Monday, October 26, 2015

Pritt Sticks to Mars

Some time ago I was at Chichester Skeptics in the Pub to see James Ward talk about his book Adventures in Stationary. The talk was fantastic, and whilst I haven't gotten around to reading the book yet, it's on my list of books to read (that list grows faster than the time available to read them). During the talk, James referenced a press release from Pritt Stick's makers celebrating their 40th anniversary, saying that the 2.5 billion Pritt sticks sold in their 40 year was history was "Enough to leave a line of adhesive extending from the Earth, past our satellite the Moon, on to Mars and then all the way back again"

James Ward was unsure how they came about with such a statistic. I don't know how they did it either, but here's how I would do it:

Firstly, what are we using for the distance? At it's maximum the Earth could be on one side of the Solar System, and Mars on the other, we would be as far from each other as possible. Or, the Sun, Earth and Mars could be in a perfectly straight line in that order, as close as we can be to each other currently. The ranges for these distances are:

Smallest: 56 million km or 34 million miles.
Furthest: 401 million km or 249 million miles.

To see where on this range the current distance is, see here. Consequently, we'll calculate two values, one for Mars at its closest, the other Mars at it's furthest.

The next thing to consider is what is meant by a Pritt Stick, for they are not a standard unit. Pritt Sticks come in a range of sizes. Let's just go for the medium size, which has a stick of glue in it with a diameter of 2.0cm and a height of 5.1cm. This gives a volume of 16.02cm3

The diameter of the Pritt Stick gives us the width of our glue trail to Mars - we'll assume it's smeared across our hypothetical surface that extends to Mars evenly. Volume = length x width x height, so some simple rearranging is need to get our height of Pritt stick smear, also remembering this smear is there and back.

One medium Pritt stick would be able to leave a trail of glue to Mars and back, so long as it was only 7.2fm to 1fm thick. This is not possible, given that our largest estimate is smaller than the radius of a gold atom's nucleus, and our smallest is not much bigger than a proton. Pritt stick cannot get this small without splitting the atom.

However, we're dealing with 2.5 billion Pritt sticks. This leaves us with a smear of Pritt stick some 17.9μm to 2.5μm thick. This seems more realistic, though my experience of Pritt stick is a smear thicker than this. For comparison a single skin cell is about 35μm across.

Let's be more charitable and go for 2.5 billion large Pritt sticks. These have a diameter of 2.5cm and a height of 6.6cm, giving a volume of 32.4cm3

Using the same mathematics as above, this gives us a smear that ranges from 28.9μm to 4.03μm which still seems pretty thin.

So, after all this, I'm with James here in not understanding how Pritt stick came up with their statistic either. If only they'd shown their working in a press release.

Either way, we've been dealing with some very different units: femtometres, micrometres, centimetres and kilometres. That's quite a range - one kilometre is 1,000,000,000,000,000,000 femtometres. Here's a lovely website to help you appreciate the scale of the universe, from the very big to the very small: The Scale of the Universe.

Sunday, October 25, 2015

How many Ferrero Rocher do you need to build the Pyramids at Giza?

My wife and I went to see Richard Harring's new show "Happy Now?" last night, and it was very funny. During the first half hour of the show though, Richard did a reprise of some of the highlights of his previous shows, as during August and September he performed them all again over 6 weeks.

This included his rather romantic gesture for the first Valentine's Day he and his now wife shared. She had on her bucket list "Build a pyramid of Ferrero Rocher like that on the Ambassador's Reception advert". So he bought her a single Ferrero Rocher, with a view to getting enough over the years to fulfill her lifetime ambition. The next Valentine's Day he bought her two, and on the third Valentine's Day he failed to realise the power of exponential growth and bought her 4. This year he bought her 128 Ferrero Rocher. He went on to joke about the implications of this, including how it wouldn't be long before there would be enough to build the Great Pyramid at Giza.

Leaving the show, as well as the funny memories and ponderings on the nature of happiness, I wondered just how many Ferrero Rocher would be needed to build the Great Pyramids at Giza. As it's half term, I have found out.

The average size of a Ferrero Rocher (sample size = 16) is 3.2cm x 3.2cm x 3.2cm. They are not a uniform shape, but we'll assume they are for this back of the envelope calculation. We'll also approximate them to perfect cubes*.

Here are the results (click to enlarge):

Fortunately, we have 23 years left before Richard Herring's romantic gesture is about the same as the current annual output of Ferrero Rocher.

However, we can breath a sigh of relief, because the adverts pyramids range in size from 8 to 12 tiers, so fewer than 1,000 Ferrero Rocher chocolates will be needed. Of course it does mean that a new romantic gesture needs to be found in 3 Valentine's Days time...

*If you've read this far and have the wit, by all means take into account that they don't tessellate, and there will be gaps in between,  and that those Ferrero Rocher on the layer above will sit in these gaps. Also, I do not know how much weight a Ferrero Rocher can take, but it isn't more than 73.9 kg (sample size one). So something else that needs considering before filing for planning permission, as the actual number may be higher than those above.

Sample size of one

UPDATE: Well, Richard Herring retweeted me, which was unexpected. Hello Richard Herring fans! You might also like this in relation to the "Give me head till I'm dead" t shirt skit: Traffic light food label for semen.

Monday, February 9, 2015

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 HeadlinesMargaret 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.

Saturday, February 7, 2015

Apeocalypse now

A friend posted this on Facebook:

She asked "Can I make the "ape-ocalypse" pun and still be scientifically accurate?" and tagged me, as I am her guru for this.

Short answer: Yes.

Long answer:

Yes, but you must be talking about any combination of: humans, chimpanzees, gorillas, orangutans (aka the Great Apes) or Gibbons (aka the Lesser Apes), for these are the apes. (You can see our extended family tree over at OneZoom).

Colloquially ape can mean "any primate except humans", but as can be seen this is not accurate. For our primate cousins to be included we would need far less catchy alternatives such Primatocalypse (which would involve the primates: Lemurs, Tarsiers, Old World Monkeys, Apes and New World Monkeys) or Simianocalypse (which would be all the moneys and apes, simians being Old or New World Monkeys and Apes).

 People often don't realise that we Homo sapiens aren't just like apes, we *are* apes. A fantastic book to look at our ape heritage is The Incredible Unlikeliness of Being by Alice Roberts. Given that we are apes, one could argue for two reasons that we are, right now, in the middle of an apeocalypse:

1) Originally apocalypse meant revelation, it comes from the Greek for uncover, and is used in the context of uncovering knowledge. Whilst we (as a species) have a long way to go, we are currently in a position of having uncovered more information about how the universe works than at any point that's ever existed. For example, as Sean Carroll has (I think successfully) argued, the laws underlying the physics of every day life are completely understood. No, really, here's the equation. It's an exciting time to be alive, and that is thankful, as science is the best way we have to resolve the second reason.

2) These days (especially for those not in the Church), apocalypse more commonly means any universal or widespread destruction or disaster. Now, if we're to look at how we as species are treating this planet overall, one could also argue we are in the middle of, or on the verge of, an apeocalypse: We are in the middle of the sixth mass extinction, human caused climate change is real and is happening and to sustain the lifestyle that humans are on average living we would need 1.5 Earths.

It's Apecalypse Now, and for our sins, we've given ourselves quite a mission to put it right.

Sunday, November 2, 2014

Does the Star Trek Odd/Even rule hold up to scrutiny?

It's all well and good being a skeptic and going after homeopathy, conspiracy theories and religion. But what about the important stuff in life? Skeptics must question everything. This includes Star Trek. Does the oft cited Odd/Even rule hold up to scrutiny?

Yes. Generally, an odd numbered Star Trek film is not as good as an even numbered Star Trek film. Out of 12 Star Trek films, only two fail to meet this rule.

I used IMDB, Rotten Tomatoes and Metacritic to get the ratings for each film. All are in a similar format, being a rating out of 10, a percentage or a mark out of 100. As I started with IMDB I converted all to the same format.

The average score for a Star Trek film is 6.7. Above avergae films are therefore "Good", average films are, well, "Average" (though none exist yet) and below  average films are "Bad".

I have included the recent re-boot, but the rule may need to be modified to just include the "original" run of films, as the two new ones rank 1 and 3 using this survey's methods.

You can see the results below:

Data accurate as of 02/11/2014
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