Today I Learned

[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[/size] 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.

 

[Fewmet]

Today I learned
1) The actor that played Vic Fontaine in Deep Space Nine also played Dr. Tony Newman in The Time Tunnel.
2) Rhode Island and Providence Plantations became Rhode Island in 2020
3) Chubby Checker's name is an allusion to Fats Domino.

(OK: I learned the last of those yesterday.)

 

[Ivan Seeking]

Today I learned
1) The actor that played Vic Fontaine in Deep Space Nine also played Dr. Tony Newman in The Time Tunnel.
2) Rhode Island and Providence Plantations became Rhode Island in 2020
3) Chubby Checker's name is an allusion to Fats Domino.

(OK: I learned the last of those yesterday.)

RIL that the old TV show Here Come the Brides, was based on real events - The Mercer Girls or Mercer Maids.

The Mercer Girls or Mercer Maids were women who chose to move from the east coast of the United States to the Seattle area in the 1860s at the invitation of Asa Mercer. Mercer, an American who lived in Seattle, wanted to "import" women to the Pacific Northwest to balance the gender ratio. The women were drawn by the prospect of moving to a boomtown with a surplus of bachelors.[1] These events formed the basis of the television series Here Come the Brides.[2]
https://en.wikipedia.org/wiki/Mercer_Girls

I've always been fond of imports.

 

[Keith_McClary]

grand-fur-baby

My neighbor has a cat from her kids (because reasons). Is there a name for that?

 

[BillTre]

Reverse Feline Inheritance (RFI)

 

[jack action]

RIL that the old TV show Here Come the Brides, was based on real events - The Mercer Girls or Mercer Maids.

The Mercer Girls or Mercer Maids were women who chose to move from the east coast of the United States to the Seattle area in the 1860s at the invitation of Asa Mercer. Mercer, an American who lived in Seattle, wanted to "import" women to the Pacific Northwest to balance the gender ratio. The women were drawn by the prospect of moving to a boomtown with a surplus of bachelors.[1] These events formed the basis of the television series Here Come the Brides.[2]
https://en.wikipedia.org/wiki/Mercer_Girls

I've always been fond of imports.

This is literally how the French Canadian population was established with the filles du roi. It's part of every history class in Québec high school:

New France, at its start, was mostly populated by men: soldiers, fur traders, and priests. The colony became more agricultural and by the mid-17th century there was a severe imbalance between single men and women in New France. The small number of female immigrants had to pay their own passage, and few single women wanted to leave home to move and settle in the harsh climate and conditions of New France. The population growth of the competing English colonies awakened concern among some officials about France's ability to maintain its claim in the New World.

To increase the French population and the number of families, the Intendant of New France, Jean Talon, proposed that the king sponsor passage of at least 500 women. The king agreed, and eventually nearly twice the number were recruited.

 

[DaveC426913]

My neighbor has a cat from her kids (because reasons). Is there a name for that?

That's a grand-fur-baby too!

This dog is my son's.

Got two sons, one has given us a grand-fur-baby, the other has given us a grand-skin-baby.

 

[BillTre]

TIL that there are crew-less ships, to go with driver-less cars.
CNN story.

The first one, a few years ago, was a ferry (in 2018), so I guess that one could carry driver-less cars.

 

[DaveC426913]

... I guess that one could carry driver-less cars.

... and thus, less driver cars.

 

[Jarvis323]

TIL that the CO2 levels in my home have been nearly constantly way above healthy levels, and that high levels of C02 can cause major cognitive impairment, lethargy, and other problems.

https://onlinelibrary.wiley.com/doi/abs/10.1111/ina.12706

It took about 1 hour leaving all of the windows open for the C02 levels go below the "acceptable" 1000ppm threshold, and about 2 hours to get to better levels of about 500 (which is still less than optimal). The only problem is that leaving the windows open let's in the smoke, and in the summer let's in the heat, and in the winter let's out the heat.

Looking for a solution, I'm now trying to figure out if indoor algae tanks marketed as CO2 reducers/O2 generators could be a viable solution.

 

[berkeman]

TIL that the CO2 levels in my home have been nearly constantly way above healthy levels, and that high levels of C02 can cause major cognitive impairment, lethargy, and other problems.

https://onlinelibrary.wiley.com/doi/abs/10.1111/ina.12706

It took about 1 hour leaving all of the windows open for the C02 levels go below the "acceptable" 1000ppm threshold, and about 2 hours to get to better levels of about 500 (which is still less than optimal). The only problem is that leaving the windows open let's in the smoke, and in the summer let's in the heat, and in the winter let's out the heat.

Looking for a solution, I'm now trying to figure out if indoor algae tanks marketed as CO2 reducers/O2 generators could be a viable solution.

Do you know the source of the CO2? What is the level indoors versus outdoors?

 

[Jarvis323]

Do you know the source of the CO2? What is the level indoors versus outdoors?

I think it's just me, because it's a small studio apartment with no ventilation system. I'm not sure what the outdoor levels are exactly, but so far at least 1000ppm lower than inside based on the drop I see after leaving the windows open for a long time.

 

[Tom.G]

You might look around to see if any gas appliances have their outdoor exhaust vents blocked (bird or mouse nests, tree leaves). Actually any flame (incense, etc) will add a bit of CO2.

Just normal infiltration in most houses will be a few air changes per hour(ACH); that is unless it is a newer building in an area with significant climate extremes, those get sealed rather well and need forced air exchanges.

Cheers,
Tom

 

[berkeman]

I think it's just me, because it's a small studio apartment with no ventilation system. I'm not sure what the outdoor levels are exactly, but so far at least 1000ppm lower than inside based on the drop I see after leaving the windows open for a long time.

Do you have a way to measure CO levels too? I don't know what can cause an elevated CO2 level in your home...

 

[berkeman]

I don't know what can cause an elevated CO2 level in your home...

It looks like it might be just you, if the air circulation is not very good...

https://learn.kaiterra.com/en/air-academy/tips-for-reducing-co2

 

[Jarvis323]

It looks like it might be just you, if the air circulation is not very good...

https://learn.kaiterra.com/en/air-academy/tips-for-reducing-co2

Yeah, it seems like a common problem I guess. There is a gas water heater; maybe it could be a factor?

I bought an Awair air quality sensor which measures C02, TVOC, PPM2.5, temp, and humidity and I can connect it to smart plugs so that I can control my air purifier and possibly a humdifier/dehumidifier. But it turns out C02 is the biggest problem and there doesn't seem to be any practical solution.