Today I Learned

[DaveE]

No, it was meant to be a nasty trick to play on a cat.

Calling the ASPCA and PETA right now! No, wait PETA says you are already cruel to keep a cat anyway.

 

[kyphysics]

https://www.yahoo.com/news/delta-infections-among-vaccinated-likely-192553854.html

In laboratory experiments, they found that three mutations in Lambda's spike protein, known as RSYLTPGD246-253N, 260 L452Q and F490S, help it resist neutralization by vaccine-induced antibodies. Two additional mutations, T76I and L452Q, help make Lambda highly infectious, they found. In a paper posted on Wednesday on bioRxiv https://bit.ly/3fpi5Fn ahead of peer review, the researchers warn that with Lambda being labeled a "Variant of Interest" by the World Health Organization, rather than a "Variant of Concern," people might not realize it is a serious ongoing threat. Although it is not clear yet whether this variant is more dangerous than the Delta now threatening populations in many countries, senior researcher Kei Sato of the University of Tokyo believes "Lambda can be a potential threat to the human society."

Third mRNA dose may boost antibody quantity, but not quality

Lambda variant shows vaccine resistance in lab ​

 

[Ivan Seeking]

https://www.yahoo.com/news/delta-infections-among-vaccinated-likely-192553854.html

Lambda variant shows vaccine resistance in lab ​

GREAT!

 

[mfb]

Lambda variant shows vaccine resistance in lab

It's not a binary thing. It shows more resistance - in the lab. If that transfers to actual infections is an open question, and what exactly that means for the vaccine efficacy is another open question. Does it go down at all? A few percent? More than that?

 

[atyy]

My guess is Lambda is not a bigger deal than Delta. Both show about the same reduction in antibody effectiveness. For Delta, real world protection from infection could be quite affected (wide range of estimates 40-80%), but protection from severe disease is uniformly quite high about 90% (with many estimates 90+%), though there may be some drop from the very high initial levels (97%). Protection from severe disease is probably due in large part to T cells. So far lab measurements show that T cell responses are negligibly affected by variants. References in https://www.physicsforums.com/threads/lambda-variant-shows-vaccine-resistance.1005754/post-6523453

So everything is the same as before. Get vaccinated when your local health authority offers it. If you are in a vulnerable group, consider still wearing masks (etc) after that is no longer compulsory. Get a booster when the local health authority offers one.

​

 

[kyphysics]

Interesting. ^^^ I'll monitor that thread. Thanks.

 

[kyphysics]

https://www.cnn.com/2021/08/12/us/san-francisco-vaccine-requirement/index.html

(CNN)San Francisco became the the first major US city to mandate proof of full vaccinations for certain indoor activities Thursday.

City residents age 12 and older will now be required to show proof they have been fully vaccinated against Covid-19 in order to enter indoor restaurants, bars, gyms and theaters, as well as large event spaces with at least 1,000 people, according to an announcement from Mayor London Breed.

Wondering if any other major U.S. cities will follow?

About 78% of San Francisco residents are vaccinated, the news release from the city said. Despite that, the city's current Covid-19 test positivity rate is 5.6%, surpassing the rate from the peak of the winter surge, which was 5.2%, the release said.

 

[DaveC426913]

TIL our Sun switches magnetic poles every 11 years.

Finding that out is a little like being a biology enthusiast for decades and then one day discovering the existence of rodents.

 

[Tom.G]

TIL our Sun switches magnetic poles every 11 years.

Finding that out is a little like being a biology enthusiast for decades and then one day discovering the existence of rodents.

My, my... What a coincidence! That is the same period as the Sunspot cycle. Think there might be a connection there?

 

[BillTre]

TIL our Sun switches magnetic poles every 11 years.

Finding that out is a little like being a biology enthusiast for decades and then one day discovering the existence of rodents.

What are these rodent things?

 

[Ibix]

What are these rodent things?

They're just the great great ... great grandchildren of some fish, don't worry about them.

 

[DaveC426913]

My, my... What a coincidence! That is the same period as the Sunspot cycle. Think there might be a connection there?

Yes. Well aware of the sunspot cycle. Certainly connected. How is unknown though.

 

[Hornbein]

Yes. Well aware of the sunspot cycle. Certainly connected. How is unknown though.

The Sun of full of flux tubes, some gargantuan. Sometimes part of the tube rises through the surface of the Sun due to "magnetic buoyancy." (This subject is called magnetohydrodynamics.) The interior of the tube is colder than its surroundings so it makes a black spot. These spots always come in pairs. The tubes are attracted to poles of the opposite polarity. When they get there they weaken the magnetic field. Eventually it flips.

This doesn't happen in the Earth because the solid inner core resists flipping.

 

[Hornbein]

As far as being embarrassed about not knowing something, for the first sixty years of my life I thought Jupiter wasn't visible to the naked eye.

 

[kyphysics]

 

[Ibix]

Courtesy of a 2am internet rabbit hole, TIL the words heterological (a word that does not describe itself, such as "long", which is actually shorter than short) and autological (a word that does describe itself, such as unhyphenated). I also learned of the Grelling-Nelson paradox: heterological is a paradox because if heterological is heterological then it is autological, while if it is autological then it is heterological. On the other hand autological is a different kind of paradox, because if autological is autological then it is autological, while if it is heterological then it is heterological.

https://en.wikipedia.org/wiki/Grelling–Nelson_paradox

 

[collinsmark]

As far as being embarrassed about not knowing something, for the first sixty years of my life I thought Jupiter wasn't visible to the naked eye.

I don't think you're alone in that.

Keep in mind that about 120 years ago and before, going back to the dawn of civilization, pretty much everybody with capable eyesight was an astronomer to some degree. There was a lot more walking back then, and using the stars was just something you did to get around after dark. People were keenly aware of the planets (well, Venus, Mars, Jupiter, and Saturn anyway), even if they didn't know what they really were. But they knew that unlike the other "stars," the planets moved around the sky. After the industrial age, with the advent of outdoor, artificial lighting; automobiles; and the corresponding light pollution, things changed; most people don't rely on stars anymore in their day to day lives.

Now I'm always looking up in the sky when I'm out and about. And if I'm loitering around somewhere, and I see something in the sky I find interesting, like one of the planets rising or whatnot, I might point it out to a stranger or acquaintance. On several occasions, the conversation went something like this:

Me: "Look, there's Jupiter," pointing to Jupiter.​

Other: "No it's not."​

Me: "Uh, yeah, that's Jupiter. You can tell it's a planet because it's not twinkling, and..."​

Other: "You can't see Jupiter."​

Me: "Sure you can. People have been tracking Jupiter for many thousands of years..."​

Other: "Jupiter is just something you see in books and sci-fi movies."​

Me: "No really, you can see Jupiter with the naked eye. As a matter of fact, it's one of the brightest objects in the sky actually..."​

Other: "It's the North Star."​

Me: "... ? ... ," muttering to myself, "Where do I even start with that ... That's not even North ..."​

I've met people who grew up in extremely light polluted cities. They were even skeptical of Carl Sagan's "The Cosmos," when Sagan would say something to the effect of, "billions and billions of stars ..." They would say to themselves, "Billions?! What the heck's he talkin' about. There's like eleven of 'em."

 

[Hornbein]

I don't think you're alone in that.

Keep in mind that about 120 years ago and before, going back to the dawn of civilization, pretty much everybody with capable eyesight was an astronomer to some degree. There was a lot more walking back then, and using the stars was just something you did to get around after dark. People were keenly aware of the planets (well, Venus, Mars, Jupiter, and Saturn anyway), even if they didn't know what they really were. But they knew that unlike the other "stars," the planets moved around the sky. After the industrial age, with the advent of outdoor, artificial lighting; automobiles; and the corresponding light pollution, things changed; most people don't rely on stars anymore in their day to day lives.

Now I'm always looking up in the sky when I'm out and about. And if I'm loitering around somewhere, and I see something in the sky I find interesting, like one of the planets rising or whatnot, I might point it out to a stranger or acquaintance. On several occasions, the conversation went something like this:

Me: "Look, there's Jupiter," pointing to Jupiter.​

Other: "No it's not."​

Me: "Uh, yeah, that's Jupiter. You can tell it's a planet because it's not twinkling, and..."​

Other: "You can't see Jupiter."​

Me: "Sure you can. People have been tracking Jupiter for many thousands of years..."​

Other: "Jupiter is just something you see in books and sci-fi movies."​

Me: "No really, you can see Jupiter with the naked eye. As a matter of fact, it's one of the brightest objects in the sky actually..."​

Other: "It's the North Star."​

Me: "... ? ... ," muttering to myself, "Where do I even start with that ... That's not even North ..."​

I've met people who grew up in extremely light polluted cities. They were even skeptical of Carl Sagan's "The Cosmos," when Sagan would say something to the effect of, "billions and billions of stars ..." They would say to themselves, "Billions?! What the heck's he talkin' about. There's like eleven of 'em."

Well then I'm not alone. I wonder how the Jupiter belief arose.

I live in Tokyo. It's a regency, not a city, with a governor instead of a mayor. It's really a bunch of towns that grew together and still have an identity. They all have community centers, some expensive ones with full-sized theaters. Some of them have planetaria. I always figured it was to show the children what the night sky really looked like.

 

[OmCheeto]

TIL that it's the 100th anniversary of "R²", aka "The Coefficient of Determination", aka "R Squared".
I joked on Facebook today that it's a "math nerd number telling you how straight the line is".

According to wiki; "Wright, Sewall (January 1921). "Correlation and causation". Journal of Agricultural Research."

Not willing to rely too heavily on wiki, I found the same information elsewhere. I also pulled out my "Annotated Instructor's Edition of a First Course in Statistics", where the authors didn't mention the history, but did dedicate the book thusly:

To Those Who Open This Book with Dismay​

It gave me a bit of a chuckle.

 

[ergospherical]

We lost a national treasure yesterday.

 

[BillTre]

Stumbling around the internet, I blundered upon Cell Cakes!

Here are some of the best:

 

[BillTre]

Here's something else I stumbled upon:

 

[DaveC426913]

TIL: why we found helium - a noble gas that won't combine with anything and is buoyant in the atmo - in the Earth. I've always just sort of wondered why it wouldn't just float up and out of the atmo.

Well, I never connected it with the ongoing production of alpha particles (i.e. helium nuclei) that radioactive ores are constantly giving off.

Two things I knew about but never quite connected. :slaps forehead:

Like different sections of a jigsaw puzzle you've worked on, but you don't know are actually connected.

Thanks The Disappearing Spoon - And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements by Sam Kean

 

[fresh_42]

TIL about another famous member of the 27 club: Robert Leroy Johnson.
(Btw. not listed on Wikipedia)

 

[DaveC426913]

:Google's 27 Club in a fit of FOMO. Is not at all a club to be part of. One star. Would not recommend:

 

[mfb]

TIL has has been a recent improvement for the traveling salesman problem (find the shortest route visiting a given set of places). Finding the exact shortest path has an unreasonable runtime once there are many places to visit. In 1976 people found an approximation that guarantees a path that's no longer than 1.5 times the shortest path in metric spaces while having a more reasonable runtime. In 2020 the paper A (Slightly) Improved Approximation Algorithm for Metric TSP found an algorithm that guarantees a path no longer than 1.49999999999999999999999999999999999 times the shortest path. Slightly improved, indeed.
While no one will use the algorithm in practice, it shows that 1.5 is not a hard limit.

 

[DaveE]

1.5 is not a hard limit

Isn't 1.5 not a hard limit, by definition? The hard limit is 1, right?

I hope the algorithm is interesting (or fast) because the difference between 1.5 and 1.49999999999999999999999999999999999 is underwhelming to engineers like me.

 

[mfb]

1 is an obvious lower limit, but 1.5 might have been a limit for this type of much faster approximation. We now know it is not.

No one will implement the new algorithm for actual problems because its improvement is negligible (and it's more complicated).

 

[mfb]

"Docker for Windows" and the completely unrelated "Razer Synapse driver management tool" cannot both run at the same time. Why? Because they copied the same erroneous code from StackOverflow.
Here is a Twitter thread explaining the problem and here is an image of the thread.
Here is the SO thread, the wrong answer was (finally) deleted after the issue became more widely known.

Similarly, the Zip Slip vulnerability spread by sharing bad code snippets.

 

[Keith_McClary]

its improvement is negligible (and it's more complicated).

And it is probably only an improvement if n>10^1000 .

 

[Astronuc]

TIL, if you can't find your dog, go to the kitchen, open the refrigerator door, turn around and the dog will be right behind you.

Our dog responds to the sound of the microwave being open/closed, sounds of food preparation in the kitchen, and/or sounds of food wrappers being opened. I assume she associates the sounds with cheese and sliced meat.

 

[OCR]

TIL, if you can't find your dog, go to the kitchen, open the refrigerator door, turn around and the dog will be right behind you.

Yeah, they're hard to find when they're in the refrigerator. . . . .
Lol. . . . j/k

.

 

[Astronuc]

Yeah, they're hard to find when they're in the refrigerator. . .

That is true. I was thinking more along the lines of turning one's head and looking over one's shoulder. In my case, the dog comes to the kitchen and sits quietly while waiting for something. Her nails are long enough to hear her coming to the kitchen. One of our cats on the other hand is very quite, and sometimes, I'll step back from the refrigerator or counter, and she'll be right behind me. So, I've learned to look behind me before I move.

 

[OCR]

So, I've learned to look behind me before I move.

Lol. . . I'll bet that learning experience required just one loud lesson. . . .

.

 

[DaveC426913]

TIL that a 12m

In my case, the dog comes to the kitchen and sits quietly while waiting for something. Her nails are long enough to hear her coming to the kitchen.

Yup. My grand-fur-baby does that when she's not expecting food except by luck.

So, I've learned to look behind me before I move.

I am training her to lie down in the far corner of the kitchen so as not to get stepped on.