The h Bar

0celouvskyopoulo7

2:00 PM

Maybe Penrose screwed up his axes

@Slereah How do I plot multiple things in Mathematica?

I want to plot the smoothing and the geodesics

Slereah

Commas

{plot 1, plot 2}

etc

0celouvskyopoulo7

For $\chi=0$ it's just the usual bump

Slereah

yeah

as expected

mathvc_

does anybody here like reading history?

0celouvskyopoulo7

@Slereah So...

It looks like Penrose's opening angle look right

I need to plot the unit circle

Wonder how I do that

::struggles::

@Slereah you gotta be impressed

It always stays on the unit circle

It's magic.

Slereah

2:20 PM

Well it is to be expected

since it's defined on $[-1,1]$

0celouvskyopoulo7

Now I'm going to try to put in the geodesics

rene

@ACuriousMind OK, no problem. I hoped you had a meta post to explain what it is for, but if this is all you have, then that is it.

user228700

@JohnR: What's for lunch?

0celouvskyopoulo7

well, and I broke mathematica

I can't get that plot anymore

@JohnRennie halp

Slereah

yeah mathematica is pretty finnicky

0celouvskyopoulo7

2:26 PM

I plot the exact same thing and it won't work now

Slereah

sometimes this might be due to defining over old variables

0celouvskyopoulo7

I'm restarting the program...

it froze

wonderful

Had to force quit

Dammit Penrose, you broke Mathematica

Slereah

he's not the first to do it

0celouvskyopoulo7

????????????

ContourPlot[
Evaluate@With[{r = Sqrt[x^2 + y^2], \[Theta] =
ArcTan[x, y]}, {r Cos[Pi \[Theta]/(Pi - 2 chi)] -
Exp[1/(r^2 Sin[Pi \[Theta]/(Pi - 2 chi)]^2 - 1)] == 0,
r^2 == 1}], {x, -2, 2}, {y, -2, 2
}]

Restarting my computer

that's the code if you want to try it

Slereah

I'd need to install it

So does the Penrose $\pi / (\pi - 2 \chi)$ work?

No need to replace it?

0celouvskyopoulo7

2:34 PM

I can't tell

I'm trying to plot the geodesics to see what happens

Ok I restarted

Well fuck, my installation of Mathematics is broken.

How does that even happen?

@JohnRennie ???

for fuck's sake can someone help

AccidentalFourierTransform

for chi = Pi/8

0celouvskyopoulo7

My mathematica refuses to do 1+1

What the hell is going on

AccidentalFourierTransform

hmm

0celouvskyopoulo7

Slereah

Is there "running" written at the top

yeah

So just wait

it's calculating

AccidentalFourierTransform

2:41 PM

restart the kernel perhaps?

0celouvskyopoulo7

I rebooted the computer already

Do you mean something else?

Slereah

or you could abort the current calculation, if you really want to know what 1+1 is

0celouvskyopoulo7

@Slereah The point is that it won't do anything

AccidentalFourierTransform

is your computer typically slow?

0celouvskyopoulo7

No

AccidentalFourierTransform

2:42 PM

or just when using MMA?

John Rennie

@Kaumudi.H This:

0celouvskyopoulo7

I just started using Mathematica an hour ago

John Rennie

AccidentalFourierTransform

uninstall it and install it again?

idk

0celouvskyopoulo7

what the fuck

@JohnRennie god dammit stop posting food and please help

4

John Rennie

2:43 PM

I'm eating lunch ...

AccidentalFourierTransform

or go ask in the MMA chatroom

0celouvskyopoulo7

where's that?

AccidentalFourierTransform

Wolfram Mathematica

Welcome! This is the main Mathematica chat room for mathematic...

6

user228700

@JohnRennie That looks incredibly unhealthy (:-) but what is it?

John Rennie

Turkey nuggets - two different kinds

With cheese ...

Bernardo Meurer

2:46 PM

@JohnRennie Why you do this

I'm hungry af

user228700

@JohnRennie Nice :-)

user228700

@BernardoMeurer I know, right? I mean, I ask him but I'm still sometimes jealous that he can eat whatever the heck he wants to.

Bernardo Meurer

@JohnRennie I'm going to go stay a couple weeks with you in the summer

Culinary school :P

John Rennie

They are indeed very unhealthy - loaded with fat and salt. But, oooh, they taste good :-)

0celouvskyopoulo7

I can't find the base user directory to perform a clean install.

I still have the download file

So I should uninstall completely?

John Rennie

2:50 PM

What is broken? I you start Mathematica does it run?

Bernardo Meurer

@0celouvskyopoulo7 Delete some RAM

AccidentalFourierTransform

nah, you should get a PC

Bernardo Meurer

And then download more ram

0celouvskyopoulo7

@JohnRennie Yes.

Bernardo Meurer

Or get Linux

0celouvskyopoulo7

2:50 PM

@AccidentalFourierTransform I have a PC.

I don't want to redownload it to there

Internet is shit rn

John Rennie

@0celouvskyopoulo7 so what doesn't work?

0celouvskyopoulo7

Anything after that.

AccidentalFourierTransform

I can download it for you and send it to you by email

John Rennie

@0celouvskyopoulo7 My version of MMA is v10 not v11, but when I start it I get a splash screen then a screen like this (hang on ...):

user228700

Sorry for interrupting but how many of u identify as Hufflepuffs?

0celouvskyopoulo7

2:52 PM

none

everyone here should be Slytherin or Ravenclaw

the other two houses are straight up trash

user228700

-_- I'm a proud Hufflepuff.

Bernardo Meurer

@Kaumudi.H Hufflepuffs don't exist

None of this BS exists

user228700

@0celouvskyopoulo7 They're not!

user228700

@BernardoMeurer Oh, it does for us.

0celouvskyopoulo7

you're like a proud deaf person then

John Rennie

2:53 PM

I'm a Ravenclaw

user228700

@0celouvskyopoulo7 deaf person?

0celouvskyopoulo7

we all know you're inferior, but for some reason you think you're actually better

@Kaumudi.H yeah

user228700

It's also JKR's favorite house so shove off with the hate

0celouvskyopoulo7

deaf culture is incredibly strange

I have zero respect for that woman, so yeah.

@JohnRennie Look, my issue is in the pictures above.

I'm going to uninstall mathematica now

Unless you have a smart solution

I keep getting a Kernel error, even after restarting the computer

user228700

...I don't want to get into an argument about this if you're not willing to be open-minded about this so never mind.

AccidentalFourierTransform

2:55 PM

dude

go as in the MMA chatroom

post that exact same picture

they'll know what to do

Secret

There are 5 tests, official or not, and I am ravenclaw

John Rennie

@0celouvskyopoulo7 what's wrong with this. It looks normal to me.

user228700

@0celouvskyopoulo7 For the record, we don't think we're better. But we're not inferior either. Cedric Diggory was the one who got chosen as the Triwizard Champion from all of the houses and he was a Hufflepuff.

0celouvskyopoulo7

@JohnRennie It's not evaluating...

It just gets stuck

It doesn't freeze, it just doesn't given an output

John Rennie

You mean if you select the "evaluate notebook" command nothing happens?

user228700

2:59 PM

@JohnRennie Makes sense. I've gotten sorted into all four houses before (over the course of several years in which I did change a lot) but I think I identify most with Hufflepuffs.

John Rennie

@Kaumudi.H Buuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuurp! Finished!

0celouvskyopoulo7

@JohnRennie Yes.

It worked an hour ago.

user228700

@JohnRennie :-)

Yashas

@JohnRennie Can you help with some issues with organic chemistry problem?

John Rennie

Ask in the MMA chat. It'll be something obscure that got changed.

Yashas

3:00 PM

It has to do with resonance effect

0celouvskyopoulo7

Should I just reinstall?

Yashas

The Chem SE people are insanely slow in replying

John Rennie

@Yashas I doubt it. I last did organic chem 35 years ago and I wasn't very good at it then. What do you want to know?

Yashas

7

A: Which of the following is the more stable carbocation?

Let's call the carbocations A and B because typing "the first carbocation" gets quite tiring (it has absolutely nothing to do with the fact that I'm lazy). So in both carbocations, the positively charged carbon is $\text{sp}$-hybridised (this allows the vacant orbital to be a $\text{p}$ orbital,...

0celouvskyopoulo7

Might as well, I have no files to save.

Yashas

3:01 PM

Why can't the bond b/w the carbocation and the phenyl ring rotate such that the empty p-orbital becomes parallel to the phenyl ring so that there can be delocalization of electrons through mesomeric effect?

John Rennie

@0celouvskyopoulo7 worth a try I suppose. But uninstall first to clear out any settings.

0celouvskyopoulo7

@JohnRennie I can't figure out how to uninstall

it seems to be just drag to the trash...

Yashas

Why can't electrons of the phenyl ring be delocalized through the p orbital which has already formed a pi bond with the terminal carbon of the aliphatic group?

The electrons can shift to the terminal carbon and the electrons of the phenyl ring can jump to the middle carbon of the aliphatic group :/

0celouvskyopoulo7

@AccidentalFourierTransform Ok, can you please help in the meantime?

Yashas

it could temporarily create double +ve charge on the carbon if the electron shifts were to be shown by drawing the canonical structures but the shifts can happen simultaneously

0celouvskyopoulo7

3:05 PM

Can you make that into a manipulate, for $\chi\in[0,\pi/4]$?

Yashas

I am not sure if such analysis is allowed because individual resonance structures don't exist

0celouvskyopoulo7

And then plot $y=\tan(\chi)x$, and $y=-\tan(\chi)x$ as well?

Secret

The point is that no matter how the p orbitals are oriented, you always have one p orbital that is parallel (and hence electrons can be delocalised through it) and one p orbital that is orthogonal, and is vacant.

Even if you rotate them, then the pi bond breaks, form again, and the previously vacant orbital become filled and the filled orbital become vacant

Yashas

@Secret I was wondering if the non-empty p orbital could be used. If a pi bond had to be formed b/w the phenyl ring and the middle carbon, the pi electrons would have to shift to the terminal carbon as the pi electrons from the ring jump in.

While drawing the resonance structures, you will notice that during that transition (which does not happen in reality) from one structure to another would temporarily increase the charge on the middle carbon.

0celouvskyopoulo7

It works!

Yashas

3:12 PM

Anyway, why can't the aliphatic group be rotated such that the empty p-orbital is parallel to the ring p-orbitals and the other non-hybridized orthogonal p-orbital could form the bond with the terminal carbon?

Slereah

@0celouvskyopoulo7 pix

0celouvskyopoulo7

Secret

I suspect the conjugation of the phenyl with the alkene (and you mentioned how drawing resonance contributors you can have the double bond moving between the 3 carbons in the cation) means the real scenario is that the electron density will be delocalised throughout the phenyl and the alkene,
which means what is drawn as a single bond in between the phenyl and the middle carbon actually has partial double bond character. This means the rotation about that bond will be hindered thus you cannot freely rotate that to align the p orbitals in the way you described

Slereah

@0celouvskyopoulo7 checks out

John Rennie

@Kaumudi.H YHM

0celouvskyopoulo7

3:14 PM

I...broke it again

what the hell?

I broke mathematica again

Yashas

@Secret Partial double bond character is harmless, right? I would fix the entire group of atoms to the vertical plane. So I won't be rotating in reality. I am trying to set the initial conditions.

0celouvskyopoulo7

I give up

hahahaha

What a trash program

Slereah

Yeah it's pretty buggy

user228700

@JohnRennie Now YHM :-)

0celouvskyopoulo7

My computer froze

I hate my life

Can I kill myself

Secret

3:18 PM

Something like this?

Yashas

@Secret :O yes

Secret

Then I guess orthocresol and ron have explained it. The delcalisation stablisation of the pi system outweight the combined stablility that can be obtained bby separately forming 2 pi systems

Yashas

None of us in the JEE prep room read the whole answer :D

Secret

Resonance stablisation and aromaticity often provide large overall contribution to the stability of the molecule, thus breaking those is in general difficult

Even for the complexes in my research, aromaticity alone can reverse isomer preferences

There are two very rough rule of thumb for organic molecules:

1. Nature loves rings, if there is a possibility to form 5-6 member rings, then it is very easy to form (e.g. lactams, lactones)

2. Conjugated systems tend to be more stablised when the electrons are most delocalised

user228700

@JohnR: I've replied. I dunno if u stop checking in the middle or what, which is why I'm pinging you here as well, sorry...

John Rennie

3:32 PM

@Kaumudi.H the mail seems to take a little while to work its way in and out of India.

user228700

Strange :-/

Jaime Gallego

Huh, BibLaTeX is giving me a hard time with references

John Rennie

There's probably a lazy mail router somewhere along the way.

0celouvskyopoulo7

0

Q: Mathematica stuck in "running" for every calculation I attempt, kernel error

I downloaded Mathematica this morning to do an implicit polar plot. I attempt to run the code Manipulate[ ContourPlot[ Evaluate@With[{r = Sqrt[x^2 + y^2], \[Theta] = ArcTan[x, y]}, {r Cos[Pi \[Theta]/(Pi - 2 chi)] - Exp[1/(r^2 Sin[Pi \[Theta]/(Pi - 2 chi)]^2- 1)] == 0, r^2 == 1}], {x, -2, 2}...

please upvote

user228700

Would u prefer it if, in the future, we used gchat instead?

user228700

3:33 PM

I suspect I have to send u an invitation or whatever...

John Rennie

@Kaumudi.H no, mail is good. I prefer to work on my PC rather than the phone.

user228700

Huh? Ur gmail usually has a side-bar with gchat on it on PC...

John Rennie

On the PC? I'll have a look ...

user228700

@JohnRennie Yeah, on the PC!

user228700

3:36 PM

^ on the left.

Sid

Oh, man, do you guys really like this annoying feed?

John Rennie

Hmm, I get:

Jaime Gallego

This thing ain't working

user228700

Right right, that's the one. Hang on...

Jaime Gallego

John Rennie

3:38 PM

@Sid Chill, the feed annoys us all but there is no way to turn it off.

user228700

I've sent u an invitation.

Bernardo Meurer

@JaimeGallego What software is that?

Balarka Sen

i only discovered a few days ago that gchat was the older name for hangouts

Bernardo Meurer

@BalarkaSen You're a summer child

Jaime Gallego

@BernardoMeurer That's TeXstudio for Windows

Bernardo Meurer

3:39 PM

@JaimeGallego WINDOWS?

WHAT IS HAPPENING TO YOU

Jaime Gallego

I am away from my computer

Balarka Sen

@Bernard "Winter kept us warm"

Bernardo Meurer

No excuses

I carry a live USB of GNU/Linux everywhere

So I can avoid proprietary malware

on the go

Jaime Gallego

Command line won't do though, I need PDF previews

Bernardo Meurer

framebuffer terminal

Or get a Mint live USB

or Antergos

Jaime Gallego

3:44 PM

Maybe

John Rennie

@JaimeGallego: don't listen to the fanatics. Windows is the one true OS. Of course there might be the occasional cryptlocker infection ... :-)

Jaime Gallego

@Bernardo Throw holy water at this man

rob

@JohnRennie "Windows is the one true OS" ... which one?

John Rennie

@rob I finally, and somewhat reluctantly, switched to Windows 10 and I find I really like it.

Jaime Gallego

My cat is being a mean bitch

Bernardo Meurer

3:46 PM

@JohnRennie The fact that we're friends is proof I am a man of peace

John Rennie

@JaimeGallego isn't that a contradiction in terms :-)

Balarka Sen

how can a cat be a dog

user228700

@JohnR: I'm usually signed out of Hangouts so you may still have to alert me the next time there is a need to chat.

John Rennie

@Kaumudi.H Noted!

Balarka Sen

a baboon on the other hand...

John Rennie

3:48 PM

I didn't know Hangouts still existed. Google seem to change their chat app every five minutes. Isn't it Allo these days?

Bernardo Meurer

@JohnRennie Dunno what Allo is, I do use Hangouts daily though

user228700

@JohnRennie Allo is similar but has some extra features, I think.

Bernardo Meurer

Mostly because DS only uses that

user228700

Hangouts doesn't update itself that often...

John Rennie

I should ask my niece - she knows these things.

Jaime Gallego

3:50 PM

user228700

Oh snap!

John Rennie

That's a worried looking budgie :-)

That cat has intents

That cat has a plan

splice them

3:52 PM

@JohnRennie What's your favorite tea?

Jaime Gallego

That's my sister's cat, she is volunteering for an animal protection association

John Rennie

@BernardoMeurer I'm not a tea connoisseur. I generally only drink coffee, but then I'm not a coffee connoisseur eithr - I just drink instant.

Balarka Sen

I'm a big fan of water.

John Rennie

@JaimeGallego The cat is volunteering for an animal protection association???

In charge of birds? :-)

Jaime Gallego

Absolutely

Bernardo Meurer

3:54 PM

@JaimeGallego How old is your sister

user228700

@JohnRennie You make dad jokes all the time even though you're not a dad yourself -_- You're an uncle though so I guess that counts as well.

Jaime Gallego

What kind of question is that

John Rennie

@BernardoMeurer Shark attack!!

Bernardo Meurer

A suspicious question

Jaime Gallego

She's the same age as Yvonne

John Rennie

3:56 PM

93?

Jaime Gallego

Yes

0celouvskyopoulo7

Not a single upvote

Seriously?

Avantgarde

Water is the best, yes. It trumps all

Balarka Sen

careful with the words

Jaime Gallego

^My sister

Bernardo Meurer

3:59 PM

@JaimeGallego I feel like you're hiding something

Don't make me stalk you

Please

Wolfram Mathematica

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