Ehm, Akshually Hrdlička…

The WaPo pieces mentioned by PZ about Aleš Hrdlička are damning. I cannot comment on their veracity since I do not have access to the evidence those articles are based on, however, there is no reason to doubt them, not really. His appalling ghoulish behavior is consistent with the time in which he lived, unfortunately. He was representing the rule, not the exception. What I find curious is that with all the illicitly amassed evidence, he almost, but not entirely arrived at the correct conclusion (emphasis mine):

“In 1898, Hrdlicka published a study of 908 White children and 192 Black children at the New York Juvenile Asylum and the Colored Orphan Asylum in New York. He measured and compared their body parts, including genitals. He wrote that “inferiorities” in the children were probably the result of neglect or malnutrition, not hereditary. But he noted “remarkable” physical differences based on race.”

Nicole Dungca, Claire Healy and Andrew Ba Tran, THE SMITHSONIAN’S ‘BONE DOCTOR’ SCAVENGED THOUSANDS OF BODY PARTS

So he did not find any inherent differences between the races that were more than superficial physical characteristics, like skin color, hair texture, etc. Yet he still persisted in holding racist views, which makes him a bad scientist – even if one were to wave away the immoral way in which he gathered data by stealing human remains (which I am not inclined to do so, although it appears to be standard for anthropologists of the time) he still has done shit science with it.

When I read PZ’s first article, I immediately looked up Hrdlička. I do not remember ever learning about him at the university, I studied biology, chemistry, arts, and psychology, not anthropology. He might have been mentioned at some point in biology, but the name definitively did not ring any bells.

And when I looked him up, all Czech sources that I could find online in the little time I was willing to give venerated him as a staunch anti-racist, in direct contradiction to the articles in Washington Post. I think this is for several reasons.

Firstly, we Czechs do suffer from a “small nation inferiority syndrome”. We feel so insignificant and ignored on the world stage that we latch onto any success achieved by any of our compatriots abroad and we are unwilling to let go. I think that it will take years, if not decades, for the true ghoulish nature of his research and his racist views to find their way into Czech media, and there will be a lot of resistance.

Secondly, I doubt that any Czech sources have had ready access to the same evidence that WaPo was using. There are inevitable limits to what can be learned about any Czech individual who lived most of their life outside of Bohemia, even if one were not inclined to ignore unfavorable evidence and overstate anything positive due to the first point.

And thirdly, it seems he was kinda anti-racist, just in a wrong, racist anti-racist way. From what I was able to find he did fight against anti-slavic racism. This is real racism and it still exists today – its latest consequential demonstration was Brexit, which was in part motivated by racism against Polish and Czech immigrants. The sentiment nowadays is not as prevalent and strong as it used to be, but there were times when the Slavs (and the Irish and probably some other nationalities) were not considered “white” in the same way as Anglo-Saxons and/or Aryans and were seen to be inferior. Apparently, Hrdlička was arguing – correctly – that all European people have common origins and he argued that they belong to the same racial group. The anti-racism bit was thus arguing against the discrimination of Slavs, and the racist bit was that he did not argue that all people are equal but that Slavs in fact are part of the “superior” race. This kind of reasoning makes his legacy even more susceptible to being spun positively if one has the bias mentioned in the first point, not to mention that there still is a lot of Czechs who argue the same.

However, I also peeked at the discussion under the WaPo article and I noticed in there one “anti-Hrdlička” argument that I strongly disagree with. Apparently, he was one of the proponents of the theory that humans arrived in the Americas via the Bering Strait Land Bridge and this theory was called “racist” and “bogus” by one of the commenters. That, to my mind, is nonsense.

Even if Hrdlička was proposing the theory for some racist reasons, that does not make the theory automatically wrong. And to my knowledge (which I admit is not completely up-to-date with modern science) there is a lot of evidence that at least some of the ancestors of North American Indians really did cross Beringia into the Americas. This includes studies of genetic markers of extant populations.

It is absolutely indisputable that Homo sapiens originated in Africa and spread from there to all the other continents in multiple migration waves. It might be that there was more than one migration wave to the Americas and it might be that some of those migration waves did not come over Beringia but sailed from Polynesia. It also might be true that humans arrived in the Americas much sooner than previously thought. But some very probably did arrive through Beringia no matter what other migration routes might have been taken. And as much as I think that Native American cultures, languages, and creation myths are just as worthy of preserving and studying as any others, they do not constitute hard evidence for how humans got to the Americas, because humans are just too good at making shit up and then believing it – even today people make nonsense theories whole cloth and believe them despite the evidence contrary, after all.

And there is simply too much other evidence that multiple migrations through Beringia happened, for both animals and plants. Just a few examples:

Bison and Wisents are so closely related that they still interbreed and produce fertile offspring despite being different species. The bovids, incidentally, originated in Africa too. American Grizzly is still the same species as the European Brown Bear. North American and Eurasian willows create a near continuum of hybridizing taxa that are a nightmare mess to untangle. Junipers on both continents are very similar to each other in appearance. And Juniperus communis is actually a circumpolar species. And a personal anecdote to underline the point – the flora of North America and Eurasia are so closely related and eerily reminiscent of each other that when I was in the USA, I confused native Heracleum maximum for invasive Heracleum mantegazzianum they are so similar. (edit – corrected accidentally swapped species)

This similarity between the ecosystems of North America and Eurasia, which is not present between any other two continents, is the biggest proof that there were easy-ish ways to migrate between the two in the not-so-distant (geologically and evolutionary-speaking) past. Saying that the theory that people migrated to North America this way is racist and somehow disproven because of it thus seems foolish to me.

It might not be complete, but no theory truly is, science is about refining our knowledge by finding things, not about having complete and inconvertible “truths” by fiat.

Look at the Grinding Noise!

I have been contacted by my previous employer, which has led me to remember the various works I used to do. One of which was measuring and evaluating noise. That has meant that I was making and interpreting pictures like this.

© Charly, all rights reserved. Click for full size.

Of course, this was only done with my phone, whereas at the laboratory I had various kinds of fancy equipment and software available. But back then I did in fact check whether this phone app measures reasonably accurately, and it does.

At the very top, you can see that grinding handles is a very noisy work indeed. When the equipment runs idle, it emits over 78 dB, which is very near to a level when the noise becomes truly dangerous (80 dB). And during work, it exceeds 89 dB. So I am indeed diligent about wearing hearing protection since that noise level would damage my hearing pretty damn fast.

Whoever knows how to interpret the above picture, can tell that when the grinder runs idly (those parts with green at the top), most of the noise – and indeed the loudest noise – is below 500 Hz. And whenever the wood touches the belt, another very loud component is added, between 5 and 80 18kHz (those parts with red-magenta stripes at the top). There is nothing I can do about the noise that is emitted during the grinding, but I could if I were inclined to spend my time on it, try and identify the spots where the loudest frequencies are during idling and try to do something about that. For example, I suspect that a significant source of the low-frequency loud noise is the tensioning wheel.

However, as much fun as it might be, I do not think I will spend a lot of time over this anytime soon. It would be fun though. I liked my previous job, the work was not the reason why I quit.

Women Educators on YouTube – Architect – Belinda Carr

This Hempwood product sounds interesting. I actually think that with a bit of tinkering and upscaling of the production, it could become cheap enough to be a viable material for large-scale construction. Definitely, it could replace for example wooden OSB plates for walling. And since the fibers run lengthwise, it could also definitively be used for making load-bearing beams.

Completely independently of this – this spring I was actually really thinking about growing Hemp in my garden for fuel, but although it is legal to grow technical hemp on a patch of land up to 100 sqm, the costs of seeds are prohibitive and there is a risk of cross-pollination with someone’s illegally grown weed so producing my own seeds for future poses risks of accidentally creating hybrids whose THC levels are above the legal limit. It is not worth the potential hassle of discussions with the police. My only hope there is that hemp gets finally legalized for personal use. Until then, I will try and grow hazels, poplars, and willows on my unused land to try and reduce my personal carbon footprint.

Edit: my PC glitched out and the article was initially published with nonsensical title.

Women Educators on YouTube – Engineer – Xyla Foxlin

I first came across her channel last year when she made a canoe. It was interesting to watch but her channel was still fairly new so I decided to not feature her here yet and wait how it turns out. But she has made some more crafting and sciencey videos since then, and those that I saw were fairly good so here is her latest, in collaboration with Derek Muller from the Veritasium channel.

Hummingbird Tongues are Weird

Last week I posted a story from kestrel about her rescue of a hummingbird. A few days later, this video crossed my desk, and it explains why the bird was likely so calm – torpor, which is a bit like going into a coma when you sleep.  The video also covers a lot of general information about hummingbirds, focusing on their perfectly adapted and unique tongues. This channel is a bit irreverent, but their videos are humorous, engaging and well researched.

Well, It Sucks, But…

My goal in mcgyvering a vacuum pump was to remain under 100,-€ – which I did – and get better results than I have achieved with my shop-vac setup – which I did too. Still, I do not know whether to be disappointed or satisfied.

I wanted to utilize things that I already have, which includes several water pumps that are used to water bonsai trees and vegetable beds in summer and pumping water out of the cellar in the winter and some spare piping from house renovations. So I had to buy only the things for making the vacuum pump itself – in combination with a water pump, the best option seemed to be something based on the venturi principle.

So I went and bought these parts:

© Charly, all rights reserved. Click for full size.

The parts were connected to each other more or less in the order as they are laid out on the picture. The black plastic hose connector was fitted into the brass one to lower its inner diameter. The brass hose connector right next to the right side of the chrome T junction is the inlet nozzle – I have glued an old tip from a silicone sealant tube (not depicted) in it to get the position and size of the nozzle correct. Into the upper brass hose connector was glued the white plastic 6 mm hose connector for the air suction.

So water comes in the T-junction from the right, gets squeezed through a nozzle which sprays into a slightly bigger opening in the outlet left, behind which is again a big pipe. The spray drags with it the air surrounding the nozzle and that way achieves suction through the top of the T-junction.

I am not able to write-up complete how-to, but this is the final product up and running in a vat of water.

© Charly, all rights reserved. Click for full size.

The bubbles show it is working. When I connected the suction tube directly to a new vacuum manometer, I got a suction of whopping 0,6 bar, which did really impress me. Unfortunately, I do not get anywhere near that when I connect everything to the jar. After a few minutes, it stabilizes at this.

© Charly, all rights reserved. Click for full size.

0.22-0.25 bar is still a bit more than what the shop-vac could achieve (which was 0.2). So it is usable and it is a definitive improvement because unlike the shop-vac it can run non-stop with zero risks of overheating anything, and it also makes nearly no noise, so a win there too. But when it achieves this, it still bubbles, so it still draws air. And when I close both ball-valves on the lid (one ball-valve is for pressure release, one for the suction), I start losing pressure in the jar really quickly. That tells me that the jar is not properly sealed and this here is not the maximum this setup can achieve, but an equilibrium between the pump and the improper sealing.

I had to make a new lid from five layers of plywood for this, with two ball-valves and the manometer, so there was a lot of potential for failure. But I did use water/airtight plastic sealant for everything and I went over all connections once more, yet I still cannot identify the leak(s). If it was a pressurized container, I might find the leaks with help of soapy water looking for bubbles, but I do not know how to check vacuum tightness.

So this is where I am now and this is where I leave this be for a few days at least. It has occupied me for three days already, time to go back to making knives.

Different Hardening Methods for N690 – Experiment

When I was hardening the blades two days ago, I have tossed in there six cut-offs as well and I have used different methods to quench them. After that I had still one piece left so I have heated that up to the 1050 °C and let it cool in the forge. Then I performed some tests and the results are very interesting.

© Charly, all rights reserved. Click for full size

These are the samples and methods used (marked by the number of notches on the edge):

0 – left to cool in the forge
1 – untreated
2 – left to cool in the air
3 – quenched between Al plates only
4 – oil
5 – water
6 – AL plates + water + Freezer fro 2 hours

None of the samples were subsequently tempered, so they should be at peak hardness.

With the sample size just 1 piece per method I cannot of course perform too many tests. The idea was to polish the samples – which I did. And already during the polishing, I have noticed that all samples seem to be hardened, except #1.

The next step was supposed to be to etch the surface and look at the structure under a microscope. Well, that did not work at all, and the reasons are a mystery to me. Just as it happened with the knives last time, it happened again here – the electrochemical method worked on some samples perfectly, but completely failed on others. I was unable to solve the problem. Another thing was that my microscope apparently does not have big enough magnification to see a difference between the original steel and the quenched one. I could re-build it and improve it about ten times, but I am still not sure if that would be enough and I do not want to get sidetracked to that now, it would be probably more than one day of work and I have already spent two days having fun instead of working.

So I did what I could with samples of this geometry. First trying to scratch them with my hardness measuring gages .

The sample # 1 could be scratched by the lowest 38 HRC gage, which was to be expected.

All samples except # 1 could not be scratched by the 62 HRC gage, so they are at hardness 62 HRC or more. Which is something I did not expect, especially not of # 0, which was left to cool in the forge – and that took definitively several hours. I was expecting this sample to be harder than the new steel, but not hard enough for a knife – but it evidently is more than enough hard for a knife, hardness 62 is in fact quite excessive.

Secondly, I have tried scratching the samples against each other, and the results became even more interesting. All samples could scratch # 1, as expected. But none could scratch #4 and #4 did scratch all, whilst the remaining five could not scratch each other, so they are all of the same hardness.

Thirdly I have put the sharpest angle of the triangle approx 10 mm into a vise and break it off. #1 has bent easily, as expected, all others have snapped off.

What can I deduce from this? Several things.

  1. Sample #4 was hardened with the method recommended by the manufacturer and did come out as the hardest of them all, possibly somewhere around 63-65 HRC, which is as hard as steel can get. It could be a fluke (remember – sample size 1), but it could be the reason why this method of hardening is recommended. It is not surprising.
  2. From a practical standpoint, the method of quenching seems to be quite inconsequential nevertheless. The oil quenched sample would be brought down a few points in heat treatment anyway and for practical purposes, anything above 51 HRC will be usable with just a bit more edge maintenance, anything above 55 HRC will have reasonable edge retention and above 57 HRC we are in the realm of no reason to complain whatsoever. In this light, the difference between the recommended oil quench and all the other methods seems to be so small as to be trivial and only interesting from a nerd standpoint.
  3. The freezer step does not seem to have done anything for this one piece, but this does not rule it out from use on larger pieces that could not be so thoroughly and consistently heated in my setup. Did not do any harm either.
  4. Although tempering was not tested, this experiment does indicate that it is just not possible to really destroy the edge on this steel by overheating it during grinding/polishing since even cooling it from the 1050°C to room temperature over the course of several hours hardened it very nearly as well as the recommended oil quenching. I will not test tempering temperatures with regard to this specifically since there are graphs to be found on the internet that show already that the hardness of N690 does not get below 56 HRC up to 900°C.
  5. If I want to peen the end of the tang, or do any other work with it, I must be careful to not heat it above the critical temperature at any point in the process. Because once heated above certain threshold, this steel hardens, I cannot prevent it and I probably cannot anneal it again.

It would be interesting to see what is the exact influence on toughness/strength once tempered. I could not find it, so I will have to test it myself. But for that, I will need another sample geometry. So maybe next time.

All in all, the N690 seems to be pretty remarkable steel. It does not have the label (and price tag, otherwise I could not use it) of “super steel”, but it is no wimp either and apparently is not very fussy about the heat treatment, apart from the requirement to heat it above 1050°C.

How Czechia Flattened the Curve (Maybe, Hopefully)

Our current prime minister has been in the past often criticized as akin to Donald Trump re: conflict of interests and use of state resources to enrich himself and his family. And rightly so in my opinion, I cannot stand the man personally and politically.

However, when SARS-CoV-2 hit the Czech Republic, he, unlike Donald Trump, has done the right thing. In response to the pandemic, he has left decisions on the policy to actual epidemiology experts from the very beginning. Thus when CZ had mere 116 cases, 12 days after the first three on March 1., he declared a state of national emergency and just two days later virtually everything was put on hold except the absolute bare minimum (grocery stores, delivery services, apothecaries and some more). It was criticized by the opposition (our equivalent of US conservatives) as needless panic-making and fearmongering and the measures as needlessly draconian and a PR for himself and his party. Especially the order of mandatory face masks (home-made and improvised masks are allowed) was met with scorn.

On March 18. I have taken the data of confirmed cases so far, plotted them on a graph and calculated the best-fit exponential curve. It was at a daily increase of 39%, an effective doubling every two-three days, approsimately the same trajectory it has had all over Europe. This growth meant we should have over 140.000 cases today, but we, luckily, do not. We have less than 5.000. Howso?

Look at this graph:

The red curve is the actual cumulative cases as reported every day at midnight. The blue curve is the exponential best fit that I have calculated on March 18. And then there is the orange curve, which is also an exponential best-fit but only for the last week from March 28. to April 3. You can see that the two best-fit lines intersect on March 21.-22.

That is, in my opinion, the day when the enacted measures started to have a visible effect – eight to ten days after they were enacted. I do not know whether I am doing the right thing here mathematically – I have dabbled in statistics at work, but not in epidemiology – but it does seem right to me.

The new rate of growth is still exponential, but instead of 38% daily it is 8% daily. And although the difference between multiplying the cases daily by 1,08 instead of 1,39 does not intuitively look like much, it means the doubling of the cases is prolonged from mere 2-3 days to 10-11 days. Still not enough for an illness that can take up to 6 weeks to heal and kills 1% of infected people, but a very noticeable drop.

And AFAIK that drop is not due to insufficient testing. Testing has grown proportionally, although still not as much as it perhaps should have. But the ratio between positive/negative tests is getting lower, and that indicates that the drop in overall cases is real.

Now there is certainly much more to it than this oversimplified graph. For example, Germany took longer to enact strict active measures, relatively speaking. That is, CZ government enacted nation-wide strict measures when we had just several hundred people ill, whilst the German government did leave many decisions to individual states and instead of strict orders tried to control the situation with recommendations only at first. This has led to a bit of inconsistent reaction and different measures being enacted (and ignored by people) in different states. It worked, but not as much as was desired. Strong nation-wide measures started being implemented only when there were several thousand people ill already- at about the same time as in CZ. And at about the same weekend the curve began to break in Germany as well.

It was similar in Italy too, there the curve began to break at around March 15. (only estimated, I did not calculate the fit curves for Italy, I am doing this in OpenOffice and that is not the best program for this kind of work), about two weeks after the most-hit municipalities were put on lock-down.

Another quick analysis that can be done just by looking at the numbers – In Italy, it took 22 days for the cases to grow from about 100 to 20.000. In Germany, it took 24 days, in Spain 18 days, in UK and France 25 days and in the USA 20 days. The Czech Republic is now 24 days from its 100th case and we are nowhere near 20.000.

So even these amateurish and quick&dirty analyses show that quick reaction, regardless of what the nay-sayers say, is essential in avoiding the worst in case of an epidemic. The enacted measures work as intended. I only hope that our government and our people do not relax too soon.

Stay safe, stay at home whenever possible, and fingers crossed for you and your loved ones.