It's a bit more complicated than that - fat and sugar

Ian Leslie has written an interesting long read for the Guardian: "The Sugar Conspiracy".

It's a good illustration of how science works. Science is a great idea and, I would argue, the best thing we have for finding out if something is true or not. I like Jerry Coyne's definition of science, broadly construed: "as the use of reason, empirical observation, doubt, and testing as a way of acquiring knowledge." Unfortunately, like many great ideas, it's carried out by fallible humans, and so whilst in principle, and practice, science has given us great leaps forward, that progress is often constrained by the personalities and foibles of those involved in the debate at the time. Max Planck's remark neatly sums this up: “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.” Leslie, referencing that same remark (and showing empirical support for it), shows how nutritional advice has followed this pattern. (To see another illustration of this in practice, you should read the excellent Big Bang by Simon Singh).

However, I have a few problems with the article:

The first is that it talks favourably about the Atkins diet, deriding those who questioned it. However, the Atkins diet is a fad diet, and not a very good one.

For starters, Leslie rightly says "Controlled trials have repeatedly failed to show that people lose weight on low-fat or low-calorie diets, over the long-term.". The problem is, the Atkins diet is also a low calorie diet.

The Atkins diet advocates high fat and protein, and virtually no carbohydrates. The diet results in people eating food that leaves them feeling full for longer. Consequently, they have a reduced calorie diet because they don't eat as many calories. Whilst patients may lose weight on the Atkins diet, the diet is not risk free - for example it may lead to damage to tissue and vascular damage, and could lead to life threatening complications.

The article also seemed a bit disingenuous to claim "Only in the last few years has it become acceptable to study the effects of Atkins-type diets." Atkins first book may have been published in 1972, but it was the 2002 book "Dr. Atkins' New Diet Revolution" that really saw the Atkins diet take off (see the Google ngram graph). It didn't take long for the scientific community to look at the efficacy and safety of low-carb diets, see "Atkins and other low-carbohydrate diets: hoax or an effective tool for weight loss?" from The Lancet in 2004 and "Safety of low-carbohydrate diets" from 2005. These are both over a decade old - does that qualify as the "last few years"?




The Atkins diet also restricts intake of fruit and vegetables - diets high in fruit and veg lower the chances of a number of diseases.

On top of that, ideally the goal of a weight loss programme should be for the weight to stay off. A recent (albeit small) study showed the Atkins diet was no more effective than other weight loss programmes, but that after the 6 month trial, the 12 month follow up showed that weight had been put back on.

My second issue with the article is that it leaves one with the impression that fats are okay, and sugar is bad, and that reducing sugar is the key to resolving the obesity epidemic (and there is an epidemic - some people will try and tell you that there isn't one, but it has become harder to deny when there are more obese people than underweight people in the world) - but it's much more complicated than that. Cutting out carbohydrates is will not give a healthy, balanced diet, after all carbohydrates are the bodies preferred energy source - in fact the NHS Eat Well guide is a very good way of thinking about how much, and of what, you should be eating. However, following a diet plan can be useful, and there is also a guide on the pros and cons of a number of diets out there on the market. Indeed cutting out carbohydrates will result in less fruit and veg being consumed - something Robert Lustig does not recommend.

This leads to another grumble - Leslie should have distinguished between refined carbohydrates ("sugar") and complex carbohydrates, like starch. The article is about the refined carbs - what people put in their tea, and yet when advocating low carb diets, this can include cutting out complex carbohydrates as well. It's a distinction that should have been made.

Lastly, Taubes is lauded for his book, but he is not without his critics - some of those criticisms are the same that Leslie is making: conclusions being made with insufficient evidence, which Taubes is also guilty of when he concludes that low carb diets are the key.

Diet is not the only factor when it comes to weight management. It is emerging that the microbiome of the gut may play a part, and of course, the other important factor absent is levels of exercise. The article makes it look like cutting out carbs will solve obesity, but his isn't the case.

Whilst there are lots of factors involved in a person's weight, achieving or maintaining a healthy weight isn't complicated. You must expend more calories than you take in to lose weight. It's simple physics - whilst people may lose weight at a different rate, the body gets its energy from the food that is eaten. If more of that energy is being used than is being taken in, then weight will reduce. As Michael Pollen said "Eat food. Not too much. Mostly plants". I would add - move yourself often.

The problem though is not informing people of these things, it's actually changing people's behaviour (see page 13 of this link) so that the information is taken on board - but if the information provided is misleading, as I feel that Ian Leslie's article is, then that won't help in that regard.

Scott Adams' Biggest Fail

In a recent blog post, titled "Science's Biggest Fail", Scott Adams (of Dilbert cartoon fame) writes:

"What’s is science’s biggest fail of all time? I nominate everything about diet and fitness."

The problem is, he goes on:

"The pattern science serves up, thanks to its winged monkeys in the media, is something like this:
 Step One: We are totally sure the answer is X.
 Step Two: Oops. X is wrong. But Y is totally right. Trust us this time."

Here in lies one of Adams' problems - his understanding of science appears to come from the media, whom he views as science's winged monkeys. This is unfortunately not the case - the media don't do science at all well, as Ben Goldacre has so ably demonstrated on many an occasion.

This is a shame as he continues:

"Science isn’t about being right every time, or even most of the time. It is about being more right over time and fixing what it got wrong. So how is a common citizen supposed to know when science is “done” and when it is halfway to done which is the same as being wrong?
 You can’t tell. And if any scientist says you should be able to tell when science is “done” on a topic, please show me the data indicating that people have psychic powers."

He obviously sees science as a cumulative process, but digests it from sources that don't - the mainstream media. This is something Adams has form for - in 2007 he posted about his pretty poor understanding of evolution after reading a Newsweek article, and it appears despite criticism at the time, he has not learned from this. In this post, he references a MotherJones article, and not the actual original research itself, for example.

Adams asks "So how is a common citizen supposed to know when science is “done” and when it is halfway to done which is the same as being wrong?" (As an aside, half way to done is not the same as being wrong. Newton's work on gravity could be described as half way to done. It was incomplete, but it certainly wasn't wrong when it comes to describe the general mechanics of our day to day living). So how is a common citizen supposed to know when science is "done"? Well it's not hard, you just need to do a bit of digging. It's not always possible to get the original research, as much of academia is behind a pay wall, and even if you do have access to it, it may not be the easiest to understand, because science is confusing and counter intuitive at times, and it helps to have someone who can put the complexities into layman's terms. The Cochrane Library offer the best analysis of our current understanding of research into health. These reviews come with a plain language summary.

It's not just academic institutions though - we live in the information age. Behind the Headlines, Margaret McCartney's blog or Science Based Medicine are just three examples of critical commentary that's freely available to help get the truth behind the often poor medical science reporting in the press. 

Indeed, blog networks like Phenomena from National Geographic, Why Evolution Is True or Sean Carroll's are all places to find out good commentary on the science news of the day.

This is to say nothing of the works of Professors Alice Roberts, Jim Al-Khalili or Brian Cox in their works efforts to increase the public understanding of science.

These references barely scratch the surface of the wealth of decent scientific information that's available to us if we're willing to look.

In 8 years he seems not to have learnt to base his views on science from what scientists actually say, but what they are reported to have said. I wonder if in the same time he still bases his ideas on his "bullshit filter":

"I’ve been trying for years to reconcile my usually-excellent  bullshit filter with the idea that evolution is considered a scientific fact. Why does a well-established scientific fact set off my usually-excellent bullshit filter like a five-alarm fire?"

The above was written in 2007 - The Selfish Gene by Richard Dawkins was published in 1976, and was followed up by The Extended Phenotype in 1982, and much more; Darwin's Dangerous Idea by Daniel C Dennet (the best book on evolution I've ever read) was written in the 1995 and in 2002 Ian Stewart and Jack Cohen released Evolving the Alien. All these wonderful books (and many more), just one book a decade since his twenties, could easily have defused the five-alarm bullshit filter, especially as he has been struggling with it for years. 

The impression I get from Scott Adams is that he knows he's right, and that's enough. Of course, I could be wrong, but given his history of things like sock puppetry, and his responses to it, I think Adams' biggest fail is his arrogance, which in places looks a lot like the Dunning-Kruger effect. David Dunning, it's co-discoverer, describes it thus: “What’s curious is that, in many cases, incompetence does not leave people disoriented, perplexed, or cautious. Instead, the incompetent are often blessed with an inappropriate confidence, buoyed by something that feels to them like knowledge.”

Fortunately, Scott Adams can resolve this issue by doing a little research and educating himself beyond what he thinks he knows.

Interesting stuff about light

This conversation happened on Facebook and there is no point in adding to it, as communication has broken down. However, the last addition* is like an itch I can't scratch, and so instead of adding stuff there, I thought I'd write about light.

A pro baseball player can throw a baseball at around 90 miles per hour (mph). If he were to do the same throw whilst standing on top of a vehicle moving at 60 mph, then the ball would be traveling at 150 mph. Now, if the baseball player where to stand still and use a torch, the light would leave the torch at 299,792,458 metres per second (m/s). If he then was on a vehicle moving at 542 m/s, and shone his torch, the light would not leave the torch at 299,793,000 m/s. It would leave at 299,792,458 m/s.

299,792,458 m/s is the speed of light. Actually, it's the speed of light through a vacuum, light travels slightly slower through the air (and slower again through water, this explains the rainbow. The red end of the spectrum slows down more than the blue end of the spectrum when light enters water, and so this is why we can see rainbows).

299,792,458 m/s is also the fastest anything can move in the universe. To achieve this speed, you must have no mass. The faster you want to throw a ball, the more effort (and therefore energy) you must put into throwing it. To move something with mass at the speed of light would require infinite energy. So far the photon (a particle of light) is the only known massless particle, though others are theorised such as the graviton.

This all might sound theoretical at the moment, but it is used practically as well. Without our knowledge of the above, Sat Navs would not work. If you were to go and drive with a Sat Nav for an hour, the satellites that work  out where you are would actually experience less than an hour. This is pretty counter intuitive.

The best way that helped me understand it is like this: Imagine you're in a car going at 60 mph. If a car drove past you at 70 mph, from your point of view in the car it would like it was moving past you at 10 mph. Likewise, if you were level with another car travelling at 60 mph, from your point of view, they would look still (and this effect is used in action movies for our heroes or villains to jump from one vehicle to another whilst they move at high speed). If you then accelerated to 70 mph, it would like the car that was next to you was now moving behind you at 10 mph.

Now if we think back to the second paragraph, light always travels at the speed of light. In all the cases above, whichever of the cars you are in, you will always see light travelling at the same speed. Speed is distance traveled over a period of time. If light always travels the same distance over a period of time, no matter how much distance you are travelling in that time, something has got to give, and this is relativity, as described by Einstein. It's called relativity because time is relative. The faster you move, the slower time passes for you relative to an external observer who is moving slower than you (or not moving at all).

This effect is called Time Dilation, and was used in the plot for the original Planet of the Apes films - Charlton Heston et al travelled on a ship going at close to the speed of light, and were on it for 18 months, however, as the ship crashes onto an unknown planet, it's noted that the year is 3978 - a full 2006 years after the crew left Earth. The satellited servicing our Sat Navs also experience time dilation, and this must be taken into account when they calculate where exactly it is we are.

Now, it's true that our understanding of relativity is incomplete, as it doesn't (yet) tie in with our understanding of gravity. But this does not mean that it is wrong. Newton's Laws of Motion do not take into account relativity (which was why they caused a headache when trying to predict the orbits of the planets), but they were not wrong when described objects moving on Earth. Working out the flight path of a plane, or the airspeed velocity of an unladen swallow, Newtonian mechanics are just fine. We know that Einstein's Special and General Theories of Relativity are good approximations of the truth, because without them, things like Sat Navs wouldn't work, and it also explains a great deal more about what we observe in the universe.

If you've found this interesting, then I'd encourage you to check out the following books, as they go into great detail about the evidence for the above, and more besides:

Big Bang by Simon Singh < Especially this one, which I think is the most accessible
The Particle at the End of the Universe by Sean Carroll
Why does E = mc²? by Brian Cox and Jeff Forshaw

*The last post in the conversation said "Particles are still physical, so in theory, like waving your hand through the air, you would push those particles away from the point of origin faster than their original speed"

Scientific evidence for the soul?

As many of you know, Radio 4 has Thought for the Day: "A unique reflection from a faith perspective on topical issues and news events. Speakers from across the world's major faiths offer a spiritual insight rooted in the theology of their own tradition. " Last Wednesday's Thought for the Day came into my consciousness as I was waking up, and I thought it said that scientific evidence had been found for the soul. I've finally had a chance to check it out.

The evidence in question relates to research done at the University of Michigan into near death experiences. The amazing Ed Yong has written about the research "In dying brains, signs of heightened consciousness" which you should read if you want a deeper understanding than the sentences that follow, which don't do the research justice. The team found that, after killing nine rats, in each one the low gamma waves of the brain got very strong. These have been associated with conscious experiences. It's early days, but these finding might help shed light on the near death experiences which are felt by 1 in 5 people who are resuscitated after their hearts stop.

For Akhandadhi Das: "...this experiment is a good example of how scientific results can be interpreted in two rather different ways.

On one hand preceding on the assumption that the brain is the source of consciousness, these results appear to show neural activity that might explain why some people who've returned from the brink of death say that they've experienced feelings of calm and peace as well as seeing visions of light or heaven, however it's possible to approach the issue from the opposite direction. Say we suppose that within the body there is a soul that is the source of consciousness, and that thoughts and emotions of the conscious soul stimulate neural activity in our brains. In this scenario a scientific mind might expect to see evidence of a short period of conscious trauma between the times when the body stops functioning and the soul actually leaves. Sure enough, there is. So the Michigan near death results could also be said to offer proof to support this theory. "

This to me is a post hoc rationalisation, which also doesn't hold up to scrutiny.

Why would you expect a short period of conscious trauma between the body stopping to function and the soul leaving the body? Why would that happen, and not the soul leaving at the same time as the body stops functioning? If the soul is the source of consciousness, why is it that the soul has to stimulate the brain? Why not the brain stimulate the soul?

Now, if it is the soul that is the source of consciousness, and we get access to this through its stimulation of the brain, this might explain why, after brain damage, someone no longer has access to certain memories, functions or feelings. The soul is trying to stimulate that area of the brain, but it is damaged. But if this is the case, how can the soul be viewed as the source of consciousness? The brain must surely be seen as the source of consciousness - for it is the organ that we are needing to experience things, and without it functioning, these things are inaccessible, even if they are (somehow) retained in the soul.

Let's suppose Akhandadi Das has it wrong though, and it's the brain that stimulates the soul. In this case, when we get brain damage, and the soul can no longer be stimulated, we lose certain memories, functions or feelings, because the brain cannot evoke these in the soul . But here, again, it is the brain that is needed, not the soul.

He also says that this evidence lends credence to the idea that "all species" have souls. All species? What about those that don't have a brain - the soul cannot stimulate neural activity then. What about species that start life with neural tissue, but finish life without it?

No, the idea of the soul is another religious idea we can consign to history. As Sam Harris says in the Moral Landscape (which is a very good and thought provoking book):

"While the ultimate relationship between consciousness and matter has not been settled, any naive conception of a soul can now be jettisoned on account of the mind's obvious dependency upon the brain. The idea that there might be an immortal soul capable of reasoning, feeling love, remembering life events, etc., all the while being metaphysically independent of the brain seems untenable given that damage to the relevant neural circuits obliterates these capabilities in a living person."

This Thought For The Day, to me, is a good example of how the faithful use science. Science and religion are mutually incompatible (science requires we take things on evidence, religion requires we take things on faith). Religious people love to use science when it backs up, or appears to back up, their religion, as this Thought For The Day Shows.

Things become a little more problematic when science disproves a religious tenet. Take Adam and Eve. Genetic research has shown that Adam and Eve did not exist. When this happens, a literal interpretation of a Holy Text has to be either jettisoned, and instead become an allegory, or a metaphor; or, the science has to be rejected. As science advances, more and more religious tenets have to be twisted to fir the science.

When it comes to science and religion, Ingersoll was on the button:

"We have already compared the benefits of theology and science. When the theologian governed the world, it was covered with huts and hovels for the many, palaces and cathedrals for the few. To nearly all the children of men, reading and writing were unknown arts. The poor were clad in rags and skins — they devoured crusts, and gnawed bones. The day of Science dawned, and the luxuries of a century ago are the necessities of to-day. Men in the middle ranks of life have more of the conveniences and elegancies than the princes and kings of the theological times. But above and over all this, is the development of mind. There is more of value in the brain of an average man of to-day—of a master-mechanic, of a chemist, of a naturalist, of an inventor, than there was in the brain of the world four hundred years ago.

These blessings did not fall from the skies. These benefits did not drop from the outstretched hands of priests. They were not found in cathedrals or behind altars — neither were they searched for with holy candles. They were not discovered by the closed eyes of prayer, nor did they come in answer to superstitious supplication. They are the children of freedom, the gifts of reason, observation and experience — and for them all, man is indebted to man. They were not found in cathedrals or behind altars — neither were they searched for with holy candles. They were not discovered by the closed eyes of prayer, nor did they come in answer to superstitious supplication. They are the children of freedom, the gifts of reason, observation and experience — and for them all, man is indebted to man."

God in the Constitution (1890).

For the full Thought For The Transcript, see below.

Fact checking "I fucking love science"

I saw this in my timeline:

As with all such things, I thought: "Is that true?" Being a sceptic doesn't mean reserving your scepticism to alternative medicine, religion and superstition etc. It means, at least as far as I see it, questioning everything - from advertsing claims to random internet forwards.

Granted, I can't help escape certain biases of my brain, but I do my best. Often, I can't find out if something is true or not, as I don't have the time. Fortunately though, it's the summer holidays, so I have the time (though I really should be cleaning the kitchen) to find out. So, with some rough and ready back of the envelope calculations, let's see how valid the above is!

These are useful to see if you're in the right sort of area with right or wrong, but, as I expect we will see, aren't terrifically accurate. I'm blogging as I do the calculations...

First bullet point: For this I also wondered "Support two humans, for how long?"

We'll assume a single tree does absorb 22.7kg/year of carbon dioxide. Why? Well, what's a standard tree? Hard to define. So we'll give them that.

The simple equation for photosynthesis (how a plant turns carbon dioxide into sugar, so it can grow etc) is:

carbon dioxide  +   water  ------- >  glucose  +   oxygen

It takes six molecules of carbon dioxide and six molecules of water to make one molecule of glucose and six molecules of oxygen. (I'd add the chemical symbol formula, but can't see how to do subscripts).

So for every carbon dioxide molecule absorbed, one molecule of oxygen is released.

If it absorbs 22.7kg of carbon dioxide, then it must release 16.51kg of oxygen in that time. This is because the relative atomic mass of carbon dioxide is 44, and for oxygen 32.

32/44*22.7 = 16.51

So, in a year, a tree will release 16.51kg of oxygen.

How much oxygen do we need each year?

At rest, humans need to breathe in about 5 - 8 litres of air a minute. It can increase to 40 - 60 litres of air during exercise. Let's just assume we have a sedentary person who's always at rest.

So, in a day, our hypothetical person needs 7,200 to 11,520 litres of air, if they stay entirely at rest.

One litre of air is about 21% oxygen, and in total weighs about 1.286g (at standard atmospheric pressure). So one litre of air contains 0.286g of oxygen.

So that means, in a day, someone at rest needs 2.05 to 3.29kg of oxygen a day.

So 16.51kg of oxygen in a year provides 8.05 to 5.01 man days of oxygen.

So, in a year, if two people stayed entirely at rest, a mature tree will provide enough oxygen to keep them going for at least two and a bit days.

Second bullet point:

The average car release 149g/km of carbon dioxide.

So it's saying an acre of tree consumes 149*41483 = 6181kg of carbon dioxide.

This means it will release 4495kg of oxygen.

We know (from above) that 16.51 kg of oxygen is, at best enough to keep one person going for eight days. So about 2kg of oxygen is about one man day.

So 4495kg of oxygen is enough for about 2192 man days of oxygen.

If we divide that by 18, that's 121.8 days. So actually, according to their figures, one acre is enough to keep 18 people going for about 3 months at best.

So that second bullet point isn't true, given the figures they've used. Remember, these calculations aren't the most accurate, but we are not even close to having an acre of trees produce enough oxygen for 18 people to live for a year. And that's even if those 18 people sat around doing nothing - not even planting more trees!

Of course, I have made the assumption that one acre of trees does indeed take up the amount of carbon dioxide released by a car that's travelled 26,000 miles.

Third bullet point: We're not told how long the tree takes to produce the oxygen. So, it's got to be true, assuming the tree doesn't die.

So, why have I just gone ahead an gone sceptic on a Facebook post that's not doing any harm, and is promoting a good message (I am a big fan of trees and plants in general!)?

Trees are important - but they're important enough that we don't have to make stuff up.

It's not as if the real figures are hard to find, this report took me 3 minutes to find using google:

Arboriculture & Urban Forestry 2007. 33(3):220–226.
Oxygen Production by Urban Trees in the United States
David J. Nowak, Robert Hoehn, and Daniel E. Crane

"A commonly cited statement is an acre of trees (100% tree canopy) can provide enough
oxygen for 18 people (e.g., American Forests 2006; TreePeople 2006), but based on this study, this estimate appears to be high by at least a factor of two. The number is more on the order of eight people per acre of tree cover (100% tree canopy)."

Trees are important, but let's make sure people know how important they really are.


UPDATE: It's been pointed out this post makes it look like I'm underselling plants. Which is a bad thing to do, let's not forget they (in no particular order, and by no means complete):

Act as carbon sinks; provide habitats for wildlife; hold soil together and help prevent erosion; provide sustainable building materials; can help clear areas of pollutants and contaminants; reduce stress.

My take home message, which I didn't make clear is that: when you have something awesome, you don't need to oversell it or make stuff up to extol its virtues.

UPDATE 2: Another thing I should have mentioned: When we breath in, we don't actually use all of the oxygen inhaled. As has been pointed out below, exhaled air is 16% oxygen, whereas inhaled air is 21% oxygen. So we're only using about 23.8% of the oxygen we breath in. So, this obviously affects the calculations. One should expect the answer to the first bullet point to be four times higher. But it is not.

"If oxygen levels are below 16% at atmospheric pressure most people faint due to hypoxia. If oxygen levels fall below 11% individuals may die by suffocation. The amount of oxygen in the air depends on its partial pressure - inhaling pressurized gas while scuba diving which is below 16% oxygen does not cause hypoxia (because the air is pressurized)."

So actually, we can only use about half of the oxygen we breath in. So this would double the man days of oxygen. Of course, this then also assumes that the trees and our people are in a sealed environment - otherwise we could talk about all the oxygen being used, and another source of oxygen to supply that which is used in the body, but which is needed so the lungs can function. But then it all starts to get more complicated, and, as I said at the start,  these were just back of the envelope calculations, I didn't want to get bogged down - it was just to see if we were in the right ball park figure. And we weren't.

Given I was being quite liberal with the assumption that the people are entirely at rest, I was happy to just leave out this line of thinking as it seemed to complicated things, but I guess I was wrong.

Proof of God: The Argument from Antiquity

I came across a novel take on the burden of proof, with respects to god's' (delete apostrophe depending on your level of polytheism) existence:

Actually, religious persons existed before aithiests (I mean, obviously otherwise there wouldnt be anything to not believe in) So religious people were worshipping and an aithiest proclaimed "There is no God". That is an accusation
In a court case the burden of proof lies on the prosecution or the accuser
Atheism is an accusatory belief (Philosophy)
To quote How I Met Your Mother:....LAWYERED!!!

I enjoy reading differing world views, especially those that help to challenge mine. When it comes to religious apologists (sophisticated theology or no) it often seems like just a game of how much flawed reasoning and logical fallacies can you spot? (I count four things in the above Argument from Antiquity).

It's not just anonymous religious commentators on the Internet though. Scientists too: Francis Collin's conversion to Christianity, fir example, occurred when he was overcome with the beauty of a waterfall. This is from a scientist who helped decode the human genome.

Neil deGrasee Tyson hits the nail on the head when he asks: "Are they both not as intrigued as I am that religiosity drops with education, especially with science education, but does not drop to zero, not even for members of the National Academy? I think that’s an amazing statistic, which tells us something about the human mind that is not yet understood."

It would be fascinating to find out what that something about the mind is.

On black athletic superiority

One need only look to look at the annals of athletic success to see that blacks are obviously superior athletes. No white athlete has reached an Olympic 100m final in over a quater of a century. 82 people have run sub 10 second 100m. Only one of them was white. This is just sprints. Just look at the huge amount of long distance running medals that have gone to Kenya. In 2011, the NBA reported that only 17% of the players where white.

The idea has been put forward that those of West African descent are better at sprinting - as is show by the dominance of Afro Americans and Jamaicans for example, and that long distance running is the domain of East Africa - Kenya and Ethopia, for example.

Indeed, there's genetic evidence too - the ACTN3 gene helps with sprinting (by affecting muscle composition - it makes more "fast twitch fibres, which are the kind for explosive power, and not so good for prolonged endurance) and is found in 98% of Jamaicans. Indeed, the slave trade has been put forward as an explanation of how this situation could have evolved - the slave trade selected those that were fitter, and thus their athletic dominance was born.

The case seems clear cut: black people make better athletes.

The trouble is, it's all nonsense. To explain why, we need to consider a few things, because there is a predominance of black athletes.

Before we begin, there is a related, and important, point to make. When talking about differences in populations, you're never far from cries of racism (or sexism or any other -ism). This is because people tend to think of traits of populations as discrete points, and not overlapping bell curves. People misinterpret a saying like "Women are better at visual memory" as meaning that all women are good at visual memory, and all men are bad at visual memory.

Here's a simple example. Men are taller than women. Here's a graph to show this:

As you can see - men tend to be taller than women, but there is considerable overlap with their heights. So it is when it comes to other differences. Saying that one group perform better than another is not to say that the other group are incapable. Their performance will overlap like the graph above. Also, such data do not support discrimination. Just because men are better at mentally rotating shapes, doesn't mean that women can't, and so, one should always base one's assessment of an individual on their own merits, and not from whatever particular group(s) they belong to.

So, with that out the way, back to the black athletic superiority.

Firstly, the notion of race is a misleading one. Genetic studies show that genetic diversity is greater within a population than it is between populations. If the zombie apocalypse happens and all that remains of humanity is the Masai tribe from Africa - the entire genetic variability of Homo sapiens will be found within their members. Of course, this is counter intuitive because we can't see genetic differences with our eyes - we can only see the colour of their skin, the shape of their face, how their hair grows etc. However, these differences are superficial and trivial in the grand scheme of things.
Luigi Luca Cavalli-Sforza, a population geneticist from Stanford University says "Classification into races has proved to be a futile exercise... All populations or population clusters overlap when single genes are considered, and in almost all populations, all alleles are present but in different frequencies. No single gene is therefore sufficient for classifying human populations into systematic categories."

Which leads us to ACTN3 gene mentioned earlier. 98% of Jamaicans may have it. But so do 82% of Europeans. And in Kenyans it's more prevalent than in Jamaicans - which is curious given their dominance in the long distance running. Genes may help, but aren't the entire story. Athletic success is largely down to one's environment - where one lives, the societal factors there, the facilities available.

Take Kenyan long distance runners for example. 90% of their runners are actually found within a sixty mile radius around the town of Eldoret. The conditions there are perfect for developing long distance running - it's at high altitude, which helps the athletes produce more red blood cells and move oxygen around their body more efficiently; children have to run to school - sometimes as far as 20km, that's a lot of running for a child, and by the time they're grown, they can reap the athletic rewards; since Kip Keino in 1968 children aspire to be athletes; running is cheap to get into unlike other sports; traditional Kenyan diet is very good for long distances runners; and Kenya has developed a good system for developing and nurturing promising young runners. All these factors contribute to their success.

This leads on to another point. One of over generalization - it's not being Kenyan that means you've got a better chance at making it as a long distance runner, it's being a Kenyan around the town of Eldoret. Likewise, generalizing that all black people are naturally better athletes because of those that do dominate the sport is likewise an overgeneralisation. There are a lot of African nations that aren't producing a surfeit of athletic success.

So what about the NBA line up and other stats about the predominance of black athletes? The overrepresentation of of African Americans in sport is mirrored by their underrepresentation in positions of economic power, suggesting that socio-economic factors are involved. If there are barriers to positions of economic power, then it makes sense to go into sport where such barriers don't exist.

Does this false notion that black people make better athletes matter though? Racism sadly isn't a thing of the past and so surely it's good that black people can show the world what they can achieve?

Sadly this isn't the case.

Received wisdom used to hold that:

"The Negro does well in certain disciplines because he is closer to primitive man than white people. It is not long since his ability to run and jump meant the difference between life and death in the jungle. He has supple muscles and his light-minded disposition is useful in the mental and physical relaxation necessary for someone who runs and jumps" Dean Cromwell, leader of the American team at the 1936 Berlin Olympics.

These sentiments haven't entirely disappeared - black athletes are rated higher in natural athletic ability than in sporting intelligence. White athletes are rated higher in sporting intelligence than in natural athletic ability. When listening to exactly the same radio basketball commentary, those that thought the player was black rated them as high in natural athletic ability. Those that thought the player was white, rated them as low in natural athletic ability, and an inferior player. This was for the exact same commentary.

Stereotypes influence how we see the world and other people, and can lead to unconscious discrimination, which can help perpetuate the false stereotypes. White athletes getting passed up for sporting opportunities and black scholars missing out on potential educational success, can lead to disproportionate mixes of the two in various fields.

Stereotypes also affect how we, ourselves, behave, via what psychologists call the Stereotype Threat. White and black former high school athletes were given a golf putting task. Both groups performed equally well, until you told them that it was a measure of "natural athletic ability", then the whites' performance dropped. It's not just in sporting tasks. A standardized test was given to undergraduates. When told it was a measure of intellectual ability, white students out performed the black students. When the test was presented as a laboratory tool, with no relevance to intellectual ability, the scores between black and white students were the same.

There may be a predominance of black athletes, but this is not because they are naturally better athletes than non-black people out there. Likewise, there is a predominance of white people in other areas of life, but this is not because they are naturally better at them than black people.

The information for this post mostly came from the excellent book Bounce by Matthew Syad which you should read.

More iPhone apps for science lovers

Unlike my last lot which were all free, one of these costs, but I feel is worth worth it!

3D Brain - The brain is the most complex thing in the known universe, and you can begin to scratch the wonderful surface of it with this app. Highlights various areas and systems of the brain, explaining what they do. It also links through to research that provides the information for the app. Good stuff!

3D Sun - This app gives you news on the Sun's current activity. I love getting random notifications of the latest Coronal Mass Ejections, and such. It gives you a gallery of pics; a 3D model of the Sun in a range of wavelengths, and also Earth side and far side; news and the current conditions of the Sun (it's got 96 sunspots at the moment, and the Solar wind is travelling at 363.1 km/s, in case you want to know). This app's also free, and comes courtesy of NASA's Heliophysics Division.

iGeology - From the British Geological Society, this lets you see what rocks are at the surface, and also the bedrock underneath where you are (or indeed, anywhere else in the UK if you want to search for it). I'm currently sat typing this above a chalk bedrock formed approximately 65 - 99 million years ago, as, back in the day, here used to be a warm chalk sea. Above the bedrock though, it's clay, silt and sand from 2 million years ago. Seas are so Cretaceous, it's all river domination these days.

Particle Zoo - This is another free app, and lists all the subatomic particles in a handy list. I will confess, some of these particles are a little over my head - I'm not sure what superpartners are in relation to quantum physics for example, but that's ok, as it gives me something to learn (and the ever increasing list of books to read includes stuff on quantum physics). The app links through to the lovely plushies produced by Particle Zoo. Gotta love the geeky toys!

Sky View - I've got the free version, but there's also a £1.49 version which I haven't got (but would if I had more money). This lets you point your iPhone at the sky (or the ground) and tells you what constellations, planets, moons etc are there. On top of that, it will use the camera, and layer this info on top of what you're seeing, so even in daylight, you can get the stars layered over the daytime sky and see the stars currently blocked by clouds, or the light of the sun.

Solar Walk - this is an excellent app (and I thank Glenn Caine for pointing it out to me). Normally it costs about £2.30, but just by chance as I write this, it's 70% off, and is well worth your spending 69 pence. It lets you explore the solar system, zooming in on the planets, and Pluto. I addition you can zoom in on some of the Solar System's more famous moons; famous satellites (old and current) orbiting the Earth (eg ISS and Hubble); geography of the Moon, Mars, Earth and Venus and also a bunch of the Milky Way's stars. Go get it whilst it's on offer!

If you know of any awesome apps, please add them to the comments! Thanks.

Some interesting stuff about sex

During the Olympic ceremony (which was infinitely better with twitter), I saw PZ Myers retweet some comments that were so wrong , they caused me psychic pain, and led me to this article, which appeared the source of the confusion.

Here is the main body of the article, in all its wrongness:

Men sow their seed hither and yon; women guard their vaginas like Fort Knox.

But is this true?

Let’s think about it logically. With each act of sex a male ejaculates semen into the female. This is an investment of physical resources that takes time for the male to replenish. So male animals are limited in how often they can have reproductively viable sex. Female animals, on the other hand, are not. The sex act has zero cost to them.

Now, the reason this obvious truth is invisible to us is because we lump in the cost of carrying young with the cost of sex. Yes, carrying young is high female investment but the sex act itself is higher male investment.

For humans who are often trying to avoid the hassle of pregnancy, this makes some sense. For female animals, it makes no sense. The whole purpose for a female animal, in going into heat, is to get pregnant. Because that’s her instinctive imperative, the hassle of pregnancy is irrelevant to her cost of sex.

In fact, for female mammals, the real risk is investing resources in sub-par offspring. Because of this it’s in their best interest to have sex with as many males in as short a time as possible. Multiple male partners improve both her chance of conception and the quality of the conception via sperm competition. This is why the majority of female mammals are polyandrous—they mate with multiple males.

It is not, however, in the best interest of the male animal to mate with as many females as possible.

Why? Because, quite simply, his sperm is in limited supply. He wants to prioritize delivery of sperm to a.) high quality females and b.) less mated females. 

Our ‘common knowledge’ about so-called male promiscuity is better termed common stupidity.

Further, the relative costs of sex and the priorities of both males and females explain why a male mammal might evolve to pair bond.

A pair-bonding male has maximized his access to a less mated female. He does trade off in terms of access to a higher quality female than himself—higher quality in terms of status and fertility—but he is less likely to obtain this higher quality female and, overall, he’s better off as a pair bonder then a promiscuous breeder. 

It's got it all the wrong. But that's ok, because it's interesting stuff, and gives me an excuse to write about it.

Firstly, sperm is not really in a limited supply for a male. We do, after all, produce 1,500 sperm a second. In fact, we can joyfully masturbate and waste entire ejaculations just for fun and still not worry about our sperm count dropping. I couldn't (quickly) find decent figures on how often men can ejaculate a day, but it is certainly in double figures. Sperm is not a limited resource about which men need to worry. We make loads of the stuff (fertility problems not withstanding).

Secondly, it's seems daft to not count the cost of carrying young in with the cost of sex (not to mention months of lactation, which isn't easy). It's akin to saying that eating at Alain Ducasse au Plaza Athénée (where, if you order certain types of tea, they bring the plant to you, and cut off leaves with silver shears) is cheap, because when you're eating, no money is passing hands. Of course you should include the menstruation, pregnancy, lactation and child rearing as costs of sex! Even if you discount those, the costs of coitus itself are fairly similar between the sexes. Granted, men do have a cost in the sperm (though sperm is cheap), but vaginas need lubricating too - which is an expense for the woman.

Consequently, for men, it can be a good evolutionary strategy is to sleep around and pass on your genes, without worrying about looking after the child. Sure, this lack of paternal investment may not be good for the child, but ultimately, it's a better use for your sperm than masturbation, or not doing anything with it at all, as you do stand a chance of passing on your genes. Of course, it can also pay to stick with a partner though - human children take years before they are ready to face the world on their own, and paternal support can help them achieve adulthood and hopefully pass (some of) the father's genes on to their own children.

Women, of course, are more choosey - they want to make sure that they get a good set of genes for their child, as they don't get many chances to produce offspring. This doesn't exclude cuckoldry of course - they may well cheat on their partner to get the best of both worlds - a partner who will invest time in the child, whilst the sperm comes from a "better" mate. Though in the long run, of course, this doesn't help propagate genes for men who stick around.

Ultimately though, it is men who have to compete with each other to have sex with women. This is why men are more up for casual sex with strangers; why victims of rape are usually women at the hands of men; why the sex industry is generally females providing services for men; why women are punished more severely for cheating than men are; why we have the term "mistress" but no real equivalent for a man; and much more besides. In fact, marriage probably evolved as a way to ensure the fidelity of a female partner.

It's also why this sentence: "In fact, for female mammals, the real risk is investing resources in sub-par offspring. Because of this it’s in their best interest to have sex with as many males in as short a time as possible." makes no sense. It only takes one sperm to fertilize an egg, and whilst getting more sperm in your vagina might increase your chances of insemination, it implies that good father candidates are all over the place - indeed, the women who sleeps around in such a fashion is unlikely to have a father that sticks around, as their is no point in looking after a child that's unrelated to you (unless your a cassowary).

This of course doesn't give carte blanche for men or women to cheat on their partners. Whatever the reasons for infidelity are, evolutionary biology is not a good excuse.

Sexual behaviour and sperm production in other primates is also interesting. Gorillas have harems - one male has almost exclusive access to many females (who generally aren't promiscuous). Consequently, they have small testicles in relation to their body size. Chimpanzees on the other hand are far more promiscuous, they have massive testicles in relation to their body size as they need to make lots of sperm to increase their chances of passing on their genes.

On top of this, there is sexual dimorphism (one of the sexes is larger than the other) - where dimorphism is high, male–male competition is commonplace; conversely, where dimorphism is low, competition among males is less frequent. Gorillas and orangutans for example have high levels of sexual dimorphism. Chimpanzees are more moderate.

Humans fall almost in the middle of these range, both in testicle size to body weight; and sexual dimorphism - which is why there is probably a bit of variety with monogamy, infidelity and polygyny (and more rarely polyandry which is, interestingly, more commonly fraternal polyandry - brothers sharing a wife. This is a good strategy where resources are scarce - even if your genes aren't passed on, your brothers might be, which is the next best thing. Which makes sense, given the beginning of this blog post).

If you want to find out more about this How the Mind Works by Steven Pinker, and (if I recall correctly) the opening chapters of The Ancestor's Tale by Richard Dawkins, are good places to start.

Of course, why stick with humans? There are lots of interesting ways that animals have sex too, and you could do worse than checking out Green Porno.

As for the promotion of "pickup culture" in the essay, I'll leave it to XKCD:

Ask for evidence, always

The excellent Sense About Science have a campaign: Ask For Evidence. As they say: "Evidence matters in many of the decisions we make - as patients, consumers, voters and citizens. If you want to know whether a claim made in a policy, newspaper article, advert or product is backed by scientific evidence, ask the people making the claim to provide it. "

Evidence matters, and it's really important to know on what basis claims are made. One of the supporters of this campaign is Dr Christian Jessen, television presenter:

“Asking for evidence is vital to ensure quality control in science, and to stop vulnerable patients from being exploited. Believing without question has no place in science and medicine.”

A noble sentiment, but sadly Dr Jessen has fallen short of this.

Dr Margaret McCartney  wrote a good article for the Daily Mail (I know!) on the dangers of unnecessary medical screening (the references for her claims are listed on her website).

Dr Jessen tweeted these (here and here):

You can see how people responded on twitter here. What struck me from that conversation was that, quite reasonably, Dr McCartney asked Dr Jessen to back up his tweet by asking "What evidence do you want to pull me up on?" Dr Jessen entirely ignored her tweets, then later said that he had blocked her, saying that "She appears to have issues with me!", which evidently wasn't the case. This isn't a very evidence based approach - all that was being asked for was the evidence to back up the claims he had made. The closest he got is this tweet:

Is this backed up in the article? No.

Examples of what screening is good:

What patients need to remember is that the pros  of screening should outweigh  the cons.
So, for example, newborn babies have a heel prick test a few days after birth to check for several rare diseases.
These need early treatment — like thyroid abnormalities — which can make a huge difference to the well-being of the child.
So the UK National Screening Committee recommends that these tests are routinely provided and fully funded on the NHS.
And people with diabetes are recommended regular eye tests to avoid complications from  the disease.

The article finishes with what patients should be doing:

Potential patients need to know what they’re getting into — well before they get into the costly screening scanner.

Dr Christian Jessen works for DoctorCall, a company which offers people the potentially needless and harmful screening Dr McCartney was writing about. Indeed, this company also offers acupuncture, which, it has been shown, does not work.

The article didn't leave me worried. But Dr Jessen's tweets did. Dr Gregory House says of full body scans (in the episode "Role model", the title of which gave me a wry smile, given the subject matter of this post) that they are useless because "you could probably scan every one of us and find fifty doo-dads that look like cancer". It worries me when a fictional TV doctor does better than a real TV doctor.

Believing without question has no place in science or medicine.

Always ask for evidence, and watch out when someone's not forthcoming with it.

Today's all about science anniversaries!

36 years ago Viking I landed on Mars.

43 years ago today, Neil Armstrong and Buzz Aldrin landed on the Moon, whilst Michael Collins orbited above.

155 years ago, Charles Darwin started writing an abstract that would go on to be On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life.

190 years ago, Gregor Mendal was born, he founded the science of genetics - before the discovery of DNA!

Atheism and love and science

Love is often used by religious apologists. Atheists like myself will point to the burden of proof resting on the religious believer, and they will reply that there's more to life than what can be proved by science such as love, and say things like "...science will never be able to prove that love exists, and it would be silly to ask that of science." The idea being that: science has nothing to say on love, and believing in love is fine, therefore, believing in god is also fine. (We'll ignore the faulty logic today). The thing is, science can say a lot about love (and religious claims for that matter, for example the efficacy of prayer).

Firstly, we have lots of evidence that love exists. We feel it and experience it - so there's something going on in the brain. There is ample evidence of the love between myself and my girlfriend, the love between my family and the love between my friends. Through the actions of those in a relationship, it's obvious to see when you are in a loving, and caring relationship, and also when you are not, by appraising the available evidence.

We can look at the physiology of people in love. Seeing someone you're in love with, or attracted to, can increase your pulse and breath rate. In fact, it can also work the other way around - meeting someone in a situation where your pulse and breath rate have been increased, can increase your attraction to that person in what's called the "misattribution of attraction". You're body is behaving as if it's aroused when you meet a person, and so you think it is that person that has caused the physiological response, not the other aspects of the environment. It's not the only case of acting "as if" you are a certain type of person, and then actually becoming that person.

Science can look at the hormones that are involved in love - for example oxytocin, often called the hormone of love, though it's a little more complicated than that (watch out, it has a darker side too).

Evolution can explain perfectly why love evolved - the love of a parent their child is understandable for the propagation of Homo sapiens, and other species (although parental care is not universal). Do other animals experience parental love for their children? One would presume less so in the sloth, who I've heard (but can't find a reference for online, and all my books are in boxes in a storage unit) leave babies that fall to the forest floor to die, as going to get them puts them at too much risk of predation. What about the love of a partner? In mammals, for example, testicle size correlates with monogamy, polygamy and harems. Gorilla's testicles are about 0.03% of their bodyweight, and they have harems. A gorilla doesn't need to produce much sperm, as it has control over who it mates with. Chimpanzees on the other hand have testicles that are 0.3%, and they are highly promiscuous - as the female chimps have many partners, a male chimp must produce lots of sperm so as to have higher reproductive success. Humans, interestingly, fall in between these two extremes with 0.08% of bodyweight being testicles.

It may be very difficult to find out if animals feel love, but certainly we can look at how they behave, and the biochemistry that's going on when they do and see how it matches up with what happens in us when we are in love. This is what makes science fantastic: Asking questions and being happy with the answer "I don't know" whilst working on a way to find out.Love is certainly within the realms of science, even if it has to take a different approach.

Now, some people might say that understanding love would spoil it. I will let Richard Feynman explain why I don't agree with that:



"I have a friend who's an artist and he's some times taken a view which I don't agree with very well. He'll hold up a flower and say, "look how beautiful it is," and I'll agree, I think. And he says, "you see, I as an artist can see how beautiful this is, but you as a scientist, oh, take this all apart and it becomes a dull thing." And I think he's kind of nutty.

First of all, the beauty that he sees is available to other people and to me, too, I believe, although I might not be quite as refined aesthetically as he is. But I can appreciate the beauty of a flower.

At the same time, I see much more about the flower that he sees. I could imagine the cells in there, the complicated actions inside which also have a beauty. I mean, it's not just beauty at this dimension of one centimeter: there is also beauty at a smaller dimension, the inner structure...also the processes.

The fact that the colors in the flower are evolved in order to attract insects to pollinate it is interesting -- it means that insects can see the color.

It adds a question -- does this aesthetic sense also exist in the lower forms that are...why is it aesthetic, all kinds of interesting questions which a science knowledge only adds to the excitement and mystery and the awe of a flower.

It only adds. I don't understand how it subtracts."

It's quite hard to find the Wattage of a swan

So, a friend tweeted about liking the idea of a Mystery Swan, and tweeted "Is it a bird? Is it a plane?"

This naturally made me want to parody this classic:

I produced these tweets:

About 1% as fast a speeding bullet, more powerful than a hair drier, able to clear tall buildings with quite a few flaps... 

...Is it a bird? Yes! Is it a plane? No. It's Mystery Swan

They took me about an hour.

Now, finding out a swan's speed relative to a speeding bullet wasn't so hard. There were a number of sources for the speed of a swan, and I opted for 50 miles per hour.

Next is the speed of a speeding bullet. I figured I'd go for the fastest bullet out there, which come from rifles, and can be as fast as 1,500 m/s.

Now, I chose to go for a lower end of the scale for the swans, as my bullet source was old, but I liked it as it also mentioned Superman, and I figured guns may well have advanced.

The next bit was trickier. What is the power rating of a swan? Power is generally measured in joules per second, in a unit called the Watt.

Try as I might, I couldn't find anything on the power involved with a flying swan. So I changed tack.

Many websites told me swans eat around 8 - 9 kg of food a day, largely pond weed, and other river based insects and such. Finding the energy content of the food wasn't so hard.

Now, I didn't know the exact breakdown of the swan's diet, but taking a (rough, mental) average of the food available, it looked as if there was a round a little over 4 kcal per g of food.

Assuming the swan meets it's daily dietary needs, and isn't putting on, or losing weight, we can see that the swan consumes 150,624,000 Joules per day (by converting kcal to Joules and working out energy content for the kg consumed per day). Diving this by 86,400 give us the Joules used by a swan, per second, which works out as 1,743. Thus, the wattage of a swan is about 1.7kW. That's more powerful than a hair dryer, as they are around 1.5kW (or lower).

Now, this isn't the most rigorous of calculations, I'll admit, and you are more than welcome to improve upon it. But I'm quite satisfied with the accuracy needed for the, by now, over laboured joke. It's not as if I'm looking for the Higgs or anything.

Sleights of mind: What the neuroscience of magic reveals about the brain

I've long loved magic - I have fond memories of the Paul Daniel's Magic Show as a child, and was chuffed to bits when I met the creator of the CBBC show Tricky Business. As I've become more of a biology nerd, the brain has always fascinated me, and so when I was perusing the popular science section with book tokens to spend, and saw Sleights of Mind, with an endorsement from Steven Pinker, I  couldn't resist.

The book did not disappoint!

One of the reasons I love magic is that I know it's not Harry Potter magic, but that there's a rational explanation. Even if I know (or think I know) how a trick is done, I love not being able to detect the magician as he pulls the wool over my eyes.

This book explains a lot of how easy it is for magicians to fool us because the way our brain works sets us up to not see things as they are. Take, for example, the amazing colour changing card trick, which you should watch before carrying on reading:

The trick works because of something called "change blindness".

The implications of the neuroscience in the book aren't just to do with being deceived by honest (or dishonest) conjurers. They have applications in the real world - for example, understanding change blindess has helped improve the safety of pilots.

Another great aspect of the book is that it provide links for a number of the tricks it talks about - it's all well and good reading a description of a trick, but it's much better seeing one for yourself.

The book also contains spoiler alerts, so if you don't wish to know the secrets behind some tricks, you can skip over those sections. I didn't, so no idea how the book reads if you choose to do his.

It also seems well written and accessible, even if you don't really know anything at all about neuroscience. Even if you do, it's well worth the reading as it's nice to revise things and, this book gives the concepts a different spin.

Well worth reading, and, I've no doubt, will make my appreciation of magic even better!

Having fun with science at home

This tweet made me think a blog post on the subject would be fun.

A good place to start is the New Scientist's book How to Fossilise Your Hamster (which I won't link to on Amazon - please support your local bookshops!). You can get started with five videos that the New Scientist put together to promote the book. These will show you how to make plastic with milk; get ketchup out of the bottle; watch the interaction of cream and tia maria; make fizzy drinks fizzier and how to extract iron from your cereal.

Another good place to start is the ever excellent Richard Wiseman especially his videos ‪Top 10 quirky science tricks for parties‬; Ten more science stunts for parties; and Another 10 quirky science stunts. You can also take part in a real science experiment with his DreamON app.


There are obviously many experiments and practicals that you can do, but as biological sciences are my favorite, here's how you can extract your very own DNA:

You will need:

Half a tea spoon of salt
250 ml of warm water
Clear dish soap
Surgical or methylated spirits, chilled (or pure ethanol if you have it).
Syringe or dropper
Cups, shot glasses/test tubes.

How to do it:

Poor water in cup, add salt, and stir. Swirl the water around in your mouth for at least 30 seconds. It can help if you rub your cheek against your teeth before swirling the water - the aim is to get your own cheek cells into the water, as this is where your DNA source is coming from.

Spit this solution into a clean cup. Add 1 to 1 1/2 teaspoons of the solution to a test tube, or a shot glass.

In a separate cup, add three teaspoons of water to one teaspoon of clear dish soap. Stir it to mix it - but do not make it foam.

Add one teaspoon of this to the test tube. Stir this, but again, being careful not to make any bubbles.

Add one teaspoon of the chilled alcohol to the test tube. Do this carefully, it must float in a layer on top of the solution. DO NOT STIR. Leave it for two minutes.

Use syringe, or dropper, to carefully remove the top layer of alcohol, and transfer it to a shot glass of the spirits. You will see white bits floating in the alcohol - that's your DNA!

The science behind this:

The dish soap is there for two purposes. Your DNA is contained within membranes, and you need to get through this membranes to get to the DNA. The detergent in the dish soap does this. The dish soap will also (hopefully) contain enzymes - these will help break down the proteins that are associated with the DNA. Once the DNA has been released, it clumps together - because of the salt right at the beginning. These clumps of DNA dissolve just fine in water, but not so in alcohol. When they get into contact with the alcohol, they form a solid (what is called a precipitate). This floats to the top, and as DNA tends to be long and stringy, it pulls more DNA with it.

You can adapt this technique - it doesn't have to be your DNA. Blended peas or strawberries, for example, can give considerably more DNA, but I chose doing your own DNA, as it's quite fun to look at your own blueprint.

The Supermoon with Phil Plait and added Dr Who

Just a quick post:

Firstly, go read this by Phil Plait. It's a cool post about the "Supermoon", and scale.

Go on, read it!

Right, now that's read, it will then put this classic Dr Who clip into a nice little bit of context:

Update on sleeping for Science

Well, I've been using the Dream:ON app for a week now. As yet, I've not actually had it influence any of my dreams as far as I can tell. Well, at least in the way intended - I've not had the desired relaxing rainforests, shuttle launches or travellings around the world. However, I have had a week of very vivid and richly detailed dreams which are always fun (and surreal), and will certainly carry on using the app.

Some of the soundscapes have woken me up - the shuttle launch has a countdown, and the travelling around the world also has people talking. These have woken me up - but spoken words often do, so I think I shall avoid these. At the weekend, wanting a lie in, I set the alarm later than I would normally get up, and, when the soundscape came on, it woke me, however, at that point I wasn't really asleep (nor really awake), so don't think that really counts, though I'd be remiss not to mention it.

The first time I used the app, I had a bit of a restless night, which I'm sure was excitement about the app. Not so since, see here the very next night:

However, when sharing a bed, whilst still feeling rested, the graph shows less deep sleep:

Ignore the dip. I briefly woke and saw the phone had slipped to the floor. I don't know if I move more during the sleep, or if we both move at different times. It would be interesting (but currently not possible) to set a phone on either side of the bed and compare graphs. However, the app info does state it's optimised for solo sleeping. Also, the mattres is different too.

 The app's reviews appear mixed, it's definitely a Marmite app. Scanning the comments it appears a lot of the one star ratings are down to:

 - having to pay for more dreams. More free dreams are promised though, and on the first day of release, when I got it, it was very clear in stating that it came with just two free dreams.

 - Others appear to have moaned that it didn't help them get to sleep. These are evidently people that cannot read...

- Moaning that they should be getting rewarded for taking part.

 -Some claim it doesn't work (which is fair), but some are claiming it's a scam as they weren't aware of a sound scape. Of course, that they were asleep at the time it played...

 One thought that has occurred to me though - is there a control? do some people not get a soundscape played, but are still asked if they were consciously aware of it?

On the flip side, the positive reviews are happy that's it's worked; not liking the haters and imploring them to read; and also some who should probably try the app before rating - "OMG can't wait to try this" isn't that helpful.

Anyway, I've given the app five stars. Whilst it's not worked for me, it seems that it can take a while for some people, and it may just be that I'm someone for whom it just doesn't work. The app is nice and simple to use and I find the sleep graph interesting in and of itself. Granted it only comes with two dreams to start with, but more are on the way, and these apps don't come cheep.  I'd like them to come with more, but that's just a quibble. Give it a whirl - it's free, adds data for the experiment, and might even work.


 If you're trying it out, do let me know how you're finding it!

Sleeping for science!

Yesterday I got the Dream:ON app. It's the brain child of Richard Wiseman, and is for a mass participation experiment: the app will play a soundscape of your choosing which can (hopefully) influence the dream you're having. It also has an alarm to wake you up, and prompts you to fill in the dream diary, where you can record if you were aware of the soundscape, and what your dream was.

I used the app last night, and selected a peaceful rainforest. However, what I actually dreamt was about eating sausages with sauce on. The alarm woke me up, and to turn it off, you're taken to your dream diary. This is a good feature for me. I like to hit snooze, but with this, it gets me doing something and being active to wake up. Here's my dream diary from last night:

As the graph shows, I had a bit of a restless night. I am aware that I toss and turn a lot in my sleep, but I've generally regarded myself as a good sleeper (hence my use of homeopathic sleeping pills for my homeopathy overdose). I don't know if that graph is the norm, or if I tossed and turned more than usual on account of being excited by the app (which I was) and expecting something to happen. We'll see, as I shall try to use it each night, and those feelings will undoubtedly pass.

I also like that you can tag friends that were involved on Facebook, which could also be fun (but not without potential problems).

One quibble and one possible problem:

Quibble: The app comes with two soundscapes and the others need buying. They're not that expensive, but it would have been nice to come with a slightly wider variety of soundscapes. That said, there'll be more soundscapes (free and paid) coming each month, and this is probably my penniless student side coming through.

Problem: I'm in a distance relationship, and so week nights I have a bed to myself, but not so at weekends. When sharing a bed, my partner's movements might get picked up by the app, leading to a false graph.

Android app is coming out later in the year too. I'd definitely recommend taking part!

Poor form BBC! Don't spread creationism from America!

An otherwise good article on the BBC was spoilt by this table:

The data comes from the Population Reference Bureau based in the USA. As you see, they have the human population starting with two individuals. This is not the case. Human population size has never been smaller than 1,200 individuals.

Alas, in America, acceptance of evolution is painfully low. A recent poll had it as low as 16%. Rejection of evolution is in America, and elsewhere, is usually because of religion (that same poll has 38% beleiving in God guided evolution, 40% believing humans were created by God in their present form).

Religion has spoilt things again - a discussion on the population bottleneck would be interesting but possibly longer than that article allows. But at least getting the table right might lead people to find out more about our origins.


UPDATE: Over at Reddit a good point was made:

LordBritish wrote:

"Alas, in America, acceptance of evolution is painfully low. A recent poll had it as low as 16%. Rejection of evolution is in America, and elsewhere, is usually because of religion (that same poll has 38% beleiving in God guided evolution, 40% believing humans were created by God in their present form)."So really acceptance of evolution in America is at 54%.

This isn't the case. Believing that God has directed evolution means that you've not quite understood evolution. Evolution is entirely unguided - it's a process that carries on, but their is no destination in sight.