The Blood Miles: a book review

The Blood Miles by Andrew Moody (382 pages, published 2023)

I’m a sucker for post-apocalyptic science fiction, and I recently read, with great enjoyment, the recent novel The Blood Miles by Andrew Moody – a self-described lay theologian and graphic designer from Melbourne, Australia. This is a YA novel, in the sense of a blog post I read once:

• The protagonist should … be aged between 15 to 18 years old (Chris Walker, the protagonist here, is 18)
• … be autonomous from his or her parents (Chris Walker has lost his parents)
• … embark on a journey which has to do with coming of age or some sort of rite of passage (Yes, he does)
• … learn something about who he or she is (Yes, in the deepest possible way)
• … have a ‘voice’ that readers can relate to (Yes, especially for male readers)

The gunfire, violence, torture, and human experimentation in this book mean that it is probably not suitable for younger readers, however.

As a post-apocalyptic YA novel with an edge-of-your-seat exciting eastward journey, The Blood Miles is reminiscent of e.g. John Christopher’s The White Mountains (1967) although, given that it is set in a desertified Australia, Lotus Blue (2017) might be a better comparison. There are also similarities with the 2010 film The Book of Eli.

Along with the desertification and bands of roving killers, everybody in this novel seems to be suffering from a mysterious “Tox” with no known cure, except for the promise of a treatment outpost at Crux, located across the mountains to the east.

The world of the novel is cleverly invented and described very well. The image above is my personal take on a description from an early chapter: “The south gate was a big metal frame made of I-beams and trench mesh that ran on wheels between concrete walls. As it slid back and we went forward, I could see the van with its battered panels, and red-X silhouette made of crossed syringes.”

The plot is loosely based on that of John Bunyan’s The Pilgrim’s Progress – the author calls it “a homage” to that work – with elements from C.S. Lewis’s The Pilgrim’s Regress and all kinds of other literature. For example, the character corresponding to Bunyan’s Evangelist is a somewhat grittier character called Evangeline Veracis: “She was middle-aged with short grey hair and a long grey overcoat that parted to reveal a ceramic breastplate and loose combat pants. Over all of it, she wore a diagonal leather strap that supported a sword from her left shoulder.”

Given that the author is an Anglican lay theologian with an interest in the Trinity, it is not surprising that there is a great deal of Christian symbolism in the novel. Some of the symbolism is very subtle (for example, the number sequence 3–7–12–1–12 might, or might not, be a reference to Malachi 1:12), while at other times it is more overt. It turns out, for example, that the red X symbolises the “Envoy,” who is named Tobias (i.e. “Yah is good”), and is “the Pantarch’s special representative,” killed by the villainous “Homeland Reaction and Defence,” but no longer dead – and, in fact, “running all the ops for the Pantarch.” The symbolism also shows up in place names like Gaia, Ockham, and Horeb. Several scenes unrelated to The Pilgrim’s Progress are clearly parables addressing issues in modern Christianity. I particularly enjoyed the sections exploring issues of truth, responsibility, and grace. Indeed, the extensive symbolism would make this novel a great candidate for a book club, as was also the case with the novel Piranesi (2020).

This is one of the best post-apocalyptic science fiction novels I have read, right up there with A Canticle for Leibowitz (1959), and I am giving it 5 stars. See also:

• the author’s launch video
• a book review by the “post-apocalyptic theology” blog
• Goodreads and Amazon links

The Blood Miles by Andrew Moody: 5 stars

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Pi Day once more (repost)

Pi Day is here again (3/14 as a US date). The number π is, of course, 3.14159265… Here are some possible activities for children:

• Search for your birthday (or any other number) in the digits of π
• Follow in the footsteps of Archimedes, showing that π is between 22/7 = 3.1429 and 223/71 = 3.1408.
• Calculate 333/106 = 3.1415 and 355/113 = 3.1415929, which are better approximations than 22/7.
• Measure the circumference and diameter of a round plate and divide. Use a ruler to measure the diameter and a strip of paper (afterwards measured with a ruler) for the circumference. For children who cannot yet divide, try to find a plate with diameter 7, 106, or 113.
• Calculate π by measuring the area of a circle (most simply, with radius 10 or 100), using A = πr². An easy way is to draw an appropriate circle on a sheet of graph paper.

You can also try estimating π using Buffon’s needle. You will need some toothpicks (or similar) of length k and some parallel lines (such as floorboards) a distance d apart (greater than or equal to k). Then the fraction of dropped toothpicks that touch or cross a line will be 2 k / (π d), or 2 / π if k = d. There is an explanation and simulator here (see also the picture below). And, of course, you can bake a celebratory pie and listen to Kate Bush singing π, mostly correctly!

This picture by McZusatz has 11 of 17 matches touching a line, suggesting the value of 2×17/11 = 3.1 for π (since k = d).

Actually, of course, π = 3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 8214808651 3282306647 0938446095 5058223172 5359408128 … (digits in red are sung by Kate Bush, accurately, although some have said otherwise).

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Mass Shootings in the US

Tragically, we have had another mass shooting in the US. The chart above summarises deaths from such events (data collated by Mother Jones). It is clear that the problem has been getting worse since about 2005 (statistically significant at p < 0.00001).

Social factors appear to be blame, since there has been no signficant change in the availability of weapons in that time. Those social factors might include mental health policy, education policy, social media, video games, drugs, the decline of religion, media coverage of past shootings, etc. It seems to me that serious study is urgently required. Some things we do know: psychiatrist Ragy Girgis suggests:

“With exceptions, many of these [perpetrators] tended to be younger males who were empty, angry, and nihilistic, felt rejected by society, were socially, occupationally and/or academically unsuccessful, and blamed society for their failures. These individuals tended to have very fragile egos and were highly narcissistic, feeling they were much more special than they actually were and deserving of fame and notoriety. They harbored a strong desire for this notoriety and infamy. Committing a mass shooting instantly produces these results in today’s culture.”

In the Mother Jones dataset (for 1982 onwards), 13 states have never had a mass shooting (Alaska, Delaware, Idaho, Maine, Montana, New Hampshire, New Mexico, North Dakota, Rhode Island, South Dakota, Vermont, West Virginia, and Wyoming), while in 13 other states, the chance of dying in a mass shooting exceeds 0.1 per million per year:

State	Total Fatalities	Annual Deaths per million
California	175	0.11
Nebraska	9	0.11
Oklahoma	19	0.11
Wisconsin	28	0.12
Washington	37	0.12
Hawaii	7	0.12
Texas	151	0.12
Florida	126	0.14
Virginia	53	0.15
Colorado	53	0.22
Connecticut	41	0.27
DC	12	0.43
Nevada	63	0.48

The relevant social factors are therefore not uniform across the United States. The map below shows the mean annual death rate per million for mass shootings in each state (for 1982 to 2023, excluding Alaska = 0 and Hawaii = 0.12):

Edit: Ragy Girgis, quoted above, notes that perpetrators tended to be “occupationally and/or academically unsuccessful.” Consequently, state unemployment rate is a statistically significant risk factor (p = 0.0148):

Even more significant (p = 0.0046) is the correlation with the Social Support Index from the US Joint Economic Committee Social Capital Project. Better social support helps to reduce the risk of mass shootings.

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Pi Day once more!

In honour of Pi Day (March 14), the chart shows six ways of randomly selecting a point in a unit disc. Four of the methods are bad, for various reasons.

A. Midpoint of random p, q on circumference

p = (cos(𝜃₁), sin(𝜃₁)) is a point on the circumference

q = (cos(𝜃₂), sin(𝜃₂)) is another point on the circumference

x = ½ cos(𝜃₁) + ½ cos(𝜃₂) and

y = ½ sin(𝜃₁) + ½ sin(𝜃₂), for random 𝜃₁ and 𝜃₂, define their midpoint.

B. Random polar coordinates

x = r cos(𝜃)

and y = r sin(𝜃), for random angle 𝜃 and radius r ≤ 1. This gives choices biased towards the centre.

C. Random y, then restricted x

Random y, followed by random x in the range −√(1−y²) to √(1−y²). This gives choices biased towards the top and bottom.

D. Random point on chord in A

Similar to A, but x = a cos(𝜃₁) + (1−a) cos(𝜃₂)

and y = a sin(𝜃₁) + (1−a) sin(𝜃₂), for random 𝜃₁ and 𝜃₂ on the circumference of the circle and random a between 0 and 1. This gives choices biased towards the periphery.

E. Random polar with sqrt(r)

Similar to B, but x = √r cos(𝜃)

and y = √r sin(𝜃), for random angle 𝜃 and radius r. The square root operation makes the selection uniform across the disc.

F. Random x, y within disc

Random x and y, repeating the choice until x² + y² ≤ 1. This is uniform, and the selection condition restricts the final choice to the disc.

Oh, and here are some Pi Day activities.

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Do gun laws save lives?

Do gun laws save lives? The chart above shows homicide rates for U.S. states (data from here) together with an A to F ranking of state gun laws from the Giffords organisation. As with my post from 2017, there is actually no statistically significant correlation (this is particular noticeable among the F’s, which include both the seven states with the highest murder rate and the two states with the lowest). In other words, the answer seems to be no.

Rather, it seems that guns don’t kill people, people kill people. The murder rate in the U.S. is driven by social factors which differ from state to state – factors which make New Hampshire and Maine pretty safe, but which produce a murder rate ranging from 14 per 100,000 to 20.5 per 100,000 in Missouri, Alabama, Louisiana, and Mississippi. For comparison, New Hampshire has a murder rate similar to that of Australia, but Louisiana and Mississippi, if they were countries, would rank among the most murderous 20 countries in the world.

There is some evidence that keeping guns out of the hands of criminals would reduce the murder rate in the U.S., but this is extremely difficult to do. The U.S. has a lengthy, porous southern border, across which there is a free flow of people, guns, and illegal drugs.

In addition, a concept from catastrophe theory is useful here. In the cusp pictured below, it is possible to “drop” from the top of the fold to the bottom, but a long roundabout journey would be required to get back up. Similarly, it is very easy to introduce guns into a society, but very difficult to remove them. Although such removal has been done elsewhere, laws forbidding gun ownership are likely to be ignored by precisely those violent criminals that one would not wish to carry them. And, of course, there is the 2^nd Amendment.

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Timeline of mathematical notation

Following up on my earlier timelines about zero and about Hindu-Arabic numerals, here is a timeline for some other mathematical notation, starting with the square root symbol (click to zoom).

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0123456789 in Europe: an infographic

Following up on my earlier post about 0 and 1 in Greek mathematics and my timeline of zero in Europe, here is a timeline for the use of Hindu-Arabic numerals in Europe up to René Descartes (click to zoom).

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The history of zero: an infographic

Following up on an earlier post about Zero in Greek mathematics, here is a timeline for the use of zero in Europe (click to zoom). I have used images of, or quotes from, primary sources where possible (reliably dated Indian primary sources are much harder to find than Greek ones, unfortunately).

Chinese uses of zero are probably also derived from the Greeks, but Mayan uses are clearly independent.

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COVID-19 and Vitamin-D

The chart above shows national Covid mortality against latitude of national capitals (open circles are for the Southern Hemisphere, solid circles for the Northern). The trend line in blue has a correlation of 0.50 (with p < 10⁻¹³). Countries further away from the equator are definitely reporting more Covid deaths.

It is possible that these numbers reflect under-counting in the tropics (although this is unlikely for Singapore = SG) and over-counting in wealthier countries away from the tropics (e.g. by reporting deaths of patients with positive Covid tests as Covid deaths, even if the actual cause of death is unrelated). However, it seems unlikely that under-counting and over-counting can explain everything here.

This paper in The Lancet notes that “It has long been clear that groups that traditionally exhibit vitamin D deficiency or insufficiency, such as older adults and nursing home residents, and Black, Asian, and minority ethnic populations, are the same groups that have also been disproportionately impacted by COVID-19. Additionally, increased time spent indoors due to strict lockdowns and shielding triggered concerns that some people might not obtain the necessary physiological levels of vitamin D from sunlight.”

My chart above is consistent with this: decreased sunshine away from the equator appears to increase Covid mortality, presumably due to vitamin D deficiency. This study in QJM notes, “vitamin D supplementation is effective in reducing COVID-19 severity. Hence vitamin D should be recommended as an adjuvant therapy for COVID-19.” Personally, I have been taking this advice for quite some time.

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Dante’s Heaven

In previous posts (Inferno, Purgatorio, Paradiso), I have mentioned the scientific content of Dante’s incredible theological poem, the Divine Comedy. Above, just for fun, is a chart of Heaven (the Solar System) in his Paradiso. Notice the sphere of fire which was believed to surround the Earth.

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