Well, technically not a scientist, but a science communicator. But that would be too wordy for a title.
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.
My personal view of the coronavirus is that outside of China, the mortality rate might significantly rise above what it has now (which is already several times higher than influenza), just as it did with the swine flu pandemic in 2009 (which my sister barely survived, but luckily nobody else in the family got). My reasoning for this is – people in China were probably at least somewhat exposed to the said virus in its non-human-infectious form, or some of its less dangerous relatives, which would give them at least partial immunity. Once the virus spreads to populations that have no immunity to its or to viruses similar to it, it will become much worse.
Since it is a pulmonary disease, our whole family is especially susceptible and in danger, since all of us have asthma, my parents are elderly, my sister has already damaged lungs and my brother is a heavy smoker. I certainly hope not to encounter it, I already had viral bronchitis this year for two weeks and I did not enjoy it in the least.
Last time I was working on this project, I had some very bad results from quench. This week I have finally managed to test one idea of correcting the problem and maybe prevent it from ever happening again in the future. And I am glad to say that it did work. Not perfectly, but the new process is definitively worth to use instead of the old one.
Here is first the comparison of the three worst blades before and after. As you can see, there are still some curls in there, but they are noticeably less pronounced and one blade is almost completely straight. They will still come smaller than intended out of the polishing process, I will still have to remove some material from the edge until I get to the straight part, but I estimate it to be about 1/2-1/3 of what it was before. On the worst blade, the curls went about 10-15 mm from the edge towards the spine, whilst now it is about 3-5 mm. That is a significant improvement, and I think that had the blades been quenched from a straight form, they would never have curled in the first place.
As I alluded to previously, the process that I wanted to use for correcting the blades is called plate-quench. It cannot be used for simple carbon steels. Only so-called deep hardening steels can be thus quenched, and N690 is such steel, according to some articles I found on the internet. Nevertheless, it is better to not have the internet at all than to believe everything you can read on it – the manufacturer recommends oil quenching.
So I have tested the process first on one blade that I accidentally broke when correcting an ever so slight banana-bend. When the broken blade hardened properly – which I have confirmed not only by scratching with my gauges, but also by breaking off a tiny piece of it – I went on with the curly ones. On one of these, I confirmed the hardening too by breaking off a tiny piece of the tip, with the remaining two I was satisfied with the scratch test only.
For the plate-quench are used two flat plates from either alluminium or copper. These two metals have very high heat conductivity and thus can cool down some steels fast enough for them to turn into martensite. Luckily I got quite a few nice slabs of alluminium on hand. And because I wanted to make the process a bit faster (despite not making time-measurements this time), I have made a simple prototype quench-jig.
It consists of two identical pieces of alluminium with a small hinge, and locking pliers. The hot blade went out of the forge between the plates with the edge towards the hinge. Then it was firmly clamped by the pliers to hold it straight. When it stopped glowing near the tang – indicating a temperature well bellow 600 °C – I dunked the whole thing in a bucket of cold water just to be sure. And just as last time, because it costs nothing, I have put the blades into a freezer straightway for a few hours before tempering them. None of the three blades cracked.
It worked reasonably well and quick. I will definitively improve it and build a proper jig when the weather is nicer and I do not freeze my nuts off in my workshop. I will add a more stable hinge(s) and maybe even screw one of the plates to the pliers.
Another advantage of this process is no burnt oil gunk on the blade, no flames and no stinking oil fumes.
I often listen to podcasts when I walk Jack, and I’ve found a new one that I think you’d really like, too. It’s called ‘Ologies’ and the host Ali Ward is an Emmy award-winning science journalist. She’s worked on such shows as ‘Brainchild’ (Netflix), ‘How to Build Everything’ (Science Channel) and ‘In The Wild’ with co-host Adam Savage of Mythbusters.
Alie Ward is a charming and humorous host, and every week, she interviews a scientist from a different ‘Ology’ or specialty area, and questions them on what their field is all about. She approaches each subject with a genuine sense of curiosity and wonder. What you hear as the end product is a bunch of scientists who are passionate about their work telling stories and talking about what they love. Each interview ends with a lightning round of questions sent in by her patrons. One of her mottos is, “Never be afraid to ask a smart person a stupid question.” Or a smart one, either – Alie, herself, has a science background and prepares well for each interview, so the conversations are compelling and intelligent with a pleasant touch of humour. As an interviewer, she allows each guest space and time to tell their best stories in that passionate way of nerds.
‘ Ologies’ is Alie’s own brainchild, something that she thought about doing for many years before finally putting it together. There are currently over a hundred ‘Ologies’ available and Alie intends to keep going. She also makes a donation on each show to the charity of the Ologists choice and then features the charity on her website. I’ve been binging on it for about 2 weeks, and I’m hooked. Give it a listen. This is the website for the show, and you should be able to find it via most podcast players.
There’s one more reason to love trees. A new study from The Crowther Lab, ETH Zurich, published in the Journal of Science, July 2019, says that targeted reforestation could isolate 2/3 of human-made carbon emissions and would be the best way to mitigate the effects of climate change.
The researchers calculated that under the current climate conditions, Earth’s land could support 4.4 billion hectares of continuous tree cover. That is 1.6 billion more than the currently existing 2.8 billion hectares. Of these 1.6 billion hectares, 0.9 billion hectares fulfill the criterion of not being used by hu-mans. This means that there is currently an area of the size of the US available for tree restoration. Once mature, these new forests could store 205 billion tonnes of carbon: about two thirds of the 300 billion tonnes of carbon that has been released into the atmosphere as a result of human activity since the Industrial Revolution.
Calculations were made based on current conditions and cities and agricultural areas were not included because those areas are necessary to support human life.
According to Prof. Thomas Crowther, co-author of the study and founder of the Crowther Lab at ETH Zurich: “We all knew that restoring forests could play a part in tackling climate change, but we didn’t really know how big the impact would be. Our study shows clearly that forest restoration is the best climate change solution available today. But we must act quickly, as new forests will take decades to mature and achieve their full potential as a source of natural carbon storage…. The study also shows which parts of the world are most suited to forest restoration. The greatest potential can be found in just six countries: Russia (151 million hectares); the US (103 million hectares); Canada (78.4 million hectares); Australia (58 million hectares); Brazil (49.7 million hectares); and China (40.2 million hectares).
I encourage you to check out the Crowther Website where you can read the report in full. The site also offers a tool that allows you to pinpoint any area on the globe to find out about its reforestation potential.
via: Science Daily
One of my favourite perspectives for photographing trees is looking up, way up, because a tall tree silhouetted against the sky is majestic. In winter their uppermost bare branches create beautiful patterns in the sky that look sculptural to me. Some trees, though, create sculptural bare spaces in the summer, too, through a phenomenon known as “crown shyness.”
If you look up toward certain types of towering trees—including eucalyptus, Sitka spruce, and Japanese larch—you may notice a unique phenomenon: the uppermost branches don’t touch. Known as “crown shyness,” this natural occurrence results in rupture-like patterns in the forest canopy that seem to perfectly outline the trees’ striking silhouettes.
Numerous scientists have been studying crown shyness since the 1920’s and several theories have been put forward, but no one knows for certain what causes it.
One possibility is that it occurs when the branches of trees (particularly those in areas with high winds) bump into each other. Another suggested explanation is that it enables the perennial plants to receive optimal light for photosynthesis. Perhaps the most prominent theory, however, is that the gaps prevent the proliferation of invasive insects.
My favourite theory is the one that postulates the trees are trying to avoid bumping into one another. It seems so polite and I can imagine woody conversations along the lines of “oops – so sorry old chap – didn’t mean to crowd you. I’ll just move over here.”
I think it’s stunning and hope I get a chance to see it someday. If you’re lucky enough see it, please take a photo and share.
Here’s one last photo from the story, but I encourage you to check out the full story and look at all the photos. The link is below.
The full story and more photos are at: My Modern Met
My thanks to rq for sending this story my way.
Can anyone tell me what the man in these photos is doing? Jack and I encountered him at our local park yesterday. He was slowly walking from one side of the creek to the other along a measuring tape laid out between the banks. He would move a step or two and stop, then fiddle with his machine and look up to the sky for a while and then fiddle with his machine again until he was satisfied with something and then he’d take another step or two and repeat the process. At the rate he was moving it would take him an hour or more to cross our wee creek. I suspect it’s related to the flooding you can see in the first photo. Two years ago they removed the concrete barriers lining the creek and naturalized the banks. It was an all summer long project and it was quite picturesque when completed. Since then, though, the area around the creek floods easily and essentially makes large areas of the park unusable.
I would have stopped to ask him what he was doing, but the children in the photo were tossing stones into the creek that kept landing close to the poor man and the 2 adults in their group let several minutes pass before stopping the action. I thought the fellow
really didn’t need anyone else annoying him. Also, I didn’t want Jack to go into the creek because the last time he did he came out smelling like a sewer. We watched for a while and finally came home with my curiosity piqued, but not satisfied. If you have a clue or a notion about this endeavor I’d sure appreciate it if you’d share.