I woke up this morning to find my twitter account hacked, distributing spam. I'm currently reading Michael Chorost's new book “World Wide Mind” and if his vision comes true the day might be near when your praise of the frozen pizza leaves me wondering if your brain has been hacked. Book review will follow when I'm done reading. If the babies let me that is. Here, I just want to share an interesting extract.

On the risk of oversimplifying 150 pages, a “clique” is something like an element of the basis of your thoughts. Might be a thing, a motion, an emotion, a color, a number, and so on, like e.g. black, dog, running, scary... It's presumably encoded in some particular pattern of neurons firing in your brain, patterns that however are different from person to person. The idea is that instead of attempting brain-to-brain communication by directly linking neurons, you identify the pattern for these “cliques.” Once you've done that, a software can identify them from your neuronal activity and submit them to somebody else where they get translated into their respective neuronal activity.

In Chapter 10 on “The Future of Individuality,” Chorost speculates on the enhanced cognitive abilities of an interconnected World Wide Mind:

“[I]magine a far-flung group of physicists thinking about how to unify quantum mechanics and general relativity (the most important unsolved problem in physics). One of them has the germ of an "aha" idea, but it's just a teasing sensation rather than a verbally articulated thought. It evokes a sense of excitement that her [brain implant] can pick up. Many cliques in her brain would be activated, many of them subconsciously. The sensation of excitement alerts other physicists that something is up: they suddenly feel that sense of aha-ness themselves. The same cliques in their brains are activated, say these: unification problem, cosmological constant, black holes, Hawking radiation.

An apparent random assortment, but brains are good at finding patterns in randomness. New ideas often come from a fresh conjunction of old ones. In a group intimately familiar with a problem, the members don't need to do a whole lot of talking to understand each other. A few words are all that are needed to trigger an assortment of meaningful associations. Another physicist pushes those associations a little further in his own head, evoking more cliques in the group. Another goes to his keyboard and types out a few sentences that capture it, which go out to the group; perhaps they are shared on a communally visible scratch pad. The original physicist adds a few more sentences. Fairly rapidly, the new idea is sketched out in a symbology of words and equations. If it holds up, the collective excitement draws in more physicists. If it doesn't, the group falls apart and everyone goes back to what they were doing. This is brainstorming, but it's facilitated by the direct exchange of emotions and associations within the group, and it can happen at any time or place.”

Well, I'm prone to like Chorost's book as you can guess if you've read my last year's post It comes soon enough in which I wrote “The obvious step to take seems to me not trying to get a computer to decipher somebody's brain activity, but to take the output and connect it as input to somebody else. If that technique becomes doable and is successful, it will dramatically change our lives.”

Little did I know how far technology has come already, as I now learned from Chorost's book. In any case, the above example sounds like right out of my nightmare. I'm imagining, whenever one of my quantum gravity friends has an aha-moment we're all getting a remote-triggered adrenaline peak and jump all over it. We'd never sleep, brains would start fuming, we'd all go crazy in about no time. Even if you'd manage to dampen this out, the over-sharing of premature ideas is not good for progress (as I've argued many times before). Preemies need intensive care, they need it warm and quiet. A crowd's attention is the last thing they need. Sometimes it's not experience and knowledge of all the problems that helps one move forward, but lack thereof. Arthur C. Clarke put it very well in his First Law:

“When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.”

The distinguished scientist may be wrong, but he certainly will be able to state his opinion very clearly and indeed have a lot of good reasons for it. He still may be wrong in the end, but by then you might have given up thinking through the details. Skepticism and debunking is a central element of research. Unfortunately, one sometimes throws out the baby with the bathwater of bad ideas. “Collective excitement” based on a sharing of emotions doesn't seem like the best approach to science.

The July issue of 'Physik Journal' (the membership journal of the German Physical Society) has an interview with Jack Steinberger. Steinberger is an experimental particle physicist who in 1988 won the Nobelprize, with Leon Lederman and Melvin Schwartz, for his 1962 discovery of the muon neutrino. He is German born, but his family emigrated to the USA in 1934. Steinberger just celebrated his 90st birthday. What does a physicist do at the age of 90? Here's an excerpt from the interview (by Stefan Jorda):

You still come to your office at CERN every day?

I came by bike until last year, but then I fell and now I take the bus. I get up at five and arrive at half past six.

Every morning?

Not on Saturdays and Sundays. But I have nothing else to do. I read my email, then I go to the arXiv and look at the new papers in astrophysics. On the average, it's about 50 to 100, many of them are very bad. I read the abstracts, this takes one and a half hour, then I print those 5 to 10 that may be of interest to me. I try to understand them during the rest of the day. Then at 4pm I take the bus back home.

Since when are you interested in astrophysics?

In 1992 COBE detected the inhomogeneities in the cosmic microwave background, that was wonderful. It was a big challenge for me, as a particle physicist, to understand it, because one has to know general relativity and hydrodynamics. Back then I was still a little smarter and really tried to learn these things. Today I am interested for example in active galactic nuclei. The processes there are very complicated. I try to keep track, but there are many things I don't understand, and a lot simply is not understood.

(Any awkward English grammar is entirely the fault of my translation.)

Should I be lucky enough to live to the age of 90, that's how I would like to spend my days, following our ongoing exploration and increasing understanding of nature. Okay, maybe I would get up a little later. And on Saturday I'll bake a cake or two because my grand-grand children come for a visit. All nine of them.

"Men love to wonder, and that is the seed of science."

Melvin the Machine: a Rube Goldberg machine with a twitter account.

Melvin The Magical Mixed Media Machine from HEYHEYHEY on Vimeo.

[via, more info]

It's been a while since we discussed the question why we experience no more and no less than 3 spatial dimensions. The last occasion was a paper by Karch and Randall who tried to shed some light on the issue, if not very convincingly. Now there's a new attempt on the arXiv:

Spacetime Dimensionality from de Sitter Entropy
By Arshad Momen and Rakibur Rahman
arXiv: 1106.4548 [hep-th]

We argue that the spontaneous creation of de Sitter universes favors three spatial dimensions. The conclusion relies on the causal-patch description of de Sitter space, where fiducial observers experience local thermal equilibrium up to a stretched horizon, on the holographic principle, and on some assumptions about the nature of gravity and the constituents of Hawking/Unruh radiation.

What they've done is to calculate the entropy and energy of the Unruh radiation in a causal patch of any one observer in a de Sitter spacetime with d spatial dimensions. Holding the energy fixed and making certain assumptions about the degrees of freedom of the particles in the radiation, the entropy has a local maxium at d= 2.97 spacelike dimensions, a minimum around 7 and goes to infinity for large d. Since the authors restrict themselves to d less or equal to 10, this seems to say for a given amount of energy the entropy is maximal for 3 spacelike dimensions. Assuming that the universe is created by quantum tunneling, the probability for creation is larger the larger the entropy, thus it would be likely then that we live in a space with 3 dimensions.

To calculate the entropy one needs a cutoff the value of which is fixed by matching it to the entropy associated with the de Sitter horizon, so that's where the holographic principle becomes important.

Not only is it crucial that they add an upper bound on the number of dimensions by some other argument, their counting also depends on the number of particles and the dimensions they can propagate into. They are assuming only massless particles contribute, and these are photons and gravitons. Massive particles even with small masses, the authors write, are "unacceptable" because then the cutoff could be sensitive to the Hubble parameter. By considering only photons and gravitons as massless particles they are assuming the standard model. So even in the best case one could say they have a correlation between the number of dimensions and the particle content. Also, in braneworld models the total number of spatial dimensions isn't necessarily the one determining degrees of freedom at low energy; a possibility the authors explicitly say they're not considering.

Thus, as much as I'd like to see a good answer to the question, I'm not very convinced by this one either.

In a recent NYT article, I learned about the "argumentative theory of reasoning," suggested by Dan Sperber, a French social and cognitive scientist, who is director of the International Cognition and Culture Institute. The essence of his theory seems to be that the evolutionary purpose of argumentation is to win an argument. That, apparently, is a groundbreaking hypothesis as his colleagues mostly argue that the purpose of reasoning is to find the truth, leaving them puzzled why the human brain works so inefficiently to that end. Sperber's postdoc Hugo Mercier has a website that lists the predictions of this theory, most of which are actually postdictions.

I think they've forgotten to disentangle argumentation by subject. There's arguably arguments that for the sake of natural selection you're better off finding out the truth. You can convince me all you want that drinking distilled water will cleanse your soul, you're not going to reproduce 6 feet under. But if the argument is about getting your way (what's for dinner?) then you might indeed be better off packing on arguments in your favor and leaving out those that contradict you. The problem is of course that it's difficult to switch from one mode of argumentation to the other. That's why it's beneficial if scientists have some formal training in which they learn, if not actually the names of well-known cognitive biases, so at least procedures that have proven efficient in avoiding pitfalls of human cognition, cognition that has evolved for other purposes than, say, finding evidence for dark matter.

In any case, this reminded me of a little book I once saw on a bargain bin, "50 ways to stall a discussion." ("50 Arten, sich quer zu stellen" by Frans Krips, you can download it here.) If you ever sat in the 5th installment of yet another seemingly endless committee meeting, consider that everybody else read the book and took the advice very seriously. Here's a sample from the 50 ways:

1. This was not sufficiently discussed
2. We don't have enough information
3. We should first find out how the matter has been dealt with elsewhere
4. This is much too fast
5. Deficient use of language
6. Inadequate standard
7. We first have to discuss some other problem
8. There are other problems of higher societal relevance
9. One just can't do it this way
10. You can't expect that from the people
11. We've discarded so many plans, who cares if we discard yet another
12. We tried this already in 1976
13. We haven't yet assessed the impact of our last decision
14. Who exactly is responsible?
15. We should contact an expert
16. We have to set priorities straight
17. We need a committee on this aspect

And then there is of course the Web2.0 deadlock: we have to agree to disagree. It too fails to differentiate between seeking for truth and seeking for compromise. We can agree to disagree on all matters of taste: Pizza or Sushi? Pink or blue? NIN or RHCP? but when it comes to science, disagreement means one of us is wrong. Finding the right answer is what science is all about. So it's Pizza tonight, dammit.

[Img Src: Very Demotivational]