The following table has appeared on my Facebook feed a few times.
I have a few points to make in response. What follows is a critique of the table above, not of the Bible or Christianity. (more…)
I’ve blogged before about my admiration for the remarkable talents of Derren Brown. However, I’ve just finished watching his latest TV offering, Fear and Faith, (Episode 2, first broadcast on Friday 16 November 2012) and I find it deeply flawed.
The show is pitched as an experiment. In particular, I’m going to discuss the segment in which “an atheist [Natalie] is given a religious conversion” via what Brown calls psychological techniques. The results of the experiment are very striking – I encourage you to watch the video, if you can.
Let’s begin by reminding ourselves of what an experiment is. Very simply, an experiment is a controlled attempt to link a particular cause to a particular effect. If you want to know whether morphine can relieve pain in humans, you might think that you just give people in pain morphine and then ask if the pain went away. However, this experiment cannot tell whether it was really the morphine that did it. Thus, we must use a control.
The idea of a control is to use two experiments that differ only in the presence or absence of what we’ll call the active ingredient. We must be able to control both the active ingredient and the other variables. It is crucial that in every other way, the experiments are as identical as possible. In medicine, one crucial variable is the mental state of the patient, which is why the trial must be double blind – to factor out the placebo effect, patients and even their doctors cannot know whether the pill is real or fake.
Thus we come to Derren Brown’s experiment. I have four criticisms.
An effect is caused, but in the absence of a control, it isn’t clear to what it should be ascribed. This points to an even deeper problem.
That one can produce a religious experience in the absence of belief in God is not an interesting conclusion. Plenty of religious people claim that a religious experience caused (and thus preceded) their belief in God. In fact, it would be much more embarrassing to the religious cause if religious experiences only happened in cases where the subject already believed in God, since that would make it seem as if the prior belief created the experience. Brown excludes this hypothesis.
Tonight I’m going to investigate what I think could be the biggest placebo of them all – God. … This innate hardwiring we have really can give a powerful experience of God, without any need for Him to exist.
God himself (if you’ll allow the traditional masculine pronoun) is the active ingredient. Brown is claiming that he can create a religious experience in the absence of any action of God.
Let’s repeat the experimental logic, as we applied it to morphine (cause) and pain relief (effect) above. To adequately test the causal connection between religious experiences and God, Brown would need to control God. At the very least, he would need to perform an experiment in the absence of God. He would need to build a divine Faraday cage, to shield the possible effects of God.
Obviously, this is not what Brown has achieved. The experiment only proves that God is not required for a religious experience if there is no God, for only then is the active ingredient known to be missing from the experiment. Brown cannot exclude God as the cause of the experience without begging the question. The most he can claim is that he can do it “without mentioning God at all”. And that, clearly, is not the same thing. (more…)
I’m going to jump back on one of my favourite high horses. I’ve previously blogged about Lawrence Krauss and his views on the question “why is there something rather than nothing?”. I’ve just finished his book, and he appeared last night on an Australian TV show called Q&A. It was a good panel discussion, but as usual the show invites too many people and tries to discuss too much so there is always too little time. Krauss’ discussions with John Dickson were quite interesting.
I’ll be discussing the book in more detail in future, but listening to Krauss crystallised in my mind why I believe that science in principle cannot explain why anything exists.
Let me clear about one thing before I start. I say all of this as a professional scientist, as a cosmologist. I am in the same field as Krauss. This is not an antiscience rant. I am commenting on my own field.
Firstly, the question “why is there something rather than nothing?” is equivalent to the question “why does anything at all exist?”. However, Krauss et al have decided to creatively redefine nothing (with no mandate from science – more on that in a later post) so that the question becomes more like “why is there a universe rather than a quantum space time foam?”. So I’ll focus on the second formulation, since it is immune to such equivocations.
Here is my argument.
A: The state of physics at any time can be (roughly) summarised by three things.
1. A statement about what the fundamental constituents of physical reality are and what their properties are.
2. A set of mathematical equations describing how these entities change, move, interact and rearrange.
3. A compilation of experimental and observational data.
In short, the stuff, the laws and the data.
B: None of these, and no combination of these, can answer the question “why does anything at all exist?”.
C: Thus physics cannot answer the question “why does anything at all exist?”.
Let’s have a closer look at the premises. I’m echoing here the argument of David Albert in his review of Krauss’ book, which I thoroughly recommend. Albert says,
[W]hat the fundamental laws of nature are about, and all the fundamental laws of nature are about, and all there is for the fundamental laws of nature to be about, insofar as physics has ever been able to imagine, is how that elementary stuff is arranged. (more…)
I remember a technology TV show in the mid 90’s showing a roller coaster simulator ride. The audience is shown a simulation or video of the view out the front of a roller coaster, and the seats jostle and tilt in concert with the footage. I was only 11, but I concluded that it was the coolest thing ever.
There is a good physics reason why these rides are almost convincing. Galilean relativity says that inertial reference frames are indistinguishable using local experiments. In layman’s terms, if you are in an enclosed plane traveling in a straight line at a constant speed, then there is nothing you can do inside the cabin to work out how fast you are travelling1. The plane could be stationary or it could be doing a thousand miles per hour, and you won’t notice any difference between walking up the aisle and down the aisle.
In a car, we gauge speed by looking out the window and watching the scenery fly past. Ride simulators can simulate a fast moving roller coaster by showing a simulation of scenery going past. They also simulate the bumps and shunts by jostling your seat – the faster your car is going, the more you will feel the small deviations from uniform motion due to potholes.
I’ve been on a few of these rides, and I’m not fully sucked in. Speed is fine, bumps are fine, but the most exciting part of a real roller coaster ride is the “stomach in your throat” feeling as you go over a crest, or being thrown to one side as you take a corner at speed. Unlike speed, acceleration can be measured locally, so it can’t be simulated with a video and a shaky chair.
There is a way to simulate acceleration. Einstein’s equivalence principle roughly states that freely falling is locally indistinguishable from zero gravity. We can illustrate this point with a thought experiment. Suppose you wake up in an elevator which is freely falling (i.e. ignore wind resistance etc). There is nothing you can do inside the elevator to determine whether you are freely falling, or whether someone has turned off gravity2. If you want to know what it would be like if there were no gravity, then go jump off a cliff (in your mind, of course). (more…)
I recently posted on Arxiv a paper titled “The Fine-Tuning of the Universe for Intelligent Life”. A slightly shortened version has been accepted for publication in Publications of the Astronomical Society of Australia. The paper is primarily a review of the scientific literature, but uses as a foil Victor Stenger’s recent book “The Fallacy of Fine-Tuning: Why the Universe Is Not Designed for Us” (FoFT). Stenger has since replied to my criticisms. The following is my reply to his reply to my article criticising his book which criticises fine-tuning. Everybody got that?
A few points before I get into details:
A major claim of my response (Section 4.1) to FoFT is that Stenger equivocates on the terms symmetry and PoVI. They are not synonymous. For example, in Lagrangian dynamics, PoVI is a feature of the entire Lagrangian formalism and holds for any Lagrangian and any (sufficiently smooth) coordinate transformation. A symmetry is a property of a particular Lagrangian, and is associated with a particular (family of) coordinate transformation. All Lagrangians are POVI, but only certain, special Lagrangians – and thus only certain, special physical systems – are symmetric. Stenger replies:
“PoVI is a necessary principle, but it does not by itself determine all the laws of physics. There are choices of what transformations are considered and any models developed must be tested against the data. However, it is well established, and certainly not my creation, that conservation principles and much more follow from symmetry principles.”
Note how a discussion of PoVI segues into a discussion of symmetry with no attempt to justify treating the two as synonymous, or giving an argument for why one follows from the other.
Of course conservation principles follow from symmetry principles – that’s Noether’s theorem. It’s perfectly true that “if [physicists] are to maintain the notion that there is no special point in space, then they can’t suggest a model that violates momentum conservation”. The issue is not the truth of the conditional, but the necessary truth of the antecedent. Physicists are not free to propose a model which is time-translation invariant and fails to conserve energy1. But we are free to propose a model that isn’t time-translation invariant without fear of subjectivity.
And we have! Stenger says: “But no physicist is going to propose a model that depends on his location and his point of view.” This is precisely what cosmologists have been doing since 1922. The Lagrangian that best describes the observable universe as a whole is not time-translation invariant. It’s right there in the Robertson-Walker metric: a(t). The predictions of the model depend on the time at which the universe is observed, and thus the universe does not conserve energy. Neither does it wallow in subjectivity.
Watch closely as Stenger gives the whole game away: (more…)
“Leave only three wasps alive in the whole of Europe and the air of Europe will still be more crowded with wasps than space is with stars, at any rate in those parts of the universe with which we are acquainted.”
I love a good illustration.
For whatever reason, I’m drawn to old popular-level science books. I just finished reading “The Stars in Their Courses” by James Jeans, first published in 1931. Jeans is best known in my field for the “Jeans length”. Suppose a cloud of gas is trying to collapse under its own gravity, but is being held back by gas pressure. Jeans showed that there is a critical length scale, such that if the object is smaller than the Jeans length then pressure wins and the cloud is stable, but if it is larger then gravity wins and collapse ensues.
Jeans gives an overview of all of the astronomy of his day. It’s mostly familiar material, of course; the interesting bit is the glimpse inside the mind of the great scientist. Here’s a neat illustration:
“If we could take an ordinary shilling out of our pocket, and heat it up to the temperature of the sun’s centre [40 million kelvin], its heat would shrivel up every living thing within thousands of miles of it.”
Repeating this calculation, I think Jeans is reasoning as follows. A shilling is about 5 grams of copper (specific heat capacity 0.385 J/gram/kelvin), and so at 40,000,000 K we have about J of energy. This is ‘only’ 20 kg of TNT – most bombs are at least a tonne of TNT equivalent, and they don’t do miles of damage. That much energy could raise the temperature of the surrounding air to boiling point for about a 10 metre radius. Not too promising. However, the coin will be emitting thermal radiation at x-ray wavelengths. A lethal dose of x-rays is about 5 J/kg, so our coin has enough energy to kill about 100,000 people. One must factor in the fraction of energy emitted horizontally, the fraction absorbed by biological material, the cooling of the coin, etc, but certainly it’s a very dangerous coin.
Peter Kreeft once commented (in a talk – sorry I can’t give a reference) that he tells his undergraduate students that “if your faith is weak and you don’t want to lose it then don’t read The Brothers Karamazov by Fyodor Dostoyevsky”. I can scarcely think of a better recommendation for a book. And as if you need more reason, observe this gem (page 274 of the Penguin paperback):
[Ivan:] … if God really exists and if he really has created the world, then, as we all know, he created it in accordance with the Euclidean geometry, and he created the human mind with the conception of only the three dimensions of space. And yet there have been and there still are mathematicians and philosophers, some of them indeed men of extraordinary genius, who doubt whether the whole universe, or, to put it more wildly, all existence was created only according to Euclidean geometry and they even dare to dream that two parallel lines which, according to Euclid can never meet on earth, may meet somewhere in infinity. I, my dear chap, have come to the conclusion that if I can’t understand even that, then how can I be expected to understand about God?
The Brothers Karamazov was published in 1880. Ivan is referring to the discovery a few decades earlier by Lobachevsky that Euclidean geometry is not unique, and thus it is an empirical matter whether or not parallel lines meet (or are unique) in our universe. This seems like a very minor loose thread in physics, and yet when Einstein pulled on it, 35 years after Ivan’s monologue, he was lead to General Relativity, arguably the greatest achievement of a single physicist since Newton. Gravity is geometry!
This quote came as quite a surprise to me. I hadn’t realised that non-Euclidean geometry had reached popular culture in the 1880′s.
This was an epoch making book for me – it was the first book I read on a Kindle. I think the Kindle is great, especially for quote miners like myself. You can highlight passages, and then with the help of an Applescript (google it), one can download the highlighted passages to note taking software EverNote. Genius. If they handled PDFs and note-taking better, I’d be very tempted to dispense with printing papers altogether.
As for the book, it was very enjoyable reading. The topic of the book is the progress made towards understanding the natural world made during the Middle Ages, which are often portrayed as an intellectual dark age. Here are a couple of notable passages:
I’ve hit something of a purple patch with books of late, so its time for some brief book reviews. Most of these will concern topics outside my area of expertise, and so I can’t offer anything like a rigorous critique.
My first book is “The Decisive Moment”, by Jonah Lehrer. I blasted through this book in a few evenings back at the hotel during a conference. It made very enjoyable reading. In particular, the author makes very good use of narrative – one is enticed into each chapter with a variety of case studies. Chapter six’s account of the serial killer John Wayne Gacy, for example, makes for compulsive reading.
The theme of the book that most resonated with me was the importance of emotion to rationality. Emotions are often thought of as irrational – we see this in expressions like “I let my emotions get the better of me” and the connotations of objectivity attached to the adjective “dispassionate”. I think this goes back at least to Plato. Lehrer, however, shows that emotions do have an important role to play in decision making. They allow for fast, unconscious decisions to be made and implemented. Those who due to brain injuries have seemingly lost the ability to form emotions find that even the smallest decisions – chicken or beef? – paralyse them like Buridan’s ass. Conscious thought can actually lead to worse decisions, as in the case of would-be jam experts (page 138). Those who simply tasted a selection of jams and reported which ones they liked best broadly agreed with the opinions of food experts. Those asked to analyse their impressions via written questionnaires suddenly preferred inferior jams. It’s a beautiful little parable, and Lehrer’s discussion of such examples is both nuanced and insightful.
The book is both practical and philosophical, ranging from how to make better decisions to the most contrived ethical conundrums. Experimental findings and anecdotes are weaved seamlessly. I read the book over a year ago, but looking back over it now makes me want to read it again.
I love David Mitchell. I love everything he’s done – Peep Show, Would I Lie to You, That Mitchell and Webb Look, Sound and Book, his work on QI, Mock the Week and any other panel show, Soapbox, and various articles. I was listening to a conversation with Mr Mitchell on CarPool with Robert Llewellyn of ‘Red Dwarf’ fame. He started talking about his time spent studying history at Cambridge, and why it interested him:
If you don’t want to explain things, then you’re a moron. As far as I’m concerned, trying to explain things through what the molecules people and things are made up of, or the chemicals and how they react to each other, is an incredibly roundabout way. You know, I don’t want to know that. I assume that will keep going whether or not I understand it. I want to know why we are in a country called Britain, why are these people in charge. That seems to me to be the direct way of generally explaining things. Obviously, I’ve got a lot of time for the scientific urge to explain. But for me, that’s always been a bit secondary to specifically explaining “what’s this stuff, and don’t tell me what it is at a subatomic level!” (more…)