Thursday, April 19, 2012
A group of 24 kids between 12 and 18 (I believe) from 12 districts are selected randomly each year to fight to the death in some large arena. The reason for these hunger games is some past uprising of these 12 poor districts against the almighty capitol. This book and the movie are extremely powerful, intriguing and generally well done. That is, for adults. Because seeing children kill other children is about as sad as it gets. Adults killing other adults is one thing, but a small girl being speared down by another small boy (and many other such instances) has a huge impact on anyone's mind.
But why on earth is this a book and movie for children? Do we really need to feed our kids' brains this kind of material? I think not, because children don't see the deeper layers of this brilliant book; they can not see it in the perspective that we can. They simply absorb the images and emotions that it conjures up and who knows how this gets processed. I dread the day we read in the newspaper about kids being inspired by this book/movie to act out its violence.
But the book also represents an extremely powerful reminder of who we once were. The ideas must have been inspired by the Roman empire that dragged slaves from conquered lands to their own little arena to fight to the death. But at a deeper inspection, one can argue that a version of this still continues today. The West exploits the developing countries with unfair trade agreements, forcing them to opening their markets. Products from the developing countries can by no means compete with the much cheaper, often heavily subsidized products from the West. As a result, many people die of hunger. Not in an arena, but in their own homes. I feel that the Hunger Games has these deeper layers and exposes them very powerfully. As such it is a brilliant book (and movie). But for adults, not for 12-year old kids.
Saturday, October 15, 2011
There is nice an argument that combines general relativity and quantum mechanics to show that our ideas of space and time start to break apart at the Planck scale (1E-35 meter). Imagine I try to constrain anything (say an elementary particle) inside a box of size 1E-35m x 1E-35m x 1E-35m (a *very* small box I will call a Planck box).
According to quantum mechanics, if we want to contain anything inside a very tiny region of space, then its momentum (mass x velocity) becomes highly uncertain. The more we try to constrain space the more uncertain the momentum becomes (the Heisenberg uncertainty principle). This means that if I would actually measure the momentum, then the outcome could be extremely large. Since momentum carries energy the energy could become so large that, just like stars, they can form black holes. This happens exactly when the box is a Planck box.
What does this say? To me it seems a really nice argument to show that at this scale the concept of space starts to break down. We can simply not contain anything inside a Planck box, for if we do, nature closes the box and we will not be able to peek inside it! A black hole is in a real sense the boundary of the universe, so if we try to look at scales smaller than the Planck scale we will be looking at the end of the universe. (As a kid I always tried to imagine how the end of the universe looked like -- maybe its all around us).
Roger Penrose has introduced a name for this trick that nature plays with us: "cosmic censorship". This principle says that anywhere where there are singularities in our theories a horizon will form around it so that we may not see it! Maybe mother nature doesn't want us to see something :-)
Sunday, June 19, 2011
We like to think that every decision we make is made out of free will. While the concept of free will seems to make some sense at an intuitive level, it seems rather slippery when trying to define it. What entity other than our brain is making the decision, and on what grounds, based on what input? And what are the laws that determine how that entity is making a decision?
It seems rather dreadful that decisions are made according to "an algorithm". In particular, a *deterministic* algorithm is rather unappealing because it implies that our genetic make-up, in combination with everything we have experienced
in our lifetime plus the environmental factors that are in play right now are input to a function that deterministically outputs a decision:
DECISION = FUNCTION(HISTORY,ENVIRONMENT,GENES).
It seems to imply that we cannot be held responsible for our actions: they are simply a deterministic function of our history and the decision was predetermined anyway. We have no free will to change that outcome.
Despite its unattractive philosophical implications, I think this is exactly what is going on. We have no issue accepting this point of view for plants, in which case the FUNCTION is rather simple. Even lower animals such as fish or even crocodiles seem highly predictable in their responses to the environment. In the case of humans this is definitely not true. Our responses are (fortunately) partly predictable
but also partly unpredictable. There may be a good reason for a certain amount of unpredictability in nature. Imagine a cheetah chasing a gazelle. If the swerving movements of the gazelle were predictable for the cheetah then the cheetah could anticipate them and easily catch the gazelle. It is therefore likely that the gazelle has developed an algorithm that is very hard to predict for the cheetah, i.e. a seemingly random strategy to swerve left or right. Also apes living in large social communities were probably prone to similar evolutionary pressures: predictable responses can lead to exploitation and manipulation by others and thus have negative fitness value.
Seemingly random behavior does not mean this behavior is not deterministic. The decision process can become so complex that the tiniest changes in the environment can cause a completely different decision. This sensitivity or instability is the definition of "chaos" and according to some, unpredictability should be the correct definition of randomness, irrespective of whether something is deterministic or not. It is not even quite clear what true randomness means to be honest. Perhaps quantum mechanics is the only theory that claims randomness at a fundamental level (e.g. not caused by chaos), but even here the jury is still out. Even if our behavior is partly random, then what does that solve in terms of free will? A decision does not become more free if it is random.
To me the only logical conclusion is that our behavior is deterministic albeit in a very complex and unpredictable way. There is some interesting evidence for such a
theory. Experiments show that decisions are made in the brain even before we become aware of them. This means that at the very least a significant fraction of our decisions we make are made completely unconsciously and our body only fools ourselves into thinking that we made this decision consciously.
Predicting human behavior (decision making) may turn out to be impossible even with the fastest supercomputers. This feels like good news, because it would be
very unsettling to have a clone build after you that can perfectly predict what you will do 1 second from now. But ultimately we may have to accept that we can build
robots that can display equally complex behavior that are in no way inferior to us.
Finally a word on the legal implications of a theory of this kind. Does this mean we cannot send anyone to prison anymore because s/he committed a murder?
Of course not! Whether actions are predetermined or not has nothing to to do with this. The reason we send people to prison is because we don't want this person to
do it again and to scare other from doing it. These functions of punishment remain perfectly valid. We should never punish out of revenge or retribution. It is useless and serves no function to society.
Saturday, March 5, 2011
Over the past centuries science has pushed humankind from its pedestal several times. First Copernicus showed that the earth is not at the center of the universe, then Darwin showed that humans are the product of evolution and direct descendants of the apes. What else awaits us? With the advance of fast and more intelligent computation we will see the realization that computers can be far smarter than humans. We passed a few thresholds: Deep Blue beating Kasparov in chess, and now Watson becoming the new champion in the television show Jeopardy. As time goes on, we will see many more of these landmarks happen. There will be a time when we will be second to computer systems in almost any imaginable task. Are there even stranger revolutions that await us?
Although it is exceedingly difficult to look in a crystal ball, there are signs that an even bigger philosophical shock awaits us. Physicist believe that the true ontological degrees of freedom are far fewer than the ones we usually entertain to describe our world. In fact, there are signs that we could pack all the degrees of freedom on a two-dimensional plane, instead of in a three dimensional world. What then are these surplus unphysical degrees of freedom? My claim is that they are imagined: they live in our head in order to make sense of our world. Remember that all our brain is concerned with is predicting the future. If you can predict better you have an edge in survival. Now imagine that the ontological degrees of freedom have very complicated laws of dynamics, i.e. their future is very hard to predict from the past. Then lets imagine that by introducing a bunch of auxiliary variables this prediction task may become easier. This is not such a far fetched thought. In fact in statistics people do it all the time. Adding variables can simplify the description of a problem. However, in physics this is also a well understood phenomenon. Almost any modern theory has so called "gauge symmetries". These are transformations that change one description of the world into another description of the world without changing the actual state of the world. For instance, Einsteins general relativity allows one to transform between two frames of references (observers) that accelerate relative to each other. One observer interprets the state of the world as "gravitational pull" while the other as acceleration.
These symmetries lead to conservation laws (Noether's famous insights). Conservation laws are constraints between variables. They simply express that we have have used too many variables to describe the state of the world and hence some variables can be solved from other variables (and in fact removed). So there are two types of variables in a theory: variables whose state can only be solved from the world state in the past and variables whose state can be solved from the state of other variables at the same time. The second type is redundant, but often very useful in writing down nice concise equations to describe our world. What I predict will happen is that we have completely underestimated the number of these spurious variables in our theories. I believe, supported by the holographic principle which states that all real degrees of freedom can be stored on a surface, that there are vastly more unphysical degrees of freedom in our theories than physical ones.
Now let's take this one step further. Our brain is also in the business of making models of our world. Everyone of us is a physicist, if you like it or not. I now propose the following leap of faith: the way we view the world is also largely made of unphysical degrees of freedom. We have evolved to use these over-parametrized models because they lead to easier prediction at the macroscopic scale in which we live and survive. But they are largely an illusion, a fantasy of our minds that we all share (like the ability to speak language this illusion has been hardwired in our brain through evolution). This is the new revolution that I anticipate: we will come to realize we live in a fantasy world.
What are the potential consequences, if what I propose is true? While the auxiliary variables may work well at the macroscopic level, they may not work all that well at the microscopic world. I believe the brain has introduced new variables that follow simple laws of dynamics themselves. In particular, together with the real degrees of freedom they make up a consistent system where (usually) cause precedes effect. However, for the unphysical degrees of freedom there is no reason why this should be enforced. In general, there may be glitches in this framework in situations that are not important to survival. These glitches in consistency may for instance involve apparent reversed causality for the unphysical degrees of freedom, but in such a way that they will not affect the strict causality necessary for the physical degrees of freedom. We should not be able to receive a message from our yet to be born daughter who instructs us to kill ourselves so she will not be born (unless all the degrees of freedom that govern this daughter are unphysical of course).
All of this is compete speculation, and I make no claims that there is evidence for it. But oftentimes, a half true story might help one to keep an open mind to explore or embrace new ideas.
Saturday, January 29, 2011
Ever given the salaries of CEOs of well known charities a second thought? Well it came as a shocker to me. Here are a few almost random picks from "charity navigator":
Amnesty International: Larry Cox, Executive Director $210,000
American Red Cross: Gail J. McGovern, President, CEO $446,867
Food for the poor: Robin G. Mahfood, President, CEO $345,245
American Cancer Society: John Seffrin, Chief Executive Officer $685,884
:Donald Thomas, Deputy CEO $1,027,306
Children International: James Cook, Chief Executive Officer: $423,114
Do I need to say more? This maddens me. Why would I support these salaries with my gift? How can they ask people with small incomes to give when at the same time there are CEO's leading these organizations with these outrageous salaries. The figures heading these organizations should lead by example. Clearly, they do not invest their time because they care. Very disappointing. Next time they call you for a pledge first ask what their CEO earns.
Monday, November 1, 2010
We live in a world that is neither completely static and stable, nor completely noisy and unpredictable. As argued in previous blogs, we live a "complex" world between too stable and too random.
This is very similar to what is known as a "second order phase transition" in physics. Take ice, it's in a highly structured state with all atoms neatly organized in a lattice. When we heat it up, the molecules start to move around chaotically and break up the nice ordered structure: ice becomes water. The transition point is a phase transition and it is between order and chaos.
People have also argued that computation is best performed on the edge of chaos. A particularly outspoken figure in this respect is Stephen Wolfram. The idea here is that computation in the ordered regime can store patterns in memory but the system is so stable that it is is impossible to manipulate these patterns. On the other end of the spectrum there is large amounts of noise and/or chaos which simply prevents one to store any patterns stably. Again, we need something right on the edge.
Since brains are computing devices, one can ask if brains are also in a critical state. And indeed, evidence has been found that this is the case. In particular, if you take a patch of brain (from a dead animal but in a solution such that it still behaves somewhat "normally") and stimulate random neurons you will very often see very small groups of neighboring neurons respond. However, rarely you will also see the entire patch become active temporarily. It's just like earthquakes: there are enumerable small ones but rarely a really big one hits (note: a quake with magnitude 7 dissipates 10 times more energy as a quake of magnitude 6).
Researchers have argued that a critical brain is a wonderful thing to have. To name a few things: there are (optimally) many meta-stable states that it can represent. Moreover, this memory can be quickly accessed. Also, it maximizes the dynamic range of "senses", in the sense that it can respond to both very faint signals and signals that are many orders of magnitude larger. This "input gain control" is necessary because the world around is complex and thus in a critical state and therefore transmits signals with wildly varying magnitude. Finally, the brain needs to both integrate many parts of the brain but also allow for many different brain states (segregate).
A telltale signature of criticality is very long range interactions between units which are only locally connected. This is both in space (all regions of the brain are correlated with each other) as well as in time (very long memory). In fact, almost anything you measure, including these long range dependencies, follows a powerlaw distribution. Without technical details this means that there is no length scale that you can identify at which things are correlated. A good example of this the size of objects in an image. You will find many extremely small (perhaps even the size of 1 pixel) objects and few very large objects. You can't quite say: all objects have a size roughly between 90 and 100 pixels.
But for me, perhaps the most interesting point to make is this. By adapting to our environment we are forced to add new patterns in our brain and forget others. We are constantly maintaining the memory content of our brain. A brain that is sub-critical is too stable and it is very hard to erase memories and imprint others. A brain that is too chaotic and noisy will not hold memories at all. Moreover, this learning process is highly dynamic and needs to happen quickly. It seems our ability to adapt and learn and our need to predict the world around us is key to understanding why we have critical brains. A lot still needs to be understood here, but the outlook seems promising.
Sunday, October 3, 2010
Just type the work "Islam" in Google images and you get a good feeling for the current sentiment towards that word. Islam is slowly becoming the equivalent of the evil force that is trying to take over the world. This trend is global, it extend from the Western world though Russia and China. The world is polarizing.
In Europe this trend is very visible. In many countries ultra right political movements are gaining force. In the Netherlands the anti-Islam party PVV is now executing its political agenda by quasi-participating in Dutch government. But anti-Islam movements are on the rise in many countries in Europe: Belgium, Sweden, Denmark, Germany and so on.
Why do I believe this trend is so dangerous?
1) The economy is bad. People suffer and need a black sheep to blame. It's true that there are serious integration issues in the big cities in the Netherlands and a small fraction of Moroccan youths cause significant trouble. But so do other minority sub-populations such as Antilleans. These problems are caused by ignoring integration problems for far too long, but they seem to have little to do with Islam.
2) Al-Qaeda Terrorist attacks fuel the anti-Islam sentiments. Every time there is an attack all Muslims get to share in the blame. This is the annoying tendency of humans to over-generalize. We find one feature that holds true of the terrorist (they are Muslim), then the logic gets reversed to infer that all people who share this feature must therefore be evil to some degree. This is a well documented psychological phenomenon. But of course, the majority of Muslims want nothing to do with terrorists, they are law abiding citizens that value democracy and freedom as much as the rest of us do.
3) The problems are global. They span China, Russia, Europe, North America and Africa. Not to forget the Middle-East. Further escalation of the conflict between Iran and Israel may spread through the world like wildfire because the tensions are already high. And it seems inevitable that at some point Israel will strike against Iran's nuclear program.
Where have we seen the concurrence of these conditions before? In particular: a group of people labeled by their religious beliefs blamed for the problems in society? We must not follow gut-feelings, we must not generalize, we must remember the conditions that led to earlier conflicts and genocide. We must educate the population at large, broadcast the friendly and hospitable side of Islamic culture, foster tolerance and compassion.
Tuesday, September 14, 2010
How good are we in estimating the uncertainty of our claims? Pretty bad in my opinion. And this may be particularly true for scientists, medical doctors or other experts. Since they have noticed that there are very few people who know more than them on a (very) particular topic they infer that they may actually know close to everything there is to know about it. I recently watched in interview with a renowned physicist about the possibility of EPS (extra perceptual sensation). This expert embarked on a long story about how all physical laws decay as one over the square of distance and that therefore the signals necessarily underlying ESP would have been detected. Problem is of course that his reasoning was solidly rooted in the physical laws as we know them and that the possibility of entirely new physics causing the phenomenon was simply denied. A clear overestimation of ones grasp of the unknown.
Ever tried to argue with a doctor why your child needs Tylenol for a mild fever? They will almost consider you criminal if you choose to deny them the medicine. But there is never a clear reason as to why they need it. It's simply the way it is. But do they have any clue as to the long term effects of poring medicine into these small bodies? Yes, of course, Tylenol was rigorously tested and approved but it's almost impossible to test for the increased risk of cancer after 20 years. They seem completely certain it's safe until a new study shows it's not (as was indeed the case with Tylenol). Why are doctors so certain about the effect of drugs or vaccinations: because they chronically overestimate their grasp of what is unknown.
Perhaps the clearest example is given by reviews of scientific papers where reviewers are asked to provide their confidence. It is very common to find two maximally confident reviewers with completely opposite opinions. Clearly one of the two must be wrong. And, this is of course very frustrating at the receiving end.
Bottom line, always keep an open mind and try not to underestimate what you don't know.
Friday, August 13, 2010
A new controversy is currently hotly debated in the press: to build or not to build a mosque at ground zero? I see two arguments, one against and one in favor. The argument against building such a mosque is that it may hurt the feelings of those who lost family, friends or loved ones in the 9/11 bombing. In fact, this seems a very strong argument because irrespective how we feel about the issue, these people will want to visit the site where their loved ones died and that experience can be severely affected by a clearly visible mosque. However, I am not sure the majority of the surviving dependents actually will be offended by a mosque. At the very least their opinion should be polled. And by the way, I am sure many moslims also died in the 9/11 attacks and wouldn't they need a place to mourn their loved ones?
Now the argument in favor. I believe the most appropriate monument we can build that expresses the tolerance of our western society towards other cultures and minorities, and expresses how much we value our constitutional rights (aka liberty of speech, liberty of religion etc.), is to precisely build a mosque at ground zero. It expresses the fact that we do not stigmatize a very large group of well willing citizens and accuse them of the crimes committed by a very small group of terrorists. It expresses the fact that we have learned from history and will not make the same mistakes again (and again). So, please let's build that islamic center at ground zero and use it to create mutual understanding and eradicate the hate that led to 9/11. Let's not think with our gut but with our head for a change.
Friday, April 9, 2010
The stock-market is a fascinating beast. It's the largest casino in the world, better compared to a huge online game for adults. If you are able to predict the future price of a stock you are in (big) business. When it rises, you buy that stock and sell later. When it drops you short-sell that stock (basically selling it now before you own it and paying for it at a later time when the price is presumably lower). But the view held by most academics is that markets are efficient, that is, unpredictable. Imagine there is some knowledge out there in the world that makes the price of a stock predictable, then the first person who knows about it will "gamble it away". It takes only a few people (or even one) to remove the predictable pattern (if it were still predictable, gamble some more until it is no longer predictable). And there is little delay in this process too (since potentially millions of dollars are involved investors will act very fast). And so the hypothesis is that the market is a random walk: utterly unpredictable.
So what are all these thousands of investors wasting their time on? A huge paradox is presenting itself here. An army of investors are presumably making money on the market every day, while an army of academics is claiming they can't. What's going on?
Hypothesis 1: the investors are seeing patterns where there are none. They believe they are beating the market but in reality they don't. Perhaps they gamble on more risky stocks which have a higher average return. It is well know that humans tend to see patterns in data where there are none (it can't be coincidence that I met my old friend in Lissabon during the summer). We hear about the successful investors who have survived but they represent 50% of the population. The other half can be found in the gutter.
Hypothesis 2: Any obvious patterns are absent, but there are hidden patterns that are not public on which you can make money. It is a well documented fact that once a pattern is made public, it will instantly disappear because investors will start using it. But it's rather stupid to post your successful trick to make money on the wall (unless you are an academic). So, we must assume investors are using their own secret rules to trade. Some figured out you should trade on the scale of seconds or less, others use complicated rules of thumb at the scale of days/months etc. The mere fact that publicized patterns disappear tells us that before they were made public they were still predictable.
To me, the markets represent an interesting collective artificial intelligence that determines the true value of stocks very efficiently. Markets have even been used to predict other facts. If you want to know the answer to an arbitrary question (i.e. who will be the next president) start a market and let people bet on it. The collective wisdom of the masses supersedes the wisdom of any knowledgeable individual. We should probably be thinking about how to use this idea for better purposes.