Doubling Down

Angela Saini has an interesting review in Nature of Skin Deep, a ridiculous book about how racial differences have no role in sports achievement. Of course, that’s just nonsense, obviously so: some Kenyan and Ethiopian populations are way better at distance races,while people of west African descent always win the Olympic 100-meter. And so on.

Now you’d think that if if you were trying to defend blank slatism, you wouldn’t want to spend much of your time on your weakest possible point, any more than a PR-wise Stalinist would go on and on about how wise and good Katyn Forest was: how the Chekists killed  those Polish POWs in self-defense, after a heroic struggle,  etc.  Arguing for zero physical differences between populations is that weak: everyone can see them, for Christ’s sake.  And a lot of people are very interested in, and knowledgeable about, sports.

Yet, in Saini’s review, she does just that.  She’s pushing obvious falsehoods – not just ones that can only be noticed by the elite that know how to do long division.

For example: “Some have speculated that Kenyans might have, on average, longer, thinner legs than other people,”

 

I wonder how anyone ever got that idea?  In order to go full Saini, you have to ignore your lying eyes, apparently forever.

Now there’s a certain logic to this: if you admit that Kenyans have a different build than the Yoruba, one that works better in the marathon, or that Pygmies are short, or that Tibetans thrive at altitudes that would wreck you, you’re admitting that regional selection can make people noticeably different.  And if they differ in those traits, they can differ in any trait.  He who has said A must say Z (mathematical induction): so you fight at A.  You try to stop them on the beaches.

So facts themselves are the enemy: “Arguing with racists on points of fact is a game with no winners. ” Facts are all against you – they all must die !

So is this triumphalism, or peak crazy?  Time will tell.

 

 

 

 

 

 

 

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Mars Direct

Trump was baiting Nasa’s head, asking why we couldn’t go directly to Mars instead of puttering around on the Moon first, bringing in Michael Collins and Buzz Aldrin on the subject.

Trump’s right: assuming that you want to send a manned mission to Mars,  Mars Direct is the most logical ( and cheapest) way.  NASA is bullshitting us.   Nice seeing the reporters demonstrate their incomplete knowledge of Hohmann orbits: but they must know more about other things.  Some other thing.

It is possible to imagine a real economic payoff for a Mars mission (I was called a person of broad imagination at the ISIR conference) but harder to see why you’d need men there.

 

The Reason Why

There are odd things about the orbits of trans-Neptunian objects that suggest ( to some) that there might be an undiscovered super-Earth-sized planet  a few hundred AU from the Sun..

We haven’t seen it, but then it would be very hard to see. The underlying reason is simple enough, but I have never seen anyone mention it: the signal from such objects drops as the fourth power of distance from the Sun.   Not the second power, as is the case with luminous objects like stars, or faraway objects that are close to a star.  We can image close-in planets of other stars that are light-years distant, but it’s very difficult to see a fair-sized planet a few hundred AU out.

 

Lifting degeneracy

Some time ago I discussed the idea that Neanderthals were fucked-up because their low effective population size led to inefficient purifying selection. But the usual harmonic-mean effective population size is not quite right: for salvage mutations, things that somewhat correct the wrongness caused by increased genetic load, the effective population size is closer to the average.  In other words, there were probably a lot more Neanderthals during interglacial periods, and these genetic consequences of those population booms ameliorated their genetic problems.

Second, Neanderthal Y chromosomes and mtdNA have even smaller effective population sizes, 1/4th as big as the autosomal effective size, and thus were even more likely to be messed up. which is why, maybe the Neanderthals seem to have picked up mtDNA from some African group closer to modern humans around a quarter of a million years ago: they needed it.

Luke Blackburn

appears to have done something downright interesting: send vomit-soaked clothes, from people that had died of yellow fever, to various locations in the North during the Civil War, with the intent of triggering yellow fever epidemics. Didn’t work, since as far as we know, yellow fever can only be transmitted via mosquito bite, mainly Aedes aegypti. 

Jeff Davis knew about this effort.

 

 

“They couldn’t hit an elephant at this distance.”

Allen Guelzo wrote a book about the battle of Gettysburg “Gettysburg: The Last Invasion” , in which he says some confused things about smoothbores and rifles. One of my regular readers noticed and mentioned this some time ago.

“Rifling bestowed greater range and accuracy on a musket, but it did so at the price of forming a trajectory for the bullet which “dropped” rather than went straight to a target. To hit a target thus required exact knowledge of the speed and distance of a target, something which in battle was rarely available.”

Which has left Wiki thinking  that rifle bullets had curvy paths while musket balls flew straight.  Not so!

Here’s a decent discussion ( by RogueOne).  The key point is that a spin-stabilized bullet can be pointy yet not tumble: so it has a smaller cross-section and experiences less wind resistance.  So it goes farther.

All the time that the bullet is flying, it’s dropping, under gravity.  If it goes twice as far as a musket ball, that takes twice as long – and it drops four times as far.  D = 1/2 g t^2 – one of the secrets of the Occident, known to but a few.

Guelzo suggests that people couldn’t really take advantage of the rifle’s greater range: but they could.  The Springfield was sighted for 100, 300, and 500 yards – and when 15,0o0 Rebels are coming at you, you have a decent chance of hitting somebody at the greater distances possible with a rifle. Well-trained sharpshooters could even be decently accurate  at those ranges, as Sedgwick found.

Charges didn’t work as well as they had with muskets.

Modern rifles have considerably higher muzzle velocities. Assume that one has four times the muzzle velocity of an 1861 Springfield: then it will take 1/4 the time to reach the same target, and will drop 1/16th as far. A flatter trajectory.  How do we do it?  Velocity !

 

 

 

 

 

Reverse salients

Edison thought in terms of reverse salients and critical problems.

“Reverse salients are areas of research and development that are lagging in some obvious way behind the general line of advance. Critical problems are the research questions, cast in terms of the concrete particulars of currently available knowledge and technique and of specific exemplars or models that are solvable and whose solutions would eliminate the reverse salients. ”

What strikes you as as important current  example of a reverse salient, and the associated critical problem or problems?