.00000000000001763981 * StrictMath.pow(z,37.0) +.00000000000000079608 * StrictMath.pow(z,39.0) -.00000000000000009420 * StrictMath.pow(z,41.0) -.00000000000000000713 * StrictMath.pow(z,43.0) +.00000000000000000033 * StrictMath.pow(z,45.0) +.00000000000000000004 * StrictMath.pow(z,47.0)); else return(+.00046483389361763382 * StrictMath.pow(z, 0.0) -.00100566073653404708 * StrictMath.pow(z, 2.0) +.00024044856573725793 * StrictMath.pow(z, 4.0) +.00102830861497023219 * StrictMath.pow(z, 6.0) -.00076578610717556442 * StrictMath.pow(z, 8.0) -.00020365286803084818 * StrictMath.pow(z,10.0) +.00023212290491068728 * StrictMath.pow(z,12.0) +.00003260214424386520 * StrictMath.pow(z,14.0) -.00002557906251794953 * StrictMath.pow(z,16.0) -.00000410746443891574 * StrictMath.pow(z,18.0) +.00000117811136403713 * StrictMath.pow(z,20.0) +.00000024456561422485 * StrictMath.pow(z,22.0) -.00000002391582476734 * StrictMath.pow(z,24.0) -.00000000750521420704 * StrictMath.pow(z,26.0) +.00000000013312279416 * StrictMath.pow(z,28.0) +.00000000013440626754 * StrictMath.pow(z,30.0) +.00000000000351377004 * StrictMath.pow(z,32.0) -.00000000000151915445 * StrictMath.pow(z,34.0) -.00000000000008915418 * StrictMath.pow(z,36.0) +.00000000000001119589 * StrictMath.pow(z,38.0) +.00000000000000105160 * StrictMath.pow(z,40.0) -.00000000000000005179 * StrictMath.pow(z,42.0) -.00000000000000000807 * StrictMath.pow(z,44.0) +.00000000000000000011 * StrictMath.pow(z,46.0) +.00000000000000000004 * StrictMath.pow(z,48.0)); } /** * Riemann-Siegel theta function * theta(t) approximation using Stirling series * @param t * @return */ public static double theta (double t) { return (t/2.0 * StrictMath.log(t/2.0/StrictMath.PI) - t/2.0 - StrictMath.PI/8.0 + 1.0/48.0/t + 7.0/5760.0/t/t/t); } }

ref:

H. M. Edwards, Riemann’s Zeta Function, Academic Press, 1974.

E. C. Titchmarsh, The theory of the Riemann Zeta-function, Oxford Science publications, second edition, revised by D. R. Heath-Brown (1986).

ZetaGrid project code

via cab1729.tumblr.com

Code Samples

2011-08-23T13:33:00.001-07:00

Core Java - Models

DirectedWeightedGraph.java

Edge.java

GraphSearch.java

TestGraphSearch.java (JUnit Test Case)

Core Java - Math Functions

ComplexFunctions.java

JavaEE

GetEmpInfoRS.java - RESTful web service with JAXB example

GetEmpInfo.java - session bean with SOAP service interface

GetEmpInfoJSPPortlet.java - JSP portlet using eclipse generated web service client

GetEmpInfoServlet.java - servlet interface to session bean

Employee.java - JPA entity bean

via http://dl.dropbox.com/u/10988984/code/index.html

Hilbert’s 10.5th Problem

2011-07-22T12:15:00.001-07:00

via rjlipton.wordpress.com

Hilbert’s Tenth Problem (HTP) is the question raised by David Hilbert at his famous 1900 Paris lecture on whether or not there is an algorithm to decide whether a Diophantine equation has a solution over the integers:

Java Code examples - Bernoulli polynomial function

2011-07-19T12:11:00.001-07:00

/**
   * return nth Bernoulli polynomial of x using Fourier expansion
   * ref: Abramowitz & Stegun 23.1.16 pp 805
   * @param n
   * @param x
   * @return
   */
  public static double BernoulliP (int n, double x)
  {
    // for n>1, 1>=x>=0
    // for n=1, 1>x>0

    // for x=0 return the nth Bernoulli number
    if (x==0.0) {
      return BernoulliB(n);
    }

    double K = -2*(factorial(n))/StrictMath.pow((2*StrictMath.PI), n);

    double S = 0.0;
    for (int k=1; k<100001; k++)
    {
      S +=
        StrictMath.cos((2*StrictMath.PI*k*x)-(.5*StrictMath.PI*n))/
          StrictMath.pow(k, n);
    }

    return K*S;
  }

Extend Java EE containers with cloud characteristics

2011-05-14T12:59:00.001-07:00

via ibm.com

"The Java Enterprise Edition (JEE) architecture is based on components with features that effectively manage application transactions and statefulness, multi-threading, and resource pooling. A JEE application is easier to write even with complex requirements since the business logic is organized in reusable components and the server provides the underlying services — in the form of a container — for each component type."

via ibm.com

Brewer's CAP Theorem

2011-03-31T07:28:00.001-07:00

Brewer's CAP Theorem

The kool aid Amazon and Ebay have been drinking

By Julian Browne on January 11, 2009. Filed Under architecture, business, strategy

On Friday 4th June 1976, in a small upstairs room away from the main concert auditorium, the Sex Pistols kicked off their first gig at Manchester's Lesser Free Trade Hall. There's some confusion as to who exactly was there in the audience that night, partly because there was another concert just six weeks later, but mostly because it's considered to be a gig that changed western music culture forever. So iconic and important has that appearance become that David Nolan wrote a book, I Swear I Was There: The Gig That Changed the World, investigating just whose claim to have been present was justified. Because the 4th of June is generally considered to be the genesis of punk rock⁶.

Prior to this (in fact since around 1971) there had been a number of protopunk bands, such as the New York Dolls and the Velvet Underground, but it was this one set by the Sex Pistols that in music folklore started the revolution that set in motion the driving guitars of the Buzzcocks, the plaintive wailing of The Smiths, the eclectic syncopations of the The Fall, the rising majesty of Joy Division and Simply Red (I guess you can't have everything).

Wednesday 19th July 2000, may not go down in popular culture with quite the same magnitude but it's had a similar impact on internet scale business as the Sex Pistols did on music a quarter of a century earlier, for that was the keynote speech by Eric Brewer at the ACM Symposium on the Principles of Distributed Computing (PODC).

The Sex Pistols had shown that barely-constrained fury was more important to their contemporaries than art-school structuralism, giving anyone with three chords and something to say permission to start a band. Eric Brewer, in what became known as Brewer's Conjecture, said that as applications become more web-based we should stop worrying about data consistency, because if we want high availability in these new distributed applications, then guaranteed consistency of data is something we cannot have, thus giving anyone with three servers and a keen eye for customer experience permission to start an internet scale business. Disciples of Brewer (present that day or later converts) include the likes of Amazon, EBay, and Twitter.

Two years later, in 2002, Seth Gilbert and Nancy Lynch of MIT, formally proved Brewer to be correct and thus Brewer's Theorem was born.

Brewer's (CAP) Theorem

So what exactly is Brewer's Theorem, and why does it warrant comparison with a 1976 punk gig in Manchester?

Brewer's 2000 talk was based on his theoretical work at UC Berkley and observations from running Inktomi, though Brewer and others were talking about trade-off decisions that need to be made in highly scalable systems years before that (e.g. "Cluster-Based Scalable Network Services" from SOSP in 1997 and "Harvest, yield, and scalable tolerant systems" in 1999) so the contents of the presentation weren't new and, like many of these ideas, they were the work of many smart people (as I am sure Brewer himself would be quick to point out).

What he said was there are three core systemic requirements that exist in a special relationship when it comes to designing and deploying applications in a distributed environment (he was talking specifically about the web but so many corporate businesses are multi-site/multi-country these days that the effects could equally apply to your data-centre/LAN/WAN arrangement).

The three requirements are: Consistency, Availability and Partition Tolerance, giving Brewer's Theorem its other name - CAP.

To give these some real-world meaning let's use a simple example: you want to buy a copy of Tolstoy's War & Peace to read on a particularly long vacation you're starting tomorrow. Your favourite web bookstore has one copy left in stock. You do your search, check that it can be delivered before you leave and add it to your basket. You remember that you need a few other things so you browse the site for a bit (have you ever bought just one thing online? Gotta maximise the parcel dollar). While you're reading the customer reviews of a suntan lotion product, someone, somewhere else in the country, arrives at the site, adds a copy to their basket and goes right to the checkout process (they need an urgent fix for a wobbly table with one leg much shorter than the others).

Consistency

A service that is consistent operates fully or not at all. Gilbert and Lynch use the word "atomic" instead of consistent in their proof, which makes more sense technically because, strictly speaking, consistent is the C in ACID as applied to the ideal properties of database transactions and means that data will never be persisted that breaks certain pre-set constraints. But if you consider it a preset constraint of distributed systems that multiple values for the same piece of data are not allowed then I think the leak in the abstraction is plugged (plus, if Brewer had used the word atomic, it would be called the AAP theorem and we'd all be in hospital every time we tried to pronounce it).

In the book buying example you can add the book to your basket, or fail. Purchase it, or not. You can't half-add or half-purchase a book. There's one copy in stock and only one person will get it the next day. If both customers can continue through the order process to the end (i.e. make payment) the lack of consistency between what's in stock and what's in the system will cause an issue. Maybe not a huge issue in this case - someone's either going to be bored on vacation or spilling soup - but scale this up to thousands of inconsistencies and give them a monetary value (e.g. trades on a financial exchange where there's an inconsistency between what you think you've bought or sold and what the exchange record states) and it's a huge issue.

We might solve consistency by utilising a database. At the correct moment in the book order process the number of War and Peace books-in-stock is decremented by one. When the other customer reaches this point, the cupboard is bare and the order process will alert them to this without continuing to payment. The first operates fully, the second not at all.

Databases are great at this because they focus on ACID properties and give us Consistency by also giving us Isolation, so that when Customer One is reducing books-in-stock by one, and simultaneously increasing books-in-basket by one, any intermediate states are isolated from Customer Two, who has to wait a few milliseconds while the data store is made consistent.

Availability

Availability means just that - the service is available (to operate fully or not as above). When you buy the book you want to get a response, not some browser message about the web site being uncommunicative. Gilbert & Lynch in their proof of CAP Theorem make the good point that availability most often deserts you when you need it most - sites tend to go down at busy periods precisely because they are busy. A service that's available but not being accessed is of no benefit to anyone.

Partition Tolerance

If your application and database runs on one box then (ignoring scale issues and assuming all your code is perfect) your server acts as a kind of atomic processor in that it either works or doesn't (i.e. if it has crashed it's not available, but it won't cause data inconsistency either).

Once you start to spread data and logic around different nodes then there's a risk of partitions forming. A partition happens when, say, a network cable gets chopped, and Node A can no longer communicate with Node B. With the kind of distribution capabilities the web provides, temporary partitions are a relatively common occurrence and, as I said earlier, they're also not that rare inside global corporations with multiple data centres.

Gilbert & Lynch defined partition tolerance as:

No set of failures less than total network failure is allowed to cause the system to respond incorrectly

and noted Brewer's comment that a one-node partition is equivalent to a server crash, because if nothing can connect to it, it may as well not be there.

The Significance of the Theorem

CAP Theorem comes to life as an application scales. At low transactional volumes, small latencies to allow databases to get consistent has no noticeable affect on either overall performance or the user experience. Any load distribution you do undertake, therefore, is likely to be for systems management reasons.

But as activity increases, these pinch-points in throughput will begin limit growth and create errors. It's one thing having to wait for a web page to come back with a response and another experience altogether to enter your credit card details to be met with "HTTP 500 java.lang.schrodinger.purchasingerror" and wonder whether you've just paid for something you won't get, not paid at all, or maybe the error is immaterial to this transaction. Who knows? You are unlikely to continue, more likely to shop elsewhere, and very likely to phone your bank.

Either way this is not good for business. Amazon claim that just an extra one tenth of a second on their response times will cost them 1% in sales. Google said they noticed that just a half a second increase in latency caused traffic to drop by a fifth.

I've written a little about scalability before, so won't repeat all that here except to make two points: the first is that whilst addressing the problems of scale might be an architectural concern, the initial discussions are not. They are business decisions. I get very tired of hearing, from techies, that such-and-such an approach is not warranted because current activity volumes don't justify it. It's not that they're wrong; more often than not they're quite correct, it's that to limit scale from the outset is to implicitly make revenue decisions - a factor that should be made explicit during business analysis.

The second point is that once you embark on discussions around how to best scale your application the world falls broadly into two ideological camps: the database crowd and the non-database crowd.

The database crowd, unsurprisingly, like database technology and will tend to address scale by talking of things like optimistic locking and sharding, keeping the database at the heart of things.

The non-database crowd will tend to address scale by managing data outside of the database environment (avoiding the relational world) for as long as possible.

I think it's fair to say that the former group haven't taken to CAP Theorem with quite the same gusto as the latter (though they are talking about it). This is because if you have to drop one of consistency, availability, or partition tolerance, many opt to drop consistency which is the raison d'être of the database. The logic. no doubt, is that availability and partition-tolerance keep your money-making application alive, whereas inconsistency just feels like one of those things you can work around with clever design.

Like so much else in IT, it's not as black and white as this. Eric Brewer, on slide 13 of his PODC talk, when comparing ACID and it's informal counterpart BASE even says "I think it's a spectrum". And if you're interested in this as a topic (it's slightly outside of what I want to talk about here) you could do worse than start with a paper called "Design and Evaluation of a Continuous Consistency Model for Replicated Services" by Haifeng Yu and Amin Vahdat. Nobody should interpret CAP as implying the database is dead.

Where both sides agree though is that the answer to scale is distributed parallelisation not, as was once thought, supercomputer grunt. Eric Brewer's influence on the Network of Workstations projects of the mid-nineties led to the architectures that exposed CAP theorem, because as he says in another presentation on Inktomi and the Internet Bubble the answer has always been processors working in parallel:

If they're not working in parallel you have no chance to get the problem done in a reasonable amount of time. This is a lot like anything else. If you have a really big job to do you get lots of people to do it. So if you are building a bridge you have lots of construction workers. That's parallel processing also. So a lot of this will end up being "how do we mix parallel processing and the internet?"

The Proof in Pictures

Here's a simplified proof, in pictures because I find it much easier to understand that way. I've mostly used the same terms as Gilbert and Lynch so that this ties up with their paper.

The diagram above shows two nodes in a network, N₁ and N₂. They both share a piece of data V (how many physical copies of War and Peace are in stock), which has a value V₀. Running on N₁ is an algorithm called A which we can consider to be safe, bug free, predictable and reliable. Running on N₂ is a similar algorithm called B. In this experiment, A writes new values of V and B reads values of V.

In a sunny-day scenario this is what happens: (1) First A writes a new value of V, which we'll call V₁. (2) Then a message (M) is passed from N₁ to N₂ which updates the copy of V there. (3) Now any read by B of V will return V₁.

If the network partitions (that is messages from N₁ to N₂ are not delivered) then N₂ contains an inconsistent value of V when step (3) occurs.

Hopefully that seems fairly obvious. Scale this is up to even a few hundred transactions and it becomes a major issue. If M is an asynchronous message then N₁ has no way of knowing whether N₂ gets the message. Even with guaranteed delivery of M, N₁ has no way of knowing if a message is delayed by a partition event or something failing in N₂. Making M synchronous doesn't help because that treats the write by A on N₁ and the update event from N₁ to N₂ as an atomic operation, which gives us the same latency issues we have already talked about (or worse). Gilbert and Lynch also prove, using a slight variation on this, that even in a partially-synchronous model (with ordered clocks on each node) atomicity cannot be guaranteed.

So what CAP tells us is that if we want A and B to be highly available (i.e. working with minimal latency) and we want our nodes N₁ to N_n (where n could be hundreds or even thousands) to remain tolerant of network partitions (lost messages, undeliverable messages, hardware outages, process failures) then sometimes we are going to get cases where some nodes think that V is V₀ (one copy of War and Peace in stock) and other nodes will think that V is V₁ (no copies of War and Peace in stock).

We'd really like everything to be structured, consistent and harmonious, like the music of a prog rock band from the early seventies, but what we are faced with is a little bit of punk-style anarchy. And actually, whilst it might scare our grandmothers, it's OK once you know this, because both can work together quite happily.

Let's quickly analyse this from a transactional perspective.

If we have a transaction (i.e. unit of work based around the persistent data item V) called α, then α₁ could be the write operation from before and α₂ could be the read. On a local system this would be easily be handled by a database with some simple locking, isolating any attempt to read in α₂ until α₁ completes safely. In the distributed model though, with nodes N₁ and N₂ to worry about, the intermediate synchronising message has also to complete. Unless we can control when α₂ happens, we can never guarantee it will see the same data values α₁ writes. All methods to add control (blocking, isolation, centralised management, etc) will impact either partition tolerance or the availability of α₁ (A) and/or α₂ (B).

Dealing with CAP

You've got a few choices when addressing the issues thrown up by CAP. The obvious ones are:

Drop Partition Tolerance

If you want to run without partitions you have to stop them happening. One way to do this is to put everything (related to that transaction) on one machine, or in one atomically-failing unit like a rack. It's not 100% guaranteed because you can still have partial failures, but you're less likely to get partition-like side-effects. There are, of course, significant scaling limits to this.

Drop Availability

This is the flip side of the drop-partition-tolerance coin. On encountering a partition event, affected services simply wait until data is consistent and therefore remain unavailable during that time. Controlling this could get fairly complex over many nodes, with re-available nodes needing logic to handle coming back online gracefully.

Drop Consistency

Or, as Werner Vogels puts it, accept that things will become "Eventually Consistent" (updated Dec 2008). Vogels' article is well worth a read. He goes into a lot more detail on operational specifics than I do here.

Lots of inconsistencies don't actually require as much work as you'd think (meaning continuous consistency is probably not something we need anyway). In my book order example if two orders are received for the one book that's in stock, the second just becomes a back-order. As long as the customer is told of this (and remember this is a rare case) everybody's probably happy.

The BASE Jump

The notion of accepting eventual consistency is supported via an architectural approach known as BASE (Basically Available, Soft-state, Eventually consistent). BASE, as its name indicates, is the logical opposite of ACID, though it would be quite wrong to imply that any architecture should (or could) be based wholly on one or the other. This is an important point to remember, given our industry's habit of "oooh shiny" strategy adoption.

And here I defer to Professor Brewer himself who emailed me some comments on this article, saying:

the term "BASE" was first presented in the 1997 SOSP article that you cite. I came up with acronym with my students in their office earlier that year. I agree it is contrived a bit, but so is "ACID" -- much more than people realize, so we figured it was good enough. Jim Gray and I discussed these acronyms and he readily admitted that ACID was a stretch too -- the A and D have high overlap and the C is ill-defined at best. But the pair connotes the idea of a spectrum, which is one of the points of the PODC lecture as you correctly point out.

Dan Pritchett of EBay has a nice presentation on BASE.

Design around it

Guy Pardon, CTO of atomikos wrote an interesting post which he called "A CAP Solution (Proving Brewer Wrong)", suggesting an architectural approach that would deliver Consistency, Availability and Partition-tolerance, though with some caveats (notably that you don't get all three guaranteed in the same instant).

It's worth a read as Guy eloquently represents an opposing view in this area.

Summary

That you can only guarantee two of Consistency, Availability and Partition Tolerance is real and evidenced by the most successful websites on the planet. If it works for them I see no reason why the same trade-offs shouldn't be considered in everyday design in corporate environments. If the business explicitly doesn't want to scale then fine, simpler solutions are available, but it's a conversation worth having. In any case these discussions will be about appropriate designs for specific operations, not the whole shebang. As Brewer said in his email "the only other thing I would add is that different parts of the same service can choose different points in the spectrum". Sometimes you absolutely need consistency whatever the scaling cost, because the risk of not having it is too great.

These days I'd go so far as to say that Amazon and EBay don't have a scalability problem. I think they had one and now they have the tools to address it. That's why they can freely talk about it. Any scaling they do now (given the size they already are) is really more of the same. Once you've scaled, your problems shift to those of operational maintenance, monitoring, rolling out software updates etc. - tough to solve, certainly, but nice to have when you've got those revenue streams coming in.

References

HP's take on CAP Theorem, a white paper entitled "There is no free lunch with distributed data"

Computer Science Notes on Distributed Transactions and Network Partitions from University of Sussex

Nice post by Jens Alfke on databases, scaling and Twitter.

Pat Helland's Microsoft paper on distributed transactions and SOA called Data on the Outside versus Data on the Inside, which he later related to CAP Theorem here

Another set of Computer Science course slides, this time from George Mason University in Virginia, on Distributed Software Systems and particularly CAP Theorem and the clash between ACID and BASE ideologies.

The 4th June 1976 is considered to be the birth of Punk Rock in the UK. Thanks to Charlie Dellacona for pointing out that the Ramones take credit for starting the movement in early 1974 in the US, though their official punk recordings are more or less contemporaneous.

Thanks to Hiroshi Yuki, a Japanese translation of this article is available.

Thanks to Daniel Cohen, a two part Hebrew translation of this article is available.

Thanks to Wang Qi, a Chinese translation of this article is available.

via julianbrowne.com

IBM Watson - How to build your own "Watson Jr." in your basement

2011-02-24T08:43:00.001-08:00

via ibm.com

Having worked with the UIMA technology on several projects, I find this very cool.

Unix

2011-02-08T07:49:00.001-08:00

Note: This wasn't written by me, but I touched up a bit of the English.

A UNIX wizard hears cries of torment from his apprentice's computer room where the apprentice is studying, and goes to investigate.

He finds the apprentice in obvious distress, nearly on the verge of tears. "What's the problem?" he asks. "Why did you cry out?"

"It's terrible using this system. I must use four editors each day to get my studies done, because not one of them does everything."

The wizard nods sagely, and asks, "And what would you propose that will solve this obvious dilemma?"

The student thinks carefully for several minutes, and his face then lights up in delight. Excitedly, he says, "Well, it's obvious. I will write the best editor ever. It will do everything that the existing four editors do, but do their jobs better, and faster. And because of my new editor, the world will be a better place."

The wizard quickly raises his hand and smacks the apprentice on the side of his head. The wizard is old and frail, and the apprentice isn't physically hurt, but is shocked by what has happened. He turns his head to face the wizard. "What have I done wrong?" he asks.

"Fool!" says the wizard. "Do you think I want to learn yet another editor?"

Immediately, the apprentice is enlightened.

Evan Martin, martine@danga.com

via neugierig.org

The Quantum Conspiracy: What Popularizers of QM Don't Want You to Know

2011-01-18T11:35:00.001-08:00

LHC plans extra year for Higgs hunt : Nature News

2011-01-01T19:54:00.001-08:00

Published online 10 December 2010 | Nature | doi:10.1038/news.2010.667

News

LHC plans extra year for Higgs hunt

Collider may run right through 2012 to find elusive particle.

Geoff Brumfiel

The extra year could be enough for the ATLAS detector to spot the Higgs particle.Claudia Marcelloni / CERN
Scientists are preparing to run the world's largest particle accelerator for an extra year in a bold bid to find the Higgs particle, part of the mechanism that is thought to endow other particles with mass.

If the plan is implemented, the Large Hadron Collider (LHC), located at CERN, near Geneva, Switzerland, will run until the end of 2012 — rather than 2011 — before entering a year-long shutdown for a major upgrade. Preparations for the extended run, which would see the 27-kilometre circular collider operating over three continuous years, are being finalized and are likely to be agreed to by CERN's management and council in January.

The decision comes with the belief that new discoveries may be just around the corner. "It would be a shame to stop," says Steve Myers, who is responsible for maintaining and upgrading the accelerator.

“It would be a shame to stop.”
Steve Myers
CERN
At stake is the particle many physicists see as the LHC's raison d'être: the Higgs. Theorists believe that the Higgs particle, together with its associated field, create a sort of cosmic molasses that endows other particles with mass. The mechanism is seen as a necessary extension to the 'standard model' of particle physics, which presently struggles to explain the origins of mass, and why some particles are heavy whereas others weigh nothing at all.

Higgs hunt
Initially, there were doubts about whether the LHC would be able to find the Higgs at the machine's current energies. Since a major accident in 2008, the LHC has been running at half its design energy. CERN managers had planned a 15-month pause in data collecting at the start of 2012, which would allow the machine to be upgraded to full power.

But now there is a growing consensus that the LHC will be able to cover most of the territory in which a standard Higgs particle might be found, even if it isn't upgraded. The best guess of most physicists is that the Higgs weighs somewhere between 114 and 600 gigaelectronvolts (10⁹ electronvolts), according to Sergio Bertolucci, CERN's director for research and computing. Its mass will determine how the particle decays — and how easily it can be detected.

“If we stop the machine with 3,000 people apiece in the experiments waiting for data, there is no way we could get home at night without having slashed tyres on our cars.”
Sergio Bertolucci
CERN
Paradoxically, a heavier Higgs might be easier to spot, Bertolucci says. That's because the heavy Higgs is likely to decay into pairs of rare, heavy particles known as W and Z bosons. Pairs of Ws or Zs would stand out sharply against the other particles created in LHC collisions. If the Higgs were lighter, its signature would blend into the background, making it much harder to detect and requiring physicists to amass and filter through data from months of collisions.

Despite the challenge, Bertolucci says that he is "very optimistic" that the LHC can cover most of the ground over which the Higgs is expected to be found. The machine has performed exceptionally well since the 2008 accident, and he thinks that it will be able to deliver the quantities of data needed over the 2011-12 running period. In addition, he says, managers think that they can collide particles at 8 teraelectronvolts (TeV; 10¹² electronvolts), up from the current 7-TeV energies, but still well below the machine's 14-TeV design energy.

Pushing it
Physicists working on the detectors built to find the Higgs are backing the plan. "My personal opinion is that we should put all the cards on the table," says David Francis, a physicist on the ATLAS detector, one of two giant detectors primarily designed to spot the elusive particle. "The experiments are going well, the accelerator is going well," adds Joe Incandela, a physicist at the University of California at Santa Barbara and deputy spokesman for the CMS detector, the second main detector for Higgs hunting. "Let's really push it to where we can get a meaningful data set to do lots of physics."

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Bertolucci says that there are also political reasons to extend the run. The world's second most powerful accelerator, the Tevatron at Fermilab in Batavia, Illinois, is nipping at the LHC's heels, and if it continues to run, might beat the larger accelerator to the Higgs. Moreover, European plans for high-energy physics, as well as a global plan for a next-generation linear collider, are facing big decisions in the coming years and will be greatly influenced by the LHC's results.
But keeping the machine running for an extra year will have consequences. The delicate alignment of the LHC's superconducting magnets could suffer, requiring extra maintenance, says Myers. And additional computing resources will have to be found to handle the flood of extra data produced by the detectors.
Managers recognize the difficulties, but Bertolucci says they have strong incentives to extend the run: "If we stop the machine with 3,000 people apiece in the experiments waiting for data, there is no way we could get home at night without having slashed tyres on our cars."
The decision will be discussed at a meeting in the French town of Chamonix in late January, and should be finalized shortly after.

Comments

If you find something abusive or inappropriate or which does not otherwise comply with our Terms or Community Guidelines, please select the relevant 'Report this comment' link.

Comments on this thread are vetted after posting.

#16683

Extending its run through 2012 will enable the LHC to play a timely role the predicted end of history on Dec. 21, 2012, as specified in the Mayan calender. Hopefully, we'll all laugh about this in 2013. There remain, however, disturbing and unrefuted scientific reasons to believe that CERN's in-house safety report was a PR whitewash and that the LHC, by potentially generating destructive strangelets and black holes, may be capable of causing global harm.
International critics groups recently released two extensive and well-documented reports that undermine CERN's safety claims (at LHC-Concern.info and HeavyIonAlert.org). Given the acknowledged uncertainties and planetary stakes, it is unethical for the LHC experiments to proceed – particularly when there is no outside oversight or regulation.

Report this comment

2010-12-10 11:42:42 PM

Posted by: Robert Houston

#16690

Why cannot we grasp that mass is more fundamental than pure energy (i.e. its mass is equal to zero)? Pure energies, for example photons, are the excitations of the Einstein spacetime â€“ this spacetime has the MASS DENSITY NOT EQUAL TO ZERO. In the Everlasting Theory, the ground state of the Einstein spacetime is a gas composed of the non-rotating binary systems of neutrinos. Photons are the rotational energies of the binary systems. Vortices of energy transform into mass in the Einstein spacetime because rotational energy decreases local pressure in the Einstein spacetime â€“ from it follows that the binary systems flow into regions with lower pressure. Such inflows increase local mass density so also mass â€“ such is origin of the famous Einstein formula m=E/c^2. This formula is not valid for pure energy in truly empty volume. Photons cannot move in truly empty volume. Energy is an attribute of mass.
The energy equation applied in the Special Theory of Relativity shows that even energy of a mathematical point moving with infinite speed IS EQUAL TO ZERO. Such points cannot lead to photons so also to mass. Higgs bosons are not in existence.

Report this comment

2010-12-11 06:08:41 AM

Posted by: Sylwester Kornowski

#16730

Yes. The Higgs does exist.
"Despite being rather majestic, Boltzmann's deep integration of probabilities into science was adopted by quantum mechanics. It was attacked from the start. The most basic line of attack at the time of Boltzmann's formulation of a statistical interpretation of the thermodynamics was his use of the never-before-seen-measured microscopic "atoms of molecules". Remember Boltzmann advanced his ideas some fifty years before the recognition of atoms by scientist such as Sir J.J. Thomson and Lord Rutherford. Boltzmann's critics were formidable, the finest physicists at the time. Ernst Zermelo, Ernst Mach, and Friedrich Wilhelm Ostwald attacked Boltzman relentlessly. Not because his viewed time as one-way, but because he had the audacity to suggest matter was made of atoms. This group became known as the Vienna Circle of "Logical positivists" and insisted that Science could be conducted only when all the objects of study were seen and understood. Their main objection to Boltzmann was that there was no means of verifying the existence of atoms and molecules, whose behavior lay at the foundation of Botzmann's probability-based version."
-Into the Cool (Energy, Flow, Thermodynamics and Life)

Report this comment

2010-12-13 09:20:12 AM

Posted by: Scott Humphrey

#16743

is it a race to find higs
or is it about who is finding it?
I mean whoever finds it it will cost tax payers a lot searching at 2 places at the world for the same thing.
I'm guessing the who part is more important, instead of its energy value; because that's how prestigious people are. I hope they can prove tax payers wrong on it, as it has cost a lot so far.

Report this comment

2010-12-13 11:43:56 AM

Posted by: Peter Boos

#16744

@ Robert
Robert, in order for anyone to take this kind of thing seriously, you'd have to demonstrate why there is a difference between collisions created in a particle accelerator versus the much higher energy collisions that are caused by cosmic rays in the atmosphere every day.
The LHC cannot ever hope to reach the energies of these kinds of collisions, and they've been going on for billions of years, without any catastrophes.
This is why I roll my eyes when I hear about these 'dangers' of the LHC and other colliders.

Report this comment

2010-12-13 11:55:25 AM

Posted by: John Cunningham

#16784

@John Cunningham,
John,
No catastrophic incidents? What about "our" own universe and perhaps the infinitive number of other universes that might have been created due to collisions of cosmic particles? Who knows? As space-time is infinitive, "catastrophes" happen forever simply said. When our lights go out one day, who cares about the cause?

Report this comment

2010-12-14 10:55:22 AM

Posted by: nick bos

#16792

The recent evidence of fourth generation of quark and neutrinos virtually excludes the finding of unique Higgs boson. It's just wasting money of tax payers and risking their lives for nothing.

Report this comment

2010-12-14 12:02:52 PM

Posted by: Zephir Zephir

#16815

The safety argument equating the LHC beams with "cosmic rays in the atmosphere," reprised above by John Cunningham, was admitted to be invalid by CERN itself. In fact, CERN's 2008 public safety report states that "collisions at the LHC differ from cosmic-ray collisions with astronomical bodies like the Earth..." (Par. 7). A crucial difference is velocity, for the magnetically focused head-on collisions at the LHC could slow some of the products to below escape velocity to plague us. Thus, in regard to neutral microscopic black holes, CERN admits: "Those produced by cosmic rays would pass harmlessly through the Earth into space, whereas those produced by the LHC could remain on Earth" (CERN, Safety of the LHC, 2008, Par. 7).
The higher energies of some cosmic rays would result in a faster exit of the products, which may contribute to the dark matter of the galaxy. The cosmic ray argument was relocated in 2008 to dense neutron stars and white dwarfs, but flaws were found in the new argument as well (see Sec. 4 of paper by German astrophysicist Rainer Plaga at http://arxiv.org/abs/0808.1415v3 ). Moreover, astrophysicists believe that neutron stars consist in part of strange matter, the outcome critics fear for Earth from strangelet production at the LHC.

Report this comment

2010-12-15 01:06:14 AM

Posted by: Robert Houston

#16837

Amazing, To put so,so much emotional energy into an outcome that tires and children would be slashed by others in the experiment of no experiment should someone embodied in the process should mis-step or default to a natural position of stasis within the compound to save their career.
The particle "Understands" your positioning and the test has been completed,actually and the resultant flow is only to stage the next scenario by the system operator.
Have fun boys,deciding who to deplete,and who to save for the final disposition.

Report this comment

2010-12-15 08:48:19 PM

Posted by: Dr.Thomas Hughes

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via nature.com

A physics pathway to the Riemann hypothesis

2010-12-23T08:40:00.001-08:00

via arxiv4.library.cornell.edu

IBM Launches Five-Year Effort To Develop Quantum Computing | Popular Science

2010-11-10T16:46:00.001-08:00

By Rebecca Boyle Posted 11.10.2010 at 2:10 pm 5 Comments

Quantum Computer Courtesy D-Wave

Ramped-up research efforts at IBM and other labs in the U.S. and Europe could lead to more powerful and more prevalent quantum computers in the near future.

IBM is breathing new life into a quantum computing research division at its Thomas J. Watson Research Center, reports New York Times. The computer giant has hired alumni from promising quantum computing programs at Yale and the University of California-Santa Barbara, both of which made quantum leaps in the past year using standard superconducting material.

Groups at both universities have been using rhenium or niobium on a semiconductor surface and cooling the system to absolute zero so that it exhibits quantum behavior. As the Times reports, the method relies on standard microelectronics manufacturing tech, which could make quantum computers easier and cheaper to make.

Related Articles
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Tags
Technology, Rebecca Boyle, computers, future of computers, IBM, quantum computer, quantum computing, quantum mechanics, qubits
The Santa Barbara researchers told the Times they believe they can double the computational power of their quantum computers by next year.
Quantum computing uses spooky action at a distance to conduct superfast calculations. Rather than using transistors to crunch the ones and zeroes of binary code, quantum computers store data as qubits, which can represent one and zero simultaneously. This superposition enables the computers to solve multiple problems at once, providing quick answers to tough questions. But observing a qubit strips it of this duality — you can only see one state at a time — so physicists must figure out how to extract data from a qubit without directly observing it. That’s where quantum entanglement comes in handy; two qubits can be connected by an invisible wave so that they share each other’s properties. You could then watch one qubit to see what its twin is computing.

None of this is simple, however; there are several competing methods for making the qubits, including laser-entangled ions, LED-powered entangled photons, and more. Google is working with a Canadian firm called D-Wave that has claimed 50-qubit computers, although skeptics have questioned that number. In most systems, the number of entangled qubits remains small, but Yale researchers believe they will increase in the next few years, the Times says.

Even better: with all this practice, physicists are getting a lot better at controlling quantum interactions. Their precision has increased a thousand-fold, one researcher said. That’s good news for anyone studying quantum mechanics.

[New York Times]

via popsci.com

IBM and Oracle change the game: A surprising alliance on OpenJDK

2010-10-28T18:22:00.001-07:00

IBM and Oracle surprised many with their joint announcement on October 11 that they would join forces to advance the OpenJDK project. Most commentators agree that the move, which redefines the Java ecosystem by bringing together two of its biggest players, is good news for the future of Java technology.

More than 60 percent of respondents to a Javalobby poll (600 at last count) said that they believe IBM's decision to co-sponsor the OpenJDK project is good for Java technology. By deciding to focus joint development efforts on OpenJDK, the companies have effectively ended speculation about an IBM-led Java fork, and what it would mean for the multibillion dollar Java industry. With these worries off the table, said Mike Milinkovich of the Eclipse Foundation, "we can get back to innovation."

At the heart of the Oracle-IBM announcement are hard choices made by an industry in flux, from multinational corporations with long-term technology investment to smaller companies and individuals deciding whether to continue developing software on the Java platform. This article presents an overview of the key factors and players involved in, or affected by, the Oracle and IBM decision. At the end of each section, you'll find pointers to web resources that address aspects of the alliance.

OpenJDK as an Oracle-IBM project

OpenJDK is the open source reference implementation for the Java platform; it encompasses Java SE, the Java language, the JDK, and the JRE. OpenJDK specification requests are subject to vote by the Java Community Process. An upcoming vote will determine whether the new proposed OpenJDK roadmap is accepted by the JCP executive committee.

Mark Reinhold, chief architect of the Java Platform Group at Oracle, has stated that IBM engineers working on OpenJDK will probably "contribute primarily to the class libraries, working with the rest of us toward a common source base for use atop multiple Java virtual machines." The two companies will likely continue to work independently on their respective JVMs, "where most of the enterprise-level feature differentiation" is found, he said.

OpenJDK governance?

The OpenJDK project has an interim governance board tasked with creating a constitution for the OpenJDK community. As Simon Phipps has pointed out, the board's status appears to be in limbo as of this writing.

Win some, lose some

The decision to reach out to IBM as an OpenJDK partner was clearly a strategic one for Oracle. Oracle's vice president of software, Adam Messinger, said that the move reflected the pressure on both companies to move quickly and address the challenges posed by evolving multicore hardware. "The agreement is a reflection of the strategic reality we both face," he said.

The OpenJDK alliance de-isolates Oracle, said RedMonk's Stephen O'Grady, effectively affirming and centralizing its role in the Java ecosystem:

If Oracle was going to pick one vendor to stand beside them in their Java efforts, IBM would be the easy choice. Besides the blind trust enterprises place in the firm — "you don't get fired for buying IBM," etc. — Big Blue has an enviable reputation with developers. With IBM now publicly on the same page as Oracle, the latter's task of preserving the ecosystem becomes far, far easier.

It was also a good move for IBM, even accounting for the obvious sacrifice of Harmony. In shifting its engineering resources from Project Harmony to OpenJDK, IBM has solidified its influence on the future of Java technology, albeit clearly under Oracle's stewardship. Both companies have said that they will work together to ensure that the JCP is fortified and enhanced as the primary standards body driving the growth of the Java platform.

Left unresolved are issues of what will happen now to Project Harmony, what the Oracle-IBM alliance means for Google (and by proxy Android), what the OpenJDK alliance (and Google's response) could mean for other vendors in the Java technology space, and how and to what extent the JCP will be reformed.

Further reading: OpenJDK and the Oracle-IBM decision

The majority of OpenJDK committers already are employed by Oracle (formerly Sun) and IBM, followed by developers from Google and Red Hat. (Oracle Java/FOSS Ambassador Dalibor Topic has more about this.)

IBM's Bob Sutor, vice president of Open Systems and Linux, lays out the reasons for IBM's decision. He addresses both the upside of IBM's improved leverage for ensuring the open source future of Java and the JCP and the upset about the decision's impact on Project Harmony.

Stephen O'Grady gives an analyst's insight into the ripple effects of the Oracle-IBM decision across the entire Java ecosystem, including speculation as to why partnering with IBM on OpenJDK was a good move for Oracle.

Mark Reinhold explains the thinking behind the new OpenJDK roadmap and its split JSRs.

Back to top
What about Project Harmony?

IBM has been a longstanding backer of Project Harmony, the open source Java runtime developed and licensed by the Apache Software Foundation. To some in the Java community, Harmony has seemed a viable alternative to the official Java platform implementation, should the need arise. Harmony also is seen as a test case for Oracle's position vis-a-vis independent Java implementations and licensing.

Bob Sutor, IBM's vice president of open source and Linux®, summed up IBM's decision to redirect its engineers from Project Harmony to OpenJDK, calling it pragmatic:

It became clear to us that first Sun and then Oracle were never planning to make the important test and certification tests for Java, the Java SE TCK, available to Apache. We disagreed with this choice, but it was not ours to make. So rather than continue to drive Harmony as an unofficial and uncertified Java effort, we decided to shift direction and put our efforts into OpenJDK.

While the move leaves Harmony's future uncertain, whether and how the project will evolve is in the hands of developers. IBM's decision "is not a good thing for Harmony" said Harmony creator and Apache board member Geir Magnusson. "But keep it in perspective: For the Apache Foundation, it's up to the community what will be done. We do what the community wants."

Initial reaction to the decision has ranged from variations on "game over (and not just for Harmony)" to the suggestion that parts of Project Harmony could make it into OpenJDK. Some have also speculated that the platform could continue to evolve under the backing of another corporate sponsor; namely, Google.

Further reading: Project Harmony, past and future

Ryan Paul, reporting for Ars Technica, gives a concise overview of Harmony's licensing history; the implications of Sun's, and now Oracle's, field-of-use restrictions; and IBM's role in championing the platform until now.

Stephen Colebourne, an ASF member, summarizes his views on both the Sun/Oracle licensing dispute and the upshot of IBM's decision.

According to Harmony creator Geir Magnusson, Harmony's future remains in the hands of its developers.

Many, including DZone's James Sugrue, are wondering what role Google might play in Harmony's future , given the subset of Harmony libraries used in Android.

Back to top
Google, Android, and the new cold war theory

While Google isn't the only Java technology vendor with a stake in the Oracle-IBM decision, it may be the vendor with the most to lose, or gain, as this story unfolds. Oracle's suit filed against Google in August (claiming multiple counts of patent and copyright infringement related to Android) was a blow to the open source ethos under which the Java ecosystem has thrived. Calls for a Java fork increased following the announcement, and some feared that developers formerly on the fence about Java technology would decamp.

That Project Harmony is without a strong corporate sponsor could be bad for Google (given that Android is built on a subset of Harmony); or it could be very good, if Google chooses to sponsor Project Harmony itself.

Whatever Google's decision, it will affect not just Android, but how vendors view and leverage Java technology in their own implementations. Moreover, as several have pointed out, we may be entering a new cold-war era — with Google, not Oracle, as the outlier.

Further reading: What's next for Google

Charles Nutter hits all the bases in his summary of the Oracle-Google lawsuit and its ripple effects across the Java ecosystem.

Greg Luck outlined a proposal for a Java fork in his October 4 blog post "Is it time to fork Java?"

Googling Google blogger Christopher Dawson discusses Google's options to fight or join and concludes that Google will 'keep on being Google'.

Google, along with IBM, Oracle, and Red Hat, is a leading contributor to the OpenJDK project.

Back to top
Reforming the JCP

Oracle and IBM have stated that they will work together to reform and enhance the JCP, ensuring that it continues to be the standards body defining the Java platform and language specifications. Oracle reps have affirmed that JCP approval is essential to Java SE development, starting with the upcoming vote on the revised OpenJDK roadmap announced at JavaOne.

Bob Sutor has said that IBM expects to see "long needed reforms in the JCP [...] to make it more democratic, transparent, and open." Some Oracle reps have also hinted not only that JCP reform is under discussion with the executive committee, but that they believe the community will be pleased with the resulting proposal.

Time will tell how the executive committee, and the community at large, respond to proposed JCP enhancements. According to Apache Software Foundation member Stephen Colebourne, the upcoming JCP vote will be an initial test case, however; not just for the revised OpenJDK/Java 7 roadmap, but for how vendors like Red Hat, VMWare, SAP, and Google react to the Oracle-IBM alliance. Colebourne has also proposed a JCP split that would leave Oracle the explicit sole voting power on the specification of the Java core (Java SE, ME, and the JVM, according to Colebourne), while declaring auxiliary libraries a separate province under the direction of a vendor-independent JCP.

Further reading: JCP reform and open source Java

Oracle reps Adam Messinger and Henrik Stahl have both hinted that JCP negotiations could please the Java community.

For an idea of how members of the JCP executive committee might view JCP reform, see the DZone panel comments from February 2010.

Stephen Colebourne has proposed that the upcoming JCP vote could be a measure of where executive committee members stand on the Oracle-IBM decision. (Reporting by Jessica Thornsby for JAXmag online.)

Colebourne has also proposed a JCP split.

Back to top
A healthier Java ecosystem?

The Oracle-IBM alliance is widely viewed as a win for Java technology: it both accelerates the OpenJDK project and enables collaboration and resource sharing among a much larger pool of engineers. The move consolidates the energies of two of the industry's most influential forces (by virtue of technology investment and revenue) on its fundamental project, OpenJDK. And it has effectively put an end to speculation about an IBM-led Java fork, which would have done more harm than good to the Java industry as a whole.

In his comments on the alliance, IBM's vice president of emerging technologies, Rod Smith, stressed its stabilizing effects on the Java ecosystem, for developers, for vendors, and for business. "This should remove some of the uncertainty about the future of Java," he said. Danny Coward (formerly of Sun) hailed the alliance as the beginning of a "new era of co-oper-tition," which Oracle's Adam Messinger said would accelerate innovation on the Java platform.

Stability is good, and so is innovation; both are essential to a healthy Java ecosystem. And while stability may rest on the shoulders of giants, innovation in the Java industry has historically been a disruptive force: an arena where small vendors and independent, loosely networked developers count sometimes more than multinational corporations. It's the interplay between those two powerful interests that keeps the Java industry both healthy and honest, and hopefully thriving.

As Fabrizio Giudici (and Gianugo Rabellino) have pointed out there is one final question, and that's the question of freedom; freedom as defined by the Free Software Foundation and codified by open source licenses. That question may yet determine whether the future of Java is founded on one core platform or two, or more.

Further reading: What makes a healthier Java ecosystem?

Fabrizio Giudici evaluates shades of gray in his discussion of definitions of freedom — Rabellino's open source versus open standards — and whether an OpenJDK fork would be worth the price.

Writing 10 days before the Oracle-IBM announcement, James Governor called disruptive innovation (and open source governance) the rule for the future of Java technology, and no longer the exception.

Resources
Learn
OpenJDK : Learn more about the open source Java platform implementation.
The JCP is the standards body that develops Java technology specifications.
"IBM, Oracle, OpenJDK, and the implications" (Scott Langingham, developerWorks podcasts, October 2010): IBM's Rod Smith and Jason Gartner discuss the implications of the Oracle-IBM alliance on OpenJDK.
IBM developer kits for the Java platform: Learn more about what IBM's runtimes and VMs
Browse the technology bookstore for books on these and other technical topics.
developerWorks Java technology zone: Find hundreds of articles about every aspect of Java programming.
Discuss
Get involved in the My developerWorks community. Connect with other developerWorks users while exploring the developer-driven blogs, forums, groups, and wikis.

About the author
Athen O'Shea is a high technology editor and writer, and former editor of JavaWorld.com. As a freelancer, he has plied his trade for developerWorks since 2001.

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Bees Beat Machines At 'Traveling Salesman' Problem

2010-10-25T16:12:00.001-07:00

Gosh, that is one hell of a bee if it has the brain of a piece of corn... or is corn not a grass anymore? At least when you take some idiotic comparison, take one that has a non-changing size. Penny is okay because all pennies at least within a country tend to stay the same. But grass seeds?
Next up is "brain the size of a pinhead". Oh okay, so there are many sizes of pin but at least we can assume some kind of standard. And that is FAR smaller then most grasses I know and see seeds of in Holland.
Otherwise intresting stuff but I loathe this "make it easier" by obuscating the facts.
Number of neurons in honey bee brain = 950,000 (from Menzel, R. and Giurfa, M., Cognitive architecture of a mini-brain: the honeybee, Trd. Cog. Sci., 5:62-71, 2001.)
Now THAT is a fact. We? We got 100 billion. So, while a bee has a tiny brain compared to ours, it is HARDLY simple. And because it is far smaller and far more primitive it doesn't need as as much intelligence to deal with things it doesn't need to. Listening and producing speech is complex, but bees don't bother with that. Living for half a century and remembring everything is complex. But bees don't do that.
This why computers can do math so fast despite being so stupid, because they only do math.
How can the bee do route calculation with close to a million neurons? I have no idea but didn't research show that far fewer rat neurons could fly a plane? I think some people fastly underestimate the complexity of the brain even small ones. We already know that a neuron is far more then a simple transistor so 1 million super transistors would make for a hell of a complex computer. Suddenly it doesn't seem to odd that a bee can do computations far more complex because THAT is what it is designed to do. You could just as easily marvle at the fact that the bee with its tiny brain can fly, while I with my large brain can't. And no I don't just mean I don't have wings, I mean that if you put me in a helicopter you would have a horrible crash in seconds and that is in the passenger seat.
Marvle at nature, learn from it but don't belittle it. It takes us year to program a robot to walk very very slowly. A deer learns it in minutes and this includes learning to control legs locked up in a womb for months. We can either accept that nature is amazing or we are very very poor programmers... as a developer, I choose to believe that nature is amazing.

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Moving from Spring to Java EE 6: The Age of Frameworks is Over

2010-10-05T09:50:00.001-07:00

There is no arguing the fact that TheServerSide.com has historically been a strong advocate for the work of Rod Johnson and the Spring framework. The J2EE platform had its shortcoming, and Spring quickly became the most prominent and pervasive framework for easily building enterprise-ready applications, while at the same time, helping developers avoid many of the pitfalls of the old enterprise Java platform.
But J2EE represents the past, and Java EE 6 represents the future. Java EE 6 promises us the ability to go beyond frameworks. Frameworks like Spring are really just a bridge between the mistakes of the J2EE past and the success of the Java EE 6 future. Frameworks are out, and extensions to the Java EE 6 platform are in. Now is the time to start looking past Spring, and looking forward to Seam and Weld and CDI technologies.
And to start shifting into a world of extensions, and moving away from frameworks, the first step is porting your Spring applications to a Java EE 6 environment. To do so, a great place to start is by checking out this article from ocpsoft.com about doing a Spring to Java EE migration.

Spring to Java EE – A Migration Experience

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Physics Buzz: Hawking & Mlodinow: No 'theory of everything

2010-09-30T11:59:00.001-07:00

In a Scientific American essay based on their new book A Grand Design, Stephen Hawking and Leonard Mlodinow are now claiming physicists may never find a theory of everything. Instead, they propose a "family of interconnected theories" might emerge, with each describing a certain reality under specific conditions.

Most of the history of physics has been dominated by a realist approach. Scientists simply accepted that their observations could give direct information about an objective reality. In classical physics, such a view was easily defensible, but the emergence of quantum mechanics has shaken even the staunchest realist.
In a quantum world, particles don't have definite locations or even definite velocities until they've been observed. This is a far cry from Newton's world, and Hawking/Mlodinow argue that - in light of quantum mechanics - it doesn't matter what is actually real and what isn't, all that matters is what we experience as reality.
As an example, they talk about Neo from The Matrix. Even though Neo's world was virtual, as long as he didn't know it there was no reason for him to challenge the physical laws of that world. Similarly, they use the example of a goldfish in a curved bowl. The fish would experience a curvature of light as its reality and while it wouldn't be accurate to someone outside the bowl, to the fish it would be.
Scientific American: The Elusive Theory of Everything (paywalled)
"In our view, there is no picture or theory-independent concept of reality. Instead we adopt a view that we call model - dependent realism: the idea that a physical theory or world is a model (generally of a mathematical nature) and a set of rules that connect the elements of the model to observations. According to model - dependent realism, it is pointless to ask whether a model is real, only whether it agrees with observation. If two models agree with observation, neither model can be considered more real than the other. A person can use whichever model is more convenient in the situation under consideration."

This view is a staunch reversal for Hawking, who 30 years ago argued that not only would physicists find a theory of everything, but that it would happen by the year 2000. In his first speech as Lucasian Chair at Cambridge titled "Is the end in sight for theoretical physics?," Hawking argued that the unification of quantum mechanics and general relativity into one theory was inevitable and that the coming age of computers would render physicists obsolete, if not physics itself.
Of course, Hawking has become rather well known for jumping way out on a limb with his public remarks and for decades he embraced supergravity as having the potential to solve theoretical physicist's ills, even hosting a major conference on it in 1982. However, but Hawking has never harbored allegiances to theories that describe a physical reality.
So, while two well-known physicists coming out against a theory of everything is compelling, it really shouldn't seem like anything new for Hawking.
"I take the positivist view point that a physical theory is just a mathematical model and that it is meaningless to ask whether it corresponds to reality. All that one can ask is that its predictions should be in agreement with observation."

Stephen hawking, The Nature of Space and Time (1996)
-Flash

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Practical Software Design - A few thoughts! | Javalobby

2010-09-29T12:57:00.001-07:00

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Mathematics under the Microscope - How good software makes us stupid

2010-09-13T10:07:00.001-07:00

An article by Dave Lee on the BBC website: the title sums it up perfectly. It quotes an earlier article by Bill Thompson Between a rock and an interface, which, in its turn, quotes a research paper by Christof van Nimwegen on user interfaces, The paradox of the guided user: assistance can be counter-effective (2008). I quote an abstract:

This project investigates the conditions under which externalizing interface information by interface controls influences users’ performance in solving problems requiring planning. Our main research question was: in tasks where planning is required, which interface style leads to more plan-based behavior, better strategy, and consequently better task performance? And besides immediate performance, which interface style causes better knowledge of the tasks and solutions afterwards in a transfer situation (with altered task/interface circumstances), or when a severe task interruption occurs? To answer our questions, two series of controlled experiments were conducted using two interface styles: one version in which certain information is externalized onto the interface (Externalization) and another version where this is not done (Internalization). In the Externalization version the operators in the interface conveyed information, in the Internalization version this was not the case. The first series of experiments used a computerized isomorphic version of the well-known “Missionaries & Cannibals” problem, called “Ball & Boxes”. The second series of experiments used a more realistic office-like application called “Conference Planner”. Immediate and delayed performance when using the Externalization interface, was worse than when performance use the Internalization interface. Also transfer of skill was worse for users of the Externalization interface, both to another task, and to another interface. These users were characterized by display-based behavior. Subjects that used the Internalization interface imprinted relevant task and rule knowledge better and were not affected by a severe interruption in the workflow, whereas Externalization subjects were. We conclude that users who internalize information themselves behave more plan-based, are more proactive and ready to make inferences. This in turn results in more focus, more direct and economical solutions, better strategies, and better imprinting of knowledge. This knowledge is easier to recall at a future point in time, and is better transferable to transfer situations where the interface, the task, or both were different, less vulnerable to a severe interruption, and better applicable to transfer situations. Human-computer interaction designers can take advantage from considerations that go beyond plain usability, even when they go against common sense. In designing interfaces we have to take care with providing interface cues that give away too much information, and must design in such a manner that the way users (should) think is optimally supported, which in turn could help the software to achieve its specific goal. Examples are situations where risky and complex tasks are performed, and where a user suddenly is confronted with a new situation. One can also think of situations in which interruptions are commonplace, or where operations come with a cost and direct solutions without deviations are the aim. Based on our findings an interaction framework is proposed that can guide decisions regarding interface design.

I had a similar experience when I used two software packages in my classes. I will write about it shortly.

Possibly related posts: (automatically generated)
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software evoloution

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Measuring Gravity: Ain't Nothin' but a G Thing

2010-08-26T16:32:00.001-07:00

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Measuring Gravity: Ain't Nothin' but a G Thing

Category: Experiment • Physics • ResearchBlogging • Science
Posted on: August 26, 2010 12:25 PM, by Chad Orzel

There's a minor scandal in fundamental physics that doesn't get talked about much, and it has to do with the very first fundamental force discovered, gravity. The scandal is the value of Newton's gravitational constant G, which is the least well known of the fundamental constants, with a value of 6.674 28(67) x 10^-11 m³ kg-1 s^-2. That may seem pretty precise, but the uncertainty (the two digits in parentheses) is scandalously large when compared to something like Planck's constant at 6.626 068 96(33) x 10^-34 J s. (You can look up the official values of your favorite fundamental constants at this handy page from NIST, by the way...)

To make matters worse, recent measurements of G don't necessarily agree with each other. In fact, as reported in Nature, the most recent measurement, available in this arxiv preprint, disagrees with the best previous measurement by a whopping ten standard deviations, which is the sort of result you should never, ever see.

This obviously demands some explanation, so:

What's the deal with this? I mean, how hard can it be to measure gravity? You drop something, it falls, there's gravity. It's easy to detect the effect of the Earth's gravitational pull, but that's just because the Earth has a gigantic mass, making the force pretty substantial. If you want to know the precise strength of gravity, though, which is what G characterizes, you need to look at the force between two smaller masses, and that's really difficult to measure.

Why? I mean, why can't you just use the Earth, and measure a big force? If you want to know the force of gravity to a few parts per million, you would need to know the mass of the Earth to better than a few parts per million, and we don't know that. A good measurement of G requires you to use test masses whose values you know extremely well, and that means working with smaller masses. Which means really tiny forces-- the force between two 1 kg masses separated by 10 cm is 6.6 x 10^-9 N, or about the weight of a single cell.

OK, I admit, that's a bit tricky. So how do they do it? There are four papers cited in the Nature news article. I'll say a little bit about each of them, and how they figure into this story.

The oldest measurement cited by Nature is the torsion balance measurement from 2000 by the Eöt-Wash group at the University of Washington. This is an extremely refined version of the traditional method of measuring G first developed by Henry Cavendish in the late 1700's.

Let's assume I'm too lazy to follow that link, and summarize in this post, mmmkay? OK. Cavendish's method used a "torsion pendulum," which is a barbell-shaped mass hung at the end of a very fine wire, as seen at right. You put two test masses near the ends of the barbell, and they attract the barbell, causing the wire to twist. The amount of twist you get depends on the force, so by measuring the twist of the wire for different test masses and different separations, you can measure the strength of gravity and its dependence on distance.

Sounds straightforward enough. It is, in concept. Of course, given the absurdly tiny size of the forces involved, it's a really fiddly measurement to do. Cavendish himself set the apparatus up inside a sealed room, and then read the twist off from outside, using a telescope. If he was in the room looking at the apparatus, the air currents created by his presence were enough to throw things off.

This remained the standard technique for G measurements for about two centuries, though, because it's damnably difficult to do better. And the Eöt-Wash group's version is really astounding.

So, how did they do better? One of the biggest sources of error in the experiment comes from the twisting of the wire. In an ideal world, the response of the wire would be linear-- that is, if you double the force, you double the twist. In the real world, though, that's not a very good assumption, and that makes the force measurement really tricky if the wire twists at all.

The great refinement introduced by the Eöt-Wash group was to not allow the wire to twist. They mounted their pendulum, shown at left, on a turntable, and made small rotations of the mount as the wire started to twist, to prevent the twist from becoming big. Their force measurement was then determined by how much they had to rotate the turntable to compensate for the gravitational force causing a twist of the wire.

They also mounted the attracting masses on a turntable, and rotated it in the opposite direction around the pendulum, to avoid any systematic problems caused by the test masses or their positioning. Their signal was thus an oscillating correction signal, as each test mass passed by their pendulum, and they recorded data for a really long time: their paper reports on six datasets, each containing three days worth of data acquisition.

The value they got was 6.674 215 6 ± 0.000092 x 10^-11 m³ kg-1 s^-2, far and away the best measurement done to that point.

So what are the other papers? The second one, in chrononogical order, is a Phys. Rev. D paper from a group in Switzerland, who used a beam balance to make their measurement. They had two identical test masses hung from fine wires, and they alternately weighed each mass while moving enormous "field masses" weighing several metric tons each into different positions, as shown in the figure at right. In the "T" configuration, the upper test mass should appear heavier than the lower test mass, as the large field masses between them pull one down and the other up. In the "A" configuration, the upper test mass should be lighter, as the field masses pull it up while pulling the lower mass down.

This was another experiment with very long data taking, including this wonderfully deadpan description:

The equipment was fully automated. Measurements lasting up to 7 weeks were essentially unattended. The experiment was controlled from our Zurich office via the internet with data transfer occurring once a day.

Their value, 6.674 252(109)(54) x 10^-11 m³ kg-1 s^-2 is in good agreement with the Eöt-Wash group's result.

If it agrees, why even mention it? It's an important piece of the story, because it's a radically different technique, giving the same answer. It's extremely unlikely that these would accidentally come out to be the same, because the systematic effects they have to contend with are so very different.

Yeah, great. Get to the disagreement. OK, OK. The third measurement, in this PRL by a group in China, uses a pendulum again, but a different measurement technique. They used a rectangular quartz block as their pendulum, suspended by the center, with test masses outside the pendulum. They place these test masses in one of two positions: near the ends of the pendulum when it was at rest (shown in the figure), or far away from the ends (where the "counterbalancing rings" are in the figure).

The gravitational attraction of the masses in the near configuration makes the pendulum twist at a slightly different rate than in the far configuration, and that's what they measured. The oscillation period was almost ten minutes, and the difference between the two was around a third of a second, which gives you some idea of how small an effect you get.

Their value was 6.673 49(18) x 10^-11 m³ kg-1 s^-2, which is a significantly larger uncertainty than the other two, but even with that, doesn't agree with them. Which is kind of a problem.

So, how do you deal with that? Well, they obviously had a little trouble getting the paper through peer review-- it says it was first submitted in 2006, but not published until 2009. That probably means they needed to go back and re-check a bunch of their analysis to satisfy the referees that they'd done everything correctly. After that, though, all you can do is put the result out there, and see what other people can make of it.

Which brings us to the final paper? Exactly. This is an arxiv preprint, and thus isn't officially in print yet, but it has been accepted by Physical Review Letters.

They use yet another completely different technique, this one employing free-hanging masses whose position they measure directly using a laser interferometer. They also have two configurations, one with a bunch of source masses between the two hanging masses, the other with the source masses outside the hanging masses. The gravitational attraction of the 120kg source masses should pull the hanging masses either slightly closer together, or slightly farther apart, depending on the configuration, and this change of position is what they measure.

Their value is 6.672 34 ± 0.000 14 x 10^-11 m³ kg-1 s^-2, which has nice small error bars-- only the Eöt-Wash result is better in that regard-- but is way, way off from the other values. Like, ten times the uncertainty off from the other values. There's no obvious reason why this would be the case, though. If anything, the experiment is simpler in concept than any of the others, so you would expect it to be easier to understand. There aren't any really glaring flaws in the procedure, though (it never would've been accepted otherwise), so this presents a problem.

So, now what? Well, in the short term, this probably means that the CODATA value for G (the official, approved number used by international physics) will need to be revised to increase the uncertainty. This is kind of embarrassing for metrology, but has happened before-- a past disagreement of this type is one of the things that prompted the original Eöt-Wash measurements.

In the medium to long term, you can bet that every group with a bright idea about how to measure G is tooling up to make another run at it. This sort of conflict, like any other problem in physics, will ultimately need to be resolved by new data.

Happily, these experiments cost millions of dollars (or less), not billions, so we can hope for multiple new measurements with different techniques to resolve the discrepancy. It'll take a good long while, though, given how slowly data comes in for these types of experiment, which will give lots of people time to come up with new theories of what's really going on here.

Gundlach, J., & Merkowitz, S. (2000). Measurement of Newton's Constant Using a Torsion Balance with Angular Acceleration Feedback Physical Review Letters, 85 (14), 2869-2872 DOI: 10.1103/PhysRevLett.85.2869

Schlamminger, S., Holzschuh, E., Kündig, W., Nolting, F., Pixley, R., Schurr, J., & Straumann, U. (2006). Measurement of Newton's gravitational constant Physical Review D, 74 (8) DOI: 10.1103/PhysRevD.74.082001

Luo, J., Liu, Q., Tu, L., Shao, C., Liu, L., Yang, S., Li, Q., & Zhang, Y. (2009). Determination of the Newtonian Gravitational Constant G with Time-of-Swing Method Physical Review Letters, 102 (24) DOI: 10.1103/PhysRevLett.102.240801

Harold V. Parks, & James E. Faller (2010). A Simple Pendulum Determination of the Gravitational Constant Physical Review Letters (accepted) arXiv: 1008.3203v2

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Comments

1
Nice writeup, and I'm ashamed to nitpick about grammar/spelling, but I believe you may have misspelled the word "Thang" in the title.

Posted by: Anonymous Coward | August 26, 2010 2:11 PM

2
Ha! It's nice to see you physicists have trouble too.

It looks as if different methods give different results (suggesting they all have different biases). How will you lot know which one is correct?

Also, would altitude make a difference?

Posted by: Bob O'H | August 26, 2010 2:43 PM

3
What usually happens in this sort of situation is that a few measurements using different techniques will turn out to agree with each other reasonably well, and that will come to be accepted as the "real" value. The data from all of these will be re-analyzed, and eventually somebody will find a plausible systematic effect that could've thrown the results off.

If I had to guess, I'd say that the Eot-Wash result is probably closer to the final value than the newer measurements. The period measurement seems to invite exactly the sort of weird twisting-wire effects that the original turntable measurements were designed to avoid, and the hanging-pendulum thing is, as far as I know, a very new technique, and the most likely to have some subtle problem that hasn't been noticed yet because people haven't been banging on it for decades like the torsion pendulum. That's just a guess, though.

Posted by: Chad Orzel | August 26, 2010 2:53 PM

4
Why do Eöt-Wash give "6.6742156" the extra digits "56" if, by their own estimates, the "2" might just as well be "1" or even "3"?

When I was an undergraduate, G was known to only three digits, so this is progress. I wonder about three-day experiments, though. At this stage they should be collecting measurements for several years before reporting.

Posted by: Nathan Myers | August 26, 2010 3:11 PM

5
Re: Nathan Myers

Re: the digits, I think there's a typo in Chad's writeup and I think you also lost a digit in your reading.

I think the numbers are:
6.674215
with an error bar of
0.000092
(times the appropriate units).

It's standard these days to give 2 digits of error bar, and write your number out to the same length, so I don't think there's anything weird here.

Re: "I wonder about three-day experiments, though. At this stage they should be collecting measurements for several years before reporting."

I disagree for two reasons.

First, precision measurement is partially about statistical error (which you can improve by taking data longer) and partially about checking for systematic errors (which don't improve through averaging). To check for systematics, typically one varies conditions and remeasures things to see how the measured value depends on stuff. To do this well, you may need to take data for almost as long under your "altered" conditions as you do when making them under your "good" conditions. And in most experiments, there are dozens of possible systematics to check. So, a good rule of thumb for a precision measurement experiment is that, when estimating what your statistical error, you allow for a day (or maybe a week) of data taking, so that you can do your systematic checks on the timescale of a couple of years. So I'm guessing that it's not that these guys are lazy or got bored; it's that they're responsible.

Secondly, if you look at their error budget in the paper, the statistical error accounts for 6 ppm error, and their total error is 14 ppm, so taking data for a few years would only make a small improvement to their error, reducing it from 14 to 12 ppm (assuming adding things in quadrature).

Posted by: Anonymous Coward | August 26, 2010 5:40 PM

6
If the exact and true value of G is discovered, creating a future time where we say "we should have seen that", it will be because it stands out in theory or is singularly distinctive in other context.

In the use of log tables, it was often necessary to extrapolate a value between those which were actually listed, by discerning the pattern of change and making a prediction. In multidimensional mappings of the values of fundamental constants expressed as common logs, recognizable as multidimensional log tables, there is one
single, unique concurrence of numerical pattern alignments which occurs for a single value of G :

http://www.outlawmapofphysics.com/NGC.pdf

Posted by: John Aikman | August 26, 2010 6:42 PM

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New Computer Model Might Turn Theory Of Galaxy Formation On Its Head

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Quantum Algorithms A Different View—Again

2010-08-25T09:14:00.000-07:00

A view of quantum algorithms via linear algebra

via Gödel’s Lost Letter and P=NP

Problem-solving flow chart

2010-08-24T18:38:00.001-07:00

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NEW math on Futurama

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post about the math from the Aug 19, 2010 episode of Futurama

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So, Does Anyone Even Use All These Darn CPU Instructions?

2010-08-21T10:05:00.000-07:00

Interesting research into the most commonly used functions in the IA32 instruction set.

via :: (Bloggable a) => a -> IO ()

Computational Complexity: What is the complexity of these problems and metaproblems?

2010-08-01T14:47:00.000-07:00

via Computational Complexity

"The following problem is from Doctor Eco's Cyberpuzzles. I have shortened and generalized it.

We are going to put numbers into boxes. If x,y,z are in a box then it CANNOT be the case that x+y=z. If you put the numbers 1,2,...,n into boxes, what is the smallest number of boxes you will need?..."

view the rest of the post here:
Computational Complexity: What is the complexity of these problems and metaproblems?

A very clever calculator

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A theory of everything?

2010-04-08T16:28:00.000-07:00

Enter the matrix: the deep law that shapes our reality - physics-math - 07 April 2010 - New Scientist

The Odlysko-Schönhage Algorithm

2009-11-29T11:55:00.000-08:00

The paper which describes the Odlysko-Schönhage Algorithm in detail. It has become somewhat difficult to locate since most of the reference links from other documents seem to be outdated. Brought to you here by your friendly neighborhood math-geek for you viewing pleasure.

The 10^20-th zero of the Riemann zeta function and 175 million of its neighbors

Java and Floating Point Math

2009-11-27T17:51:00.000-08:00

Good article from IBM developerWorks. Contrary to somewhat still popular belief, Java can do math.

Java's new math, Part 2: Floating-point numbers

Happy Birthday Uncle Albert

2009-03-16T19:14:00.000-07:00

Saturday was Pi day and Albert Einstein's birthday which reminded of my own uncle Albert who I credit as the person responsible for getting me hooked on math and science at a very early age. It was the simple act of giving me a set of magnets to play with to calm me down from some major meltdown tantrum I was throwing over who knows what. One of those things that a six year old thinks will be the end of his world as he knows it if he doesn't get it. Like a butterfly flapping it's wings on the other side of the world, that simple act caused a cascade effect of intense, unending curiosity that 48 years later still shows not the slightest trace of slowing down any time soon (maybe when they can pry my cold dead fingers from my math books). Thank you Uncle Albert for that wonderful gift.

My uncle Albert passed away in the early 70's after losing his battle with cancer. It was many years before I could hear the song "Uncle Albert/Admiral Halsey" without tears flowing. To this day I still get misty-eyed.

Warning: Solving the RH can be hazardous to your health...

2008-09-24T07:38:00.000-07:00

A friend posted this on my facebook wall:

Fire in the Hole

2008-09-10T07:54:00.000-07:00

Well, it's on and I'm still waiting for that giant black hole that's supposed to swallow the earth whole (and let me know when Elvis gets here...)

Link

The Ultimate Capcha

2008-05-12T13:43:00.000-07:00

“No Premium User. Please solve the Riemann Hypothesis.”

via Ho John Lee's Weblog

Link

Google Aprilfoolery

2008-04-01T12:36:00.000-07:00

Always enjoy these.

Gmail Custom Time
Google Wakeup Kit
A Cool World: Enjoy a rosier future as a Virgle Pioneer

Problem solved? Not so fast...

2008-03-25T07:25:00.000-07:00

Another "proof" from de Branges. Maybe if he has it right this time we can all move on to the next great unsolved math problem: How many licks does it take to get to the Tootsie Roll center of a Tootsie Pop...

(I believe a wise old owl had a proof once and it was 3... or maybe 3.141592653589793238462643383279...)

Link

Galactic Death Ray Discovered - News - OmniNerd

2007-12-31T15:09:00.000-08:00

"Witness the power of this fully operational gamma ray burst!"

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The Hollywood Uncertainty Principle

2007-12-10T15:44:00.000-08:00

So I had the tv on this weekend (usually to provide background noise) and happened to catch part of a movie called "A Sound of Thunder" which is based on a Bradbury story. One scene which particularly caught my attention was one character's response to being told that there is no room for error in the procedure they were setting up (something involving time travel).
His response (not verbatim):

"When I was a physics student we studied something called 'The Heisenberg Uncertainty Principle' which states that there is no such thing as zero tolerance". Some more dialog followed along the lines of the inability to have sufficient information to detect all possible errors. I was ROFLing too hard at this point to pay much attention.

Hollywood science strikes again. If you want a more scientifically accurate explanation, stick with Samantha Carter on Stargate SG-1.

PS If you get this, you don't need any more explanation

Q: Why was Heisenberg's wife always frustrated?
A: Because when he had the time he didn't have the energy and when he had the position he didn't have the momentum

Jarosław Przygódzki » Proof of the Riemann hypothesis

2007-12-06T05:41:00.000-08:00

A mathematician has been invited to speak at a conference. His talk is announced as

Proof of the Riemann hypothesis. When the conference actually takes place, he speaks about something completely different.
After his talk, a colleague asks him: “Did you find an error in your proof?”
He replies: “No - I never had one.”
“But why did you make this announcement?”
“That’s my standard precaution - in case I die on my way to the conference…”

link

Ben Stein and Intelligence

2007-11-28T14:48:00.000-08:00

On a recent Glenn Beck show on the CNN Headline News channel, Ben Stein made an appearance promoting among other things a documentary titled "Expelled: No Intelligence Allowed". This purports to portray the plight of the poor researchers who have their grants taken away because their area of interest involves "Intelligent Design" (I have no details on this film so I'm going strictly by what was discussed on the show). Of course the conversation quickly degenerated into the "why can't we have a discussion on the two sides of the issue" with Mr.Stein using the tired example of how evolutionists would like to have us believe that out of a lightning bolt hitting a mud puddle we got something of the complexity of a 747. Well, Mr. Beck let me attempt to explain why you can't have a two-sided discussion on this issue (well non-issue, really), when one side is an accepted scientific theory with over 150 years of supporting evidence and the other side is religious mumbo-jumbo wrapped in a lab coat. Needless to say any such attempt would quickly degenerate into nothing more than an Argument Clinic sketch. I believe that's why we have a National SCIENCE Foundation, not a National Faith Foundation (well we do if you want to count the so called Discovery Institute). So Mr. Beck in conclusion let's recap: there are no two sides, there is no "controversy", just a bunch of idiotic, deluded dumb-asses who seriously believe they can take science teaching back to the 14th century.

And Mr. Stein, please, when it comes to science, stick to what you know best: "Bueller... Bueller... Bueller..."

Good Math, Bad Math : Why did Set Theory start with transfinite numbers?

2007-11-12T03:59:00.000-08:00

Interesting, although somewhat misstated commentary on Set Theory (from ScienceBlogs)

link

Time to overhaul Newton's theory of gravitation?

2007-10-31T06:47:00.000-07:00

Galaxy cluster models cast doubt on dark matter

more on the MOND/MOG vs Dark Matter fish slapping dance
(from physorg.com)

"My God, it's full of blogs"

2007-10-29T17:48:00.000-07:00

This blog is unprovable under PM

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