The h Bar

enumaris

00:29

oh dear

offers for FTE is much more complicated than offer at Contractor loool

@ACuriousMind apparently I transferred my cold to you through the internet

parvin

01:20

hi.

I know that in lever and fulcrum, in a special condition we need to use less Force than usual.
But what I want to know is that does using less force mean spending less energy?

@JakeRose I want to know if we use lever for a robot it leads to using less ENERGY, meaning, less electrical power

danielunderwood

02:10

@enumaris I warned you about those internet-transmitted sicknesses!

enumaris

02:58

@danielunderwood lol, u been busy at work or something? Don't see you around much anymore

dmckee

@JohnRennie "since the genre didn't exist when I was a young adult." I believe they were called "mammoth operas"...

Though, I admit that things had moved on to hot, new bronze-age technologies in my day.

ZeroTheHero

03:25

@DanielSank right... simple enough: there a MathJax plugin for GitHub that works so smoothly i managed to install it and make it work at the first trial.

Anonymous

03:42

@parvin You asked the question on the main site just a couple of minutes ago (so I removed it). Just be a little patient! :) See my previous rant on this. And now that makes me hope that I don't come across as an old grumpy mod these days... :P

DanielSank

@ZeroTheHero Very good.

Anonymous

73

A: Is anti-matter matter going backwards in time?

To the best of my knowledge, most physicists don't believe that antimatter is actually matter moving backwards in time. It's not even entirely clear what would it really mean to move backwards in time, from the popular viewpoint. If I'm remembering correctly, this idea all comes from a story tha...

Leaky Nun

04:38

6 hours ago, by Jake Rose

@LeakyNun https://physics.stackexchange.com/questions/391/is-anti-matter-matter-going-back‌wards-in-time

@Blue you're sniped by 6 hours :P

Anonymous

04:57

@LeakyNun Uh oh. :)

John Rennie

05:25

@dmckee I meant the young adult genre didn't exist in my time :-)

Rumplestillskin

06:35

Hi there all! Is anyone familiar with Doppler shift for navigation? I just read about it and I'm not entirely sure I understand!!

John Rennie

Doppler shift for navigation?

Rumplestillskin

As is using doppler shift from a signal from an earth orbiting satellite to determine your posiiton

position on Earth

John Rennie

Ah. No, sorry, it isn't something I've ever studied.

It should be well documented through since it's been used for 50 years :-)

Rumplestillskin

@JohnRennie no problem! I actually understand what is going on in principle. I am just really confused by one particular point which I am misunderstanding or reading too much in to!

Leaky Nun

07:26

what do I see if I look outside from inside a black hole?

user2723984

just for fun I'm trying to simulate a planet orbiting the Sun in MATLAB using simply the differential equations for a classical particle in a central potential and solving them with ode45

but my planet's orbit just decays, it gets smaller and smaller and it crashes into the Sun

is it something I can solve or it's just a too naif numerical approach?

oh for some reason ode23 works much better

Leaky Nun

07:43

?

user301074

@LeakyNun You're stationary in the interior of the black hole or in free-fall?

Leaky Nun

idk

user301074

Probably you will see the ingoing Light-rays from the outside of the black-hole

Leaky Nun

but infinite time would pass outside before even a nanosecond passes inside right

then what would I see one second later

John Rennie

07:59

@user2723984 that's a common problem if you use a simple integrator. It's because a simple integrator does not conserve energy.

user301074

I don't know your math/physics Level, but here's a penrose diagram of the situation i.sstatic.net/XUokp.gif

John Rennie

@user2723984 You'd have to use a ridiculously small step size to get a reliable orbit. The way round this is to use a symplectic integrator instead:

Symplectic integrator

In mathematics, a symplectic integrator (SI) is a numerical integration scheme for Hamiltonian systems. Symplectic integrators form the subclass of geometric integrators which, by definition, are canonical transformations. They are widely used in nonlinear dynamics, molecular dynamics, discrete element methods, accelerator physics, plasma physics, quantum physics, and celestial mechanics. == Introduction == Symplectic integrators are designed for the numerical solution of Hamilton's equations, which read p ˙ ...

user301074

The light-rays are freezed (how you stated) just for an infalling observer from the ouside of the black-hole

John Rennie

@LeakyNun You can see the universe outside the event horizon but it looks a bit odd. Actually calculating what you see is rather complicated.

I think there are web sites that show calculated images of what the view from inside the black hole looks like.

user301074

outside*

John Rennie

08:03

@LeakyNun have a read through this:

11

Q: What would be the view like from inside a black hole looking towards the event horizon?

Ignoring the fact that we would be torn apart by gravitational gradient and assuming we get some time to make some observations before hitting singularity, what would we see looking towards the event horizon or in any other direction away from the singularity?

user2723984

@JohnRennie we used symplectic integrators in a course in numerical physics because of the same problem, though the problem was much less noticeable, here it's noticeable already in 2 orbits

I remember something about the Verlet algorithm

well maybe I'll review it, can't hurt, thanks

Slereah

morning

John Rennie

@user2723984 I found exactly the same thing when I wrote my first orbit calculator as an enthusiastic but underinformed young student :-)

user2723984

I thought about that, but google didn't tell me that straight away so I thought that maybe there was another problem, silently hoping not to have to look at symplectic integrators again

the word symplectic scares me

John Rennie

@user2723984 :-) Verlet integrators are pretty straightforward.

1

Q: MATLAB: Verlet Algorithm -

Below is my code for the Verlet function, to be called from my main script. % verlet.m % uses the verlet step algorithm to integrate the simple harmonic % oscillator. % stepsize h, for a second-order ODE function vout = verlet(vinverletx,h,params) % vin is the particle vector (xn,yn) x0 = vin...

algorithm matlab verlet-integration

user2723984

08:16

I'm trying to simulate Mercury's orbit both with Newton's law and General Relativity in the weak field approximation

tired of calculating Christoffel symbols by hand

user301074

Nice

PiKindOfGuy

Hi

user301074

Heyo

Leaky Nun

08:43

> But the failure of binocular vision is merely a limitation of beings who have evolved in flat spacetime. Trinocular vision would work fine. The three-eyed ape at right, drawn by my daughter Wildrose, would have no problem leaping from tree to tree in a highly curved spacetime.

w0t

user2723984

08:54

this is useful, it's making me understand that I understood nothing of general relativity. The geodesic equation is $\ddot{\gamma}^i + \Gamma^{i}_{jk}\dot{\gamma}^j\dot{\gamma}^k=0$, all the derivatives are wrt proper time, is it correct that then $\gamma^0$ represents the time for an observer that sees the planet having some nonzero initial condition $\gamma^i, \dot{\gamma}^i$ at proper time 0?

Slereah

$\gamma^0(\tau)$ represents the time in the coordinate system chosen at the proper time $\tau$

user2723984

what do you mean "coordinate system chosen"?

Slereah

the coordinate system you're working in

user2723984

I don't think I understand, suppose I want to find the trajectory of a planet, and I have some initial position and velocity of the planet with respect to the Sun. Then I'm an observer stationary with respect to the Sun and $\gamma^0(\tau)$ is the time coordinate for me

if I wanted to plot position as a function of time for me I would plot $(\gamma^0(\tau), \gamma^i(\tau))$

is this right?

user301074

You're working with weak-field limit, then time dilation is negligible i.e. $\frac{d(\gamma^0)}{d(\tau)}$ approach $1$

user2723984

09:03

yes, but I was wondering what initial condition should I impose to $\gamma^0$, and I realized I don't really understand what it represents

John Rennie

$\gamma$ is a funny symbol to use for the position in spacetime. Why not just $\mathbf x$?

user301074

^

user2723984

uhm yes we used $\gamma$ in the lectures to note curves, we usually use this symbol and really the trajectory is $x(\gamma(\tau))$ for some chart $x$ but it's just clumsy newbie notation

user301074

$\gamma^0$ represents the time coordinate, if you want write position as a function of $\gamma^0$ set $\gamma^i = (\frac{d(\gamma^i)}{d(\gamma^0)}) d(\gamma^0)$

John Rennie

@user2723984 in GR we don't normally think of things evolving in time because time is just a choice of some coordinate system. Typically a geodesic is a curve $\mathbf x(\tau)$ where $\tau$ parametrises the curve. $\tau$ may or may not have a physical meaning.

For a timelike curve $\tau$ is normally taken to be the proper time of the observer following that trajectory, but for a null geodesic $\tau$ has no physical meaning ( guess this also applies to spaelike curves).

So first you choose your coordinates, which in this case I guess will be the Schwarzschild coordinates $(t, r, \theta, \phi)$ then the geodesic equations tell you how the values of $t$, $r$, $\theta$ and $\phi$ evolve with $\tau$.

user2723984

09:17

@Zober $\gamma^i = \frac{d\gamma^i}{d\gamma^0}d\gamma^0$ ? What is $d\gamma^0$?

John Rennie

So $\mathbf x(0)$ would just be the position you start from.

user2723984

@JohnRennie I have no problem setting the spatial parts of $\mathbf{x}(0)$ and $\dot{\mathbf{x}}(0)$, but I'm confused about the time part. In the weak field approximation I would guess it's $x^0(0)=0, \dot{x}^0(0)=1$

John Rennie

$x^0$ is just the time shown on a clock held by the observer watching from infinity. Just set $x^0(0)$ to zero i.e. reset your stopwatch at the moment you start following the orbit.

user301074

I mean't (there's a $d$ in the front, sry for the error): $d(\gamma^i) = (\frac{d(\gamma^i)}{d(\gamma^0)}) d(\gamma^0)$ and $d(\gamma^0)$ represents the infinitesimal change in $\gamma^0$, how i said before, $\gamma^0$ represents the time coordinate, then $d(\gamma^0)$ is the infinitesimal change in time

user2723984

Ah, MATLAB just shows me a bunch of NaN if I set $x^0(0)=0$ lol

@Zober so I can find the position of the body at the time $t$ from my frame as $x^i(t)=\int_0^t d\tau \frac{d\gamma^i}{d\gamma^0}\gamma^0$ ?

but that seems to just give me $\gamma^i$ back

user301074

09:41

ye, just write $x^i(t)=\int_0^t \frac{dx^i}{d(\tau)} d\tau$ and use the geodesic equation to find $x^i$ that you obtained from $\ddot{x}^i + \Gamma^{i}_{jk}\dot{x}^j\dot{x}^k=0$

user301074

i have to confess that im getting very confuse with that gamma's and x's notations

user2723984

I must be missing something huge in what you're saying, $x^i(t)=\int_0^t d\tau \frac{dx^i}{d\tau}$ is just like the fundamental theorem of calculus

I'm more confused than you

let's drop the gammas altogether: I set up some variables $x^i, i=0,1,2,3$ and the Christoffel symbols for the weak field, I made MATLAB solve the equations and I set $x^i(0), \dot{x}^i(0), i=1,2,3$ at some initial positions and velocities, and $x^0(0)=0, \dot{x}^0(0)=1$

now, MATLAB spits out some NaN unless I put an $x^0(0)\neq 0$, like $0.1$, but then I get nonsensical results, most importantly that $x^0(\tau)$ is pretty much constant

I just want to know if the problem is in the code or if I completely misunderstood the physics, I think $x^0(\tau)$ should be approximately equal to $\tau$

John Rennie

@user2723984 Yes $x^0(\tau) \approx \tau$ in the weak field.

user2723984

ok, then I must've screwed up the code

I'll stop monopolizing the chat now, sorry

thank you for the help :)

John Rennie

$\dot{x}^0(0) = 1$ only if your object starts out stationary (in your chosen coordinates).

In general $\dot{x}^0(0) = \gamma$, where I'm using the conventional notation that $\gamma$ is the Lorentz factor.

(in the weak field approximation $\dot{x}^0(\tau) \approx 1$ for any $\tau$)

@user2723984 this is exactly the sort of thing the chat is used for, so no need to stop!

user2723984

09:55

@JohnRennie yes I just realized it, I tried to change it to gamma but it's so close to 1 it really shouldn't matter

ok :) just tell me if it becomes too much

John Rennie

If you're talking about physics there is no too much.

user2723984

I think the worst problem is that $x^(0)=0$ produces NaN, it really should not

John Rennie

Indeed it should not ...

user2723984

well I'm talking about things that are probably obvious and not really interesting to many more advanced users, I just worry about that :)

Slereah

NaN is generally a bad sign

user2723984

10:03

Ah! I have no words

OdeToVectoerField was messing with the order of the variables

I inputed x0,x,y,z and it spit out x,x0,y,z for some reason

Slereah

heh

user2723984

it still doesn't work, but now in less horrible ways

I was initializing $x^1(0)=0$, directly into the Sun

no wonder it gave NaNs

Slereah

TO THE SUN!

user301074

What spatial coordinate-system are you using?

user2723984

Cartesian, I'm using the metric $$ \left( 1+\frac{2\phi}{c^2}\right)dt^2 -\left( 1-\frac{2\phi}{c^2}\right)(dx^2+dy^2+dz^2)$$

John Rennie

10:08

@user2723984 wouldn't polar coordinates be easier?

user2723984

where $\phi=-\frac{GM}{\sqrt{x^2+y^2+z^2}}$

John Rennie

Also I'm 99% certain the sign of the term in $\phi$ should be the same in both brackets.

user2723984

@JohnRennie no I don't think so, the minus arises then approximating the $(1-\frac{2M}{r})^{-1}$ in the Schwartzschild metric

John Rennie

Ah, oops, yes you've expanded the ()^-1

user2723984

and would polar coordinates change much? I would just have the same thing with $dr^2$ instead of $dx^2+dy^2+dz^2$ and an angular part

John Rennie

10:12

Polar coordinates would feel more intuitive to me. But I guess it makes no difference to the calculation.

user2723984

yes, they are more intuitive, thing is, I already calculated the Christoffel symbols for this one haha

well I verified they were right comparing with a solution of an exercise sheet so I'm fairly sure of them

John Rennie

Ah yes, the joys of calculating Christoffel symbols.

Slereah

eh it's mostly alright

even by hand, if symmetric enough

user2723984

I'm glad the universe is torsion free

Slereah

Or is it

though even with torsion, GR is mostly simple

Since almost every matter source is torsion free

unless you're doing spinor fields you're fine

user2723984

10:19

I'm struggling enough already with the vanilla torsion free weak field metric for the moment

and spinor fields in flat spacetime

Slereah

the horrible part comes if the connection isn't metric

dun dun duuun

John Rennie

If we demand that the universe be torsion free is that an extortionate demand?

Slereah

womp womp

although

Torsion doesn't actually affect geodesics

so it's not extremely problematic

for that task, anyway

since ${\Gamma^a}_{bc} u^b u^c$ only requires the symmetric parts

user2723984

halleluja

Slereah

that is a circle

There are better algorithms to do circles

John Rennie

10:28

That looks a bit eccentric to me :-)

user2723984

natural units screwed me, $x^0(0)=c\gamma$

well it's an ellipse

why should it be a circle?

John Rennie

Shouldn't it be precessing?

user2723984

it's only one orbit

now I'll try multiple orbits

John Rennie

You'll need to make it pretty eccentric to see precession on timescales of a few orbits

user2723984

and it iiiiis....

not precessing

trying more eccentric

ok I'm not sure if it's precessing or if it's just an error of the numerical algorithm, which is not symplectic. I'll try to use Verlet

John Rennie

10:31

Bear in mind that the precession of Mercury is 44 arcseconds per century, which is techically known as bugger all.

Slereah

just make the sun bigger

or make the orbit closer

user2723984

this is not precessing, this is a numerical problem

Slereah

indeed it isn't

user301074

thonk

user2723984

well this looks more like it, turns out matlab has a symplectic integrator ready to go

still crashes into the sun though

John Rennie

10:45

@user2723984 that's OK, we've got plenty more astronauts

2

user2723984

nope, still numerical, it precesses with Newton too

Slereah

It might be some rounding errors accumulating

user2723984

11:15

yeah, I think this task is beyond me. I can use a symplectic integrator for Newton but I have no idea where to start with Einstein

oh well, I tried

user129412

12:28

Does anyone here (from the top of their head) remember how the size of a superconducting gap depends on perpendicular magnetic field, for a type 1 superconductor? Away from the critical field lets say.

Slereah

'fraid not

danielunderwood

12:52

@enumaris yeah I started a new job and I'm still getting used to the schedule. It's like they want me to actually show up and work!

Slereah

13:16

Damn the man!

danielunderwood

Yeah work would be a lot easier if I didn't have to do stuff

and didn't have to go places

Slereah

that's why you should work for the government

danielunderwood

13:33

Suddenly I like doing things and going places

Slereah

14:36

"This art of epsilon management, once mastered, is not terribly difficult – it basically requires one to mentally keep track of which quantities are “small”, “very small”, “very very small”, and so forth"

"In addition to the usual analytical interpretations, we can also interpret the concept of a limit as a voting system, in which the natural numbers n are the voters, which are each voting for a real number $x_n$, and the limit $\lim x_n$ is the elected “winner” emerging from all of these votes."

Don't blame me, I voted for Kodo

"In the voting theory interpretation given earlier, this means that we abandon the pretense that the election is going to be “fair”; some voters (or groups of voters) are going to be treated differently than others, due to some arbitrary choices made in designing the voting system. (This is the first hint that the axiom of choice will be involved.) "

Nooooooo

danielunderwood

"voting theory"

Mathematicians want to do everything, huh?

Anonymous

15:09

@danielunderwood They're a nosy bunch. ;)

Anonymous

@danielunderwood Oh wow. Data science job? Or software?

Physics Meta

15:23

-2

Q: Don't agree with the votes to close the question "Why is the MKS unit of time the same as the CGS unit?"

I don't agree with the vote to close the question "Why is the MKS unit of time the same as the CGS unit?". The question is, when Giorgi proposed to replace the CGS system, could he alternatively have chosen to replace the unit of time instead of the unit of mass. The answer is "no", because Giorg...

discussion

VARUN.N RAO

15:36

Guys I need some quick help in delayed quantum choice eraser, is there anyone who knows something about it?

Anonymous

16:14

@VARUN.NRAO Don't ask about asking, just ask.

danielunderwood

16:30

@Blue well it's partially data engineering, but hopefully I'll get a chance to do data sciencey things at some point

Anonymous

@danielunderwood Nice!

enumaris

@danielunderwood data engineering...mmmhm

enumaris

16:55

welp, gave my current comp a chance to match the offer...seems like it's unlikely...D:

John Rennie

17:05

@enumaris you've had a job offer?

enumaris

indeed

John Rennie

A job you want?

enumaris

Yeah, everything's pretty good about that job except the commute

John Rennie

Cool :-)

enumaris

But I'm not unhappy at my current job or anything, it's just I am on a 1 year contract so it's time for negotiations. It seems like my current company is unlikely to match the offer tho.

I'm pretty impressed w/ myself tho, Data Scientist to Senior Data Scientist in 10 months :D

John Rennie

17:08

With a permanent job I've advise against asking your current employer to match an offer, but when you're on a temporary contract that doesn't apply. Is the new job also contract, or permanent?

ACuriousMind

17:19

@enumaris Goddamn viruses. The internet was a bad idea :P

enumaris

17:50

@JohnRennie new job is permanent

@ACuriousMind lol

John Rennie

@enumaris that sounds perfect then. Congratulations :-)

enumaris

@JohnRennie thanks :D

why would you advise against asking a current employer to match an offer tho?

bad relationship?

John Rennie

Yes, it feels a bit like blackmail: pay me more or I'll quit

Even if it worked it would sour the relationship for the future

If an employer isn't paying a competitive salary then either they can't or they're taking the piss. Either way the best option is to find a different employer.

enumaris

I see

I'll keep that in mind :D but yeah my current contract is expiring so we were gonna go into negotiations anyways so, I think it's pretty fair in this case

John Rennie

Yes, I agree. If you were only on a one year contract you'd be renegotiating anyway so this would be an ideal time to tell them they aren't paying a competitive salary. But bear in mind they could (grudgingly) agree to match the offer and then refuse to renew in 12 mnths time.

enumaris

17:58

yeah, true

I did ask about how long their contracts are termed for and my boss basically said it's "industry standard" to be "at will" basically

ACuriousMind

@JohnRennie Well, it is blackmail. The only question is whether your bargaining chip is good enough that it will work :P

@enumaris "at will" as in "fired at will"?

enumaris

Seems that way

I'm not entirely sure what that means exactly

John Rennie

@enumaris if the new job is permanent I'd view that as a big plus. You can always move closer to the job in a year or two if the commute is getting to be a pain.

enumaris

I assume it means it's not necessary to only fire "for cause"

@JohnRennie the current renegotiation at my current company would be for a permanent role as well though

John Rennie

@ACuriousMind they like to fire their employees with enthusiasm!

@enumaris ah, OK, fair enough then.

enumaris

18:01

I would no longer be a contractor and presumably I'd get all the employee benefits (health, dental, PTO, etc.)

@JohnRennie the commute is gonna be a pain from the get go though, it's a 35 mile commute from where I am currently...in traffic...loool

I think that their "core" working hour starts at 10 though so maybe I can avoid traffic...

John Rennie

Well if you've been a year in your current job the company will know whether you're a valued employee ™ or just another serf. If the former they will be actively seeking to have to stay as a permie, and that would be your cue to ask about the salary.

If not then you probably won't get the raise anyway.

enumaris

I think they definitely want to keep me on, it's just the offer I got is a bit higher than the raise they were thinking in their heads which itself is quite a bit higher than what I'm getting paid right now.

Chief marketing exec wants to talk to me so we'll see what happens at that time...

John Rennie

18:17

@enumaris I'd say that was a good sign

If they're being positive I'd be especially disinclined to beat them around the head with threats of offers from other companies.

vzn

@enumaris congratulations on your new offer! you are indeed in a delicate situation so its crucial to be very diplomatic, but merely mentioning it during your current negotiations is not a "threat". its probably better to mention it than not, but you dont have to be specific. you can just say "its moderately higher". it may seem like rationally companies make offers independent of other offers, but thats not really how capitalism works...

enumaris

I have to mention it because that's the time-related driver. This offer doesn't last forever.

I am not trying to threaten anybody, I'm just being candid

at least that's what I'm going for

Emilio Pisanty

yo @ACuriousMind, can you clarify this surname?

scholar.google.co.uk/…

enumaris

I've also kept my supervisor in the loop the entire time I was looking for jobs. He knew this day was coming.

ACuriousMind

18:32

@EmilioPisanty What's there to clarify?

Emilio Pisanty

is that even German?

what's with the üe?

isn't it normally either the umlaut or the e?

and what's with the k without a preceding c?

ACuriousMind

@EmilioPisanty I think it's just an 'ü' followed by an 'e' - i.e. not a diphtong or umlaut, just an umlaut followed by a standard vowel. It sounds vaguely Northern/Friesean to me.

@EmilioPisanty Happens with some dialectal words, cf. e.g. the Berliner schnieke ( roughly translates as 'classy')

enumaris

@ACuriousMind are you familiar with the city of Walldorf? Is it nice there?

South of Frankfurt

ACuriousMind

@enumaris I work there

Emilio Pisanty

@ACuriousMind ugh

enumaris

18:36

@ACuriousMind well then...is it nice?

It's the headquarters of the company that gave me the current offer

Emilio Pisanty

@ACuriousMind damn. Then I'm not sure how you'd pronounce it. Is it common?

enumaris

if I do develop w/ the company and take a senior role, I may have to go work at their headquarters for a couple years

Emilio Pisanty

¬¬ with German.

ACuriousMind

@enumaris It's the location of SAP's headquarters. I actually can't say much about the town itself because I only drive through it on the way to work

Emilio Pisanty

Super regular, except when it isn't.

ACuriousMind

18:37

@EmilioPisanty Just as it's written ;) Three syllables: Drü - e - ke.

enumaris

@ACuriousMind oh, I see...is it...a big city vibe or more suburban?

ACuriousMind

@enumaris It's a small town, very suburban with lots of small row houses. The next big cities are Heidelberg/Mannheim and Karlsruhe, between half an hour and an hour away depending on where exactly you want to go.

enumaris

I see

Thanks for the info :D

ACuriousMind

np

Emilio Pisanty

@ACuriousMind hmmmm. And I guess you can't have the non-diphthonged Dru-e-ke?

or how would you spell it?

ACuriousMind

18:45

@EmilioPisanty That is a possible interpretation, but the use of the trema is so rare in German that that will be no native speaker's first guess. (E.g. the somewhat archaic spelling Köordinaten (cöordinates) is usually pronounced with an umlaut by people who first encounter it :P)

And I actually find it easier to pronounce with 'ü' than with 'u', fwiw

enumaris

200

Q: Potential Employer Cancels Return Flight

A company I was interested in just flew me out for an interview. It was on the other side of the country so they paid for my flight and hotel. Unfortunately, the interview went disastrously. I blew every question and I could tell that they didn't like me personally. When I got to the airport ...

interviewing travel expenses

Emilio Pisanty

@ACuriousMind "trema"?

enumaris

oh wow...that seems so uber shitty on the Employer's part...

ACuriousMind

@EmilioPisanty Also called diaeresis

Emilio Pisanty

@ACuriousMind you mean "diaeresis, also occasionally called trema", I think

=P

@ACuriousMind wait, so does "umlaut" refer to the typographical diacritic, or does it refer to the phoneme change?

@ACuriousMind also "the use of the trema is so rare in German" - wait, what?

ACuriousMind

18:52

@EmilioPisanty I call it trema because diaeresis is what one calls the gap in the middle of a pentameter :P

enumaris

There's probably a linguistics SE that would be interesting here right

Emilio Pisanty

there's tons and tons of ös and üs and äs about

ACuriousMind

@EmilioPisanty Both. It refers to the phonetic change, and the diacritic when it is used to denote the phonetic change.

Emilio Pisanty

ugh

ACuriousMind

But when the diacritic is used to denote "non-diphtongization", it's a trema, not an umlaut

Emilio Pisanty

18:53

ah

grand

16 mins ago, by Emilio Pisanty

Super regular, except when it isn't.

enumaris

<----- this line of conversation

<----- my head

2

ACuriousMind

:(

No love for the irrationalities of language?

Emilio Pisanty

@ACuriousMind I do

just not for languages that market themselves as lacking such irrationalities

=P

Loong

@ACuriousMind hm, but the trema belongs on the second vowel letter

ACuriousMind

See, it's so rare I don't even know where it goes!

@enumaris The starred version looks as if "this line of conversation" is being pursued by your head.

Loong

19:01

Yes it's rare. Actually, there is no trema in current German orthography at all, except in a few names.

ACuriousMind

@EmilioPisanty I don't think people who argue about the correct grammatical gender for Nutella can claim to lack irrationalities ;P

Every family has their own tradition for this, and whenever people from two different factions meet, they have to argue about it. It's the law.

Emilio Pisanty

@ACuriousMind seriously, though. You're saying that Dru-e-ke is something that would be considered as phonemically appropriate within the German language, but that there's no way to notate it unambiguously, and that the only way to attempt to do so will be misinterpreted by anyone not clued into what it's supposed to sound like?

Loong

2

ACuriousMind

@EmilioPisanty Yes, except that I'm not sure whether I'd call 'Dru-e-ke' "phonemically appropriate". German doesn't have strong rules for composition of phonemes as far as I know, but it feels kinda awkward for me to say.

@Loong I am happy to see that the deviants who believe in a male Nutella are outnumbered.

Emilio Pisanty

@ACuriousMind ok, fair

thx =)

user2723984

19:07

"Nutella" is feminine in Italian, which is the original language I think

so that's a way to set a winner

ACuriousMind

@user2723984 Yes, but it's a brand name and the brand owner has officially proclaimed that they accept all three grammatical genders in German.

So there is no way to settle this once and for all, which is precisely why it's continually debated

user2723984

they found it too funny that this was actually an ongoing debate to settle it I guess

Emilio Pisanty

@Loong that's hilarious

I'm tempted to stick to male Nutella just for the sake of being contrarian

but that's so far out of whack with the Spanish gendering that that's a non-starter

I'm still having trouble with Gabel, Messer and Löffel

Sir Cumference

TIL german has grammatical gender

ACuriousMind

I'm guessing the Spanish genders are some permutation of ours? :P

Sir Cumference

19:18

Oh wow a lot of languages like Russian and Hindi also have grammatical gender. I assumed it was a romance language thing

danielunderwood

Are all physicists part linguist?

ACuriousMind

@danielunderwood only the good ones

Sir Cumference

Blame the social science classes

ACuriousMind

@SirCumference what?

Sir Cumference

@ACuriousMind It's a thing most US colleges mandate. Ya gotta take a certain number of non-STEM classes

ACuriousMind

19:22

Sure, but neither Emilio nor I went to a US college afaik :P

Sir Cumference

Usually around 6 to graduate

@ACuriousMind Envy you guys :P

Anonymous

@SirCumference Same here. Sociology, English and Philosophy.

t t t t

in south america where i was, it was all physics and math. 0 chemistry, 0 anything else

Sir Cumference

@Blue Huh, you need to take one from each of those categories? At my uni you need to take 3 humanities courses and 3 social science courses

Anonymous

Wait, EVS is a pseudo-STEM thing. Was not sure whether to include it. :P

Anonymous

19:25

@SirCumference Yeah. 3 courses in total.

ACuriousMind

@tttt Yeah, it's that way here, too. You can choose to take something different - there's a "general credit" part where anything non-physicsy counts - but you can also just stay with physics and math.

t t t t

IMO at university level, all required courses should be physics/math and optional courses, anything else

Sir Cumference

@tttt That's how it should be :P. I'm never going to use my knowledge of medieval history or music theory. Wish I could take e.g. geology and explore stuff that sounds interesting.

Due to the social science/humanities requirements I can't fit any earth science or chemistry into my schedule :/

t t t t

non related courses suck, and it's unfortunately a high school thing (unfortunately). But I'm an extremist.

Sir Cumference

@Blue Do you guys have writing requirements? Here you also need to take 4 Writing Intensive courses (i.e. you write ~20 pages per course)

Anonymous

19:29

@SirCumference The English course had some essay and comprehension tests. But apart from that, no.

Sir Cumference

@tttt It's pain. The idea is to make you more worldly but they just get in the way

ACuriousMind

20 pages is "writing intensive"? :P

Sir Cumference

@ACuriousMind Yep. Luckily some physics lab courses count as writing intensive

ACuriousMind

I was just about to say I've written single lab reports that were longer

Sir Cumference

Oh ._.

t t t t

19:31

yeah there's already not eniough time to satisfyingly cover what I'd call a nice physics education in the undergrad, why on Earth would one put a ton of useless unrelated courses

if in the end one does not understand how a laser work, nuclear physics and feynman diagrams...

Anonymous

@SirCumference Our lab reports are each ~100 pages (at least). 4 labs in total (per semester).

t t t t

100 pages, man that's a phd thesis

Sir Cumference

@Blue Wait what the hell

Anonymous

@SirCumference We spread out the writing throughout the semester. So it's not that much load. :)

ACuriousMind

@tttt Universities are products of a humanistic tradition, and humanists believe that a wholesome education is a necessary prerequisite for participation in the intellectual public life.

Anonymous

19:35

There are around 10 experiments for each lab. And each experiment takes around 10 pages.

t t t t

@ACuriousMind they already pollute elementary school and high school levels. university is supposed to be serious

ACuriousMind

For original humanists, the purpose of a university is not foremost to prepare you for any particular subject or career, but to provide to you the education necessary to make an informed choice about who you want to be and what you want to do.

Sir Cumference

@ACuriousMind Welp at least that sounds more interesting than writing about e.g. the political commentary of novels no one cares for

Anonymous

@tttt In an ideal world, all courses should be made optional. :P

Sir Cumference

@ACuriousMind Yeah that sounds like fluff :P

t t t t

19:37

i want the educational system tuned to build the next landau's

Sir Cumference

I just want to explore science, which I inevitably plan to go into

But it feels like I have to put all my eggs into one basket (physics). I mean yeah I love it, but perhaps there's something I could find an even bigger passion for :/

t t t t

physics is vast. condensed matter, astrophysics, computational physics, theoretical physics, etc

ACuriousMind

@SirCumference It sounds like fluff, but my life would have been much poorer hadn't I learned all those useless things. Music theory, dead languages, ancient poetry, philosophy. And, well, you know, two years ago I was rock-sure I'd be a physicist my whole life and would have agreed with you that's the only thing I "needed". Now I'll likely never "need" it again, yet I don't regret for a single moment spending six years learning it.

3

t t t t

you found a job @ACuriousMind , what happened?

ACuriousMind

@tttt Do you mean "what happened that anyone was mad enough to hire you?" or "what happened that you went looking for a job?" ;)

t t t t

19:41

ah ok

ACuriousMind

There's been some miscommunication here, "ah ok" doesn't scan as an answer to my question :P

Sir Cumference

@ACuriousMind I mean, my point is that mandating non-STEM requirements for STEM majors isn't going to help them figure out what they want to go into. Literally the only STEM courses I can fit into my schedule are physics, math and comp sci.

Perhaps I could've found biology interesting, or climatology

t t t t

im frozen @ACuriousMind

Sir Cumference

I won't know because I have to take music theory instead

t t t t

i dunno what to answer. i mean i imagine you either wanted to leave academia and find a job, or that it was possibly a B plan if academia had no job to offer or not phd/postdoc

ACuriousMind

19:45

@SirCumference Well, I'm not sure whether I want universities to enforce some level of general education, but I'm very strongly opposed to "we should only learn what we personally consider useful".

t t t t

dont worry there is a lot of extra math a physicist learns that turns out not to be useful

yet it's still much more valuable than anything else that's not math

Sir Cumference

@tttt I want to be a mathematical physicist :P

@ACuriousMind I don't disagree, I would have loved to take 2-3 non STEM courses, but 6 is pushing it

ACuriousMind

@tttt Well, I a) realized that theory research does not fit me well personally - too long timeframes, too little measurable progress and b) hated the general atmosphere in current academia.

Anonymous

@SirCumference 6 is too much, yeah.

ACuriousMind

Or, well, maybe I just hated the particular bits of it I saw. Either way, I wasn't sufficiently motivated to commit for another years-long stretch leading to a life I was no longer sure I wanted.

Anonymous

19:51

@SirCumference Still be glad that you get to study actual physics. Our courses are loaded with fake-physics stuff like transistors, generators, motors, etc. I so wish I had more choice when choosing an undergrad stream. :P

t t t t

bbbbbbhhgtttkkvbcssdxxx

ACuriousMind

Please call an ambulance if you're having a stroke

Loong

Jan 1 at 13:39, by t t t t

2 years old son ^^

Anonymous

Maybe it's the cat this time.

Sir Cumference

@Blue Your uni merges Physics with Engineering?

t t t t

19:58

my 2 years old son took the control, im back maybe for a few seconds

Sir Cumference

Admittedly that would make you more employable tho

Anonymous

@SirCumference Engineering is "applied" physics. ;)

ACuriousMind

@tttt I'm now imagining the son appearing behind your shoulder with an evil grin as you say that ;)

Sir Cumference

So you guys don't have more theory based Physics?

t t t t

@ACuriousMind are you still mentally challenged in your job?

Anonymous

19:59

I don't think it merges. It's just the basic electrical/electronics courses.

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