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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.

1. There is no control.

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.

2. The active ingredient is not supposed to be belief in God.

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.

3. The active ingredient is supposed to be God.

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. Continue Reading »

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. Continue Reading »

How much does the altitude at which a cricket (or baseball) match is played affect the flight of the ball? If you’re only interested in the answer to that question, then skip ahead. But there is a reason I am particularly interested in this question, and it has to do with a freakish cricket match played in 2006.

Every sport has its fables and epics, and nothing attracts a story like an outlier. In statistics, an outlier is an event that is way out on its own, deviating significantly from the rest of the population. In cricket, for example, the primary statistic that measures how good a batter is is the batting average, defined as the average number of runs per dismissal. The details aren’t required here; it will suffice to say that an average of above 50 in test cricket marks out one of the greats. Below (top) is a plot of the batting averages of all those who have played test cricket.

We see few players with an average greater than 50, and even fewer above 60. And then comes the outlier, way off to the right – Donald Bradman, with a career average of 99.94. His other career statistics are similarly off-the-scale. The premier achievement for a batter in a match is to score a hundred runs in a single innings, a century. Bradman did it 29 times in his career of 80 innings. Of the 7 batters who have scored as many or more centuries, all required at least twice as many innings. Cricket is one of the few sports in which the question “who was the greatest?” attracts little debate.

Cricket has also seen freakish matches. Continue Reading »

(Via Luke Muehlhauser).

Oh dear. I know fundamental physics can be difficult, but this is ridiculous.

Time magazine recently posted 30 nominations for its ever-popular “Person of the Year” award. Tucked in between President Barack Obama and the Korean rapper Psy is an unlikely candidate for the “Person of the Year”—a subatomic particle. As Scientific American readers are well aware, physicists at the Large Hadron Collider announced this summer that they had found something that looks much like long-elusive Higgs boson, causing a brief but wondrous worldwide bout of Higgsteria.

Under ordinary circumstances, we would be all for the elevation of the Higgs to “Person of the Year” status, if only to further honor the heroic efforts of thousands of scientists and engineers who made the discovery possible (more on that below). But Time’s nomination threatens to do more harm than good. Every single sentence in Time’s nomination contains at least one serious error. The magazine scores a perfect five for five. …

Sentence 4: But it was not until last summer that a team of researchers at Europe’s Large Hadron Collider — Rolf Heuer, Joseph Incandela and Fabiola Gianotti — at last sealed the deal and in so doing finally fully confirmed Einstein’s general theory of relativity.

Error: Where to begin? Let’s start with Einstein. I honestly have no idea why the author would make any connection between the Higgs and general relativity. None! Because there is none. Einstein did teach us that energy and mass are two sides of the same coin (and that insight is a consequence of his special, not general, theory of relativity), but this teaching works at cross purposes to the author’s repeated assertions that the Higgs somehow transforms energy into matter.

How does a science writer with 20 years experience make this many errors? Laziness? Too many over-hyped press releases? There are thousands of scientists he could have had check those five sentences.

There will be a Solar Eclipse early on the morning of Wednesday 14th November  (less than 1 week away). The path of totality will begin at sunrise in the north of Australia in Arnhem Land and cross Cape York to near Cairns before moving out into the Pacific. For the rest of Australia outside the path of totality the eclipse will be seen as a partial eclipse of the Sun in the early morning or at sunrise. In Sydney the eclipse begins at 7.07am and ends at 9.04am. Mid-eclipse is at 8.03am when 67% of the Sun’s disk will be covered. At that time the Sun will be 27 degrees above the eastern horizon. More details here.

(Don’t stare at the sun, kids! Suitable ‘eclipse glasses’ are available locally from reputable astronomy shops and the Sydney Observatory.)

One of my favourite pieces of science writing is called “Total Eclipse” by Annie Dillard, from her book Teaching a Stone to Talk: Expeditions and Encounters. Here are a few highlights.

Now the sky to the west deepened to indigo, a color never seen. A dark sky usually loses color. This was a saturated, deep indigo, up in the air. Stuck up into that unworldly sky was the cone of Mount Adams, and the alpenglow was upon it. The alpenglow is that red light of sunset which holds out on snowy mountain tops long after the valleys and tablelands are dimmed. “Look at Mount Adams,” I said, and that was the last sane moment I remember.

I turned back to the sun. It was going. The sun was going, and the world was wrong. The grasses were wrong; they were platinum. Their every detail of stem, head, and blade shone lightless and artificially distinct as an art photographer’s platinum print. This color has never been seen on earth. The hues were metallic; their finish was matte. The hillside was a nineteenth-century tinted photograph from which the tints had faded. …

I saw, early in the morning, the sun diminish against a backdrop of sky. I saw a circular piece of that sky appear, suddenly detached, blackened, and backlighted; from nowhere it came and overlapped the sun. It did not look like the moon. It was enormous and black If I had not read that it was the moon, I could have seen the sight a hundred times and never thought of the moon once. (If, however, I had not read that it was the moon – if, like most of the world’s people throughout time, I had simply glanced up and seen this thing – then I doubtless would not have speculated much, but would have, like Emperor Louis of Bavaria in 840, simply died of fright on the spot.) It did not look like a dragon, although it looked more like a dragon than the moon. It looked like a lens cover, or the lid of a pot. It materialized out of thin air – black, and flat, and sliding, outlined in flame. …

The second before the sun went out we saw a wall of dark shadow come speeding at us. We no sooner saw it than it was upon us, like thunder. It roared up the valley. It slammed our hill and knocked us out. It was the monstrous swift shadow cone of the moon. I have since read that this wave of shadow moves 1,800 miles an hour. Language can give no sense of this sort of speed – 1,800 miles an hour. It was 195 miles wide. No end was in sight – you saw only the edge. It rolled at you across the land at 1,800 miles an hour, hauling darkness like plague behind it. Seeing it, and knowing it was coming straight for you, was like feeling a slug of anesthetic shoot up your arm. If you think very fast, you may have time to think, “Soon it will hit my brain.” You can feel the deadness race up your arm; you can feel the appalling, inhuman speed of your own blood. We saw the wall of shadow coming, and screamed before it hit.

This was the universe about which we have read so much and never before felt: the universe as a clockwork of loose spheres flung at stupefying, unauthorized speeds. How could anything moving so fast not crash, not veer from its orbit amok like a car out of control on a turn? … Continue Reading »

How to win at the races

I’ve rambled about this before, but with the Melbourne Cup - “the race that stops a nation” – a few days away and Tom Waterhouse’s annoying face on TV too often, it’s worth repeating.

Don’t bet on the horse you think will win!

More precisely, don’t necessarily bet on the horse you think will win. Here is the only betting system that works:

  1. For each horse in the race, and before you look at the price offered by the bookmaker, write what you think the probability (as a percentage) is that the horse will win. I.e. if the race was run 100 times, how many times would this horse win? You’ll have to do your homework on the field.
  2. For each horse, take your probability and multiply it by the bookmakers price. Call that the magic number.
  3. If any of the horses have a magic number greater than 100, bet on the horse with the highest magic number.
  4. If none of the horses have a magic number greater than 100, don’t bet. Go home.

The magic number is how much (on average) you would make if you bet $1 on the horse 100 times, so it better be more than 100. The way that the bookmaker guarantees that they will make a profit in the long run is to ensure that no magic numbers are greater than 100. Because of the bookmakers slice (the overround), the odds are stacked against the average punter. You will only end up with a magic number greater than 100 if either you have made a mistake on step 1, or the bookmaker has made a mistake on his price. This leads to the following advice.

You should only bet on a horse if

a) You know more than the bookmaker, and

b) The bookmaker has significantly underestimated one of the horses.

Thus, the better the bookmaker, the more reason not to bet. And so, we come to Tom Waterhouse’s online betting business:

“I’ve got four generations of betting knowledge in my blood. … Bet with me, and that knowledge can be yours.”

This is exactly the information you need to conclude that you should never bet with Tom Waterhouse. The ad might as well say “bet with me;  I know how to take your money”. You don’t want a bookmaker who knows horse racing inside-and-out, from horse racing stock, armed will all the facts, knowing all the right people. You don’t want a professional in a sharp suit surrounded by a analysts at computer screens. You want an idiot. You want someone who doesn’t know which end of the horse is the front, armed with a broken abacus and basing his prices on a combination of tea-leaf-reading, a lucky 8-ball and “the vibe“. You want a bookmaker that is going out of business.

The more successful the bookmaker, the further you should stay away. The TAB was established in 1964, has over a million customers, 2,500 retail outlets, and made a profit of $534.8 million in 2011, up 14%. Translation: never bet with the TAB. Betfair’s profits were $600 million, SportingBet made $2 billion in 2009.  With those resources, they’ll always know more than you. If you’ve heard of them, don’t bet with them. Go home.

Hopefully you’re getting my point. Don’t bet on sports. If you go to the races, put on a nice outfit, drink a few beers and give the money to charity. If you must bet, have a random sweepstakes with your friends. You’ll get much better odds that way.

Intuitively, there is an optimal mass for a ball being thrown. If it’s too heavy then we won’t be able to give it a large initial speed. Too light, and it will be slowed down very quickly by air resistance. A shot is too heavy, a tennis ball too light.

To calculate the optimal mass for a projectile, we need to have a model for how a thrower accelerates the ball before release. I will make what is perhaps the simplest assumption: the force applied by the throwers arm and the distance over which that force is applied are held constant. This is equivalent to assuming that the thrower will impart a fixed amount of kinetic energy (K) to the ball. Then, the initial speed (v) of the ball varies with the mass (m) as,

v = \sqrt{\frac{2 K}{m}}

K will be fixed using the fiducial case of a cricket ball thrown with initial velocity of 120, 140 and 160 km/h. As before, the launch angle is chosen to maximise the range of the throw for a 1.8m tall thrower.

The plot shows that, as expected, there is a mass which maximises the range of the throw. It is quite close to the actual mass of a cricket ball (0.16 kg, dashed vertical line) and a baseball (0.145 kg), which is a satisfying result. The optimal mass increases slightly with the force applied by the thrower (i.e. the fiducial initial velocity v_0).

Next time: how much easier is it to hit a six (or a home run) at higher altitudes?

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