The same unexpected behavior

As the sun loses energy by radiation, it becomes hotter and not cooler. Since the sun is made of compressible gas squeezed by its own gravitation, loss of energy causes it to become smaller and denser, and the compression causes it to become hotter. For almost all astronomical objects, gravitation dominates, and they have the same unexpected behavior. Gravitation reverses the usual relation between energy and temperature. In the domain of astronomy, when heat flows from hotter to cooler objects, the hot objects get hotter and the cool objects get cooler. As a result, temperature differences in the astronomical universe tend to increase rather than decrease as time goes on. There is no final state of uniform temperature, and there is no heat death. Gravitation gives us a universe hospitable to life. Information and order can continue to grow for billions of years in the future, as they have evidently grown in the past.

Freeman Dyson - How We Know [a review of James Gleick's The Information]

Turtles all the way

...the non-fundamental ontology of everyday life (solids and fluids) can seem as a kind of "coarse-grained" macroscopic approximation to the more fundamental microscopic ontology of quarks and electrons; indeed, the former should be (at least in principle) derivable as a logical consequence of the underlying fundamental theory.
...
...it means that what appear in the older theory to be a fundamental entity is, in reality, a non-fundamental entity derivable as a "coarse-grained: version of something deeper.
...
In this view, reality is composed of a hierarchy of "scales"... The theory on each scale emerges from the theory on the next finer-scale by ignoring some of the (irrelevant) details of the latter. And the ontology of the theory on each scale - in particular, its "unobservable" theoretical entities - can be understood, at least in principle, as arising from the "collective" or "emergent" effects of a more fundamental theory at a finer scale.

Alan Sokal, Beyond the Hoax, p242-54

The farther we stray from intuitions

...the deeper we probe into the nature of things, the stranger they tend to look. That is not surprising: the deeper we probe into the nature of things, the farther we stray from the intuitions about macroscopic objects (and about human psychology, etc.) that were sculpted into our brains by natural selection.

Alan Sokal, Beyond the Hoax, p240

Patterns emerging from granular matter

Patterns emerge from a rotating tube filled with colored balls of different sizes. Very cool that there are still mysterious things happening with simple objects at the macroscopic scale.

It's just a coincidence, because they used white and orange balls in the video, but it reminded me of the Turing patterns [below] in this post [which is mostly Rudy Rucker].


I've been sick a few days and even slower / more stupid than usual, sweating heavily and dragging myself through dull files. But today the recovery is taking hold, and with the gathering strength other patterns are also emerging in my life, but that's all stuff for another time.

More from Wired on the above

The appearance of time

Sarah Heinrichs

For more than a decade, [Carlo Rovelli, a physicist at the University of Marseille in France] has been working with mathematician Alain Connes at the College de France in Paris to understand how a time-free reality could give rise to the appearance of time. Their idea, called the thermal time hypothesis, suggests that time emerges as a statistical effect, in the same way that temperature emerges from averaging the behavior of large groups of molecules.

Imagine gas in a box. In principle we could keep track of the position and momentum of each molecule at every instant and have total knowledge of the microscopic state of our surroundings. In this scenario, no such thing as temperature exists; instead we have an ever-changing arrangement of molecules. Keeping track of all that information is not feasible in practice, but we can average the microscopic behaviour to derive a macroscopic description. We condense all the information about the momenta of the molecules into a single measure, an average that we call temperature.

According to Connes and Rovelli, the same applies to the universe at large. There are many more constituents to keep track of: not only do we have particles of matter to deal with, we also have space itself and therefore gravity. When we average over this vast microscopic arrangement, the macroscopic feature that emerges is not temperature, but time. "It is not reality that has a time flow, it is our very approximate knowledge of reality that has a time flow," says Rovelli. "Time is the effect of our ignorance."

Is time an illusion? New Scientist

The Book of Disquiet, text 150

Bumble heaven

No problem is soluble. None of us unties the Gordian knot; we either give up or cut it. We brusquely resolve with our feelings problems of the intellect and do so because we are tired of thinking, because we are too timid to draw conclusions, because of an absurd need for support, or because of our gregarious impulse to rejoin others and rejoin life. Since we can never know all the factors involved in an issue, we can never resolve it. To reach the truth we lack both the necessary facts and the intellectual processes that could exhaust all possible interpretations of those facts.

More from Pessoa's The Book of Disquiet.

I'm sure the passage above is about personal problems, but I came to it thinking about chaos in general, and the importance of long practice and then a lack of awareness when engaged in the task at hand. Being prepared and then letting things happen

...the only system that can replicate the behavior of the Universe in every detail is - the Universe itself. Even if...the Universe is entirely deterministic and the whole future is contained within its present state, there is no way at all to predict or know the future, except by watching the universe evolve. Whether or not we have free will, the Universe behaves as if we have free will, which is really all that matters. The Universe is ignorant it's own future, and is its own fastest simulator.

John Gribbin, Deep Simplicity, p69

Things that happen all the time

Two cool videos of Rayleigh-Bénard convection.

Feynman on light

Nice clip of Feynman tripping on the mess of light around us.

Mario many-worlds traffic death

What I lack in logic I often make up for in certainty, it's another one of my winning qualities. I get the idea of the many-worlds interpretation of quantum physics about as well as any other innumerate liberal arts graduate. My main objection is where would it all go? But that's not the point of this post.

I had a minor traffic accident the other night. I wanted to make a turn and a car backed up and hit my motorcycle, making it / me topple over into the road. Fortunately the important lights were red, so it wasn't into the path of a vehicle, but still I felt the rush of adrenalin, boosted by the fumes from the gasoline that leaked out of the tank. The sense of death being just a few seconds / centimeters away, and how many times I've been in situations like that. For all that my life is or is not, there've been many occasions when things should've gone a lot worse. Hit by a car and falling down in a small pool of gasoline, it felt like death streaming around me, as if, in most other other worlds, something terrible had happened.

It made me think of this video:



Which is what? It's someone doing a level of a Mario game with all the failed attempts / dead Marios overlayed. Scroll down this until So what’s this about quantum physics? for more details , and here's where I originally came across it.

My motorcycle is 20 yrs old and in very bad repair. I'm going to buy a new scooter and pay attention when I drive.

Awareness of ignorance

A series of three lectures from David Gross called "The Search for a Fundamental Theory of Reality" [scroll down, April 2006], each about 1hr 40min. There's no math, the guy speaks well, and he won a Nobel prize in physics - three things that rarely come together on the topic.

In the third lecture [1hr 15min in], Gross dismisses the idea of progress in science being like peeling an onion, getting closer and closer to the truth. Instead he sees knowledge as expanding outward, like a growing sphere.

Since ignorance exists at the boundary of knowledge, more knowledge = greater awareness of ignorance. But, thinking in terms of the sphere, we can see that the volume is knowledge and the surface is ignorance, which means there is a net gain, even as ignorance increases. He ends the idea with this formula:

wisdom = knowledge / ignorance.

Now, I have no idea what Gross means by wisdom, but I like that image of learning. It reminds me of Nassim Taleb's point about Umberto Eco's library, which runs like this [lifted from a pdf accompanying a Taleb talk]:

..the interesting thing about Umberto Eco is that he has a library, and he has two kind of visitors. His library has 30,000 books, so two kinds of people come to pay homage to Professor Eco. The first category is people who tell him, "Oh wow, how many of these beautiful books have you read"? And you have a second category of people who realize that the value of a library does not lie in the books you've read, but in the books that you haven't read.

So really there's some people who use a library as a tool for self promotion or to convince themselves that they're very smart and look how much I've read. Basically people focus on what they know. Or, you can use it to humble yourself. Every morning you wake up you go down to your library, you have your cup of coffee and look at it and it reminds you how ignorant you are. So this is the idea of a library.