On the intractability of free will

[Author's note: the thoughts here originated as a Letter to the Editors at New Scientist, in response to a somewhat throwaway remark, in an article about randomness, that chance may be essential to the existence of free will. I felt that the point deserved delving into in more depth. New Scientist did publish the letter, but as is typical edited it down for publication -- in particular, many of my adverbs did not survive. Consequently, I wanted to share the full text here.]

Randomness may be necessary to "admit free will" in an otherwise-mechanical universe ("Chance", New Scientist 14 March 2015, p.28ff) but by itself it is not sufficient. It's hard to argue scientifically about the existence of free will in the absence of a rigorous definition of what it is, but we can say something about what it does. And at a minimum, it's existence requires that the outputs of my brain -- my actions -- are not completely determined by the inputs plus initial state. This is, of course, an astonishing proposition that is contrary to any other known physical system or law. Even if we introduce randomness, we merely allow a range of outcomes distributed probabilistically, but we still have no element of intentionality or purpose, the other essential ingredient in free will. Randomness alone would make us no more free than tumbling dice.

One intriguing possibility, however, is that whatever free will actually is, randomness provides a means for it to influence the brain without apparently violating known physical law; a curtain behind which it can hide. Imagine that free will is able to influence apparently-random outcomes deep in the brain, to achieve a desired output, but is also constrained by the need to appear random over the long term. The brain would be like a rigged casino where the roulette wheel comes up red or black at the casino's own choosing, but it must still ensure that the two come up equally over the long term if it is not to be caught breaking the rules. Correspondingly, we might speculate that free will rigs the brain game by influencing individual apparently-random quantum outcomes, which chaotic systems in turn amplify to macroscopic scale, but is limited in the long run because the overall outcomes must match our probabilistic quantum expectations.

Intriguingly, existing psychological experiments are consistent with this model of free will. For example, we know that behaviors that are usually considered exercises of free will such as "paying attention" or "resistance to temptation" are limited and can be exhausted, requiring time to recharge, even though they don't seem to be associated with anything as obvious as depletion of specific neurotransmitters or saturation of synapses. Yet this is exactly what we expect if free will can only influence a limited number of outcomes while staying hidden within known physical laws.

Whatever free will turns out to be -- assuming it exists at all -- understanding it will take at least as great a conceptual leap as that from classical mechanics to quantum theory. And perhaps it is only the reality of chance that connects these three views of reality into a consistent, scientifically explicable universe.

Athens and Sparta: A Parable About Open and Closed Source Software

Among all the city-states of Classical Greece, the most famous are certainly Athens and Sparta. Sometimes allies, often enemies, despite their shared language and culture, these two could not have been more different. So in the rivalry between Athens and Sparta, who ultimately emerged the winner?

In the 5^th century BCE, the dominant city-state was Sparta. It was hierarchical, authoritarian and ruled by tyrannical kings and aristocrats. It’s greatest cultural values were discipline and conformity, and the kings of this highly militaristic state were also its generals. Sparta was incredibly effective at concentrating its resources to conquer a chosen goal – the phrase “the tip of the spear” could have been invented for them. As a result, Spartans were feared in battle across the Greek world, and Sparta was able to impose its military will on its neighbors.

But then, Athens began to rise to prominence and oppose the hegemony of Sparta. It became a famous center of creativity in the arts, learning and philosophy, home to Plato's Academy and Aristotle's Lyceum. Athens also gave the ancient world Socrates, Pericles, Sophocles and many more philosophers, writers and politicians. Its schools and forums were often lively, open-air marketplaces for competing ideas. It thrived on chaos. Even more remarkable were its experiments in democracy that included a unique combination of direct and representative democracy: everybody was expected to participate in and contribute to Athenian civic life. In stark contrast to Sparta’s general-kings, Athens elected its generals according to the needs of each war.

For a century, Athens and Sparta were in almost constant conflict for dominance of the Greek world, pausing occasionally and briefly to unite against a common enemy. Finally, in 404BCE, Athens was defeated for good and fell under Spartan rule. So did this mean that Sparta had won? Not exactly: Sparta’s dominance was short-lived. Neither Athens nor Sparta ever fully recovered from the costs and destruction of their wars, which impoverished most of the Greek world and ushered in the end of Greek pre-eminence.

So if both Sparta and Athens lost, who won? While Sparta and Athens were exhausting themselves in civil war, far to the west a small village called Rome was growing into a regional power. Rome was something strange and new: it borrowed many ideas from the Greeks, but had no real artistic culture of it’s own. Its sculpture, painting and poetry were second-rate derivations, sometimes even direct copies, of the works of the Greeks. It contributed no significant advances in mathematics or science, and barely anything to philosophy. Even the gods that the Romans claimed to worship were obvious imitations of the Greek pantheon. And yet, the Romans were exceptional engineers, great builders and implementers of others’ ideas. While the Greeks declined, Rome conquered a vast empire, convincing native populations almost everywhere that it was in their best interests to assimilate into Roman ways.

In the end, neither Sparta nor Athens won: both lost to Rome.

De-cluttering

My three step plan for de-cluttering my house:

1. Rent a storage locker
2. Fill it with all the junk that I never use and / or really don't need
3. Default on the rent

Diet

A friend of mine who is big into "natural foods" told me never to eat anything I couldn't pronounce, which is why I don't eat quinoa or acai.

What would Jesus do?

A church in San Francisco has promised to remove controversial sprinklers it installed to deter rough sleepers, reports the BBC. "After an outcry, the city's archdiocese admitted it had been "ill-conceived" for St Mary's Cathedral to treat homeless people in this way", it goes on.

The new policy replaces the sprinklers with landmines and automatic machine guns.

Physics and the Marvel Movies

Broadly speaking, the Marvel studio movies have managed to remain largely physically credible; and by this I mean that, while there are conceits that you simply have to accept for the sake of the story, and much of what goes on is often beyond current engineering, medical science, and so on, it is at least plausible. For example, in the Iron Man movies, the suit itself is a fairly reasonable extrapolation of current and experimental military exoskeletons; the arc reactor power source, however, you're just going to have to take at face value.

By the way, I'm referring here to the interlocking movies produced by Marvel themselves, also known to fans as the MCU, for Marvel Cinematic Universe. The movies made by other studios, such as the X-Men and Fantastic Four franchises, threw credibility overboard a long time ago.

Next year (2015), the MCU is going to get seriously weird, however. With the introduction of Quicksilver and Wanda to the Avengers, and a Dr. Strange movie -- Stephen Strange was name-checked in Captain America: The Winter Soldier, so presumably this will take place in the same continuity -- it's hard to see how Marvel will explain itself without just shrugging and saying "Magic".

Before that happens, therefore, I wanted to jot down some notes on the least physical elements of the movies to date, basically because I enjoy this sort of thing. Oh, and I probably shouldn't need to say this, but obviously:

SPOILERS!

• Iron Man 1: Deceleration is the big issue here. Stark pulls some serious Gs in his flight maneuvers, especially when he opens the flaps to evade the fighter jets; but that's not the biggest problem -- let's just accept that he has invented the world's best pressure suit. No, the big issue is when he lands hard, going from full speed to a three-point landing in nothing flat. It doesn't matter how good his airbags are, his body is coming to a stop in a very short period of time. In any realistic scenario, when they open up the suit after a landing like that, they're going to find a can of Tony Stark soup. (By the way, when I first watched the movie, that wasn't the thing that made me go "Oh, c'mon!". No, that was when Tony returned from Afghanistan and he wants a burger... so he goes to Burger King. He's in California: obviously, he's going to go to In'n'Out. Let's try to keep this at least a little realistic, OK?)
• Iron Man 2: The "internal problem" in this movie is that Tony's arc reactor is poisoning him so he needs to replace the palladium that is a key component. Using instructions left to him by his father, he creates... a new element. Did anybody involved look at the Periodic Table and ask "Gee, where will this new element, which is chemically and electrically very similar to palladium, fit? I wonder why nobody else noticed that gap?". I suppose it's possible to dismiss this as one of those conceits I mentioned, but a much better solution is at hand: have Tony create a room-temperature superconductor. Not only is this a reasonable extrapolation of current science, it's an area where researchers are exploring many different approaches, so there's plenty of room for Tony to try something new and solve the challenge. Also, Tony is a genius at engineering, not basic science (notwithstanding the Avengers, where he just a generic STEM genius), so it's a better fit for the character. 
• Captain America: One could quibble about just how the Super Serum works, but the big physical problem here is simply conservation of mass: Steve Rogers bulks up by at least 100 pounds in a matter of seconds, so where did all that matter come from? Note that the naive answer "it came from the energy they drew from the electrical grid" doesn't work, because it takes an enormous amount of energy to make a very small amount of mass. To give a sense of scale, consider the Soviet Union's Tsar Bomba, the largest hydrogen bomb ever tested. That bomb yielded on the order of 50 megatonnes-equivalent, roughly 10 times all of the conventional explosives combined used in World War II. In order to create Steve Rogers' 100 pound gain, you would need to harness the energy yield of approximately twenty Tsar Bombas, and do so in just a few seconds. 
• The Avengers: This has been well addressed elsewhere, but the most obvious engineering problem is whether or not the helicarrier could fly; and the likely answer is No. At the depicted size of carrier, the rotor blades would have to be much larger. Or at the size of rotor shown, they would have to spin much faster, but then you get into problems of material science (the blades would break apart) or tip speed (what happens if the tip exceeds the speed of sound?). 
• The Hulk: One of the nicer touches in the Hulk movies (and his appearance in the Avengers) is that they take seriously what happens to the ground beneath him when the Hulk jumps and lands. But as with Captain America above, where does the extra mass of the Hulk's body come from? In the comic books, the Hulk is the result of exposure to a fictional "gamma bomb", but as noted even the largest nuclear explosions convert only a few pounds of matter to energy, so even if you could capture all that energy, turned back into matter it would still only amount to the same few pounds. The most plausible explanation I can come up with is that the Hulk, in fact, weighs the same as Banner and his huge size comes from the fact that he is inflatable -- really, they should call him The Inflatable Hulk. I do realize, however, that this theory may be difficult to reconcile with other depicted elements of the character.
• Guardians of the Galaxy: Obviously there's a lot we just have to take for granted in this movie because aliens, but my gripe is with a very Earthbound technology. Peter Quill has been playing the same cassette tape for over 25 years, and it still isn't a tangled, broken mess? He even plays it in a Sony Walkman without damaging it, which is just downright ridiculous. (On a lesser but related note, when he finally unwraps Awesome Mix 2, it's amazing that the tape hasn't degraded to the point that it is hopelessly stuck together.)

I'm sure there's more to be found in the movies not mentioned above, but that's all for now. Comments welcome.

Quantum Leap: the Movie

Like many people, I found the ending of Quantum Leap unsatisfactory. I've long had an idea for a story that would wrap it up both more neatly and provocatively.

And by the way, if anybody from the copyright holder (or anybody who knows somebody...) happens to be reading: I disclaim all rights in this idea. Use if freely. I'd far rather see this made than get paid (although a "from an idea by..." credit would be nice.)


[fade to black]
Open on: the same set and title card that closed out the original TV series.

 Burn in: Dr. Sam Beckett never returned home.
[crossfade to]
Burn in: ...Until today

Open on Sam, emerging from a leap. He is in an anonymous office bathroom, could be anywhere in America, any time from the 1980s to the present day. POV over his shoulder, he looks into a wall mirror and sees...

…himself, as young as he looked at the beginning of the project.

Sam: Oh boy!

[Titles]

The story then unfolds: after many years of leaping, Sam has somehow leaped into his own body. It is 1999 [the "present day" of the project in the original series], just a few days before the experiment that launched his first leap. And Sam has just days to decide: knowing what he knows now, does he take the leap or not? If he does leap, he knows he may never get home again. This may be his one and only chance to break out. But if he doesn't leap, does he change history and erase all the good he has ever done? He has no idea... and no help (at first).

Back in his own timeline [our present day], a long-retired Al dozes in a chair. The QL project was shut down years ago. They had lost contact with Sam, and after months with no sign of him, everybody had assumed he was lost in time. The one exception: Al never gave up hope, and even though the project is mothballed, he still has the comm device gathering dust in a drawer of his desk.

And after all these years it blinks into life, and starts bleeping, waking Al.

So now Al, with the help of a grown-up Sammy Jo, tries to reboot Ziggy, contact Sam in 1999, and figure out the consequences of his decision. But the closer they get to the choice to leap or not, the more erratic and unhelpful Ziggy becomes: instead of converging, her predictions and probabilities are bouncing wildly, as every choice Sam makes seems to involve terrible paradoxes and instabilities. Whatever Sam chooses seems to be wrong...