I use this blog as a soap box to preach (ahem... to talk :-) about subjects that interest me.

Friday, December 28, 2012

Authors' Mistakes #8 - Graham Tattersall (addendum)

I’ve given up reading Geekspeak. It is too stupid.

In four sentences that appear towards the end of Chapter 11 (pages 103 and 104), Tattersall refers three times to the bomb dropped on Hiroshima as an atomic bomb, and three times to modern multi-megaton bombs as nuclear bombs. He must think that there is a difference between an atomic bomb and a nuclear bomb!

So, here is somebody with a PhD (probably in Math) who doesn’t know that the Hiroshima bomb was a nuclear bomb.

The front flap of the book jacket says: Dr. Graham Tattersall, a confirmed and superior geek, and, later: Math has a new champion, and the Geeks a new King.

BS, I’d say.

Authors' Mistakes #8 - Graham Tattersall

Geekspeak, by Graham Tattersall is a little humorous hard-covered book containing a collection of essays about how to calculate odd things.

Tattersall, in his attempts at making complex calculations easy, cuts too many corners. For the sake of simplicity, he says things that are not right.

For example, at the beginning of Chapter 8, when estimating the number of people who die every year in the UK, he states:

You can estimate the figure quite easily from the average lifespan in this country, which is roughly 75 years — and rising. Imagine for a moment that all births in Britain stopped today, that from now onwards people die off and aren’t replaced.
Each year more die, until, after the time of the average lifespan of 75 years, there will be very few of today’s 60 million people left. So, if ages are evenly spread [my observation: a dubious assumptions, but let’s let it pass], an average of 60 million divided by 75 people will die every year. That’s about 800,000 per year.

He then comments that the actual figure is 500,000 and that the discrepancy can be explained by the fact that our lifespan is growing.

Perhaps. But there is a problem with his estimate due to his erroneous use of statistics: you cannot state that the ages of death are “evenly spread” between 0 and 75 while, at the same time, claim that “very few” live beyond the average. What average is it if there are very few people that live longer?

Tattersall’s assumption that very few people live longer than average is not only conceptually flawed, but also factually wrong, because it turns out that many people happily survive the average age of death. I looked at the US statistics and discovered that almost 60% of people live longer than average.

As an aside, you might wonder how it is possible that more than half survive the average age of death. It seems unreasonable. The reason is that the distribution is highly skewed. I will explain it with an example that, although not completely realistic, proves that for steeply decreasing distributions the number of points above the average can exceed the number of points below the average: Assume that you have a population of 100 people and that 55 of them live 60 years, 30 live 70 years, and 15 live 75 years. The average age of death is (45 x 60 + 35 x 70 + 20 x 75) / 100 = 66.5, with 55 people above average and only 45 below average. Convinced now?

Another example of his “pseudo-scientific” but confusingly imprecise presentations is in the small “Speak Geek” section at the end of Chapter 5. He states that A man who weighs 100kg at the North Pole would weigh only 99.65kg at the equator.

This is roughly correct (it’s actually close to 99.67kg). It is due to the fact that the surface of Earth, which spins at the rate of about 40,000km every 24 hours, is not an inertial system. We are kept in place by the presence of gravity. Otherwise, we would keep moving on a straight line along the tangent. From our local point of you, this appears to us as a force directed away from the axis of the Earth. This is the same apparent force that pushes us away from the centre of a car when we take a curve.

So far so good. Tattersall calls the centrifugal force an “upward ‘flinging’ force”, and that is were I have a problem. After mentioning gravitation, he explains the centrifugal force as follows: The second force is upwards, and is caused by the rotation of the Earth constantly trying to fling your body into space like a stone on a string being swung round your head.

This is misleading in too many ways to be acceptable. First of all, Earth doesn’t try to fling us anywhere. Secondly, the slingshot works because we exercise a pull on it off-centre. Therefore, to compare Earth to a slingshot is not right.

You could dismiss my objections by saying that he explains things in a colourful way and that I am just being my usual hair-splitter and boring self. But when he says that the centrifugal force is upward, he is plainly wrong. The centrifugal force is outward. It is upward at the equator, but to say it in general is badly misleading.

Finally, I would like to report a horrible mistake in Chapter 7. He starts it with the following two sentences: Captain Picard has been sorting out a spot of bother on some planet or other, while the Enterprise orbits at a safe distance. A radio command is sent to the ship: ‘Beam me up, Scotty.’

How can he not know that Scotty was the chief engineer under Captain Kirk? What a shame! And he calls himself a geek? It is painful.

I usually report problems in a book after reading it. In this case, I couldn’t hold back after reading about a third of it. I will probably have to report more...

Thursday, December 27, 2012

Authors' Mistakes #7 - Lee Child (again)

Lee Child definitely knows how to write thrilling crime novels. The Visitor, published in the US with the title Running Blind, is a good read, all 500 pages of it.

I’m amazed that, despite Child’s experience and Bantam’s professional editing, a mistake still found its way into the published book. I already reported on this blog a mistake I found in another Lee Child’s book: Die Trying.

What follow is a paragraph in Chapter 22, on page 352 of my paperback edition of The Visitor:

The apartment they wanted was on the eighth floor. Reacher touched the elevator button and the door rolled back. The car was lined with bronze mirror on all four sides. Harper stepped in and Reacher crowded after her. Pressed eight. An infinite number of reflections rode up with them.

Do you see it?

It’s easy enough: When the door opens, it slides away (incidentally, rolled is not the verb I would have used, but then, who am I to criticise?)  Then, how can Reacher see that the interior of the door is lined with a mirror? He is even still standing outside the lift. Child should have swapped the sentence “The car was lined...” with “Harper stepped in...” In fact, Reacher could have only seen the inside of the door after the door closed.

Thursday, December 20, 2012

Authors' Mistakes #6 - Michael Crichton & Richard Preston

I just read Micro, the novel left unfinished by Michael Crichton when he died and completed by Richard Preston.

Crichton is a great author and I enjoyed several of his novels, and especially Timeline, Airframe, and Jurassic Park. Micro is also a very entertaining story, but this time, in my opinion, he went too far with his scientific (or not) speculations.

That an extremely high magnetic field can shrink objects is difficult to take, but what happens when objects are shrunk violates the basic laws of Physics in an unacceptable way.

According to Crichton and Preston, when people are compressed, they become very light and strong. This might make for a nice story, with people jumping around like fleas and falling from great heights without getting hurt, but it is not scientifically credible.

For one thing, where does the mass go? The principle of conservation of energy-matter has been proven correct uncountable times. Even if we accept that the space between the molecules and atoms (and perhaps subatomic particles?) is reduced, why should the mass of a person be reduced as well? It doesn’t make any sense.

Then, there is the issue of body temperature and thermoregulation. Crichton and Preston mention that shrunken humans have some problems with maintaining their body temperature, but it is not an issue that one can dismiss easily.

If you reduce the linear dimensions of something by a factor of 1000 while maintaining its shape, its volume is reduced to one billionth of the original one and its surface to one millionth. This means that the surface per unit of volume would grow by a factor of 1000. No way that the human body could function under those condition. It would lose all its heat and die.

Finally, the authors don’t even try to explain how the shrinking process can be reversed. To shrink people to 1/1000 of their original size, they apply three times a strong magnetic field. Every time, the people shrink by a factor of ten. Then, without any explanation, when they apply again a magnetic field, the people return to their original sizes. This goes against logic. What is it? Three is a charm? Give me a break...

Tuesday, December 18, 2012

Authors' Mistakes #5 - Academic textbook on research methods

I have been reading Practical Research Methods for Media and Cultural Studies: Making People Count, by Máire Messenger Davies & Nick Mosdell, Edinburgh University Press 2006, ISBN 978-0-7486-2185-9.

On page 62, to explain methods for random sampling, the authors describe how to make a sample of 50 students from a population of 150.

When they explain the stratified method for random sampling, they say: your population list may be divided into two lists of seventy-five males and seventy-five females and you sample each list randomly until you have twenty-five of each.

The statement that out of a total population of 150 students the genders are equally split is in general not correct. You might think that it doesn’t really matter whether the two lists don’t have exactly the same length, and that the method remains valid. But this is not the case, because if there are, say, 90 males and 60 females, a sample built with 25 males and 25 females would obviously not represent the population.

Now, rather than studying a sample that represents the whole population, you might like to investigate differences between male and female students, regardless of how many of each gender are present in the population. Then, it would make sense to do the split and pick equal numbers of students from the two lists.

But how they put it, they are definitely wrong. And they keep doing it. Here is how the text continues: You then subdivide the two lists into age groups to ensure you have sufficient numbers of, say under- and over-thirties (assuming that age is relevant to your research question). As you can see, if you are going to subdivide your sample into particular demographic subgroups, your subgroups will become smaller and smaller the more categories you include, until the sample size for these subgroups cannot be seen as reliably representative.

So far so good, but now comes the blunder: For instance twenty-five females, split equally into under- and over- thirties will give you only twelve or thirteen people in each group.

How can you split equally 25 students on the basis of age (if you define the discriminating age in advance)? It’s plainly wrong.

And they go deeper and deeper in their nonsense: If you want to look at four age categories, you will get only six or so people in each age and gender subgroup.

You might think that with a couple of “on average” added in the crucial places, everything would make sense. But that is not the case, because their explanation would still imply that the age distribution of students is flat, which is not.

It’s sad to see such mistakes in academic textbooks...

Monday, December 17, 2012

Kill, kill, kill!

In memory of Emilie Parker, one of many.

The second amendment to the US Constitution says:

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

It was adopted on 15 December 1791.

Today, we wouldn’t place a comma between subject and predicate, but grammar is not the only thing that has changed over the past 221 years.

In 1791, the USA had been independent for five years and counted fourteen states (Massachusetts, New Hampshire, Vermont, New York, Rhode Island, Connecticut, Pennsylvania, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia), plus the District of Columbia, two territories, and land disputed by Spain in the South and the U.K. in the North.

According to the 1791 census, the population of the fourteen states was 3,723,418, including 681,850 slaves. The current population of the 50 states is approximately 315 millions.

Much has been said about the American citizens’ right to bear arms. I only want to make a couple of points.

Firstly, the US doesn’t need a militia, as it was perhaps the case in 1791. They have federal, state, and local police, whose work is actually made more difficult and dangerous by all the weapons that are in circulation (an average of almost one per person).

Secondly, assault automatic weapons, contrary to what the lobby groups like the National Rifle Association claim, have nothing to do with sportsmanship. Cheap weapons designed for high fire power to kill at short range might be suitable for criminals, but have nothing to do with a civilised society.

I say: ban all automatic weapons, standardise and enforce registration laws, and make it difficult to buy ammunition.

Monday, December 10, 2012

A Prank

I don’t get it.

Two DJs called the hospital where Kate Middleton was being treated and claimed to be Queen Elizabeth.  A nurse believed them.  Then, the next day, apparently, the nurse felt so humiliated that she committed suicide.  Now, everybody blames the DJs.

It seems to me that somebody who commits suicide for having been duped must have some psychological problems.  I know that what I’m saying is not politically correct, but who in her right mind would kill herself for being victim of a prank?

I am really sorry for the nurse.  Nobody should be so desperate and alone to arrive to the point of taking their own life.  But the prank was only a trigger.  Probably the small stress that brought the nurse’s state of mind over a tipping point.  The fact that that particular nurse answered the phone was an unfortunate and tragic accident.

The DJs only did their job.  They didn’t even expect that their prank would succeed.  I understand that they feel bad.  I would too.  But they should be reassured that they are not to be blamed.

Nobody could have possibly considered the possibility that a prank call would result in a suicide.  After all this hoopla, the poor DJs will probably live the rest of their lives thinking that they caused the death of a vulnerable nurse.  But they did not.  They are not responsible for it and should receive our sympathy instead of our scorn.

Every act, even the most insignificant, can have horrible consequences, and we focus on the consequences of an act because they are observable and measurable.  The tendency of focussing on what can be measured is understandable, but in many cases also completely wrong, because very often, people “get away” with unconsidered acts that could have very serious consequences.

For example, we are always shocked when we see on TV horrific pictures of car accidents, but how many times people drive dangerously and are not caught only because, by chance, they don’t cause any carnage?  In my opinion, whether an accident occurs or not is less important than what could have happened if it had occurred.