"Peaceful" Muslim protestors in London

They are protesting about some cartoons that appeared in a Danish newspaper, by openly calling for the extermination of Europeans.

None of these protestors were arrested.

What the hell?

For the first time since Babylon 5, there's actually a good science fiction show on the box.

It's called Battlestar Galactica (it's vastly different from the crappy original series). It's riven with paranoia and realism, and has none of that plastic optimism of the Star Trek programs, and none of the general sheer-awfulness of things like Stargate.

It's on at 9 pm on Sky One on Tuesdays.

RIP Cian Dempsey

A guy I knew in school died last Friday. Cian was a good bass player and singer (I was in a band with him for a while), and it's a shame that he died so young (he was only 23).

The End of the Universe

The end of the Universe intrigues me. It is the end of all. Everything that ever was, or ever will be.

The largest consideration here is entropy - the unstoppable, irrevocable rise in disorder accompanied by an unstoppable, irrevocable decrease in free energy.

The Universe is expanding, and whats more, this expansion is accelerating.(There is, apparently, a positive Cosmological Constant, which results in exponential expansion).

This dictates that eventually all galaxies will disintegrate - individual stars over time acquire enough kinetic energy to escape, and because the density of galaxies is decreasing as the Universe expands, the net result is more and more isolated stars.

In 10^23 years, this process will be complete.

Incidentally, this is analogous to leaving a pan of water outside. The water's temperature is way below boiling point, yet if you leave it for a few days much of it will have evaporated away, due to random individual water molecules gaining enough energy to escape the liquid phase.

The life cycle of the consituents of galaxies (stars) envolve fusion of lighter nuclei into heavier ones, resulting in energy output. Eventually all stars run out of fuel. What happens then is dependent on the size of the particular star - you either get white dwarfs, neutron stars or black holes (also possibly quark-stars, but this is still speculative).

The time it takes for a star to become one of these is roughly proportional to its mass^(-2.5). In other words, more massive stars die a lot quicker than smaller ones.

White dwarfs and neutrons stars will cool down, and as they do so, will slowly lose material, for much the same reasons that the galaxies will fall apart. If they reached absolute zero Kelvin, this would stop, but of course thermodynamically this can't happen. Indeed, if the Universe's expansion keeps accelerating, the Universe will eventually reach a stable non-zero temperature.

So, ionization takes place - it this doesn't destroy neutron stars first, another process will - quantum tunneling into Black holes. If this doesn't get brown dwarfs first (white dwarfs that have cooled), they will quantum tunnel into Iron (which has the lowest binding energy per nucleon), and then into Black holes.

The time scale for these processes is absolutely staggerly long.

Black holes also will also evaporate (via Hawking Radiation). However, an unfeasibly large black hole could grow forever, if it's Hawking Temperature was below this plateau background temperature - this almost certainly won't happen. It would have to be on the order 10^22 solar masses, which is pretty close to the mass of the whole observable Universe !

All of this suggests the ultimate destiny of the Universe - individual electrons, protons and neutrinos, each cut off from all the others by an Event Horizon created by the Universe's expansion. They will grow ever more distant from each other as time goes on.

All the civilizations that undoubtable exist throughout the Universe (try applying Drake's equation to the whole observable Universe), will have to eventually cease.

There is an upper temporal ceiling on all life.

Eventually, ineluctably, the chain of life must cease throughout the whole cosmos.

Art from space

Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

This reminds me of minimalist art.

This photo was taken from the Cassini spacecraft. In the foreground is one of the smaller moons of Saturn (Enceladus, which has a diameter of only 500 KM), and in the background is a portion of the famous rings of Saturn.

Incidentally, when this was taken Cassini was one million kilometers distant from Enceladus.

Experimental evidence of a lack of genuine free will?

If someone, while being PET scanned, is told that they can move their finger at any time they want, a very interesting thing happens

Between one second and three quarters of a second before the finger actually moves, a "Readiness Potential" is detected in the brain of the subject.

However, the apparently conscious decision to move the finger is almost simultaneous with the finger actually moving.

It is as if some part of the brain is pre-empting the actual decision to move the finger, by between 1 and 3/4 seconds.

What exactly is happening here is not at present known, but it must be one of two things:

1. There is a time delay brought about by the propogation of electric signals in the neural network of the brain, and evolution has conspired to give a time delay to the awareness of the conscious decision, timing it to coincide better with the actual action undertaken (in this case, moving a finger).

2. There is a genuinely robotic process at work here. The decision is made sub-consciously, in a computer-like manner, and the apparent consciousness of the decision is merely an artifact of some feed-back loop in the neural net - it's not really a conscious decision at all !

Based on my earlier post, even if "1" is the case, "free will" still doesn't actually exist.

Free will is an illusion

This is an idea I just got today. I might expand upon it later.

Basically, the processes by which our brains function must either be classical in nature, or envolve a combination of classical and quantum mechanics.

Let us for the moment suppose it is the former.

The very nature of classical physics is determinacy - if you know the positions and momenta of a group of particles that act classically, with enough computing power you can determine precisely what condition the system will be in at any point in the future. Sure, even a simple scenario (eg three planets in orbit around each other) can get very complex indeed. But the point is, it's possible, in principle, to predict with utter precision, because all the particles follow determinable ballistic trajectories.

Therefore, if the brain functions in a purely classical manner, it would be theoretically possible to predict how any individual's brain will respond to any particular set of sensory input.

Therefore, a classical brain means that free will doesn't exist. With the state your brain is in right now, the next thing you think is predictable. The next action you take is inevitable.

Specifically, the information needed to theoretically predict what a particular brain will do next, is the layout of the neural network of neurons and axons, the chemical composition of the fluid that exists between the individual synapses, the current state of electrical signals being sent down all the individual axons at this present moment in time, and the sensory information that is being fed into the brain.

However, these are mere details: the central point remains - a wholy classical brain has no free will, no freedom of thought, and no freedom of action. Only the illusion of these is present, due to some feedback loop of the neural network.

Now lets consider a quantum scenario:
Simply put, if an individual neuron can be considered to be a quantum system, the state of this individual neuron may be described as a|A> + b|B> where "A" corresponds to the neuron doing nothing, and "B" corresponds to the neuron firing. "a" and "b" are associated probability amplitudes, and are complex numbers (i.e. of the form c + id).

The point is, that here nothing is certain - by definition, quantum mechanics envolves probabilites. While these probabilies can be calculated with utter precision, the outcome of measurements cannot, of course, be determined precisly beforehand.

The neuron doing nothing has a probability equal to the complex conjugate of "a" (a*a), that of it firing is b*b.

Obviously, our brain are not entirely random. However, the point is that evoking possible quantum mechanical effects in the brain, as some (eg Roger Penrose) have, yields randomness, to a varying degree.

Inherent randomness, however, also kills the idea of free will. It means that our minds are by definition unpredictable, within certain bounds, but also removes any supposed power of choice that we have, at least up to a point.

However, I will say this also: the computer I'm writing this on is reasonably impressive. It boasts 2.8 GHz of clock speed, and 512 MB of RAM. It is utterly predictable. Knowing the source code of a particular program, how the particular compiler used works, and the internal workings of the CPU etc, will tell you exactly how a particular program will function. Computers are classical in nature.

I strongly suspect classical mechanics holds sway in our brains also. Quantum mechanical effects (for example Heisenberg uncertainity of position of molecules in the synapses) are undoubtably present, but probably cancel each other out on average, and have zero net effect on the thought processes.

Either way, free will simply doesn't exist. Our brains are nothing but biological computers, classical or not.