Today I Learned

[OmCheeto]

James Prescott Joule, born 24 December 1818, along with being a physicist, was also, a brewer.

hmmm... that might explain some things...

 

[collinsmark]

Today I learned a lot of important things pertaining to vectors. I also learned that the symbol representing the vector differential operator is called "nabla".

Yup. More commonly called the "del" operator, it is represented using the nabla symbol. (It looks like an upside down, capital "delta" symbol.)

It is represented in $\LaTeX$ using

\nabla

so you can write cool things like
$$\nabla f = \frac{\partial f}{\partial x} \hat x + \frac{\partial f}{\partial y} \hat y + \frac{\partial f}{\partial z} \hat z$$

It's also used in different, yet related ways to represent the divergence $\left( \nabla \cdot \vec v \right)$, curl $\left( \nabla \times \vec v \right)$ and Laplacian $\left( \nabla \cdot \nabla = \nabla^2 \right)$.

 

[collinsmark]

Today I learned, or more accurately realized, that "cosmic" and "comic" are only one letter away.

 

[TheDemx27]

It's also used in different, yet related ways to represent the divergence $\left( \nabla \cdot \vec v \right)$, curl $\left( \nabla \times \vec v \right)$ and Laplacian $\left( \nabla \cdot \nabla = \nabla^2 \right)$.

Today I learned what I want to learn next.

 

[PeroK]

Today I learned that sheep can dig snow holes! I was out walking in Scotland when suddenly a sheep fought its way out of a bank of snow about 20m away. Then three more followed it. As far as I could tell they had completely buried themselves. Probably to stay warm. Extraordinary!

 

[alan2]

Today I learned that the University of Chicago police will approach you in the bathroom and ask for identification after you've been in a car for 4 hours and really need to use the facilities. As a bonus, I learned why my daughter will be attending graduate school in Westwood.

 

[Medicol]

Today I learned that if I randomly pick 100 men in the US, the probability that I can get 3 - 5 of them as gay or bisexual is about 95%-99%. Is this a normal distribution ?
I'm glad to see people prefer living the life they like to leading the one unwillingly! :)

 

[epenguin]

Today I learned that Laplace's http://Méchanique Céleste (1799 - 1825) was used by Sir Isaac Newton.

I learned this from p.240 of "Differential Equations for Dummies" by Steven Holzner, which surely was also used by Sir Isaac Newton.

 

[alan2]

Today I learned that crows winter with their parents then help to build the nest and raise their siblings in the spring.

 

[lisab]

Yesterday I learned I was probably coming down with flu, despite my flu shot.

Today I learned I'm probably not coming down with the flu.

 

[JorisL]

Yesterday I learned I was probably coming down with flu, despite my flu shot.

Today I learned I'm probably not coming down with the flu.

Had a similar experience minus the flu shot, a semi-good night of sleep sure helps.

 

[OmCheeto]

Just found out that photons have a "shape".

This really throws a monkey wrench into my bestest, and unfortunately, the last of my crackpot theories.

I guess, it's time, to wash the dishes.

 

[TheDemx27]

Today I learned that euler's identity is abbreviated $cis(x)$. Now I can make some offensive math joke with ties to trans/cis people.

 

[zoobyshoe]

Today I learned the first microwave oven was made in 1947.

 

[metapuff]

Today I learned that the quotient group Z / (i - 2) is isomorphic to Z / 5Z. Pretty neat, eh?

 

[Greg Bernhardt]

This is the molecule for propane. I got it wrong at trivia tonight :(

 

[dlgoff]

I learned some frogs like tropical islands

 

[Vagn]

I learned that iron atoms flouresce under illumination with copper K-$\alpha$ radiation.

 

[Borek]

This is the molecule for propane. I got it wrong at trivia tonight :(

I hope you don't expect me to like that post.

 

[Greg Bernhardt]

I hope you don't expect me to like that post.

I was wishing I could "phone a friend" :D

 

[iDimension]

Today I learned that I really should start listening to my parents as they genuinely do know best.

 

[zoobyshoe]

Today I learned there's a Ford F series truck sold every 43 seconds.

 

[nuuskur]

Today I learned that I really should start listening to my parents as they genuinely do know best.

once you realize this, you no longer need to heed their advice. It's weird, I know.

 

[Borek]

Today I learned that I really should start listening to my parents as they genuinely do know best.

This lesson is a classical part of a process called "maturing".

 

[Pythagorean]

This lesson is a classical part of a process called "maturing".

Another version of maturing is that you realize your parents are uneducated bigots and that you don't need their blessing.

 

[TheDemx27]

Another version of maturing is that you realize your parents are uneducated bigots and that you don't need their blessing.

Today I learned that I really should start listening to my parents as they genuinely do know best.

It's most likely going to be somewhere in between the two extremes: blinding accepting everything they say, and completely rejecting everything that comes out of their mouths. I bet where you fall on the spectrum between these two situations depend on: How smart your parents are and how you were raised when you were young.

 

[Borek]

How smart your parents are

and how smart you are.

 

[TheDemx27]

and how smart you are

The way I see it, the two possible things you can base your intelligence on is heredity and the environment you were raised in at an early age; both are provided by your parents. Of course after you come of some age you start acting for yourself, but the largest influence by far comes from the very early years.

 

[Pythagorean]

The way I see it, the two possible things you can base your intelligence on is heredity and the environment you were raised in at an early age; both are provided by your parents. Of course after you come of some age you start acting for yourself, but the largest influence by far comes from the very early years.

There's actually something called a 50-0-50 rule in psychology that pertains to personality and intelligence. It states that intelligence and personality are 50% genetics, 0% correlated with raising, and 50% with peers. They found this by comparing monozygotic twins raised by their biological parents to twins raised by adopted parents. And, obviously, its's a rough approximation. I believe some studies find a higher balance towards genetics with intelligence (like 64-0-35 or something).

 

[zoobyshoe]

Today I learned there is something called a 50-0-50 rule in psychology that pertains to personality and intelligence.