Today I Learned

[Stephanus]

When I was in high school many years ago, my chemistry teacher once posed this question on a test:

If a mole could dig a mole of holes in a day, how many holes could a mole of moles dig in a mole of days?

Wow, around 216 * 10⁶⁹?

 

[DrGreg]

 

[Pepper Mint]

Wow, around 216 * 10⁶⁹?

Are "Colorless green ideas sleep furiously"'s spread either by default or by design ? I guess it is the latter that is to hook up something systematically.

 

[256bits]

Recipes calling for molasses require caution. You may not be aware that "molasses" means different things in different countries.

Never knew the caution.
So that is something new I learned today, but not sure what it is.

A Molasse is a sedementary rock formation - stones in coffee, might be gritty.

Definitions doesn't show any other than the refining process towards sugar of beets and sugarcane, and some other plants.

 

[Pepper Mint]

Wow I think I learn what molasses is today.
By the way, stevia can make sugar too.

 

[1oldman2]

A mole of moles?

Excellent! I love xkcd.

 

[fresh_42]

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

 

[Jonathan Scott]

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

Isn't that just the wacky ones?

 

[1oldman2]

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

Good one !

 

[1oldman2]

Isn't that just the wacky ones?

TIL, that would be a lot of "whack a mole"

 

[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.[COLOR=#black]..[/COLOR]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.