Today I Learned

[Larry Gopnik]

Today I learned that I should never dye my hair by myself.

I got it dyed black a few months back and decided today to return it to my natural colour - sort of gingery brown. I went wrong. It's now highlighter orange, the shops are shut and I have work tomorrow...

 

[fresh_42]

Today I learned that I should never dye my hair by myself.

I got it dyed black a few months back and decided today to return it to my natural colour - sort of gingery brown. I went wrong. It's now highlighter orange, the shops are shut and I have work tomorrow...

Take the positive part of it. I have an Irish friend. No matter how large a crowd might be, she cannot get lost.

 

[jtbell]

Today I learned about "corn sweat" and how it contributes to summer heat waves in the midwest US.

http://www.cnn.com/2016/07/17/weather/extreme-weather-heat-dome/index.html

(I actually grew up in the midwest, but it was in a steel-mill town, not among the cornfields.)

 

[OCR]

Today I learned about "corn sweat" and how it contributes to summer heat waves in the midwest US.

Lol... I just learned that myself, about two hours ago... 'cause my wife told me...So, to borrow from your signature...

I don't need no stinkin' signature...

Internet??... Internet?

I don't need no stinkin' internet...

 

[Stephanus]

Today I learned,
that if you pack 250 moles of moles in a mole hole, it will become a black hole.

Spoiler: Schwarzschild Radius

G = 6.674 * 10^-11
Mole = 6.022 * 10²³
Weight of a, ehm, mole ≈ 500 gr
$R_{schwarzschild} = \frac{2GM}{c^2}$
$R_s = \frac{2 * 250 * 6.022 * 10^{23}\text{ } * 500gr * 6.674 * 10^{-11}}{9 * 10^16}$
$R_s = 1.12 * 10^{-1}m = 0.112 m = 10 cm$ About the size of a mole hole.

Even if my calculation is wrong, the hole still black.

 

[Stephanus]

And I always thought moles had to do with avocados ...

Ahhh, I didn't get the joke. Avogadro?

 

[Jonathan Scott]

Ahhh, I didn't get the joke. Avogadro?

Double joke (not sure whether intentional). Firstly, Avocado could be confused with Avogadro. Secondly, Avocado is used to make Guacamole (sounds something like "whack a moley").

 

[Kaura]

Today I learned,
that if you pack 250 moles of moles in a mole hole, it will become a black hole.

Spoiler: Schwarzschild Radius

G = 6.674 * 10^-11
Mole = 6.022 * 10²³
Weight of a, ehm, mole ≈ 500 gr
$R_{schwarzschild} = \frac{2GM}{c^2}$
$R_s = \frac{2 * 250 * 6.022 * 10^{23}\text{ } * 500gr * 6.674 * 10^{-11}}{9 * 10^16}$
$R_s = 1.12 * 10^{-1}m = 0.112 m = 10 cm$ About the size of a mole hole.

Even if my calculation is wrong, the hole still black.

Today I learned through using that equation that one would have to shrink a mole weighing 100 grams to a size of about 1.48x10^-28 which is smaller than a Neutrino in order to make the mole into a black hole

 

[mfb]

which is smaller than a Neutrino

It is expected that neutrinos are point-like, and there are no indications of any size. Experiments set upper limits on a possible size.

 

[1oldman2]

neutrinos are point-like

TIL, https://docushare.icecube.wisc.edu/dsweb/Get/Document-58012/dumm_thesis.pdf
Very soon into reading this I was wondering why the southern sky registered so many more events than the north.
("The data sample contains 36,900 events: 14,121 from the northern sky, mostly
muons induced by atmospheric neutrinos and 22,779 from the southern sky, mostly
high energy atmospheric muons.")
I quickly came upon,
( "in the southern hemisphere these neutrinos are swamped by the downgoing cosmic-ray muon background.") Which of course brought up...http://icecube.wisc.edu/
This led to wondering about tau... http://www.scientificamerican.com/article/let-s-use-tau-it-s-easier-than-pi/,
Which in turn brought me to...

Soon I'm watching...

(Ain't the internet great!)
Thanks mfb, this has been a good "TIL day" (I'm hoping for some feedback/opinions on pi v.s. tau)

 

[Stephanus]

I'd like to check if we can copy paste a picture without upload it in a post.
https://www.physicsforums.com/attachments/103459
And this a thumbnail
https://www.physicsforums.com/attachments/103460

And copy paste the formula.
And formula
$a = b + c$
And font
And color
$\text{and font with formula } a = b + c$
And font and color and styles
$a = b + c \text{ } \text{styles and color in formula}$

This won't work even without copy paste
##\text{Different styles } \text {and color won't work}##

 

[1oldman2]

I'd like to check if we can copy paste a picture without upload it in a post.
https://www.physicsforums.com/attachments/103459
And this a thumbnail
https://www.physicsforums.com/attachments/103460

And copy paste the formula.
And formula
$a = b + c$
And font
And color
$\text{and font with formula } a = b + c$
And font and color and styles
$a = b + c \text{ } \text{styles and color in formula}$

This won't work even without copy paste
##\text{Different styles } \text {and color won't work}##

Drag and drop is about as complicated as I get.

 

[OCR]

I'd like to check if we can copy paste a picture without upload it in a post.
https://www.physicsforums.com/attachments/103459
And this a thumbnail
https://www.physicsforums.com/attachments/103460

And copy paste the formula.
And formula
$a = b + c$
And font
And color
$\text{and font with formula } a = b + c$
And font and color and styles
$a = b + c \text{ } \text{styles and color in formula}$

This won't work even without copy paste
##\text{Different styles } \text {and color won't work}##

The only picture I can copy and paste is a screen grab using the Snipping Tool...

 

[OCR]

 

[Stephanus]

I'd like to post three postings at once. So the trick is, I "create" a thread, then I write the posts and calculation there. Then when it's done, I just copy paste to the thread that I want to answer. And I want the graphs will be there, too.
Because this three post are related each other. I'll give you the link.
https://www.physicsforums.com/threa...ant-speed-of-light.878697/page-2#post-5524020
But edding three post at once with graphs will remove the graph. Oh, my. Luckily PF Forum has edit feature.
Okay..., today I learned that if I want to write three posts at once, I have to be careful with the graphs.

 

[Stephanus]

Yes, @OCR , but it's not the screen that I want to capture. See my links. They are all 2 minutes separated. The only way to do that is to write all of them one by one ant post them at once.
But once I post, I didn't see my graphs.
I have to upload them again. Perhaps the server just save the graph for each user, not for each browser window opened.

 

[mfb]

TIL, https://docushare.icecube.wisc.edu/dsweb/Get/Document-58012/dumm_thesis.pdf

The "point-like" in that title has nothing to do with neutrino sizes, it means they all come from the same place in the sky (within the angular resolution).

IceCube is at the South Pole, so naturally things from the South look different from things from the North.

I rarely use $\pi$ without a factor 2, so $\tau$ would be more convenient.

Yes, @OCR , but it's not the screen that I want to capture. See my links. They are all 2 minutes separated. The only way to do that is to write all of them one by one ant post them at once.
But once I post, I didn't see my graphs.
I have to upload them again. Perhaps the server just save the graph for each user, not for each browser window opened.

You can always write a single post and put everything in that.

 

[NascentOxygen]

I'd like to check if we can copy paste a picture without upload it in a post.
[ATTACH=full]103326[/ATTACH]

You can, almost. Instead of the ATTACH tags, turn the attachment number into a valid IMG image link to the original image, e.g., the above becomes [ATTACH=full]189275[/ATTACH]

N.B., you do need to obtain (or guess) the correct filename suffix: jpg/png/gif, etc.

 

[mfb]

N.B., you do need to obtain (or guess) the correct filename suffix: jpg/png/gif, etc.

Right click on the image -> show image details (or similar, browser-dependent), gives you the exact path.

 

[Stephanus]

Today I'm going to learn whether I can post 3 posts with graphs simultaneously.
My first image.

 

[Stephanus]

You can, almost. Instead of the ATTACH tags, turn the attachment number into a valid IMG image link to the original image, e.g., the above becomes [ATTACH=full]189276[/ATTACH]

N.B., you do need to obtain (or guess) the correct filename suffix: jpg/png/gif, etc.

Right click on the image -> show image details (or similar, browser-dependent), gives you the exact path.

Thank you all for the suggestion. But, when I write the post, I haven't click the "POST REPLY" button, yet. How can my files be in PF server?
My case is like this.
I want to answer to a certain thread in 3 different posts. So I open 3 browser windows, then I wrote them until I finished. Then I click POST REPLY button.
But as @mfb suggestion...

You can always write a single post and put everything in that.

Oh my God. Three different browser windows!. I'm going to try it.
[Add: No, it still didn't work. The other posts only show link to the file]

 

[mfb]

I want to answer to a certain thread in 3 different posts.

Why do you want to do that? Put everything in one post. Much better to follow threads like that.

One browser window and one post is everything you need. If you want to attach images, click the "upload" button, upload the image, include it in the post (there is a button to include it as full image, or use the thumbnail version).

 

[Stephanus]

Why do you want to do that?

These are my posts I just want to post them in 3 different section so it is neat. But next time, perhaps I will do it with the help of the spoiler button. So the OP can click any detail that he wants to read.

 

[Ibix]

Today (at about 2am) I learned that foxes can make some really strange noises when arguing over territory. I also learned (a few hours later...) that it is called "gekkering".

https://www.google.co.uk/search?q=gekkering

 

[NascentOxygen]

Thank you all for the suggestion. But, when I write the post, I haven't click the "POST REPLY" button, yet. How can my files be in PF server?

I still don't follow exactly what you are trying to do, but ...

before you click on POST REPLY you have already clicked on UPLOAD to attach the file to your post, so by hovering the mouse over that filename link at the foot of the edit space you can see the attachment number your file has already been allocated. I have used that information to present the pic 3 ways above ⤴⤴⤴ before I click to POST this. I think the ATTACH tags are restricted to the post to which the file is actually attached, and for all other posts you must use IMG tags.

 

[OCR]

Lol... OK, I just copied and pasted your image... I know that isn't what your talking about, but I wanted to see if "Copy Image" worked...

It seemed to...

 

[Stephanus]

Okay, so, here the catch

Okay, I'll do it again.

 

[Stephanus]

This is the second email.

And this is the second email

 

[Stephanus]

This is the third post.

This is the third email.

 

[Stephanus]

Ah, I see.
So the catch is this.
You have to open your browser tabs first before you do the editing or click reply.
Then you click reply. And do the editing there.
But I don't know if it will work when we edit the post more then 30 mins.
This is what I want to do. Posting more than 1 post simultaneously.

 

[Stephanus]

I still don't follow exactly what you are trying to do, but ...
View attachment 103509 View attachment 103509

before you click on POST REPLY you have already clicked on UPLOAD to attach the file to your post, so by hovering the mouse over that filename link at the foot of the edit space you can see the attachment number your file has already been allocated.

Okay...

I have used that information to present the pic 3 ways above ⤴⤴⤴ before I click to POST this. I think the ATTACH tags are restricted to the post to which the file is actually attached, and for all other posts you must use IMG tags.

Yes but not 3 graphs in a post. 3 posts with graphs in them. And posting them simultaneously.

Okay..., IMG should do the trick. But the file must be in PF server before I type IMG.
Furthermore, click the browser refresh, will somehow delete our draft?
If you write 3 different post in 1 thread, then I think click the browser refresh button will clear your draft also.

And one more thing. How big is PF Forum server? I mean, this.
If we create a thread, and upload some image. So the image will be in the server, right.
Then, before we click [POST], we simply close the browser. Will the image still be there?
That's one thing that I should find out by myself. Anybody want to try that?

 

[NascentOxygen]

Okay...Yes but not 3 graphs in a post. 3 posts with graphs in them.

Is a graph not an image?

 

[NascentOxygen]

This is what I want to do. Posting more than 1 post simultaneously.

I think you mean "in quick succession", because "simultaneously" just can't happen when it's inescapable that each posting requires its individual mouseclick.

 

[Stephanus]

Is a graph not an image?

Nope, they are different class

I think you mean "in quick succession", because "simultaneously" just can't happen when it's inescapable that each posting requires its individual mouseclick.

Yep, quick succession. And PF denies quicker succession (less then 10 seconds).

And today I learn something, too...
If you click [CREATE THREAD], upload some image in them. Save the image links to a text file or clipboard. But don't delete them.
And then copy your link:
Then you can close your browser, open it again. Or you can even turn off the computer.

Now, you paste the link in a new thread or new post.
{IMG}https://www.physicsforums.com/attachments/calculus-jpg.103552/?temp_hash=6e11f591c20b6db233c08a96fd612316{/IMG}
The curly braces { is intentional as a replacement of square bracket [, so bulletin don't treat it as BBCode.
The image is still in the server.

I hope this come to admin attention for each graph in the server, admin should know who post them to prevent spamming.

[Add: This is the SOLUTION of my problem. Now I can create more than 1 post and post them in quick succession, without worrying about the image.]

 

[NascentOxygen]

Nope, they are different class
View attachment 103549

TGraphic.JPG, an image file! As far as forum software is concerned, an image is an image. Your graphs are captured as images, and are displayed as images.

 

[OmCheeto]

So far today, I have learned several things.

1. How to activate the "On this day" function on Facebook. It's under "Apps", on the left hand side.

2. I needed this, as I had earlier seen, that on this day in 2015, I learned that they did animal testing in my city, back in 1931, but had navigated away from the entry.

ST. JOHNS BRIDGE FIRST TESTED BY ELEPHANTS FOR STRENGTH OF SPAN
June 13, 1931
"dad said when they crossed it their were elephants in town from a circus & he said the elephants went across first to prove the suspension style bridge could do the job as I guess there were some doubts due to that design." ​

3. PETA was founded on March 22, 1980

Not sure if anyone still uses elephants to test new bridges anymore.
(google, google, google)
Still not sure, but it appears Portlanders were not the first to think of this method:

4. The elephants that tested the Brooklyn Bridge, May 17, 1884
ps. It was P.T. Barnum's idea, and his elephants.

Ok, that's enough for today.

 

[jim hardy]

We have several smaller violins which the kids used for learning, and four full sized ones, one of which is electric and one of which I have lent to my daughter. I also have a viola, and I sometimes play my wife's second best cello. Apart from those we also have a baby grand piano, a digital piano, a couple of classical guitars, flute, clarinet, some recorders, some ocarinas and odd percussion bits such as triangle and tambourine.

@Jonathan Scott
You seem knowledgeable

does this look like one of those 19th century reproduction labels?

My friend Harry is rebuilding several of his old violins
Good to see him so enthused - at 84 he's short on physical strength so gave up construction and has gone back to the hobby he had fifty years ago .

He's curious about this one.

 

[Jonathan Scott]

@Jonathan Scott
You seem knowledgeable

does this look like one of those 19th century reproduction labels?

View attachment 103610

My friend Harry is rebuilding several of his old violins
Good to see him so enthused - at 84 he's short on physical strength so gave up construction and has gone back to the hobby he had fifty years ago .

He's curious about this one.

Sorry, I know very little about the history of violins. You need to ask an expert, not an amateur player!

I see from some Googling that Petrus Schultz is a known maker of good violins but also a known subject of extensive copying, including carefully copied fake labels (looking very similar to the above) and sometimes even with fake certificates of authenticity!

My own main violin is a Wolff Brothers one from 1901 (and isn't as good as it was before being very unfortunately dropped on a concrete floor after a faulty case catch spontaneously sprang open, after which it was professionally and very expensively repaired with a lot of glue and little bits of wood to hold the splits back together). The rest are all modern.

 

[Stephanus]

...My own main violin is a Wolff Brothers one from 1901 (and isn't as good as it was before being very unfortunately dropped on a concrete floor after a faulty case catch spontaneously sprang open, after which it was professionally and very expensively repaired with a lot of glue and little bits of wood to hold the splits back together).

Oh, no, sorry to hear that. But it's been fixed. Good, then.

 

[OmCheeto]

On this day, two years ago, I learned what "Minions" were called.

Before that, I think I referred to them as "those tylenol pill looking cartoon creatures".

ps. It was @Tom Mattson who informed me of the fact.

 

[RonL]

The appearance of Bandersnatch here prompted me to finally look up the term. I have never read any Lewis Carroll stuff. So today I learned that, all linguistic cues to the contrary, a "bandersnatch" is not in fact a chastity belt. I now take my leave.

I suspect that this is Danger's last post, he was in very poor health as I understand, does anyone know if he is still alive ?
I kinda miss him

 

[Stephanus]

I suspect that this is Danger's last post, he was in very poor health as I understand, does anyone know if he is still alive ?
I kinda miss him

Truly sorry, if this is true. It's sad to have a friend in trouble. My prayer to Danger, I hope he/she will get well soon. Amen.

 

[Astronuc]

TIL How a Guy From a Montana Trailer Park Overturned 150 Years of Biology
Biology textbooks tell us that lichens are alliances between two organisms—a fungus and an alga. They are wrong. Lichens are formed from three organisms.

http://www.theatlantic.com/science/...er-park-upturned-150-years-of-biology/491702/
Lesson 1 - if the path is blocked, find an alternative path.

At 19, he got a job at a local forestry service. Within a few years, he had earned enough to leave home. His meager savings and non-existent grades meant that no American university would take him, so Spribille looked to Europe.

Thanks to his family background, he could speak German, and he had heard that many universities there charged no tuition fees. His missing qualifications were still a problem, but one that the University of Gottingen decided to overlook. “They said that under exceptional circumstances, they could enroll a few people every year without transcripts,” says Spribille. “That was the bottleneck of my life.”

Lesson 2 - we don't have all the answers; there's always more to learn

In the 150 years since Schwendener, biologists have tried in vain to grow lichens in laboratories. Whenever they artificially united the fungus and the alga, the two partners would never fully recreate their natural structures. It was as if something was missing—and Spribille might have discovered it.

He has shown that largest and most species-rich group of lichens are not alliances between two organisms, as every scientist since Schwendener has claimed. Instead, they’re alliances between three. All this time, a second type of fungus has been hiding in plain view.

“There’s been over 140 years of microscopy,” says Spribille. “The idea that there’s something so fundamental that people have been missing is stunning.”

Lesson 3 - don't give up. If necessary, find a mentor with an open mind.

The path to this discovery began in 2011, when Spribille, now armed with a doctorate, returned to Montana. He joined the lab of symbiosis specialist John McCutcheon, who convinced him to supplement his formidable natural history skills with some know-how in modern genetics.

Pretty amazing story.

 

[Astronuc]

I suspect that this is Danger's last post, he was in very poor health as I understand, does anyone know if he is still alive ?
I kinda miss him

Danger was last seen: Mar 12, 2015. He browsed the forum but did not post since 2014.

 

[Stephanus]

Today I learned that
The French revolusion caused https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure
How can NASA be so foolish?
Metric system

 

[Pepper Mint]

Danger was last seen: Mar 12, 2015. He browsed the forum but did not post since 2014.

Is Danger someone I know ?

 

[Astronuc]

Is Danger someone I know ?

No, he was before your time at PF.

 

[Astronuc]

Today I learned that
The French revolusion caused https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure
How can NASA be so foolish?
Metric system

It wasn't only NASA.
https://en.wikipedia.org/wiki/Gimli_Glider

As they communicated their intentions to controllers in Winnipeg and tried to restart the left engine, the cockpit warning system sounded again with the "all engines out" sound, a long "bong" that no one in the cockpit could recall having heard before and that was not covered in flight simulator training.[4] Flying with all engines out was something that was never expected to occur and had therefore never been covered in training.[6] Seconds later, with the right-side engine also stopped, the 767 lost all power, and most of the instrument panels in the cockpit went blank.

In line with their planned diversion to Winnipeg, the pilots were already descending through 35,000 feet (11,000 m)[3] when the second engine shut down. They immediately searched their emergency checklist for the section on flying the aircraft with both engines out, only to find that no such section existed.[4] Captain Pearson was an experienced glider pilot, so he was familiar with flying techniques almost never used in commercial flight. . . . .

What luck!

Expect the unexpected.

 

[Borg]

It wasn't only NASA.
https://en.wikipedia.org/wiki/Gimli_Glider

That is an amazing story. Even more amazing to me is that the plane was repaired and flown again for many years.

The aircraft was temporarily repaired at Gimli and flew out two days later to be fully repaired at a maintenance base in Winnipeg. Following the successful appeal against their suspensions, Pearson and Quintal were assigned as crew members aboard another Air Canada flight. As they boarded the aircraft, they realized that airplane was the same one involved in the Gimli incident. After almost 25 years of service, the aircraft flew its last revenue flight on January 1, 2008.

 

[mfb]

Today I learned that
The French revolusion caused https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure
How can NASA be so foolish?
Metric system

I would instead blame the only government not pushing to adapt the system 95% of the world population uses.

We would have way more accidents like this if every country would use their own units.