Today I Learned

[mfb]

He says taking the lead out of brass ruined its machinability.

It also "ruined" (reduced) its toxicity. If you plan to drink the water, it is a good idea to replace old lead pipes.

 

[jim hardy]

If you plan to drink the water, it is a good idea to replace old lead pipes.

Did you see the NOVA show on Flint's water supply?
http://www.pbs.org/wgbh/nova/body/poisoned-water.html
You really need that layer of scale on the inside of lead pipes. Until they're replaced keep the water chemistry such that it won't dissolve the scale.

Program Description
Water. Turn on the faucet and it’s always there. Without it we perish. But how safe is our tap water? In this special report narrated by Joe Morton, NOVA investigates what happened in Flint, Michigan, when local officials changed the city’s water source to save money, but overlooked a critical treatment process. As the water pipes corroded, lead leached into the system, exposing the community—including thousands of children—to dangerous levels of poison. NOVA uncovers the science behind this manmade disaster— from the intricacies of water chemistry to the biology of lead poisoning to the misuse of science itself. NOVA follows ordinary citizens and independent scientists who exposed the danger lurking in Flint’s water and confronted those who turned a blind eye. And discover the disturbing truth that reaches far beyond Flint—water systems across the country are similarly vulnerable. How can we protect ourselves from poisoned water?

They're all steel pipes on this rural system. Mine had a healthy limestone lining. . I buried a new PVC line for when my fifty+ year old steel one corrodes away. It's tied into the white one in my picture.

old jim

 

[BillTre]

Interesting to know that about the brass fittings @jim hardy.
I like pipe paste.

 

[mfb]

You really need that layer of scale on the inside of lead pipes. Until they're replaced keep the water chemistry such that it won't dissolve the scale.

That is better than nothing, but not better than lead-free pipes.
Germany for example stopped installing leaded pipes 50-100 years ago, but there are still some old pipes around. The limit is 10µg/l in the water, these old pipes typically lead to water exceeding that limit.

 

[jim hardy]

That is better than nothing, but not better than lead-free pipes.

What made the Flint problem acute was their new water supply chemistry dissolved the scale that had lined the old lead pipes .

One can't defend pure lead pipes this day an age .
But one can blast Flint water officials for first refusing to acknowledge then trying to hide their problem. NOVA did a good job IMHO of presenting the facts about lead and scale in pipes, and bureaucracy .

When one changes something that causes another problem does he not own the new trouble too?

Looks like i too will become a fan of Teflon thread paste.

 

[OmCheeto]

What made the Flint problem acute was their new water supply chemistry dissolved the scale that had lined the old lead pipes .

One can't defend pure lead pipes this day an age .
But one can blast Flint water officials for first refusing to acknowledge then trying to hide their problem. NOVA did a good job IMHO of presenting the facts about lead and scale in pipes, and bureaucracy .

When one changes something that causes another problem does he not own the new trouble too?

jedishrfu posted a thread about that on Friday. Beings that I don't watch TV anymore, I really appreciate notices of excellent programs.
I did some further research about it, and discovered that the chemicals they decided not to add would have cost them $200 a day.

“For $200 a day, had the leadership put phosphate in the water as an anti-corrosive, this wouldn’t have happened,” Schuette says. [ref: Time]​

The highest estimate I've seen so far to fix the problem is $1.5 BILLION.

Many residents have called for state money to replace the city’s old pipe infrastructure — which the mayor has said could cost up to $1.5 billion — and a fund to address any developmental impact on children. [ref NY Times]​

hmmm... $200/day * 365.25 days/year = $73,000/year
$1,500,000,000 / ($73,000/year) = 21,000 years.
hmmm...
I'm guessing they probably would have replaced all the old broken pipes by then. I wonder how long lead water pipes last.

Looks like i too will become a fan of Teflon thread paste.

When I bought my house 28 years ago, I didn't know there was a problem with the plumbing.
It took me a month to replace all of the broken fittings and pipes and fixtures.
The house had sat vacant through two winters, and although a note on the water heater said everything had been "winterized", it was obvious that it hadn't. Or, perhaps the meant a "Southern California" winter.
In any event, even though I had no training as a plumber, it still hasn't leaked..
(knocks on wood)

 

[jim hardy]

That is better than nothing, but not better than lead-free pipes.

Hmm looks like there's science to back getting the lead out of our brass.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808929/
so far as i can tell that journal doesn't charge much to publish, about a hundred Swiss Francs
so i hope they're reputable
surely they won't mind this pointer to their interesting paper
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808929/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808929/figure/ijerph-13-00266-f003/

Though it's way less drastic than real lead pipes.

Still,
if i go away for a week or more i'll run enough water to flush the lines .

Okay - today i learned that, too !

old jim

 

[jim hardy]

I wonder how long lead water pipes last.

Somebody must've found some left from the Roman days...Another interesting paper on the mechanism...

http://homepages.uc.edu/~maynarjb/Frontpage%20sites/603/GeochemWater/Brass_corrosion.html

 

[1oldman2]

Today I learned, well that about sums it up.

 

[mfb]

Today I learned: Abstract nonsense is actual mathematics.

And who bothers studying pointless topology?

 

[dkotschessaa]

Today I learned: Abstract nonsense is actual mathematics.

That I knew about.

And who bothers studying pointless topology?

That I didn't. (I realize I'm supposed to say a joke like "I don't see the point." But I won't. It would be pointless.)

-Dave K

 

[fresh_42]

And who bothers studying pointless topology?

That's for all who don't like Alexandroff extensions. (The German terms hits it better: 1-Point-Compactification.)

 

[Ibix]

And who bothers studying pointless topology?

I dunno, but I'll go out on a limb and suggest that they're strongly correlated with people who are bored of answering "so what's the point of your work? Geddit? Point?"

 

[dkotschessaa]

That's for all who don't like Alexandroff extensions. (The German terms hits it better: 1-Point-Compactification.)

How do you say that in German? (I don't imagine google translate is going to be helpful here).

 

[mfb]

Einpunkt-Kompaktifizierung?
It is a literal translation.

 

[fresh_42]

Einpunkt-Kompaktifizierung

 

[dkotschessaa]

Wow,yes, that's very literal.

 

[DrGreg]

And who bothers studying pointless topology?

Don't know who. But where? Almost nowhere?

 

[Pred]

Today I learned that studying abroad is a great way to learn new things, new culture, ideas, lifestyle as well as education system. We all know that we are living in a world with full of diverse people, and by studying abroad, we can try to experience dealing with those people and learn something from them that would help us be a better individuals and be prepared for next generation's global leaders.

 

[dkotschessaa]

Today I learned that one of the least visited national parks is Dry Tortugas National Park. 70 miles away from key west, accessible only by boat or plane, primitive camping only, and I want to go very, very badly.

 

[jim hardy]

Today I learned that one of the least visited national parks is Dry Tortugas National Park. 70 miles away from key west, accessible only by boat or plane, primitive camping only, and I want to go very, very badly.

It's way more pleasant in January.

Be sure to take enough fuel for the round trip plus a snorkeling run while you're there..
https://www.nps.gov/drto/planyourvisit/boating-sail-and-power.htm

Bringing your own boat to Dry Tortugas National Park will provide you with the most opportunities to explore this remarkable national treasure. Situated approximately 70 miles west of Key West, Florida, with no food, water, or fuel available in the park, proper planning is a must.

 

[fresh_42]

Today I learned that one of the least visited national parks is Dry Tortugas National Park. 70 miles away from key west, accessible only by boat or plane, primitive camping only, and I want to go very, very badly.

What? To visit billions of mosquitoes, pythons and alligators? Or did it get away with those invasions as an island?

 

[dkotschessaa]

It's way more pleasant in January.

Be sure to take enough fuel for the round trip plus a snorkeling run while you're there..
https://www.nps.gov/drto/planyourvisit/boating-sail-and-power.htm

I hadn't considered taking my own boat (I don't have one, but maybe by then I will?). They have a ferry you can take.

Of course yes, any outdoorsing in/around Florida I would only do in the "cold" seasons.

-Dave K

 

[OmCheeto]

Today I learned why my lettuce isn't dying, in spite of the fact that they are in a black flower pot.
Lettuce roots appear to be most comfortable at 75°F[ref], and that is their current temperature.

 

[dkotschessaa]

What? To visit billions of mosquitoes, pythons and alligators? Or did it get away with those invasions as an island?

Yes, those things are mostly on the mainland. I'm less certain about the mosquitoes, but that is why one goes in January.

-Dave K

 

[BillTre]

TIL that drones similar to those used in a Video class I took can be used to capture 3D data and make topomaps, 3D point clouds, and for making comparisons to CAD files for buildings under construction.

 

[phinds]

TIL that drones similar to those used in a Video class I took can be used to capture 3D data and make topomaps, 3D point clouds, and for making comparisons to CAD files for buildings under construction.

Jeeze, for $3,700 they better be whilstlin' Dixie while they do it !

 

[jtbell]

Today I learned that Joey Chestnut, who won the Nathan's Hot Dog Eating Contest at Coney Island today for the tenth time, doesn't just eat hot dogs. He's also won competitions in eating:

deep-fried asparagus
grilled cheese sandwiches
waffles
hamburgers
bratwurst
chicken wings
pizza
matzo balls
gyoza
macaroni and cheese
wontons
corned beef sandwiches
poutine

He's also eaten a 72-ounce steak with salad, baked potato, shrimp cocktail and roll in 8 minutes 52 seconds at a steakhouse in Amarillo, Texas.

https://en.wikipedia.org/wiki/Joey_Chestnut

The organizers of the Okra Strut Festival in Irmo SC (near Columbia) should invite him to compete in their okra-eating contest!

 

[jim hardy]

Actually it was yesterday or day before when i saw this on PBS

http://www.bbc.co.uk/programmes/articles/3t902pqt3C7nGN99hVRFc1y/which-oils-are-best-to-cook-with
Butter may not be so bad after all..

 

[mfb]

Today I learned: The easiest (!) way to express 74 as sum of three integer cubes is 74 = (−284650292555885)³ + 66229832190556³ + 283450105697727³

It is unclear if there are any solutions for 33 or 42.

 

[phinds]

Today I learned: The easiest (!) way to express 74 as sum of three integer cubes is 74 = (−284650292555885)³ + 66229832190556³ + 283450105697727³

And we have another winner of the "I've got WAY too much spare time on my hands" award

 

[mfb]

I didn't find that solution, I found a webpage discussing the general problem.

 

[Demystifier]

Today I learned that there is the list of the top 7 quirkiest physics papers with character on the arXiv, and that one of my papers is on the list:
http://www.symmetrymagazine.org/article/quirks-of-the-arxiv

 

[phinds]

Today I learned that there is the list of the top 7 quirkiest physics papers with character on the arXiv, and that one of my papers is on the list:
http://www.symmetrymagazine.org/article/quirks-of-the-arxiv

Catchy title

 

[mfb]

If "if Bohm were born before Born" implies Born was born, then the answer is clearly "yes" from a purely logical point of view.

Great title.