Quantum Bayesian Networks

November 18, 2014

Houston, Tranquility Base here, the Dragonfly has landed

Filed under: Uncategorized — rrtucci @ 9:18 pm
Houston, Tranquility Base here, the Dragonfly has landed. (image based on NASA photo from here)

Houston, Tranquility Base here, the Dragonfly has landed.
(image based on NASA photo from here)

Pacific Spiketail Dragonfly (Photo from here

Pacific Spiketail Dragonfly (Photo from here)

The new Artiste logo reminds me of a dragonfly. Like many people, I’ve been fascinated by dragonflies since I was a child. Here are some interesting facts about dragonflies (taken from references at the end of this blog post):

Dragonflies and damselflies are often called the “jewels of the pond”.

Damselflies rest with their wings closed like butterflies. Dragonflies, on the other hand, keep each wing pair at opposite sides of their thorax when at rest.

Dragonflies are among the fastest flying insects. (which, however, is not that fast). In general, large dragonflies like the hawkers have a maximum speed of 10–15 meters/sec (22–34 mph) with average cruising speed of about 4.5 meters/sec (10 mph).

Dragonflies can fly in all 6 directions: front, right, left, up, down and backwards. They can fly upside down, and can change direction quickly. They can hover for as long as a minute.

Each of their 4 wings has a separate muscle and can be maneuvered independently.

They can eat and mate in midair without need to alight.

Food Chain
They have a voracious appetite, especially for mosquitoes. They will use a person or other mammal (e.g., horses or cows) as bait. They will hover right above their bait, and when the bait attracts a mosquito, they will pounce on it.

Besides mosquitoes, they eat other small insects like flies, bees, ants, wasps, and very rarely butterflies.

Though dragonflies are predators, they themselves are subject to being preyed upon by birds, lizards, frogs, spiders, fish, water bugs, and even other large dragonflies.

Life cycle
From egg to underwater gilled larva (called a naiad or nymph) to adult flying stage. Larval stage may last anywhere from 2 months to 5 years depending on species. Adult flying stage can last anywhere from a few weeks to 6 months depending on species.

Adult dragonflies do not normally bite or sting humans. They don’t have a stinger at the end of their tails; they use that to lay eggs. If you trap one in your hands without crushing it, it will try to bite you with its mouth, but it will fail to break your skin. Nymphs, however, are capable of delivering a painful but harmless bite.

Hunting Effectiveness
African lions capture prey about 25% of the time
Sharks about 50% of time
Dragonflies about 95% of time.

A dragonfly comes equipped with very sophisticated target acquisition and Kalman filtering capabilities. It is able to focus on a single target prey amid a cloud of similarly fluttering insects. It is able to make very subtle mid-course corrections to intersect that moving target.

They have a nearly full (4pi) field of vision. Each eye has about 30,000 facets. But they can’t hear at all and they can’t smell very well either.

Their order is Odonata, which means “toothed ones” — because of their noticeably serrated mandibles. Infraorder Anisoptera (from the Greek for “uneven wings”)

They first arose in the Carboniferous period, about 300 E6 years ago. For comparison, the Earth is 4.5 E9 years old, and the six animal classes are this old:

  1. Invertebrates- 600 E6 years
  2. Fishes – 510 E6 years
  3. Amphibians – 370 E6 years
  4. Reptiles – 315 E6 years
  5. Mammals – 200 E6 years but exploded 65 E6 years ago after great extinction
  6. Birds – 150 E6 years

Some dragonfly species migrate long distances each year, a still mysterious phenomenon not unlike the celebrated flight of the monarch butterfly. Recent studies have shown that green darner dragonflies migrate in sizable swarms each fall and spring between the northern United States and southern Mexico, while the globe skimmer dragonfly lives up to its name: it has been tracked crossing between India and Africa, a round trip, multigenerational pilgrimage that may exceed 10,000 miles.


November 9, 2014

Are Feynman Path Integrals Useful In Quantum Computing?

Filed under: Uncategorized — rrtucci @ 5:20 am

Contemporary High Energy physicists seldom formulate their new theories in the Schroedinger picture (or associated operator pictures like the Heisenberg or Interaction pictures). They prefer instead to formulate their theories in terms of Feynman path integrals because such integrals exhibit the symmetries of the theory more explicitly without having to worry about operator ordering. So an important question to ask is, are Feynman path integrals useful in Quantum Computing too? I would say, yes, absolutely. This is how I personally see it:

operator pictures ~ quantum circuits

Feynman path integral picture ~  quantum Bayesian networks

The analogy is not perfect, but it’s very close, in my opinion.

A related post is:
Quantum Circuits in the Dirac, Quayle and Bayes Conventions

November 8, 2014

I’m a Born-Again Group-Pest

Filed under: Uncategorized — rrtucci @ 9:23 am

Trying to learn Newtonian mechanics without a priori or concurrently learning Calculus is not a good idea, in my opinion. (I mean here Calculus taught in a non-rigorous, applied way; I don’t mean rigorous Mathematical Analysis). Indeed, non-rigorous Calculus is extremely helpful and insight-giving in doing Newtonian mechanics. It’s not surprising that both disciplines were invented concurrently by the same guy, Isaac Newton.

Analogously, I think that trying to learn Quantum Mechanics (QM) without a priori or concurrently learning Group theory (GT) is a terrible idea. (Again, I mean here GT taught in a non-rigorous, applied way). Non-rigorous GT is extremely helpful and insight-giving in doing QM. GT and QM were not invented concurrently by the same physicist, but they could easily have been. Mathematicians like Schur, Frobenius, Young, Galois, etc., had already developed GT to a high degree before QM came along, but there is no doubt that the invention of QM has spurred the invention of many new tools in GT.

As one can see from the Wikipedia “Timeline of Quantum Mechanics”, most of the fundamentals of QM were discovered during the miraculous decade 1920 to 1930. Note, for example, that in
1923 – Louis de Broglie extends wave–particle duality to particles,
1930 – Dirac’s textbook “Principles of Quantum Mechanics” was published

Note also that Hermann Weyl (1885-1955) came out with his book “The Theory of Groups and Quantum Mechanics” (available as a Dover edition) in 1930 and Eugene Wigner (1902-1995) with his book “Group Theory and its Application to the Quantum Mechanics of Atomic Spectra” in 1931. So already during the miraculous decade, and certainly long thereafter, Weyl and Wigner were common household “group-pests” who never lost a chance to point out to anyone within earshot how closely related QM and GT are.

As you can see, the observation that a knowledge of GT greatly helps one to understand QM is an observation that is almost as old as QM itself, and this observation has been widely publicized by some of the patron saints of QM.

I learned QM from some books that I think are very good (for example, the 2 volume set by Cohen-Tannoudji, Diu and Laloe), but, unfortunately, those books don’t use GT explicitly. Then I learned a bit of GT from some books that I think are pretty lousy. Either because of the shortcomings of my first GT books or due to my own shortcomings, or both, it took me a long time to feel comfortable with GT. The tide first started to turn for me when I read the two volume set by Elliot and Dawber entitled “Symmetries in Physics”, two books which I find truly wonderful and excellent. Using the Dawber and Elliot books as my “base camp”, I was able to explore GT further and read other more recent and specialized GT texts. You might prefer different books than I do. The field of GT is so vast, I think no single book or author can cover everything in detail and satisfy the topic selection and stylistic tastes of everyone.

Nowadays, I feel much more comfortable with GT, and I feel compelled to analyze in GT language everything that I do in QM, and I mean everything, be that physical chemistry, AMO (atomic-molecular-optical) physics, condensed matter physics, nuclear physics, particle physics, or relativity. It’s amazing how widely applicable GT is in physics.

Of course, finding applications of GT to quantum computation and quantum Bayesian networks is high in my agenda. My latest patent, number 12 in this list, is about GT. Two previous blog posts of mine on GT are

November 4, 2014

Self-Reparing Androids And Quantum Computers

Filed under: Uncategorized — rrtucci @ 6:33 pm

Henning Dekant (author of the WaveWatching blog) and I (and some others) are in the process of refurbishing the old Artiste company, a quantum computing software company. Henning and I decided we would keep the old website (http://www.ar-tiste.com) intact, plus start a new Artiste website (http://www.artiste-qb.net). The old website is “Artiste classic” with antiquated HTML technology and the new one is “Artiste modern” (or art deco, or futuristic).

I’ve always thought of Artiste as a company that combines Science and Art, the way Leonardo DaVinci was fond of doing. That is partly why I chose Artiste for the name of the company. Recently, I started using at the old Artiste website a logo of Leonardo DaVinci’s Vitruvian man (a nice picture of a cadaver doing jumping jacks) circumscribed by an italic letter “a“.

Henning came up with the brilliant idea of using for the modern website the same logo as the one in the classic website, but with the “Vitruvian man” replaced by a “Vitruvian robot”. Not only that. In a fit of brilliant artiste inspiration, Henning added a special effect to his Vitruvian robot that I find totally awesome. He modified some JavaScript code that he got from here and a picture of the robot “Maria” from Fritz Lang’s 1927 movie Metropolis. (Italian and German children seem to have different icons). The final result is a Vitruvian robot that when touched by the cursor, it explodes at the point of contact, but then the explosion is time reversed and the robot self-repairs and heals itself, like the Terminator robots. I find Henning’s masterpiece mesmerizing. It reminds me of alien technology, like quantum computing software. Check it out.


The animation is located at the old Artiste website rather than directly in this blog post, because one can’t put Javascript in a wordpress.com blog. Henning informs me that his animation doesn’t work on browsers that are behind the times in implementing the DOM API (this is especially true of Internet Explorer.).

October 3, 2014

First Ever Photo of Majorana Fugitive

Filed under: Uncategorized — rrtucci @ 4:55 am

The Majorana Fermion (alias The Major) has been sought by police authorities for more than 75 years; in fact, since 1937, when his daddy, Ettore Majorana, first reveal his existence to the world. And now, finally, that elusive fugitive has been captured, and put into a bound state, or prison cell. Detectives were able to lure him into an iron wire, and then cornered him at the end of that wire. It is believed that in such a bound state, The Major will lose his anti-social fermion behavior and start behaving more gregariously, like an anyon. Here is a mugshot of The Major, while in his prison cell:
This rainbow-colored picture is meant to convey, respectfully, the fact that The Major is LGBT (he is neither a fermion nor a boson, but something gay in between). Leon Lederman calls him The Gay Particle.

For a police report describing the events that led to The Major’s capture, see


And here is a Wikipedia profile of this most wanted fugitive:


So what will come next? A quantum computer composed of millions of gay particles? The conservatives are horrified at this prospect, and have vowed to do everything in their power to oppose the building of such an abomination, a gay quantum computer, something which is explicitly forbidden by the Bible.


October 1, 2014

Monty Hall Problem, as discussed by a 5 year old Illuminati

Filed under: Uncategorized — rrtucci @ 9:52 pm

A friend just sent me a link to the following NYT article:

The Odds, Continually Updated by Flim D. Flam (would I lie to you?) Sept. 29, 2014, New York Times

Even though the article doesn’t mention the obvious fact that quantum computers will someday soon revolutionize the Bayesian field (because they will be able to do Bayesian calculations much faster than classical computers), it’s not such a hopelessly outdated, clueless piece of reporting. Really. The article doth sing the praises of Bayesian techniques, so it ain’t that utterly bad.

The article makes a big deal about the Monty Hall problem. It’s a cute problem, for a five years old. Correction: A five year old that has been taught Bayesian networks. We B net advocates teach our children Monty Hall on day one, of pre-kindergarten. It’s quite conceivable that an intelligent 50 year old kid who has been taught only the frequentist canon might spend hours on such a problem, and ultimately give up.

Here is how a 5 year old illuminati who is conversant with the language of B nets would discuss such a piddling problem:

Let \theta({\cal S}) stand for the “truth function”. It equals 1 if statement {\cal S} is true and 0 otherwise. For example, \theta(a=b)=\delta_a^b is the Kronecker delta function.

The Monty Hall problem can be modelled by the B net shown, where

c= the door behind which the car actually is.
y= the door opened by you (the contestant), on your first selection.
m= the door opened by Monty (game host)

If we label the doors 1,2,3, then m,c,y\in \{1,2,3\} and



P(m|c,y)=\frac{1}{2}\theta(m\neq c)\theta(y=c)\;\;\;+\;\;\;\theta(m\neq y,c)\theta(y\neq c)

It’s easy to show that the above node probabilities imply that



So you are twice as likely to win if you switch your final selection to be the door which is neither your first choice nor Monty’s choice.

September 21, 2014

Martinis’ Dog Ain’t Barking, He Ain’t Spilling the Beans

Filed under: Uncategorized — rrtucci @ 2:42 pm

The recent (Sept. 2) news about plans for a Martinis/Google quantum computer has left me thoroughly perplexed. And I’m not the only one, as evinced by comments in Scott’s and Henning’s blogs.

So I thought I’d get some inside information by approaching the mascot of Martinis’ group, a perky Pomeranian called Qubit. I sent Qubit the following email, via his master, John Martinis.

From: "Robert R. Tucci"
To: "John Martinis"
Subject: question for pooch Qubit
Date: Fri, 19 Sep 2014 14:45:28 -0700

Dear Prof. Martinis, I'm crazy about dogs and I would like to interview Qubit.
Could you please ask him:

Will Master Martinis work in the next 5 years on BOTH, his old gate model machine and the Google annealer with surface-code error correction, or will Master stop work on the gate model machine?
One bark if only one machine, two barks if two machines.

No reply so far.

He could have won a fine piece of chicken or a package of MilkBones or a new ball to fetch, by granting this interview. But the darn dog ain’t budging. He ain’t barking. He ain’t spilling the bean chow. He has chosen to remain true and loyal to his Master.

September 13, 2014

Academic Peer Review

Filed under: Uncategorized — rrtucci @ 2:11 pm

This is a gif snapshot taken from the link


I think of this blog as a sort of scrapbook of mine, and I wanted to save a copy of this in my scrapbook. Notice my comment at the end. It was put in before any of the sciters had added their scite, so they all saw it. Others may add their scite to this list in the future. It’s possible to remove a scite after adding it. peer-review
Theodore J. Yoder, Guang Hao Low, Isaac L. Chuang, Andrew Childs, Aram Harrow, Dave Bacon, Māris Ozols, Stephen Jordan, unethical, plagiarism, plagiarist, stealing, cheating, dishonest, quantum computing

September 5, 2014

The Winds of War

Filed under: Uncategorized — rrtucci @ 3:29 pm

As we speak, the Millennium Falcon is being refurbished, in preparation to do battle with the mighty Google. We shall fight them in Quantum Computer Software Space. We shall fight them in the streets. We shall fight them in the hills. We shall never surrender!

Excerpt from Winston Churchill’s speech to House of Commons, June 4, 1940:

“We shall not flag or fail. We shall go on to the end. We shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air. We shall defend our island, whatever the cost may be. We shall fight on the beaches, we shall fight on the landing-grounds, we shall fight in the fields and in the streets, we shall fight in the hills. We shall never surrender!”

More Churchill quotations

August 31, 2014

Looking For Co-founder For Quantum Computer Software Company

Filed under: Uncategorized — rrtucci @ 1:50 am

Okay, as I mentioned in a previous blog post, I’m trying to start a QC software company, incorporated, with all the legal trappings. I posted a proposal on AngelList, but my proposal still needs a lot of work. I’ve got to start filling the gaps in it, pronto. One glaring gap is that I don’t have a co-founder. The accepted wisdom is that startups that have more than one founder are much more likely to succeed, because multiple founders can complement each others strengths, give each other moral support, and one founder can take over the helm when another is indisposed.

Desiderata: In my case, I don’t have any startup experience so I would like a co-founder who has at least one successful startup (in the USA) under his belt (or maybe a whole string of unsuccessful ones which have taught him OR HER what not to do.) I would also like the co-founder to have at least an undergraduate degree in science or engineering or programming. The applicant must also read this blog regularly. Well okay. Maybe that would narrow the field too much. At least you are probably reading this particular blog post, the one that really counts.

Please email me at “tucci*AATT*ar-tiste.com” telling me a little bit about yourself if you are interested and you meet the above desiderata. I may email you back with some follow-up questions.

If you are a person coming directly from Academia, with no startup experience, it’s unlikely that I will choose you as a co-founder, but if you have a close friend that does meet the above desiderata, please encourage him or her to email me (and then he/her can hire you as one of the first employees?)

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