Snowden: Internet encryption useless against eyes in NSA, GCHQ

Both HTTPS, SSL, and VoIP only good against little fish

Edward Snowden has provided The New York Times and The Guardian and others with some eye-catching revelations:

N.S.A. Able to Foil Basic Safeguards of Privacy on Web (NYT)

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NSA and GCHQ unlock privacy and security on the internet (Guardian)

The two U.S. and U.K. intelligence agencies "are investing in groundbreaking cryptanalytic capabilities to defeat adversarial cryptography and exploit internet traffic" according to Director of National Intelligence who was quoted in the latest Snowden document about the $52 billion black budget. See also skeptical, technically sophisticated remarks by Wired. HTTPS, SSL, and VoIP are no longer safe; the correctly implemented strong encryption seems fine.



Of course, I got a bit excited: Have the agents finally built operational quantum computers? Have they made some progress that proves that \(P=NP\), after all?




Well, not really. Already the subtitle of the article in The Guardian makes it clear that the weapons that the agencies use aren't some groundbreaking advances in quantum computation or classical algorithms. Instead, they abuse the weaknesses of the human factor. Some big progress occurred in 2010, we're told.




So it seems that $250 million is spent every year to "encourage" the tech companies to insert weaknesses (backdoors and trapdoors) into their products. I suppose that to decrypt a message using state-of-the-art encryption programs, you either need to input a very long nonsensical sequence of characters that changes every day or you have to type "My name is Bond, James Bond". ;-) This sounds like a joke but it may be very close to the truth, too. NSA influences international agreements about encryption standards. Lots of supercomputers are running to break the codes by brute force but this hard work would be useless if the agencies didn't have secret agreements with folks in the tech companies.

Analysts aren't allowed to ask or speculate about the sources of the data or methods used to make the data readable. Having watched many superagent movies and having seen that I couldn't complete, I won't ask or speculate, either. NSA claims that without this control, the U.S. couldn't allow the access to the cyberspace to remain unrestricted. This claim surely sounds tough but it may have a point, too. A GCHQ team works with the "big four": Google, Facebook, Hotmail, Yahoo.

Well, as long as I feel that those agencies don't use their behind-the-scenes powerful tactics to harm free individuals for something that should always remain legal, I find the reports above just a little bit chilling. On the other hand, every capability or influence may be abused and what we're hearing seem to be extraordinary powers, indeed. It still sounds a bit more plausible when these powers belong to institutions whose composition may be refreshed according to the desires of the American (and British) voters.



Does this serious Gentleman have his own capabilities, too?

The British GCHQ seems to be among the "top two". That couldn't stop Dmitry Peskov, a Putin spokesman, from overlooking Northern Ireland and calling the United Kingdom "just a small island no one listens to" that plays no major role in the world politics and whose Chelsea and other upmarket London districts is being bought by Russian oligarchs. Cameron et al. claim that they believe that the U.K. continues to be a superpower. It's up to you to decide whose perspective is more ludicrous. ;-)

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Thiel-Kasparov debates

If you have 52 minutes, you may want to watch this video full of intelligent enough debates between the renowned chess player Garry Kasparov (a chronic world ex-champion and a sort of a political activist in Russia) and the renowned venture capitalist Peter Thiel (the founder of PayPal, the first major Facebook investor, a libertarian, and the supporter of world-changing projects, especially by college dropouts):



Video posted via Kasparov's YouTube channel

The topics include Google and its vision for the world, the replacement of humans by machines, the bad consequences of any looming nuclear war, politics in Russia, simultaneous chess games (in which Kasparov hasn't lost since 2001; Thiel is a very good player as well, he was surely strong enough in Nice a few years ago to beat your humble correspondent pretty much "reliably" back in Nice – but my chess scalp is surely not a source of pride for anyone who actually plays the game regularly).




They should have co-authored a book, The Blueprint, but the project has apparently been canceled. Maybe it was just delayed and renamed to The World of Fake Values where they argue that despite the widespread opinions, the world is switching to a slow development of technologies (Kasparov's words around 4:00 sound like an anti-singularity theme...). But maybe the comments about that other books are also obsolete and the book under this title was cancelled, too.




I am interested in your reactions to their ideas. This blog entry was later updated and extended.

At the beginning, Kasparov praises Thiel's intelligence and the breadth of his interests. I must confirm that. He was listening and meaningfully commenting on my remarks about particle physics and e.g. the discoveries that the LHC was or wasn't going to make back in 2010. And that was just a minor interest relatively to biology and evolution (or the lack of it) that he knows a great deal about – partly because he used to study it somewhere, or something like that. He also followed the climate debate (Richard Lindzen was the main speaker about this topic).

Around 3:30, Thiel betrays that it's really a program for Germans and he was born in Germany – he speaks German for a while. (Update: At the end, I learned that it was aired on ZDF, the Second German Public TV Channel, in 2010.)

At 5:00 or so, Kasparov says he had visited Google some weeks ago. It was about Deep Blue and computerized chess. Kasparov thinks that brute force "solved" the problem of computers playing chess well. Well, it's not a fully solved game, I would add, but the computers got better than the humans.

The discussion switches to the question whether machines or machine-human combinations are better and why. Thiel says that the Google ideology says that the computers will replace humans in 20 years. Technology advocates don't like to speak about the failures of technology, Thiel adds. To question a technology has become the greatest heresy, he thinks.

The next topic around 9:00 is whether politicians are smarter people, what they want to spend the money on, and whether Obama is a socialist. In an elevator, near 9:30, we learn that Kasparov isn't optimistic about too many things. Perhaps about the ability to convince the people to look for new ideas. Robots (and ancient ones; and some robots with GPS and cameras) showed by a guy. Another robot chap says that robot got faster and they're asked about the dates when robots will do certain things.

At 12:40, a 2010 Oslo talk by Thiel is shown, saying that technology may be used both for freedom and against it. We shouldn't be utopian about technology. Instead, it's important for us to use it, use it as the first ones, and use it now. At 13:10, Kasparov laughs as he describes the Internet just as a by-product of some work at CERN. Kasparov argues that except for speeds, iPads etc. can't do anything that PCs couldn't do 25 years ago. ;-) It sounds a bit exaggerated to me but I surely agree that the science-fiction novels written half a century ago were more optimistic about the speed of the robotic progress than the present reality. 40 years after Nixon's great words, we still don't have a cure for cancer. We're 40 years closer to the solution, however. ;-) Thiel adds that no one believes that the cure will come in 5 years. (I am actually ambivalent.)

15:50 – some fancy cars I've been in, too. ;-) 16:40 – chess was a good benchmark to measure the computers' progress because it has wisdom. Well, I surely disagree with that proposition. Chess has always been clearly just a particular game that is being won by brute force and the progress in the algorithms etc. was pretty much guaranteed to be just a gradual evolution, not a result of revolutions. There are other, deeper tasks that do require qualitative breakthroughs to be mastered by machines. BTW we're told that over a million of games a day is played via the Internet. At 18:00, they visit a chess club. A minute later, Kasparov doesn't want to play Thiel – it sounds like he doesn't want to crush Thiel but I am not sure whether he realizes that Thiel wouldn't necessarily be hopeless. ;-) Finally, Thiel plays a speedy game against the chess club manager. Thiel (white) doesn't accept draw at some moment. However, it seems he loses at the end and Kasparov is telling him what he should have played differently. Maurice Ashley, a British chess grandmaster, appears.

In the car, 25:40, Thiel says that when he's facing stronger players, he feels that the doom is coming gradually. Kasparov is skeptical and suggests that it depends on the strength of the opponent ;-) (he clearly wants to say that if Thiel played against Kasparov, Kasparov would destroy him rapidly, after a single move that turns out bad). Kasparov mentions his insane record in the simultaneous exhibitions (20-30 opponents at the same moment): no loss since 2001. Kasparov modestly tells us that he just has the stamina to walk around, keep pressure, and the 20-30 enemies just collapse. ;-)

At 28:00, they enter the Empire State Building. It sounds like I have been to the top more often than Thiel. :-) Kasparov boasts he knows the date of the construction. Thiel says that the inability to build a new World Trade Center for 9 years is a bigger failure than 9/11; this suggests that the video is from 2010, at least this part of it. Kasparov talks about some craziness in Russian politics. Kasparov said that the opposition wasn't important, the internal fights under the surface are more important, and young people massively want to flee Russia. Anywhere. Older folks are upset. A general degradation of the country follows.

They visit a human rights activist (in the Human Rights Foundation). He says things are getting worse. That's why they exist etc. Kasparov says that the West doesn't want to interfere, another problem. Thiel mentions a correlation between human rights and the economics (I mostly agree – after all, the human rights are a luxury that the wealthier ones are more likely to afford) – and a country with some ten-to-fourty inflation. The host prepared about 10 different coffees for Kasparov, all kinds – a repayment of the same debt. They discuss the immense inefficiency of the U.N. and lame excuses why it's inefficient (12 languages: but Marriott etc. can do these things profitably, anyway). Thiel says that in 20 years, the iconic status of the U.N. evaporated. The host partly disagrees – some people worship the U.N. – but he says that the U.N. isn't helpful. What should we do, the host asks? Shout loud, Kasparov suggests. Both famous guys propose technological progress as a solution to make the good guys and nations more influential. I am not sure it's this straightforward.

The host says that the human rights fight has become bureaucratized and therefore unappealing for the young; it is mostly a business for old folks in suits who talk in the U.N. The foundation wants to change it. They want to bring in Thiel and his technology and Kasparov and his brain that defeated the IBM computer – and the host believes that he did. ;-) Thiel is frustrated mostly by places that are screwed for a very long time. The host says that we're "racists of low expectations" who think that Haiti won't achieve much which is why we're not holding them accountable. Nice but your humble correspondent of course adds that it's the rational attitude because the expectations aren't just pulled from the air. They are built on lots of hard data that probably won't go away and it would be foolish to think that they may be ignored and the countries may be suddenly totally different than they are. The host says that every country may switch from liberal democracy to dictatorship in a decade. Well, yes, but certain other key things – that also determine the potential to return to liberal democracy – won't really deteriorate this quickly. Kasparov says that democracy has become just a word that may cover terrible atrocities, too. It may but it is a valuable arrangement by itself, one that increases the nations' chances to be decent, too. The host gives the Russian skateboard to Kasparov and the Chinese (?) skateboard to Thiel. Kasparov asks why Thiel received the Chinese ones, the answer is incoherent, but Thiel doesn't get offended easily. ;-)

41:30 – skateboards loaded to the cars. How will it end, Thiel asks? Growth etc. is the only optimistic scenario. For Kasparov, Martians' landing is more likely. Huh? Various degrees of recession and depression are discussed along with the world war (I was never into these doomsday scenarios much). Another bad outcome is a move to the left: governments confiscate the wealth everywhere. If the money doesn't have any value, the system doesn't work. I think these are sort of weird conspiracy theories. Money had an important value even in the communist world. You just can't suppress such basic parts of the human nature and the life of societies.

44:20 – dinner. Peter: a moment for classical liberalism to return. (Klaus is perhaps returning to top Czech politics, as a savior.) Kasparov talks about Buffett who predicts America's fall (China is next). Thiel points out that Buffett is all about avoiding the technology completely. Even on Mars, people will eat candy bars. ;-) Regardless of China, Thiel feels that you can only do decent things in the U.S. Kasparov says that Obama et al. don't care about technologies. Obama is just the community organizer, not a leader. Thiel says that they're not focusing on important things. Kasparov says that they can't even identify them. Thiel idealistically says that technology is "doing more with less" (austerity is "less with less", printing is "more with more"). Food arrives. Worries about propagation of nuclear weapons. Thiel thinks that the risk is underestimated. Kasparov points out that nations value life differently. Dictatorships are powerful because of fossil fuels etc., if the dependence on them is reduced, things get better. Well, I think that he contradicts his previous comments. A reduced dependence on fossil fuels will make the fossil-fuel-producing countries poorer and therefore even more screwed. Thiel asks what makes Kasparov continue while being pessimistic about most day-to-day issues. Kasparov is a born optimist, we hear. There will be too many questions and a few people who will give answers.

End of dinner, good bye, it was fun.

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Discussion about old and new theoretical physics forums

I am not taking any positions about these matters – and about the Stack Exchange forums, their contents, and their moderators, among related topics – but this blog entry was written with the only purpose: to allow the exchange of information and opinions between users who are interested in the debate about the sufficiency of the existing forums and about the possibilities to create and sustain new ones (and about their desirability and role).




However, I must assure everyone that it is not easy to create and maintain a discussion forum and to guarantee the appropriate amount of quality traffic, especially if the forum is supposed to be focused on a narrower class of topics than the Physics Stack Exchange – and "purely theoretical" physics questions represent a small subset, indeed.




Years ago, we established a USENET group, sci.physics.strings, that was supposed to be dedicated to string theory and other topics in particle and theoretical physics that aren't beloved by the armchair physicists who dominated in a related and larger USENET group, sci.physics.research.

It was moderately hard to go through the bureaucracy and technical arrangements needed to create a new USENET group. We (with Arvind Rajaraman, Urs Schreiber, and perhaps others) won the existential vote. Hundreds of quality contributions and threads (400+ threads?) were posted but it needed lots of work. The traffic tends to be low especially because serious researchers don't have the free time and desire – or they think that they don't have the time and desire – to discuss on the Internet.

I think that at the end, the USENET group was closed for some technical reasons. Some scripts became dysfunctional on an updated Linux or something like that. I forgot what was that exactly. USENET was arguably an outdated technological framework for any discussions from the beginning of sci.physics.strings, anyway. Those are the reasons why I attribute some credit to the "owners" or "managers" of similar forums and assume that this service they're doing for the world gives them some natural rights, too.

The debaters below are encouraged to maintain some professional tone, especially if they're discussing about the people (and their work) who can't defend themselves here.

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New iPhone likely to have a fingerprint scanner

One year ago, Apple bought AuthenTec, a Prague-based security company (7 Husinecká Street), for $356 million. One may now check the Czech commercial register shows two key people from Cupertino, California, aside from a Czech male and Czech female name that started the company with the basic registered capital of $10,000 (too late for great investments). ;-)



Yesterday, the Czech technological media reported that the iOS7 beta4 code contains a BiometricKitUI.axbundle folder along with some sentences suggesting that the fingerprint scanner will read your thumb when it touches the home button.




The Apple Insider (plus others) quickly added some extra comments about the new technological approach to the fingerprint reading that this Apple/AuthenTec team chose. As you may imagine, the fingerprint must be sufficiently tolerant so that it doesn't reject the actual owner when his or her fingerprint changes a bit for whatever temporary or other reasons. On the other hand, it shouldn't be too tolerant which would make the security non-existent.

There's a special concern here as well – criminals may acquire a copy of your fingerprint. The authentication in general depends on what you have, not necessarily what you are. If they have the information about your skin (they don't even need to cut your thumb for that), they could fake you even though their fake thumb isn't live and connected to your body. ;-)




The Apple Insider suggest that while the usual approaches were building on simple optical or thermal quantities, the new approach uses a combination of capacitance- and radio-frequency-based data to read the fingerprints – not just what you see on the very surface which contains some dead cells but what is actually hiding in the layer of live skin underneath the surface.



Some sources argue that a problem of coating interfering with the sensor will inevitably cause delays. Incidentally, it is also expected – because of plastic "iPhone 5C" boxes spotted in China – that Apple is going to offer a cheaper/colorful version of the newest iPhone 5S, too.

Quite generally, I would guess that there's a huge potential for various security devices that may be produced cheaply and that may be rather effective these days. For example, I think that I could design a system for a few dozens of dollars that detects someone who breaks into your house or apartment or car and quickly notifies the most appropriate person or office. Similar for a stolen smartphone or stolen laptop and so on.

Some people are bound to earn many more billions while the not-so-illegal consumers are likely to benefit.

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Amazon: 3D printers below $1,200

When Howard Wolowitz bought a 3D printer to print figures of himself, Rajesh Koothrappali, Bernadette Rostenkowski-Wolowitz, and other heroes of The Big Bang Theory, he had to be chastised by Bernadette because it was her money and it was $5,000 of them.

(Incidentally, I made some research of the 1200 XT 3D modeler PRO device that appeared in the CBS sitcom and I am pretty confident that it's a renamed 3D Systems InVision XT 3D Printer.)

But an ex-president of the Harvard Funds and the famous Pirate of Prague, Viktor Kožený, a technological enthusiast who has just gotten access to $22 million of dollars from his (mother's) cottage in Aspen, Colorado but who became a target of a new execution in Czechia at the same moment (he once offered me to become a shadow minister of education which I kindly refused), recommended me to check the rather new 3D Printers Category at amazon.com and I was kind of impressed how accessible those things have become.




The FlashForge 3D printer is available for $1,199. This price can't be approximated by infinity too well. It's an accessible price, I would say. And the reviews look really encouraging, averaging at 4.7/5.0 stars.




The Afinia printer for $1,599 is often claimed to be used by professionals who say that it works perfectly - and it's a professional quality printer. Top software included. Alternatively, you may check some free software right now.



Afinia 3D printer is printing a Klein bottle, a closed non-orientable manifold with Euler characteristic \(\chi=0\). Sped up to 1 minute. See a 3-minute presentation of a bigger 3D printer.

Does any TRF reader have real-world experience with 3D printing? If you do, what have you used the gadget for? If you don't, what are your dreams what you could print if you had one? Has someone studied the details of the technology, how it actually works?

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Novim Group: "Just Science" AGW app

Paul O. helped me to possess an iPod Touch, because of my modest contributions to his Our Climate app. I have downloaded about 500 applications on the device and the new addition today is called Just Science. This free app occupies about 50 megabytes on your iDevice.



It was created by the Novim Group led by Michael Ditmore at UC Santa Barbara; the Berkeley Earth Surface Temperature team led by Richard Muller belongs to the group.

The application does one thing only – it shows you a map of the globe with animated colorful maps showing how the temperature was changing between 1800 or so and today in various regions around stations that reported and on a monthly basis.




So it's really a mundane visualization of a single well-known public dataset. If you listen to this interview with Michael Ditmore, you will learn about a $40,000 award for the "best science app" from an unknown foundation.

You will probably agree that $40,000 is a somewhat excessive amount of money for having written a code that would take one line in Mathematica – an animated colorful map applied on a public dataset. You can zoom in or zoom out the globe, too. But that's probably not enough to justify the large amount, either.




However, the rest of the interview will inform you that the people who collaborated on this trivial, effectively one-line code have divided about one million of dollars among themselves. This is really painful. I can't understand how you could call these people "not corrupt" if they get paid $1 million for $100 of work. It doesn't matter whether they pretend to defend one side or the other side or the middle side; they're still corrupt. To say the least, you effective promise to scream that this work of yours is important (worth $1 million) even though it obviously isn't ($100), something that Mr Ditmore is clearly doing, and this confusion already contaminates the science and the scientific debate by lies.

The Novim Group seems to be linked to groups that promote geoengineering.

Needless to say, the app doesn't change anything whatsoever about the climate debate. You may see the graphs you have seen many times in a somewhat more localized, colorful form. I guess that you have seen similar visualizations, anyway. None of these animations answers anything about the cause of the temperature changes – which were mostly going in the positive direction but the imbalance is really compatible with (approximately pink) noise.

Moreover, these graphs not only fail to show the cause. They also fail to show the significance or, more appropriately, insignificance of the temperature changes since 1800. Whatever the temperature difference between two moments or two places is, you may visualize it in such a way that one temperature will be crimson and the other one will be light green or dark blue or anything else – two or three completely different colors. But this obscures the overall scale and the fact that we are talking about tenths of a degree of temperature change in two centuries – a temperature change most of us can't even detect when it takes place instantly or within a second.

Now divide, dilute, and slow down this temperature change from 1 second to 200 years, add it superimpose it with the constantly changing weather (where the outside temperature routinely jumps by ten degrees within a day) and try to answer the question whether this temperature change and its rate – whatever their cause is – is something that a rational person should become scared of or obsessed about or something that a rational society should spend billions or trillions for.

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PhysX PBF: breakthrough in simulation of water

A decade ago, the state-of-the-art computer simulation of moving water looked like the 0:20-0:40 segment of the Mafia I trailer. In the following years, the progress was relatively modest up to very recently.

PC games have become nearly photorealistic but flowing and splashing liquids are still hard. In some sense, one needs to simulate individual (enlarged) molecules and/or the Navier-Stokes equations – both tasks are difficult when it comes to the required computer power etc.



See also a lighthouse etc. and one more bunny bath.

The video above shows what the simulation of water looks like using the newest technologies. A single graphics card, GTX 580 which you may buy for $350, was used to produce the video in real time.




The video uses NVIDIA's Position Based Fluids: introduction, technical paper, pretty much the same approach that was used to simulate moving clothes and other things. See some examples how Mafia II exploited PhysX (2010).




The simulation with the bunny etc. looks almost perfect and some clever and efficient simulation of legitimate physics – especially a better iterative solver to maintain incompressibility – is responsible for this progress. Some additions are sort of cheating from a physics viewpoint, however. The tension-like filaments don't quite appear because of the right formulae for surface tension; they arise because of a new artificial pressure term that looks good but doesn't seem to be given by the right physics formulae.

Vorticity confinement is a new theme that allows to conserve the energy – which you may pump back to the system.

At any rate, because the water simulation looks almost perfectly realistic and water is among the most difficult things to simulate, we may say that we're pretty much entering the era in which your PC at home has all the required power and cleverness to produce videos of reality that may be indistinguishable from the real reality...

See Google News.



Incidentally, the gas explosion in Prague made it to the #1 event on Google News at some moment. (The explosion was caused either by gas or by Sarah Palin. ;-)) It seems excessive because nothing excessively serious has happened, after all. I should have debated some folks in the National Theater last Thursday but I said no at the end, partly because of preparations to a string/LHC mixed talk (2 hours including many questions) I was giving today in Pilsen. Note that the National Theater has burned twice – in the 19th century – and the Czechs always collected new funds to rebuild it. ;-)

The video above is somewhat more realistic and less sorrow because life didn't stop; this one or this one almost reminds me of my visits to Manhattan shortly after 9/11. You may imagine that I know the place extremely well – I am going around the National Theater almost every time when I visit Prague. There's also the Academy of Sciences where I was doing an exam with Prof Niederle as an undergrad and many other familiar buildings whose windows were broken today. ;-)

I suppose that when everyone can smell gas in the street, it's better to run away – and maybe some employees should try to stop the leak and/or extract the gas from the building in some way. I am no expert. It's not even clear to me whether someone breached his duties in any way – whether the existing regulations are supposed to prevent such events.

Prague is significantly richer than Pilsen but I feel that even the supposedly luxurious neighborhood of the National Theater is still sort of dirty relatively to Pilsen. Is it just me?

BTW Czech president Zeman offered one of his classic witticisms in Austria today. He said he's ready to terminate the expansion of our Temelín nuclear power plant – if Austria rents their Zwentendorf nuclear power plan (that was stopped by a modest 50.5% majority in a late 1970s referendum) – but cheaply. By this joke – which wouldn't necessarily have to be a joke if Austrians were a little bit more pragmatic! – Zeman joined the Start Zwentendorf NGO, a brotherly organization of the Austrian Stop Temelín NGO. ;-)

Maybe I shouldn't promote Temelín and its safety a few paragraphs after comments about a gas explosion in Prague? ;-) But I am really not afraid...

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Democritus on the QM operating system

Comments on some extra chapters were added at the end

This reading report will be much more favorable than the previous one, one on minds and machines.

Chapters 5, 6, 7 etc. are dedicated to the classes of problems that may be solved in a reasonable time. They are full of arguments showing that if one type of a problem may be solved [at all AND/OR with some limitations on time AND/OR with some limitations on memory AND/OR with some probability of success AND/OR with some secret hints etc.], then another type of a problem may be solved at all.

This leaves a network of classes of algorithmic problems that are not known to coincide. This network is a result of simplifications resulting from some known proofs – proofs demonstrating the equivalence of some classes etc. – which have been taken into account. There's a lot of mathematical arguments that I have only partially verified but it seems clear that they have no good reason to be wrong because the researchers doing them aren't stupid (they're rather rigorous mathematicians) and there aren't any real subtleties that would require some "special kinds of intelligence" behind conventional math skills and rigor.

As an introduction to complexity, it's a wonderful resource. But I don't plan to memorize all the things that are known about the classes and particular problems and algorithms; instead, I know a good source where some basic things may be found if needed. ;-)




The last pre-quantum chapter is dedicated to cryptography. You learn about various simple and hard codes; functions that are easy to compute but hard to invert; various proofs that various coding systems may be cracked in one way or another, with or without some extra information, with or without a quantum computer.




One of the holy grails of the chapter is the explanation of the RSA algorithm. You want to send some information – e.g. your credit card number – somewhere – e.g. to amazon.com (by the way, the company just decided to build its 1st-2nd largest European logistical center in Czechia, not Poland; the other one is in Germany) so that no one except for amazon.com may decode it. How is it done? Amazon.com picks random large prime integers \(p,q\) which may be done quickly and computes \(N=pq\). It sends just \(N\) to you. You don't know \(p,q\) yourself. Your computer computes \(x^3\mod N\) where \(x\leq N-1\) is an integer representing your secret message (or credit card number).

It's probably impossible to efficiently revert this exponentiation i.e. to compute the cubic root modulo \(N\) directly. It's also impossible to quickly enough find factors \(p,q\) of the composite number \(N\). It's probably impossible to compute \(x\) out of \(N\) and \(x^3\mod N\) even indirectly – such a task probably can't be done without the impossible tasks in the previous two sentences. However, amazon.com knows \(p,q\) as well and with this extra knowledge, it may calculate \(x\). For technical reasons, \(p-1\) and \(q-1\) shouldn't be multiples of three. Safe. Probably. Only you and amazon.com can know \(x\): you know it because you used it to calculate \(x^3\mod N\); amazon.com knows it because it's the only server that knows \(p,q\) which is probably needed to compute the cubic root.

There is a lot of stuff of this kind in the book and if you're interested in cryptography, the book is recommended to you. However, I want to say a few words about

The quantum mechanics operating system

There are lots of the "discrete bias" in the book; I will mention it again below. But I was impressed by Scott Aaronson's first approach to quantum mechanics because it largely agrees with mine – and some detailed uniqueness claims and arguments supporting them are almost exactly equivalent to my text arguing that quantum mechanics can't be any different.

So Aaronson says that the conventional undergraduate approach to teaching of quantum mechanics deals with lots of technicalities like differential equations and ends up viewing the new conceptual framework as an ultimate mystery. He takes a different approach – quantum mechanics is presented as a new generalization of the probability theory.

It is correctly said that there are just three frameworks that are worth considering: classical deterministic systems; classical probabilistic systems; and quantum mechanics. Arguments are given why quantum mechanics has to be based on squaring the (absolute values of the) amplitudes; why the complex numbers are the only right, "Goldilocks", number system for quantum mechanics (their being algebraically closed is also mentioned, much like the natural counting linked to the fact that complex representations of groups are the default ones); why operators have to be linear, and so on.

Some of the arguments are literally the same as mine. For example, the reason why the probabilities are given by the second power is explained by the fact that only for the exponents \(p=1\) and \(p=2\), one may find some unitary-like transformations of the probability amplitude vectors that preserve the norm and that are nontrivial i.e. more complicated than permutations with sign flips.

The unitary matrices are cleverly presented as the quantum answer to the stochastic matrices in classical physics. There isn't any other comparably interesting and nontrivial class of matrices with similar properties which is a part of the reason why classical and quantum physics are the only two frameworks to deal with probabilities in physics.

Of course, this introductory quantum chapter also discusses the cloning no-go theorem, tensor products, entangled states, and similarly basic notions, along with the quantum teleportation and even quantum money and other less rudimentary concepts in applied quantum physics (including references to some papers by Aaronson himself).

I don't really believe that there will be a single person who doesn't know quantum mechanics in advance but who will learn it from the book – the introduction to quantum mechanics in this chapter is arguably too concise – but I do think that it could be helpful to reorganize the teaching of quantum mechanics along these lines.

At the beginning, the author also says that quantum mechanics (the general postulates etc.) is "somewhere in between maths and physics in the hierarchy of scientific disciplines that continue with chemistry and biology". It's more physical than just maths and the ordinary probability theory in maths; but it's less physical than particular physical theories. It's an operating system on which particular physical models run as applications. I couldn't agree more.

Aaronson's computer-science bias only begins to emerge – at least I hope so – when he discusses what the actual applications are. So he apparently believes that all the applications, including those defining the fundamental laws of physics, should be of discrete nature which ain't the case. The quantum mechanical operating system perfectly allows the observables with continuous spectra and some operators of this kind are always needed to define the physical laws for the adults.

His flawed perception that bits, and not nats, are physically natural units of information and entropy is also imprinted in at least one characteristic error. The book doesn't avoid mathematical formulae and they're largely accurate. However, he applies the prime number theorem incorrectly to compute how many prime numbers with at most \(N\) bits are there. What do you think the result asymptotically is, including the right prefactors of order one? ;-)

Such annoying prefactors have to occur everywhere simply because \(2\) is an unnatural base for exponentials and logarithms much like a bit (and qubit) is an unnatural unit of information and entropy. But I am learning how to sharply separate these misconceptions of folks like Aaronson from the "operating system"-level of knowledge (including the quantum one) that they apparently understand correctly.

Quantum computers

Chapter 10 finally jumps at the inevitable union of computation and quantum mechanics, quantum computation. My intro to quantum computation is here. Sadly, one of several promising quantum computers that exist on Earth, one inside a diamond, was eaten by an 80-year-old grandma yesterday.

The author marvels that only in the 1990s, people started to ask which problems may be feasibly solved by computers allowed by Nature's being quantum mechanical. I also find it amazing that this branch of computer science wasn't born earlier.

He talks about the Hadamard gate etc. (replacing the universal NAND gate of classical computers), reasons why quantum computers may do everything that classical (even classical probabilistic) computers can do, and so on.

There are interesting two sections at the end of the chapter in which Aaronson debunks the super-naive "quantum computer as exponentially parallel classical computer" meme and the related misconceptions promoted largely by David Deutsch that quantum computation "proves the many worlds interpretation". Scott doesn't say as much as I did e.g. in this criticism of the many worlds but he does say certain things, for example that MWI can't say what is the preferred basis into which the world "splits" (it also can't say when and how etc. and the very claim that it does irreversibly split is wrong because at least in principle, there's always a nonzero chance of "reinterference").

The related idea that the "quantum computation is a massively parallel classical computation" is flawed and this big blunder may be illuminated in many ways. First of all, it's not true that the streams in the "massively parallel set of classical calculations within a quantum computer" are independent. Quite on the contrary, the result announced by a quantum computer depends on interference i.e. "collaboration" between these streams or "different histories".

Moreover, the textbook example of a problem you may want to massively speed up – the search of something in a database – can't be exponentially sped up by a quantum computer. Instead, Grover's algorithm only provides us with a power-law speedup. In fact, it's been proved before the algorithm was found that a faster quantum algorithm than the power ultimately realized by Grover's algorithm can't exist! As always, any attempt to sell quantum mechanics as some "kind of a classical theory" (whether it's parallel or not, whether it has hidden variables or not, whatever are its preferred observables etc.) may ultimately be proven deeply misguided. Quantum mechanics isn't classical, stupid.

Aaronson also extends his collection of classes of problems waiting for algorithms with classes that allow some/complete solution using a quantum computer. He reinterprets Feynman's path integral as the proof that one class belongs to another. That's what Feynman got his Nobel prize for, we learn. It's an amusing attempt of a computer scientist to "devour physics" but at least historically, it's completely wrong because Feynman shared their Nobel prize for QED, an application of his computational methods (including the path integral), not for the path integral itself (although his Nobel lecture essentially was mostly about the path integral).

Moreover, Aaronson only presented one particular application of Feynman's path integrals. Any physically meaningful question about a quantum system may be answered using Feynman's path integral which makes it kind of silly to associate this method with some "very special problems".

Chapter 11 is about Penrose, namely his opinions that Gödel-theorems-based reasoning can show that artificial intelligence is impossible and the human brain has some super-remarkable abilities (apparently exceeding any omniscient quantum computer or God you may think of) that can't be simulated. I agree with 100% of what Aaronson says here (why Penrose's arguments are ultimately irrational, illogical, unstable, not solving the original "problems", and wrong) – and there's a lot he says.

Initially I thought that I would fully endorse every sentence of Chapter 12, one on decoherence and hidden variables. In the early passages, it says all the important right things. Decoherence is the right phenomenon that contains all the genuine processes people call "collapse" sometimes and its right description is the hopeless entanglement with the environment which converts quantum bits to effectively classical bits. It's irreversible and from some viewpoint, decoherence is just a new nearly equivalent way to describe the second law of thermodynamics. The reversal is as difficult as Pamela Anderson's attempts to regain privacy by targeting all the hard disks in the world that contain her photos – I liked this joke, indeed. ;-)

In the following sections about hidden variables, it lists most of the reasons why they're wrong – they only allow one to discuss measurements of particular observables (positions) but we need to predicts others and it's not possible to have classical "beable" states for all of them (Kochen-Specker theorem). Hidden-variables fundamentally violate relativity because they need superluminal communication to explain the correlations, whether or not it may be used in practice. Some important criticisms are omitted – like what happens with the insanely propagating, diluting pilot wave after the measurement or absorption of the particles etc.

However, the final "positive" sections on the hidden-variable theories have dramatically lowered my opinion about the chapter. He discusses "flow of oil", Schrödinger's, and Bohm's theories. Aaronson fails to notice that (and why) some of them are really equivalent to each other. He seems ignorant about the Bohmian and equivalent theories' history – it was started by Louis de Broglie in 1927. Most importantly, he suddenly seems to forget all the right criticisms he previously raised: violations of relativity; need for privileged observables and bases, etc. So at the end, I think that the chapter is a rather eclectic mixture of "mutually contradicting but not confronted" right and wrong statements that suggest that Scott hasn't thought about these matters too carefully (despite his having published papers on hidden variables). I was also irritated by the criticism against the Bohmian hidden variables (which are really equivalent to the "flow of oil" when looked at properly) for their infinite dimension of the Hilbert space. Every realistic theory of the "real world" has an infinite-dimensional Hilbert space; this is surely not something one could use as a criticism (although the existence of discrete degrees of freedom such as the spin is another way to see the inadequacy of the hidden variable theories). Again, we see the limitations of a "discrete computer scientist" Aaronson here. Also, I don't believe that a reader who hasn't studied decoherence (or hidden variables) previously will learn what it is (or they are).

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Minds and machines

Let me say a few words on the fourth chapter of Scott Aaronson's book, Minds and Machines.

It's about complexity of problems as well as the differences (or equivalence) between human brains and artificial thinking machines.

When one reads this fun stuff, he may see how these complexity folks are thinking and – even if he knows the principles – he realizes which of them are considered important (and, in many cases, more important than they deserve) by the complexity theorists.

I would say that not even Aaronson would claim that this chapter has anything to do with physics but I have been surprised many times in my life so I am not certain.




Mathematical problems may be easy-to-solve or harder. We may order their difficulty in a way. Two problems may be equally (qualitatively) difficult. If one is harder than another, it means that an algorithm to solve the former implies the existence of an algorithm solving the latter but not the other way around. And so on. Are there intermediate difficulty problems between two known classes? You can imagine what he writes about.




A central thesis worshiped by these complexity theorists is the Church-Turing thesis: algorithmically solvable/calculable problems are exactly those that may be solved/calculated by a Turing machine – a particular structurally simplified model of a universal enough computer.

The complexity theorists including Aaronson are clearly impressed by this thesis. Your humble correspondent – and, I believe, most theoretical physicists – would decide that the thesis is mostly ill-defined or a vacuous tautology or potentially wrong, depending on the definition of "algorithmically solvable problems". The complexity theorists' obsession with the thesis and similar theses may be a part of the reason why they haven't done too much genuine progress in artificial intelligence and other things, as discussed below.

Their excitement isn't too difficult to understand. The key insight is that all intelligent enough thinking is in principle the same activity. Even if you have a different architecture of a microprocessor (80386, 6510, ARM...), you may still employ the chip to interpret a programming language. An interpreter of another programming language may be written in your preferred programming language which runs on any computer deserving the name; the task to write these interpreters is more or less straightforward. So all computers and languages may simulate each other so they're equally potent. To some extent, this must hold about differently thinking human brains, too.

It's great to realize this fact about the universality of computation but once we realize it, we should also realize it's vacuous.

(The Church-Turing thesis may be more than a vacuous statement but one would first have to give an exact definition to the "algorithmically calculable functions/problems" that don't refer to a particular machine. Clearly, this required definition will refer to some particular machine or some particular machines, and for different choices, the Church-Turing thesis may be both right or wrong. If you build the definition on Turing-equivalent machines, it will be right and vacuous. If you insert some other hypothetical machines, probably physically impossible ones, it may be wrong. Garbage in, garbage out. You don't learn anything.)

Physicists are also enthusiastic about similar equivalences of something – namely theories – but they only become elevated in the case when the equivalence is more surprising and nontrivial than a straightforward translation of a program from one programming language to another. When the equivalence between these theories is surprising and hard to prove, physicists call it a "duality". Exactly because it's not trivial, a duality is very potent. It seems to me that the complexity theorists never switch to the mode of thinking in which they call a spade a spade – in which they decide that a trivial insight is trivial – and that's why they sometimes remain stuck in the quagmire of trivial and vacuous insights.

After all, the chapter also mentions that Turing correctly predicted that the capacity and performance of the computers would grow by a huge (nearly realistic, it turned out) factor within 50 years. But he incorrectly predicted the rise of artificially intelligent machines that would become indistinguishable from humans.

Another idea that Aaronson's criticizes is "meat chauvinism", namely the assumption that thinking machines composed of proteins (a set that includes a majority of commenters on this blog) are more conscious or intelligent etc. than artificial machines etc. If a computer program simulates a human, it or he or she must be given the same status and "approved consciousness" and human rights, Aaronson thinks.

Well, I have mixed feelings about that. More precisely, I agree that 1) the inner functioning is a more essential part of an intelligent device and its "identity" than the precise nature of the transistors or cells or technical architecture, but 2) the clever computers clearly don't have to be given human rights. It's up to people or a society – at least as long as the people are in charge – whether they respect the human rights of such computers. As I have argued many times, science cannot answer moral questions.

The very usage of the word "chauvinism" shows that Aaronson is prejudiced in these matters – and his opinion differs from mine. This word "chauvinism" is arguably meant to sound negative – at least that's my conclusion after years in which extreme leftists were surprised when I felt proud after they identified me as a chauvinist of any sort. But let me tell you something: chauvinism is often a great and essential policy. For example, computers may be equivalent to humans in many respects but they're not equivalent in others and it's legitimate for me and every other voter or politician to consider the replacement of humans by computers undesirable. So from my viewpoint, it's right to "discriminate" against computers.

But I don't want to talk about these "political questions" only – even though the number of essays criticizing PC, egalitarianism, and similar junk ideologies is never high enough. The very idea that a smart enough computer could be "really equivalent to a human mind with all of its consciousness etc." could be wrong. In particular, if you create a classical simulation with a random generator that "behaves" indistinguishably from a quantum system, it could be fundamentally a different thing when it comes to its consciousness etc.

I am referring to the Conway-Kochen free will theorem. The randomness implied by quantum mechanics may be shown to arise locally in the very region where the value of an observable is decided for the first time – that's what is meant by the "free will" here. However, this property is violated if you supplement an artificial engine with an external random generator. In that case, the decisions are really made by this generator where a big part of the "identity" lies. And you don't want to give human rights to a random generator because it's just too dull. Again, science doesn't imply what the right policies are but because there is a fundamental feature in which the actual quantum object and its classical simulations are inequivalent, it's surely legitimate to treat them differently. (Every ideology claiming that A and B should be treated equally in situations C and D is based on the fact/claim that A and B are equivalent in some respects E, F while totally overlooking the fact that they're inequivalent in other respects G, H: it is always an example of an ideological cherry-picking.) I don't say it's desirable or necessary. It's just a sensible possibility that some people may prefer.

At the end of the chapter, the author solves a problem from the previous chapter. Spoilers follow. The \(n\)-th Busy Beaver number \(BB(n)\) grows faster than any computational function, it may be proved. This number is defined as the maximum finite number of steps after which an \(n\)-state Turing machine terminates. The sum \(\sum_{n=1}^\infty 1/BB(n)\) over \(n\) is an incalculable real number as a consequence.

To partially summarize, these are interesting topics although – I believe – most of us have been exposed to computational complexity and artificial intelligence at various points and the most general impressions we get after a few hours arguably agree with what the experts believe (in this sense, the complexity science is a much less esoteric science than theoretical physics). It seems to me that these topics have very little to do with physics.

There's one point at which Aaronson may have tried to suggest that physics is relevant. He wrote that the black holes (and their singular spacetime geometry) could be used to construct computers whose speed doubles after every step and they could quickly calculate problems that require infinitely many steps etc. (The black holes were added as a "hope" to "sex his argument up".)

However, this is not the case. If such gadgets were possible in principle, the world could probably be shown to be inconsistent. Quite generally, the laws of physics tend to avoid such traps. So if you ask how the black holes may affect the speed of computation – I mean practical computations that the observers outside it may want to perform – their influence is exactly the opposite. They slow things down. Objects in a gravitational field display red shift, not blue shift, much like objects that are drifting away from us. This "prevalence" of red shift relatively to blue shift in physics is exactly what prevents moving computers from becoming too fast, from becoming the "NP-completeness oracles" or, using Aaronson's terminology when he was a student, "fairies". In most cases, physics has limitations that make the maximally efficient physical computer less efficient than the fastest design you could think of if you knew no physics.

This chapter also touches the question whether computer-assisted proofs may be counted as proofs. Well, I agree that people want to "feel" that they understand the reasons why something is true. A very large number of steps or tests that may only be done by a computer limit this "perceived direct contact with the truth".

At the same moment, I need to emphasize that this perception is subjective. And if someone doesn't "feel" a proof, it doesn't mean that the proof doesn't exist. After all, someone may "feel" it because he or she is a better mathematician. It's extremely important for people to understand that if they don't understand something, it may be just due to their personal limitations and not because there is something wrong with the thing they don't understand! Someone else may be smarter and understand it but even if there's no one like that in the world today, someone may emerge in the future who will understand it! The truth isn't the same thing as the subjective feelings of the truth; the latter are less eternal and less accurate and the former – the actual truth that is independent of individuals – should be considered superior.

Personally, if I may write down a program that verifies some steps that are needed to complete a proof (think about the Four Color Theorem as an example), I will believe the proof. A more direct proof that doesn't need a computer may be preferred. But let me admit, my motivation to search for such a computer-free proof diminishes rapidly once I know a proof that the statement is true – and I do count computer-assisted proofs among proofs. After all, I realize that computers are less likely to make well-defined particular errors than my brain because sharply cut silicon is more reliable than fuzzily connected proteins. In this sense, I believe the steps that were done by a computer more than I believe the steps that could have been plagued by a human error!

But anyway, the knowledge of the truth is far more important for me than the efficiency with which the truth may be reached or proved. Some important truths simply are just hard to find and hard to understand – and this is what actually makes them more important than the low-lying fruit-truths in average.

It seems to me that Scott Aaronson and others disagree about these points, too. In my opinion, they're victims of irrational emotions. Instead of looking for the cold hard truth, they may be looking for some emotions. As they're doing that, they may completely miss rather important meta-facts such as the fact that their brains are more likely to make errors in executing an algorithm than a silicon-based computer! And they may miss many other facts, too.

Complexity and P vs NP

Chapters 5 and 6 are dedicated to "Paleocomplexity" and "P probably isn't NP". These pieces of text are wonderful discussions about the scaling of the time and memory needed to solve various algorithmic problems. I have never been any professional expert, of course, but I got educated in this background many years ago. Aaronson wittily discusses many algorithms, their clever conversions to each other, and so on.

The problem promising you $1 million is the "P is or is not NP". Here, P are the problems that may be solved in polynomial time; NP are those whose solution may be verified in polynomial time. If the classes are equal, "P = NP", it means that every problem that can be "checked quickly" may also be "solved quickly". Because the finding of solutions looks "more creative" than their verification, people generally believe that "P is not NP" but a proof doesn't exist yet.

I am not so sure that "P is not NP", although I find it a bit more likely that the classes are not equal. However, if "P is NP" according to the definitions, it still doesn't imply that the procedures needed to solve a problem are really practical. The exponents in the power laws may be very large, and so on.

As a guy who's had some successes in math olympiads etc., I could have some probability – like many others – to solve similar problems, e.g. "P is or is not NP". However, the fame and perhaps the money is the only major motivation here for me, and it's too little. The reason why those things don't really excite me at the visceral level is that they're not really unique. They're elements in an infinitely tall power of ever more refined and complex mathematical claims that may wait for their resolution.

Imagine you prove that "P is not NP". But new problems are immediately waiting. One may divide the problems into finer classes and new sets and lots of new questions about their identity arise. Aaronson discusses many examples. In principle, this is a neverending sequence of questions. However, one can't really say that the more complex problems are negligibly important because they're qualitatively the same thing as the "P is not NP" question you decided to solve.

In physics, the search for a theory of everything is a much more unique and "terminal" process. And even some more modest goals in physics seem more unique and "terminal" than the problems in the complexity theory.

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Online and collaborative TeX: ShareLaTeX

A handy tool for people who write papers in \(\rm\TeX\)

This blog entry is just a very short reference to

ShareLaTeX.com (click)

You must register (ten seconds, no confirmations) but once you do, you will have the opportunity to start with \(\rm\LaTeX\) in the most pedagogical way possible, to edit your \(\rm\LaTeX\) sources from any place in the world, to collaborate on the files with other people in the world, and to instantly see the resulting document in PDF.



A sophisticated Javascript does the job. No need to install complicated \(\rm\TeX\) compilers on your PC. No lockings. A simple debugging of the logs. Many templates, customization.




I believe that all physicists who are co-authoring papers in \(\rm\TeX\) should try this gadget and it seems likely that I would have been using it if it were available when we were writing such things.




Quite generally, I think that the sophistication of the software industry has reached high enough levels so that even rather specialized activities – like writing papers in \(\rm\LaTeX\) – are now being given state-of-the-art software solutions with all the recent IT developments like collaboration, clouds, and so on. In particular, I've been very happy about MathJax that does the \(\LaTeX\) job on this blog but there's still room for improvements.



Four minutes of work with ShareLaTeX. See more YouTube videos.

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We don't live in a simulation

In 2011, I already wrote a text about the theories that our universe is a computer simulation:

Rebooting the Cosmos

Needless to say, a regular reader has seen lots of other criticisms of discrete physics, a more general concept. Let me return to this topic – and change the focus somewhat – in the wake of a sensible text at Backreaction,

The simulation hypothesis and other things I don’t believe

As David Tong explained using different words in his Silver Prize Winning Essay written for a crackpot foundation whose basic mission does include the promotion of the "Simulation Hypothesis", there is strong scientific evidence today that the world isn't discrete (and it isn't simulated).




We do encounter integers and discrete mathematical structures in physics but in all the cases, we may see that they're derived or emergent. They're just limited discrete aspects of a more general and more fundamental underlying continuous structure, or they're a rewriting of a continuous structure into discrete variables (eigenstates in a discrete spectrum) which makes it impossible to understand the value of certain parameters.

Quite generally, if the Universe were fundamentally discontinuous, it couldn't have continuous symmetries such as the rotational symmetry, the Lorentz symmetry, and even descriptions in terms of gauge symmetries (which aren't real full-fledged symmetries but redundancies) would be impossible. In a fundamentally discrete world, many (or infinitely many) continuous parameters would have to be precisely fine-tuned for the product to "look" invariant under the continuous transformations.




I am not saying that it is "impossible" for all these parameters to be fine-tuned for the product to look e.g. Lorentz-invariant; I just say it is very unlikely. The scientific theory that requires this huge unexplained fine-tuning is less likely than scientific theories that work with no fine-tuning (or less fine-tuning). It's less likely simply because given any sensible, quasi-uniform a priori distribution of the parameters, it is insanely unlikely that they will have the "right" values if there are so many wrong values.

EPR-style experiments show that local realism is incompatible with the observations. Locality must be fundamentally respected because it may only follow from the Lorentz invariance, the Lorentz invariance is observed to hold as well, and making it accidentally hold in a fundamentally Lorentz-violating theory would require the nearly infinite amount of luck and fine-tuning, as explained in the previous paragraph. So the reality is local but non-realist. It is quantum, stupid.

It means that the proposal that our Universe is a simulation run on a classical computer is ruled out immediately. This is a very naive idea, indeed. Again, I am not saying that it is "impossible" to write a computer program that behaves in a way that resembles the reality. It may have a wave function treated as a collection of classical degrees of freedom; it can make the wave function "objectively collapse" at various points (although this guarantees that some disagreement with the observations is inevitable, as I have often emphasized). But it may look "more or less OK".



But when a simulation may "look OK", it's a different statement than the statement that the simulation may "be" the reality. These are totally different questions. The simulation may do a good job in emulating Nature around us. However, we may still prove by the scientific method that it must be a simulation, not the real deal!

I wrote a lot about the flawed idea of discrete physics. But in this blog entry, I want to write a few more words about a more ambitious aspect of this reasoning, the idea of an "Overlord". We are a simulation that a more intelligent "Overlord" is playing with. This is such a childish and mathless idea that we are really leaving proper physics. The first thing I would say – in agreement with Sabine Hossenfelder – is that this idea is just religion in "modernized clothes" and its details reveal unusually naive anthropomorphism that we usually associate with very primitive forms of religions.

But some people apparently think that if they replace the old Gentleman floating on the cloud by a modern (or slightly futuristic) computer with its data floating in the cloud, it's not only much cooler but also much more scientific. Well, it's not. The decoration and makeup may look modern, technological, and geeky but the central idea in this scenario is still the same primitive religion.

(Some IT companies may think that their cloud technology is the newest state-of-the-art invention but clouds have been a basic tool used by the Overlords for thousands of years.)

Brian Greene promoted these ideas in the last 2 chapters of his latest major popular book, The Hidden Reality. It's a fun reading that tries to suggest that it's connecting physics with the ideas of science-fiction movies and books. However, it is not. These ideas are pure science-fiction. They don't contain any "physical added value" whatsoever. They show a physicist trying to make an excursion to the world of science-fiction.

Don't get me wrong. I do like many of these books and movies. I think that some of them are clever in the ways how the rules of the game are sketched. I have watched some of these movies many times, thought about them, and I have perhaps tried to write my own science-fiction novels, too. Those activities may require some thinking. However, it is important to realize that this thinking is certainly not scientific thinking.

The Ultragirl who plays with the simulation is usually visualized in a totally anthropomorphic way. She is a girl so she just wants to have some fun. She may be bored. She doesn't want to be bored. She may have bought the device with the simulation in the mall. She may even be sexy and tease you. She may even look like a human babe.

Needless to say, all these ideas are preposterous. If there were a totally new fundamental layer beneath our Universe, and I have argued it can't exist, it would not only have no reason to include beings that are physically similar to humans with the same kind of lust. Even broader feelings such as fun and boredom would almost certainly be irrelevant. They're as silly as they are in the case of Moses and the Lord who apparently created the Solar System within a week some 6,000 years ago but who needed to relax on the sixth or seventh day (sorry, I am really uncertain at this point!) because all the workers want their weekends to be relaxing.

But the anthropocentric delusions don't stop with fun and boredom. Some people, including Brian Greene, are even promoting a scenario in which the simulation runs on a limited device that only simulates something or uses rougher, approximate algorithms to simulate things that aren't too important because the simulated beings aren't observing these aspects too accurately (or they don't observe them at all).

It may be a good idea for you to buy a cheaper computer if you don't need the most powerful one. You may have good reasons to save some electricity and run simpler programs if you don't need the state-of-the-art ones. You may pay smaller bills and you may save some money for other things. But to imagine that the underlying Overlords are trying to save the money in the same sense as we do is the ultimate anthropomorphic naivite. It's not just anthropomorphic: it's an idea that envisions a layer underlying the whole observable Universe to resemble the early 21st century culture of the U.S. urbanite teenagers.

Holy Christ and Saint Simulator, we must ask: Why? All these assumptions about the Overlords are completely irrational. There is absolutely no reason to assume that the beings underlying our existence would resemble the U.S. urbanite teenagers of 2007. In fact, if we have some experience and if we can imagine a reasonable "landscape of possible ideas", we must agree that the probability that the underlying reality respects these principles is virtually zero.

Brian Greene faithfully yet uncritically sketched many other arguments in favor of the "Simulation Hypothesis" that I find utterly idiotic. One of them is a sort of the anthropic propaganda. He says that in the asymptotic future (of our particular Universe or perhaps the whole multiverse), there will probably be so many computers with so much power that the number of simulated TRF readers will be vastly greater than the number of biological TRF reader. For this reason, Brian thinks, it's far more likely that you are a simulated being, not a physical or biological one.

There are several reasons why this argument is dumb. One of them is that there is no such a law that the probability that you belong to a subset S of the whole set W is equal to the ratio of the number of elements N(S)/N(W). In most cases, the ratio isn't even well-defined because both the numerator and denominator are infinite. But even when they're finite, there's absolutely no reason why the probability should be equal to the ratio and in almost all cases, it is not equal. Only if all elements of W are equally likely – and that pretty much occurs only when there is a reason why they are equally likely (thermalization balancing all the microstates, for example) – the probabilities may be represented by the ratio. But it is a negligible fraction of the situations. There isn't any symmetry or democracy between biological and simulated beings because they're qualitatively different objects so there can't be any justification of the "equal odds" assumptions.

Regardless of the number of simulated beings "somewhere", we may still present scientific evidence that there is no "simulated layer" in our reality. The continuous symmetries are such an example. If you want to deny this argument, you may deny it by saying that your meme that "the number of simulated beings is vastly greater than the number of genuine beings" is so powerful (because the number of simulated beings is so high) that it may render the smallness of the "we are simulated beings" prior probabilities irrelevant.

But such a method to render rational arguments and calculations irrelevant is just a sleight-of-hand. It is exactly equivalent to the statement that all scientists and atheists are deluded a*s*oles because God is infinite and by His infinite powers, He may neutralize any scientist, his arguments, and inflate an arbitrarily unlikely possibility into the most likely outcome. To argue in this way means to totally abandon rational discourse and replace it by a kindergarten boys' pissing contest trying to find out whose God or Father is more infinite. You're just showing that your faith is infinite and won't be affected by any finite evidence, however extensive. But this only proves your bigotry. It doesn't prove anything about Nature.

Moreover, one may conjecture equally convincingly that in the future world, the number of biological beings will be vastly dominant; yes, I am just saying that the other side could be active in the pissing contest, too. I don't want to spend too much time with these anthropic arguments because they're just totally unjustifiable. In fact, there aren't any infinite numbers in physics that could ever "strengthen an argument". All physically meaningful numbers are always finite (some renormalization etc. is sometimes needed to see it) and if you think about possible infinite numbers such as the volume of our not-only-observable Universe, they never affect probabilities of observable propositions. The latter are only affected by intensive or local, and therefore finite, quantities. Someone's infinite size as the "ultimate argument" belongs to religion, not to physics.

Another would-be scientific yet unscientific line of defense that the champions of the Simulated Universe Hypothesis often employ are the demands of loyalty towards our Overlord. Some of them are as dead serious about this line as the most hopeless religious fundamentalists. They say that the Overlord may be deliberately trying to mislead us and we must just stay humble and respect Her great power because we're such tiny insects.

Nice.

Well, let me say that I know that this Overlord doesn't exist but even if I had doubts about Her existence, as a scientist, I don't have and can't have any respect towards Her "authority" that would affect my reasoning. Such an influence of fear on reasoning is just not kosher for a scientist – and I would surely extend this moral principle to North Korean scientists and simulated scientists, too. It's just about the most important, defining features of science. So even if the Overlord exists, she may politely sc*ew Her own asshole, or whatever f*cking parts of the body She is expected to have. Give me a break with this stuff. Worshiping a being, especially one that doesn't exist according to all the rational reasoning, is just plain stupid.

When She is presented as omnipotent in this way, the champions of Her dominion over the world have no problem to say that She may fine-tune things to values I find unlikely because it's Her right. She has the right to confuse me, too. Because these folks live in a mental world that assumes that She exists as if it were the most reliable and universal axiom of science – in a complete analogy with religious bigots in Christianity, Islam, and perhaps other old-fashioned religions – they consider their uncritical faith to be a sign of their being scientific.

But it's exactly the opposite. In religion, one can make assumptions (such as the Simulator's omnipotence) and require that everyone else worships these assumptions and treats them as facts. All other facts must be distorted, adjusted, or completely overlooked so that they become compatible with the basic religious axioms and of course that if you're willing to say awkward things, it's possible to a large extent. However, this approach is unacceptable in science.

In science, we always question the assumptions. We're comparing competing theories whose assumptions differ. That's really another defining feature of science. So feel free to create a personality cult around the Female Simulator but a person who is thinking scientifically will always question it and will always try to estimate the probability (and probable truth values of various assumptions) using the most rational, indirectly empirically based, arguments that are available.

Let me phrase this point about "Her right to confuse" differently. Some champions of the Simulation Hypothesis (and religions) think that if they postulate that "She" can arrange things in such a way that scientific strategies to investigate the foundations of the Universe become misleading or impossible, they make their Simulation Hypothesis more likely because they "hurt" the other hypotheses. But the answer is the opposite one. They only hurt their own, Simulation Hypothesis because they are adding additional unnatural assumptions to it: they are making it less likely. The probabilities of the competing (scientific) explanations can't be lowered by axioms done within the Simulation Hypothesis because – with apologies to the Overlord – the competing scientific explanations lie beyond the Overlord's power. So if the Simulation Hypothesis contains additional axioms that "hurt the Overlord-free scientific explanations" and if someone believes that the scientific explanations really become less likely because of that, he is a victim of circular reasoning. He can only prove what he wants (scientific explanations are disfavored or impossible) if he assumes it from the beginning, anyway.

For the question of fine-tuning, a rational argument is that the fine-tuning of 40+ parameters of the Lorentz-breaking Standard Model to the Lorentz-preserving values is almost infinitely unlikely, so a fundamental theory that doesn't respect the Lorentz symmetry is almost fully excluded. That's true for the Sexy Simulator Hypothesis, Loop Quantum Gravity, or any other silly fairy-tale of this sort. It doesn't matter that you may imagine that such an unlikely scenario is true and you may collect a billion of gullible simpletons around the religion that it is actually true. Science is still saying what it is saying and it is saying that the probability that such an assumption about the Simulator holds is basically zero. It's the strongest way how science may disfavor a hypothesis. So science is against you in the most violent way that the cautious and peaceful structure of science admits.

To summarize, I think that if you admit that there is a difference between science and religion, the proponents of the Simulated Universe Hypothesis are squarely on the religious side and all the feelings that their theories are modern, geeky, technological, and advanced are just about the makeup, not about the essence of the hypothesis that is the same primitive religion that the mankind has played with at least for thousands of years.

And that's the memo.

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Feed URLs for blog categories

This is a purely technical blog entry. Magnus Andersson asked me to create a feed with the climate articles only.

Blog posts on this blog are assigned several categories or labels – see "other texts on similar topics" beneath each post or the list of categories or labels in the right sidebar. This feature only appears in the widget-heavy, green template, not in the mobile one.

If you have a favorite category, you may find its feed at URLs such as

http://motls.blogspot.com/feeds/posts/default/-/climate

---

http://motls.blogspot.com/feeds/posts/default/-/weather records

The second URL was mentioned to show that spaces may be included in the URLs. If your browser happens to have problems with spaces, replace each with %20

(I couldn't add the period after the last sentence because it would be misleading.)

Your humble correspondent has created a Feedburner copy of the climate feed – in a new format – on a special URL.




The Feedburner climate feed URL is at

http://feeds.feedburner.com/blogspot/trfclimate

If you want another category to be put on Feedburner, let me know. The Feedburner version of the blog-wide Disqus comment feed has also been created.

I don't expect the number of subscribers to these feeds to reach a number similar to the number of subscribers for the main TRF feed which is about 17,000 right now (16,000 out of it is via Google Feedfetcher) so it may be a waste of time to preemptively prepare too many feeds.

Let me mention that in the right sidebar of the widget-heavy, green template, you find several colorful feed icons such as

which link to assorted feeds with or without Google Reader (add http://www.google.com/reader/view/feed/ right before the http URL of the feed), feeds for Disqus (whole blog), Twitter (whole blog: I am de facto not using Twitter for anything else aside from the automatic alerts to blog articles), and so on. Try to hover over the icons or click at them to see what they do.



If you don't know what feeds are and who is actually feeding whom by what, don't worry: the video above explains it.

Also, at the bottom of the Disqus comment section of each blog entry, there is a special "comment feed" for that article as well as "subscribe via e-mail" (try to click it, may be undone by another click on the same link). You will also subscribe to the feeds (or via e-mail?) if you star a discussion.

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