Today I Learned

[Pepper Mint]

My dad had stones in his kidney. One night it got really bad; it's the only time I've ever seen him cry.

I had a family member having them too. The cold and fever like symptoms the patient exhibits look terrifying. I once almost had one on my right as diagnosed by my doctor and she advised me to take a lot of fresh water and daily physical exercises. I almost couldn't take it when trying to bend my body down if I didn't do what she told me within two days; you know the muscle fatigue arose around my waist and my whole body skin became more sensitive than usual when the pain came.The problem went away after a few months following her advice. Now I'm having a habit of taking a pretty large amount of water every day.

 

[beamie564]

she advised me to take a lot of fresh water and daily physical exercises

That helps. My dad was also told to drink barley water and ( as Sophia mentioned) non alcoholic beer.

 

[Fewmet]

No, just now learned it , Thanks !

But i was excited by the Poundal, force to accelerate a pound of mass one ft per second² , so is around a half ounce.

Today I learned these posts are about physics, not invertebrate biology.

 

[Tsu]

I was able to enjoy (!) my first kidney stone last October. My stone was 5mm and I took drugs for over a week to try to pass it but ended up with hydronephrosis and almost became septic. My doc finally scheduled me for surgical laser lithotripsy after I puked in his office and he blasted my stone and put in a stent that tap-danced all over the top of my urethra for two weeks. Miserable! I was off work for a month!

 

[OmCheeto]

TIL that it is not illegal to drive a car barefoot.
It was apparently an urban myth.

Driving Barefoot: The Eighth Deadly Sin? [Car Talk]
Tim Cotton
SEP 2, 2016

 

[Stephanus]

Today I learned about RODC (Read Only Domain Controller).
I've had a confusion for a week.

"What if you log on a RODC and add a user there?"
So it was a WRONG question.
The right question would be
"What if you log on a RODC and run ADUC (Active Directory User and Computers) to add a user?"
The answer would be:
ADUC will add the user to the DC (Domain Controller) with which it connects to.
And ADUC will never be able to connect to RODC. Even though it runs on RODC.

 

[Pepper Mint]

If you are unsure about what you learn, you can make questions about it directly on board.
TIL that a man having a female portrait or face shape can grow some beard to increase his masculine look. He'll look a lot better than most of other bearded men who usually look a lot more masculine after shaving. I want to do that but I seem to have always had such a low testosterone level since my birth that no hair grows on my face at all.

 

[Drakkith]

Today, in my C programming class, I learned:

while ((studentInClass == true) && (studentAwake > 0)
studentAwake = (studentAwake - 1);

if ((studentInClass == true) && (studentAwake <= 0))
return(ZZZzzz...);

 

[mfb]

If your program works properly, you can replace it by
if(studentInClass == true && studentAwake>0) {
studentAwake==0;
return(ZZZzzz...);
}

Assuming studentAwake is an integer.

 

[jim hardy]

what do the double operators in mean, == && ?
Does C use integer 0 and -1 for true & false , like Basic ?

 

[Ibix]

C has the fun feature that you can do assignment anywhere. So if(x=1) assigns 1 to the variable x, and 1 counts as true. So x is set to 1 and this if block always executes; the else block never will. The double equals is a comparison - so what I probably intended was if(x==1). To avoid the gaping pitfall here you will often see C programmers write if(1==x) because if they accidentally forget the second equals they'll get an error trying to assign a value to 1.

The double && is an and statement. A single & is a bitwise-and. It treats its arguments as binary and returns the result constructed from doing an and on each bit in turn - so 2&3 is interpreted as 010&011 and returns 010, which is 2.

 

[mfb]

"a=5" means "set a to 5", so the comparison needs a second "=".
"a && b" is just the regular logic "a and b". "a & b" is bitwise and.

0 is false, everything else is true.

 

[jim hardy]

Thanks guys.

As you see, i never learned to "C"

old jim

 

[Pepper Mint]

...
Does C use integer 0 and -1 for true & false , like Basic ?

C'ers also use true and false as 2 boolean values.
bool doX(bool x)
{
If (x) return false;
else return true;
}

 

[Drakkith]

Assuming studentAwake is an integer.

Opinions differ. Some say studentAwake is an integer, but may not have been properly initialized in the morning. Others say the student was never declared awake in the first place.

 

[Stephanus]

Today, in my C programming class, I learned:

while ((studentInClass == true) && (studentAwake > 0)
studentAwake = (studentAwake - 1);

if ((studentInClass == true) && (studentAwake <= 0))
return(ZZZzzz...);

Shouldn't it

char *Laugh(char *s) { return("ZZZZzzzz"); }
for(;studentInClass && (studentAwake>0);studentAwake--);
if(studentInClass && (studentAwake<=0)) return(Laugh("LOL"));

 

[Astronuc]

TIL that "The Texas health department doesn't track deaths . . . from antibiotic-resistant infections, and neither does the CDC." Apparently, many states don't require notification, and death may be attributed to other causes - "only 17 states require notification of C. difficile infections, for example, while just 26 states and Washington, D.C., do the same for MRSA."

Patients need to know this information.

'Superbug' scourge spreads as US fails to track rising human toll
http://www.foxnews.com/health/2016/...s-as-us-fails-to-track-rising-human-toll.html

 

[Stephanus]

what do the double operators in mean, == && ?
Does C use integer 0 and -1 for true & false , like Basic ?

I'm afraid if I answer this I'll get warning . But everybody did,
Okay here we come.
"==" is comparison, as everybody else says.
But "=" is an assignment and AN OPERATOR.
Okay, here's the example.
Let's say we involved 2 variables. B and C
A = B == C, a will be 1 (in C, -1 in BASIC) if B equal C, 0 (either C or BASIC) if otherwise.

In C
A = B = C, A will be C (and B will C as well). It's an assignment and operation.
In BASIC
A = B = C, A will be -1 if B equal C, 0 if not. It's a comparison not assignment.
Pascal
A:=B:=C, is an error expression.

Well actually the above example
A = B == C is error in BASIC there's no == operation.

What's interesting in C is = is an operator. Consider this format
A = B + C;
A = B - C;
A = B = C;
A = B / C;
All are valid.

What is && as compared to &?
&& is a logical operator.
& is a bitwise operator.
Because this is not programming language forum, I can't go further on the risk of getting kicked .

And I will conclude this post by BOLT
Binary One, Logical Two!
& is binary AND
| is binary OR

&& is logical AND
|| is logical OR

 

[Stephanus]

...0 is false, everything else is true.

Yes and ... no.
b = 5;
if (b) printf("Morning\n"); else printf("Night\n");
b = 8;
if (b) printf("Morning\n"); else printf("Night\n");
Both will print "Morning"
But, b = 4 > 3, b will be 1 (-1 in basic). Not everything else .

It's been a while with BASIC.
Do anybody remember?
B = 5
if B then print "MORNING" else print "NIGHT", will B have to be 5 not -1?
This I forget.

 

[mfb]

If you assign "true" to an int or a float it will be stored as 1, it cannot get multiple values of course. But ever non-zero value will be interpreted as true if it gets converted to bool (e. g. in an if statement).

 

[jim hardy]

Today i learned about "Able Archer", a 1983 military exercise in Europe

It so worried the Russians that they made preparations to 'shoot first and ask questions later' .

http://nsarchive.gwu.edu/nukevault/...War-Scare-Declassified-PFIAB-Report-Released/

Towards the end of the War Scare, President Reagan asked his Ambassador to the Soviet Union, Arthur Hartman, "Do you think Soviet leaders really fear us, or is all the huffing and puffing just part of their propaganda?"

Six years later, after the Cold War had ended, the 1990 PFIAB report answered President Reagan's question: "There is little doubt in our minds that the Soviets were genuinely worried by Able Archer… it appears that at least some Soviet forces were preparing to preempt or counterattack a NATO strike launched under cover of Abler Archer" and that "the President was given assessments of Soviet attitudes and actions that understated the risks to the United States." According to the PFIAB, the US Intelligence Community's erroneous reporting made the "especially grave error to assume that since we know the US is not going to start World War III, the next leaders of the Kremlin will also believe that."

chilling report here
http://nsarchive.gwu.edu/nukevault/...sified-PFIAB-Report-Released/2012-0238-MR.pdf

 

[BillTre]

The Gaia star-mapping mission has a positional accuracy of 300 microarcseconds (the width of a human hair at 30 kilometers).
Their second data release is supposed to have an accuracy up to 10 microarcseconds (the width of a human hair at 1000 kilometers).
A pretty astounding thing to think about!

I wonder which size of human hair they are using? I have read they can be ~20 to 200 microns wide.

 

[mfb]

I wonder which size of human hair they are using? I have read they can be ~20 to 200 microns wide.

They have a reference hair of one of the leading scientists.

No, seriously: using those numbers, the hair has a diameter of 40 µm.

10 microarcseconds allows to measure the distance of a star at 20000 light years distance (~center of our galaxy) with a precision better than 10%.

10 microarcseconds is about the diameter of an atom within the size of Gaia.

 

[BillTre]

No, seriously: using those numbers, the hair has a diameter of 40 µm.

I think 40 is considered average.

I like this better though:

They have a reference hair of one of the leading scientists.

It could be The Hubble Hair (found hanging off his old telescope after his death).

 

[fresh_42]

They have a reference hair of one of the leading scientists.

In Paris, I suppose.

 

[Stephanus]

Today Now, I learned about "now".
http://[URL="https://www.physicsforums.com/threads/twin-paradox-help.884180/page-4#post-5570064" ']Twin Paradox Help

 

[DrGreg]

Today I learned that $n! \neq (n!)!$ (here). It's called a "double factorial" but its alternative name of "semifactorial" seems more appropriate to me.

 

[Pepper Mint]

TIL that I would definitely have to hire a representative for my company instead of me being the CEO and having to appear in public all the time. Because
1. I can do all the businesses with the guy only. It is safer for me since I have the money and am known to local people particularly those in my area.
2. I have no headache from time to time in the business I am staying behind .
3. I also have time to invest my $$$ into other businesses (may also be seasoned ones - not long termed)

What do you think about what I learned ? Could the person I hire take all my money away ?

 

[OmCheeto]

TIL that an inch is exactly 2.54 mm cm 0.0254 meters long.

That made me wonder where the "inch" originated, and I learned a whole bunch of other interesting and fun things.

From wiki; "The earliest known reference to the inch in England is from the Laws of Æthelberht"

I sort of lost my interest at that point about "the inch", and went searching for "The Laws of Æthelberht", which I promptly found.
Unfortunately, the laws were written in Old English, and I could barely understand anything.
But the words were somewhat entertaining, as they seemed to be a mix of German, English, and Latin, and that just furthered my interest.

Wiki had the following to say about the document; "The code is concerned primarily with preserving social harmony, through compensation and punishment for personal injury. Compensations are arranged according to social rank, descending from king to slave".

About an hour later, I found a modern English translation.
It only got funnier from there.

It would appear that things back around 600 AD were at the same time, quite different, and completely the same, as they are now, which I will get to at the end.

They were different, in that every part of the human body had different values, and they had different values for different types of people. (Kings to Slaves)

It was my impression, that the common currency was the "Shilling".
Another denomination was the "person price", which was apparently 100 shillings, from; "24. If a person kills someone, let him pay an ordinary person-price, 100 shillings."
Another was the "Sceatta", which was 1/20 the of a shilling. A version of the American "Nickel", I suppose.

So anyways, while I was looking for the "inch" reference, I ran across the most valuable body part, in terms of "If you cut this off, you owe him this much", which is why I tried to decipher the monetary units.

And...

Spoiler: You guessed it

64. If a person damages the genital organ, let him pay him with three person-prices. [300 shillings!]

So then, if you should time travel back to medieval England, and should accidentally cut someones wiener off, be sure and kill him, and sew the wiener back on, as it will cost you only 1/3 as much.

ps.

Punching someone in the nose would have cost you 3 shillings, and pulling someones hair would have cost you 2.5 shillings.

And the first documented mention of the "inch":

67. If a person stabs through a thigh, for each thrust 6 shillings.

67.1. If [the width of the wound] is over an inch, a shilling;
67.2. for two inches, two [shillings];
67.3. over three [inches], 3 shillings.​

1 inch = 3 barleycorn lengths = width of the average man's thumb at the base of the nail

hmmm...

I have a slightly less than average thumb...

references:

Modern English translation of The Laws of Æthelberht
Wiki on the history of the "inch"
Wiki on the Laws of Æthelberht​

 

[mfb]

A murder was equal to pulling the hair 40 times? Interesting ratio.

 

[Bystander]

inch is exactly 2.54 m[insert]c[/insert]m

 

[fresh_42]

.

As if you knew how thick his thumb is.

 

[Bystander]

The devil made me do it.

 

[OmCheeto]

I was actually going to put that down as one of my "pet peeves" today.

(which is why the 1 inch=25.4 mm is exact by definition)

Almost all of my calculations are now done in SI in base units. No millis. No micros. No nanos.
As I invariably will slip a decimal point.

ps. Thank you. It's fixed.
I think.

 

[OmCheeto]

A murder was equal to pulling the hair 40 times? Interesting ratio.

Well, if you look at the title of my first reference, it says; "“BARBARIAN” LAW CODES"

Funny. Someone was bad mouthing Leviticus on my Facebook feed yesterday. I wish I'd known about this document. The olden days were apparently quite different for quite a long time.

Did you know, that when I was born, only 5% of Americans thought mixed race marriages were ok?
I found this out just a few months ago, and was like; "What?? Really? Wow."