Today I Learned

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Today I learned that cleaning a white hat can be done with bleach cleaner, but it’s important to rinse it before wearing it again. I also discovered that "oyster veneering," a woodworking technique from the late 1600s, is experiencing a minor revival despite its labor-intensive nature. Additionally, I learned that the factorial of 23 (23!) equals 25,852,016,738,884,976,640,000, which interestingly has 23 digits, a unique coincidence among factorials. I found out that medical specialists often spend less than 10 minutes with patients, and that watching TV can contribute to weight gain. Other insights included the fact that a kiss can transfer around 80 million microbes, and that bureaucracy can sometimes hinder employment opportunities. The discussion also touched on various trivia, such as the emotional sensitivity of barn owls and the complexities of gravitational lensing around black holes.
  • #4,351
TIL that there are at least eight levels of minor league baseball.
 
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  • #4,354
TIL the trebuchet was invented in China circa the 4th century B.C. .
 
  • #4,355
During the last several days I have been learning the Lebesgue integration theory for functions with values in a Banach space by S.Lang's "Real Analysis". The narration is pretty nice and clear.
Since the construction is very general it does not rely on accidental things like an order in the space of values. This straightens the structure.
 
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  • #4,356
wrobel said:
During the last several days I have been learning the Lebesgue integration theory for functions with values in a Banach space by S.Lang's "Real Analysis". The narration is pretty nice and clear.
Since the construction is very general it does not rely on accidental things like an order in the space of values. This straightens the structure.
Is your picture Von Neumann?
 
  • #4,357
pinball1970 said:
Is your picture Von Neumann?
C. S. Lewis
 
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  • #4,358
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  • #4,359
Oldman too said:
I will read all those links. No passwords? That seems crazy!
 
  • #4,360
pinball1970 said:
I will read all those links. No passwords? That seems crazy!
They authenticate using your phone. We do this at the hospital.
 
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  • #4,361
DaveC426913 said:
They authenticate using your phone. We do this at the hospital.
Not keen though Dave.
 
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  • #4,362
DaveC426913 said:
They authenticate using your phone. We do this at the hospital.
Same with most banks.
 
  • #4,363
pinball1970 said:
I will read all those links. No passwords? That seems crazy!
Sounds risky on first look, the links explain it pretty well though. The hackers are already at a work around for this unless I miss my guess. Still it is an improvement over the current system, we'll see soon enough.
 
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  • #4,364
pinball1970 said:
Not keen though Dave.
? You mean you don't like it?

I have hundreds of passwords. If I haven't been back to somewhere in over six months I have to reset it.

Oldman too said:
Same with most banks.
Not mine yet.

I confess, I did not like it at first - having to have a second device handy. But now I always have my phone, so it's not such a hardship.
 
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  • #4,365
TIL there are ##\LaTeX## coffee stains!
1651804041136.png

1651804014568.png
 
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  • #4,366
DaveC426913 said:
Not mine yet.
Sorry, I should have specified, that only applies to bank employees. My granddaughter works in a bank and it's their default authentication for all employees. Seems to work great for them. There seems to be a fallback recovery method should you lose your phone.

DaveC426913 said:
I confess, I did not like it at first - having to have a second device handy. But now I always have my phone, so it's not such a hardship.
I'm not even using it yet personally but I'm rarely without the phone handy, I'll be glad to get rid of password authentication.
 
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  • #4,367
wrobel said:
C. S. Lewis
1651836019646.png


Definitely some likeness
 
  • #4,368
TIL

CS Lewis was actually Irish and had a hatred of the English for a while after coming to England.
He was an atheist and interested in mysticism before converting to Christianity.

John Von Neuman was a very impressive individual! Too much to mention but one thing I noticed reading his wiki page was he had a guard over him while he was dying at a military medical centre.

He was medicated and military was worried about him talking about US secrets as he passed.
 
  • #4,369
Supposedly, the only question Hilbert asked Von Neumann at his Ph.D. defense was

"In all my years I have never seen such beautiful evening clothes: pray, who is the candidate's tailor”​

 
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  • #4,370
pinball1970 said:
John Von Neuman was a very impressive individual! Too much to mention but one thing I noticed reading his wiki page was he had a guard over him while he was dying at a military medical centre.

He was medicated and military was worried about him talking about US secrets as he passed.
I can not explain that but I feel something not good to pass in such a way.
 
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  • #4,371
His was an ugly death. Some sort of cancer and he knew that his mind was not functioning well.
 
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  • #4,372
pinball1970 said:
CS Lewis was an atheist and interested in mysticism before converting to Christianity.

My favorite book is his last, Til We Have Faces. It's pagan, and about the the meaning of life.
 
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  • #4,373
caz said:
His was an ugly death. Some sort of cancer and he knew that his mind was not functioning well.
He would have been on morphine I would guess. Anyway the list of contributions he made was something else.
Focus on the positives.
 
  • #4,374
Hornbein said:
My favorite book is his last, Til We Have Faces. It's pagan, and about the the meaning of life.
Not read that only the Narnia books.
 
  • #4,375
Now I have to go find my copies of Perelandra and ... I read in high school and I remember them as almost terrifying, but I'm not sure now why.
 
  • #4,376
DaveC426913 said:
? You mean you don't like it?

I have hundreds of passwords. If I haven't been back to somewhere in over six months I have to reset it.Not mine yet.

I confess, I did not like it at first - having to have a second device handy. But now I always have my phone, so it's not such a hardship.
My system is now part of it! It's just another thing, another layer. I cannot authenticate without my phone. Great!
Solution is simple, make sure you always have your phone available, charged and ready to give up the authentication code.
Just like your car? You need to get to work so just have the car there ready and waiting, it's not as if anything could go wrong between house and work is it?
Thing is the car goes rogue you get a cab to the tram / railway station.
 
  • #4,377
pinball1970 said:
My system is now part of it! It's just another thing, another layer. I cannot authenticate without my phone. Great!
Solution is simple, make sure you always have your phone available, charged and ready to give up the authentication code.
Just like your car? You need to get to work so just have the car there ready and waiting, it's not as if anything could go wrong between house and work is it?
Thing is the car goes rogue you get a cab to the tram / railway station.
There's no doubt it's not ideal. But we don't have ideal yet.

The question is: overall, is it better than juggling two hundred hackable passwords?
 
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  • #4,378
Oldman too said:
going passwordless
I haven't seen this yet. I do have accounts where I type my password in, then it asks me to give the code they send to my phone. That seems like a good idea; someone breaking into my account needs to know the password and have my phone. For things like bank accounts, social security, medicare... I really do not mind, in fact, I like the added security.
 
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  • #4,379
DaveC426913 said:
There's no doubt it's not ideal. But we don't have ideal yet.

The question is: overall, is it better than juggling two hundred hackable passwords?
Yes Dave but I am not keen. Next it will be a link sent to a different e mail account which I verify via a 7 digit number sent to my phone. Once verified I go through some security steps and I have access to the security platform. This requires a 13 character code with upper lower case number and something else, *. At last now I get clearance to complete the on line profile of 6 step process which verifies my identity with respect to all the stuff I just did. The next step confused me so I was timed out. I need another code but need a different e mail account as the first has now been designated, 'not secure'

IT explained that if I get an authentication code on my phone on a Sunday or three in the morning then it's not from me.
Thank heavens for these people. They hack for fun then get paid to teach companies how to avoid it.
 
  • #4,381
LORENZ gauge! LORENZ, not Lorentz!
Unbelievable. Now i see the world with different eyes.
 
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  • #4,383
TIL that my keyboard actually has four extra buttons which I've never noticed before.

I just had to tear apart the thing for it's first ever thorough cleaning for this revelation...
 
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  • #4,384
Rive said:
TIL that my keyboard actually has four extra buttons which I've never noticed before.

I just had to tear apart the thing for it's first ever thorough cleaning for this revelation...
What?? :oops: Were they, like, molars waiting to erupt??
You have Wisdom Keys?
 
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  • #4,385
DaveC426913 said:
What?? :oops: Were they, like, molars waiting to erupt??
You have Wisdom Keys?
My guess is: Annie Key, Lost Key, Stuck Key, and Boss Key.
 
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  • #4,386
Oldman too said:
TIL, A SMBH can reverse it's magnetic field.
https://arxiv.org/pdf/2203.07446.pdf
According to the no-hair theorem a black hole doesn't have a magnetic field. The paper says an Active Galactic Nucleus reversed its field. So I'd say that it's all the junk in the accretion "disk" that reversed.
 
  • #4,387
Hornbein said:
According to the no-hair theorem a black hole doesn't have a magnetic field. The paper says an Active Galactic Nucleus reversed its field. So I'd say that it's all the junk in the accretion "disk" that reversed.
Right. The accretion disk and the complicated mechanism that forms the jets of highly accelerated material that shoot out from either side, perpendicular to the disk.

(For clarity, I would highly doubt the accretion disk itself changed its direction of rotation. That would be a bit much. But the mechanism for the jet formation has been long thought to be powered by magnetic field interactions, and its not a trivial subject. There's a lot going on there.)
 
  • #4,388
DaveC426913 said:
You have Wisdom Keys?
Kind of o0)

Somebody just made the power buttons look like LEDs.
And since I've never used them, they just lingered there, unnoticed :doh:
 
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  • #4,389
LCSphysicist said:
LORENZ gauge! LORENZ, not Lorentz!
Unbelievable. Now i see the world with different eyes.
It's fine, there is the Lorentz-Lorenz equation!
 
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  • #4,391
TIL there will be a double Nova show (two hours!) on PBS today, on the recent (last few years) findings on the meteor impact that ended the Age of the Dinosaurs. David Attenborough is the narrator.
It has my interest.
 
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  • #4,392
BillTre said:
TIL there will be a double Nova show (two hours!) on PBS today, on the recent (last few years) findings on the meteor impact that ended the Age of the Dinosaurs. David Attenborough is the narrator.
It has my interest.
Is there a link to watch it on-line? (no TV here)
 
  • #4,393
There are probably PBS outlets with it if your are PBS site enabled (a member).
Here (https://www.pbs.org/video/dinosaur-apocalypse-the-last-day-h80ueb/) is one for me in Oregon. Don't know if you need to be a member to get there since I am a member and my computer automates these things. I found it with Google (Dinosaur Nova).
 
  • #4,394
It may be available through on-line services also.
 
  • #4,395
The link in your post works fine, Thanks!
 
  • #4,396
Rive said:
Kind of o0)

Somebody just made the power buttons look like LEDs.
And since I've never used them, they just lingered there, unnoticed :doh:
I checked my keyboard after reading your post and there are three keys on there I have never used. No idea what they do, still don't but work got in the way so I didn't get round to checking.
 
  • #4,397
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  • #4,398
Hornbein said:
According to the no-hair theorem a black hole doesn't have a magnetic field. The paper says an Active Galactic Nucleus reversed its field. So I'd say that it's all the junk in the accretion "disk" that reversed.
Hi, sorry if the wording on my related post wasn't perfectly clear. It was made on my 42 wedding anniversary, about two margaritas into the celebration.
I'd like to clarify a couple of important points about the SMBH-reversal that I referenced. I wasn't implying that the accretion disc had reversed rotation, although MAD is referenced, I'm not certain that they are stating that's the disk's state either. What I was mentioning, is the magnetic field reversed as depicted in the attached image. Pages 17-18 of the arxiv paper are particularly useful information.
This is another way of viewing things, https://phys.org/news/2022-05-surging-distant-galaxy-black-holes.html
Mag field flip.PNG
 
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  • #4,400
Today I learned a bit about elliptic curves.
 
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