Brian Clegg's Blog, page 94

How I rattled PETA's cage

To be honest I have always felt that the animal rights campaigning organisation PETA is a little flaky (in part, I suspect because it is a very American organisation, so culturally takes a very different approach to us Brits). But a recent campaign by them has really dropped them to the lowest of the low in my estimation.

PETA has been pushing the idea that there is a link between autism and dairy products, using the poster illustrated above. This is a classic example of making an incorrect deduction from very limited trials which certainly don't show what is being claimed, and is particularly appalling after the parallel 'autism and MMR' disaster caused by the Wakefield fiasco.

I was able to find very quickly two surveys of the research, one from Cochrane and one from the NHS/University of York that concluded that the evidence does not support the suggestion. I retweeted the tweet that originally alerted me to this, only to have PETA respond with a classic 'anecdote as data' response. This really isn't good enough.


You might as well argue (to deliberately pick an argument that PETA probably wouldn't run a campaign on) that wearing fur coats is good for your health, as if you ask people wearing them on a cold day if they feel better than people in a short-sleeved T-shirt, they will say yes*. This campaign is about as helpful.

* In case anyone thinks I am advocating the wearing of fur coats, I am not. Please read the words.

What's the chances? Think AND

Probability comes into our life in all sorts of ways, as I explore in Dice World , from the obvious toss of the dice and outcome of a lottery draw, through the way we assess risk, to the fundamental level of probability in the quantum particles that make up everything around us. This presents a bit of a problem because, frankly, our brains aren't wired to get the hang of probability. It doesn't fit with what we normally consider to be common sense.

There's one very simple aspect of probability that people often struggle with, but that can very useful, and that's combining the chances of something occurring in two or more separate events. I think there's a very easy way of getting your head around this by considering the magic AND (as they would say in primary school).

Here's the deal. Say, for instance, you like to play the UK lottery's game Thunderball. This has a special ball (you guessed it) the Thunderball, for which you get a prize if you match just that single ball. It can be anything between 1 and 14, so you have a 1 in 14 (or to put it another a 1/14) chance of winning the Thunderball part with a single ticket. But what if you enter both the Friday and Saturday draw with your number? How does that change your chance of winning?

Common sense would probably say, clearly you are more likely to win with two goes, so let's add the probabilities together. 1/14+1/14 = 1/7 - you have a one in seven chance of winning. Unfortunately for common sense, this is clearly wrong. If it were true, you could guarantee a win by entering 14 draws, so you would have 1/14+1/14+1/14... fourteen times, adding up to 1. An absolute certainty of winning. But clearly this isn't the case. It's entirely possible that after fourteen draws your number still hasn't come up. What's more, what would happen if you entered 15 draws? Somehow you would have a 15/14 chance of winning, whatever that means.

You can, of course, guarantee a win with 14 tickets, but only by buying 1 ticket for each of the 14 numbers and just entering 1 draw - but that's not we're about here.

Okay, you might think, maybe we combine probabilities by multiplying them together. So if there's a 1/14 chance with one draw, you've a 1/14 x 1/14 = 1/196 chance with two draws. That's clearly rubbish. It suggests you are less likely to win by entering two draws. But it all makes sense if you read that 'x' as 'AND'. Because multiplying two probabilities together is the same as saying whats the chance of the first AND the second thing both happening - in this case, what's the chance of winning in both the first AND second draws, which if obviously is much smaller that just winning one.

Once you've got AND on board, it's easy enough to see how to use it to work out the chance of winning something in either draw. We just need to work out the chance we won't win in the first AND won't win in the second. Then the remaining chances are where we do win something.

The chance we won't win in the first draw is 13/14. So is the chance we won't win in the second. So the chance we won't win in the first AND the second is 13/14 x 13/14 = 169/196. So the chance we will win something is 1 minus this. 1-169/196 = 27/196.  That's about 0.14 - a 14% probability,  between 1/8 and 1/7. So not quite double the chances, but a lot better than with just one go.

Combining probabilities like this? Simples.

The toilet roll dilemma - an online experiment

Every now and then I feel the urge to do an online experiment - today we are dealing with one of the biggest social issues to face humanity. Which way do you put the toilet roll on the holder?

I am personally convinced there is only one way for a sane person to do this, but not everyone agrees.

So what do you think? Which way up should we put the toilet roll? I'd be grateful for as many replies (here or on Facebook/Twitter @brianclegg) as possible.

Please don't just vote, though - I would like a logical explanation, with workings where relevant.

Thank you in anticipation. Littlendians and Bigendians have nothing on this one.

DIY volcanoes with ammonium dichromate

One of the saddest things about the way chemistry teaching has progressed is the way experiments have been made safer and safer. In our after school chemistry club I once did an experiment using hydrogen cyanide as an ingredient - somehow I can't see it being employed today. And the modern idea of a chemical volcano is the impressively bubbly but totally un-volcano like result of combining sodium bicarbonate and vinegar.

But back in the day we could produce much more impressive volcanoes that threw out sparks and sent ash flowing, as you will discover in my latest Royal Society of Chemistry podcast.

To find out more about ammonium dichromate, take a listen by clicking play on the bar at the top of the page - or if that doesn't work for you, pop over to its page on the RSC site.

And in case you'd like to see it action (though the real thing is better):
 

The ecologic of streaming

...ishIt might seem obvious that streaming a video is more environmentally friendly than going to get a DVD and watching it, but one of the rules of ecologic is that in the environment, common sense doesn't always deliver the right results. Think, for instance, of tomatoes, where British tomatoes raised in greenhouses have a worse carbon dioxide footprint than Spanish tomatoes, despite all those extra food miles.

It would have been entirely possible that the heavy energy use at the data centre, plus the transmission costs balanced out the production, shipping and driving back and forth that is the life of a rental DVD - but no. Streaming services like Netflix and Amazon Prime really do have an environmental benefit (for the reasons above, and also because DVD players take a lot more energy than a streaming box like an Apple TV or a Smart TV with built-in streaming services) - and there's a study to prove it. 

Researchers from Lawrence Berkeley Laboratory and Northwestern University have come up with impressive savings that suggest  if all DVD viewing in the US in 2011 was shifted to streaming services, around 2 million tonnes of CO2 emissions could have been avoided and around 30 petajoules of energy saved—the equivalent of the amount of electricity needed to meet the demands of 200,000 US households. Not trivial.

It seems the impact of online rental/purchase of DVDs had a similar impact to streaming, but renting or buying DVDs from a physical store is much more energy intensive because of the impact of the drive. Clearly this would also be true in the UK, but my suspicion is that the impact here would be less, as car journeys in the UK tend to be shorter, and cars tend to be more environmentally friendly than those in the US. And 2011 was a long time ago in the video watching world - I suspect significantly fewer of us now drive to get a DVD (bye-bye Blockbuster).

As streaming increases, the report's authors suggest that effort should be put into improving the efficiency of end user devices and network transmission energy to bring down the energy use even further.

Even so, those of us who have largely moved from DVDs or Blurays to streaming can feel suitably smug.

If you are the kind of person who likes to dig into the actual paper, you can find it by clicking this link.

Fast Facts courtesy of your friendly neighbourhood Institute of Physics:
An estimated 1.2 billion DVDs were purchased in the US in 2011 An estimated 17.2 billion hours of DVDs were viewed in 2011 in the US An estimated 3.2 billion hours of movies and television programmes were streamed in the US in 2011 The percentages of total video streaming viewing time attributable to computers, televisions, and mobile devices in 2011 are estimated at 20%, 77%, and 3%, respectively  This has been a Green Heretic production

The dangers of name calling

Could I apologise to people who like this blog for the science/entertaining bits that this is yet another piece on politics - but the good news is that I promise to shut up on the matter now until the general election next year.

I pride myself that my friends on Facebook and the people I follow on Twitter are nice, intelligent people, with a far better understanding of science than the average member of the public. Which is why I have been very disappointed by the social media storm coming from them during the recent UK election.

I don't normally discuss my political affiliations, but I think I ought to say up front that I am one of the few remaining Liberal Democrats in captivity, in case anyone makes assumptions from what I am about to say.
What I think has been very silly is the swathes of abusive posts and tweets about UKIP, calling them fascists and racists. (Or just launching ad hominem attacks.) Now, bearing in mind I am a Lib Dem (come on, I'm called Clegg), I should stress that I strongly dislike UKIP policies and I would never support them or vote for them. But. Name calling is not the answer. We need proper debate, not spittle-powered invective.

Some of the people who were doing the name calling identified themselves as Greens. Now you can do exactly the same thing with the Green party if you want to, but using the opposite wing of extremism. You could easily label the Greens as Marxist. Not because they are, but because a number of their policies overlap with Marxist ideas, just as a number of UKIP policies overlap with fascist ideas. It's easy to forget, but Marxism is a totalitarian, anti-democratic system just as much as fascism is. I've done work in the past with a charity that helps in Belarus, and I can tell you that if you doubt this, you have never seen Marxism in action.

But my point is not that we ought to be pointing fingers at the Greens and calling them Marxists, because mostly their supporters and activists aren't, but rather we shouldn't be pointing fingers at UKIP and calling them fascists, because mostly their supporters and activists aren't. (In both cases, the parties will contain some extremists from their respective wings.)

Instead, if parties want our respect, they should be pointing out their own policies and explaining why they are better for us, not spending all their time in attack mode. The European election gives a strong message that people are fed up of the EU as it is currently constituted, and I can understand that. It is a bloated bureaucracy. It does waste vast amounts of money and interfere where it shouldn't. I've been involved indirectly in 3 EU funded projects, and every one of them wasted vast amounts of money and didn't achieve what they were trying to do, because they were all about bureaucracy and ticking the boxes.

So tell us how you will sort the EU out. Tell us how you will make the UK work better! But don't bombard us with 'I hate UKIP' messages, because they are counter-productive and actually encourage support for more extreme parties. When the general election comes round in just under a year's time, focus on your policies and how they will things better. If you fight a negative campaign, attacking another party - however much that party's ideas may be wrong - you are making a big mistake. 

The penalty dilemma

Anyone who knows me will tell you that I am passionate about football - specifically I am passionate about avoiding it at all costs, which is why the current relentless advertising on ITV for World Cup coverage is filling me with dread. But I did read something the other day that was a really interesting point on the subject of the dreary game.

It was in Think Like a Freak, the latest tome from the guys who brought us Freakonomics (review follows soon) and they were applying their usual sideways thinking to the matter of the England team's favourite occupation, the penalty shootout. It is a tiny bit of psychological warfare between the player taking the kick and the goalie, as the goalie has to dive before it is clear which direction the ball is going in.

What Levitt and Dubner point out is that the best way to win is actually to kick straight at where the goalie is standing, as that way it is likely to get through whichever way he dives. Of course you couldn't do it every time, but it's certainly a winning tactic if it comes out of the blue. And yet players don't do it. Why? Because of the cost of failure. If you guess the direction of the dive wrong, or just miss because you are trying one of those fancy shots that skims in at the top of the net, then it's fair enough. But if you kick the ball straight at the goalkeeper and he just stands there and stops it, you are the kind of football player I used to be. You would be mocked and derided. Most of the time this won't happen, because the goalie will dive. But you can't be sure - and that fear of being belittled is enough to make sure that footballers don't take the option that is most likely to win.

Neat. (Please don't bombard me with footballist theories on why this is wrong. A) It's not my idea and B) I don't really care, it's just the dilemma that interests me.) You can see more about Think Like a Freak at Amazon.co.uk and Amazon.com

What message does your vote send?

So, polling day in the European elections is upon us. As I've mentioned previously, I really don't want to vote for any of the options available, but I do intend to vote, so what to do? Let's have another go.

Logic says something like this. Of itself, this vote won't make anything happen, because it doesn't really matter what party our Euro MPs belong to, as it won't make any difference to what the European parliament does (which is pretty limited anyway).

So the only point of the vote is to send a message to the political parties about Europe ahead of the election that really does matter, next year's general election. Some people think that they will also send a message about other policies, like the NHS or the environment, but I think this misses the point. The message that will be received will simply reflect the relevant party's attitude to Europe.

So here are my options (in order of the latest poll I've seen):

Labour: Let's be vaguely in favour of change in Europe, but not really do anythingUKIP: Let's get out of the EUConservative: Let's try to negotiate a change (almost impossible) and if we don't get one then have a referendumLib-Dem: Let's learn to love EuropeGreen: Make the EU even more bureaucratic and ineffective by having a 'multiplicity of independent bodies' and do away with free tradeEnglish Democrats: Let's end democracy as we know itOkay, they are caricatures, but close enough. Realistically, only Labour or Conservative can form the next government (with or without a coalition) - so they are the target for whatever message I send. The question is, what should that message be?
Sigh. I'm going to have to wait until I'm standing in that booth and hope inspiration comes at the last minute.

Has the Daily Mail gone too far?

The Daily Mail's ongoing mission to boldly assign everything we eat or drink into the categories 'causes cancer' or 'cures cancer' is a cause of much amusement, but essentially harmless. However, its latest magnificent misunderstanding when it comes to science could actually cause serious harm.

A couple of days ago a Mail travel reporter (note they didn't let their science person, if they have one, anywhere near it) gave us the striking headline shown above (spot the typo). You will note there is no suggestion that there is no known scientific reason why this stuff should work - we are told straight 'just a teaspoon will offer three hours' protection' and apparently with a straight face that it causes your skin to vibrate and cancel out ultraviolet light.

The article goes on to explain that the liquid sunscreen, retailing at £17 a bottle, works, according to its manufacturer, as follows: 'If 2 mls are ingested an hour before sun exposure, the frequencies that have been imprinted on water will vibrate on your skin in such a way as to cancel approximately 97% of the UVA and UVB rays before they even hit your skin... This is similar to the amount of UV reflection created by SPF 30 titanium/zinc sunblocks but distinctly better than UVB chemical sunscreens which prevent certain damage that leads to the visible/painful/inflammation reaction we identify as sun damage.'

The article also reproduces testimonials from users including 'My year and a half year old drinks it as well and hasn't burned once this summer and is out everyday!'

The suggestion seems to be that somehow the frequencies ‘imprinted on the liquid’ can cancel out light the way noise-cancelling headphones cancel out noise. If this were possible, the military would be rushing out to buy this product for their planes as ‘cancelling out light’ would make them invisible. But in fact light is nothing like sound – you can’t cancel it out with a vibration, even if something you drink could make your skin vibrate with a particular frequency – which it can’t.

The real concern is that people will use this product and then undertake dangerous levels of sun exposure – and a particular concern is that such a simple apparent solution would be ideal for children. There’s no worse job when arriving on a beach than having to coat your children in sunscreen. Imagine how attractive the idea is of just being able to give them a drink and they are protected. But should parents do this, they will be exposing delicate skin to the sun’s rays without protection, which can result in very serious outcomes.

Of course scientists are coming up with new treatments and products all the time – but when the description of how a product works is one that bears no resemblance to known science, when the product has not been tested by any authorities for safety, and when the result of it not working could have very serious health implications, it was extremely irresponsible of a newspaper to cover it in this way.

The Mail does provide a few provisos:

The company's claims have not been approved by the US FDA - but there is no suggestion that they never will beA representative of the British Skin Foundation is quoted as saying they 'advise extreme caution of any product claiming UV protection using methods not supported by clinical research' and emphasising it is important to stick to tried and tested methods when protecting children's skin - which is all good stuff, but hardly the kind of warning that is necessaryWhen it comes down to it, all the editorial in the piece, apart from the remark about the FDA, is positive and reads more like a press release than an article. There is no suggestion that the advertised basis does not make scientific sense. There is no warning from the Mail about the consequences of relying on this product. Frankly, this article is very disturbing indeed.

Who makes the public ignorant?

I was interested to be pointed to these survey results in '12 things the British Public Are Completely Wrong About' on Buzzfeed (and finally to the actual survey results here at IPSOS Mori). This is partly fascinating because two of the results simply don't show what the headline suggests, yet no one seems to have noticed this, and partly because it's interesting to think about why public perception is wrong on these issues - and a large part of the blame has to go to politicians, TV and newspapers.

Let's deal with that little quirk where the figures don't reflect what's being said. We are told that 29% of people think that the government spends more on Job Seekers Allowance than pensions and, by coincidence, 29% of people think foreign aid is one of the government's top three expenditures. (In reality we spend 15 times more on pensions than JSA, and foreign aid is not even in the top 10.) The actual figures were 29% and 26%, which surely don't support the headline hypothesis 'Things the British Public are Completely Wrong About'. The title tells us that most of the public are wrong, and yet we are talking about a quarter of those polled. My suspicion is that one reason some people did get this wrong is that it involves doing comparisons with ridiculously large numbers, because the numbers spent on the health service, say, makes anything else seem negligible. In reality, for normal people, as opposed to the government, the £7.9 billion spent on foreign aid is still a massive number, which could easily make it sound like one of the higher expenditures.

But it is particularly interesting to take a look at some of the other assertions (which do seem to be more representative of public views) and see where they might have come from.
On average, those questioned thought that 15% of girls under 16 get pregnant each year. This is the most bizarre statistic of the lot. Assuming girls can get pregnant from around 12, this would require more than half of those who could get pregnant to get pregnant every year. In fact if you look at the breakdown of responses, around 70 people thought that 40% of girls under 16 got pregnant - which means every single girl who was capable of becoming pregnant doing so, plus rather a lot of others. Boggle. It certainly demonstrates a poor understanding of basic statistics. Where does the wrong impression come from? Probably right wing politicians, reinforced a bit by the media, who talk about teenage pregnancies far more than the actual data (which is a rate of about 0.6%) suggests is necessary.58% do not think that crime is falling and 51% think violent crime is rising (again the Buzzfeed article got a number wrong). There's an element of politicians talking too much about this, but the fault is primarily with the media. Admittedly I have heard several times on the news that crime rates are falling, but there is always a 'but' immediately afterwards where after some scraping around they manage to find some crime statistic (any crime statistic) that is rising. They can't just report good news, it goes against their miserable natures. And, of course, day after day crimes are reported in the way many other things that happen day after day aren't.We think that there are nearly as many muslims (24%) in the country as christians (34%) where the figures are actually 5% and 59% (sort of, though that second figure is an overestimate by most measures). This has to primarily be a news agenda thing. I can't remember when I last heard a news bulletin that didn't mention muslims in some way - in large part because a lot of world problems are happening in muslim countries. So the religion gets more media coverage than is representative of the muslim presence in the UK. It isn't helped when we get the silly halal meat type blowups, when people will assume that surely restaurants wouldn't make a change like that to accommodate such a small percentage of the population. This is a hard one to do anything about because the news agenda is so driven by strife.We thing 31% of the country are immigrants and 30% are black and asian, where actual numbers are around 13% and 11%. The immigrant side of the equation surely comes from the politicians making such a fuss about it. My suspicion is that the black and asian misjudgement is mainly because the media is so London-based, so whenever they, say, visit a school it has a different black and asian mix from that you would expect in the country as a whole. The media also tries so hard not to exclude minorities that there is a tendency to have a higher representation of black and asian presenters in some parts of the media than reflects the national average, though strangely the percentages tend to be too low in many dramas.It seems a mix of poor understanding of statistics (I still can't get over that '15% of girls under 16 getting pregnant'), disproportionate focus by political parties and imbalanced reporting in the media, which is always happier, for instance, to tell us about crimes than about the eradication of crime, means that the British public is sadly misinformed. 
If you'd like to see some more detail on the data behind the headlines, take a look at these slides:

Perils of Perception: Perception Gaps from Ipsos MORI