The h Bar - 2015-09-24 (page 2 of 2)

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user54412

6:00 PM

@xnor Not only is it Zeno's paradox (which means it's faulty reasoning), but there's no basis to quantizing space. Quantum mechanics quantizes energy levels of bound states -- the idea that it makes everything discrete is just... wrong and unfounded (but widely believed for some reason).

@xnor : that's garbage I'm afraid.

user54412

Even then, people have looked for things like vacuum dispersion of photons that tend to be predicted by such theories, and they consistently find nothing (see e.g. arxiv.org/abs/0908.1832)

@Slereah : Ho ho ho ho.

I know it's like the dichotomy paradox

whose "solution" is an infinite sum

user54412

@skillpatrol Stuff like this is reported in certain states, because it fits with the fairy tales people want to believe, all of the form "those other people are worse than me, just look at their behavior in <cherry-picked example>."

6:07 PM

one thing that immediately came to mind is that it takes literally no time to move an infinitely small distance

so in any finite time period an object can move infinitely many times an infinitely small distance

user54412

@0celo7 My high school actually put doll lynchings to excellent use one time...

@ChrisWhite You're gonna have to elaborate on that one

that may be described as "faulty reasoning", yes, that infinite positions business

Doesn't LQG literally quantize spacetime?

user54412

@0celo7 The school somehow got the idea "wouldn't it be great if 17-year-olds took on parental responsibilities for no justifiable reward?"

6:13 PM

oh right this guy also wanted to tell me that space is definitely quantized because we have the Planck length.....

and same for time

user54412

So we had this semester-long class where you had to pair up and take care of one of those realistic baby dolls that recorded whether you fed it, paid attention to it, got up in the middle of the night to change its diaper, etc.

user54412

All the downsides of being a parent, without any emotional connection or promise of future slave labor.

user54412

This all came to an abrupt end when the health ed teacher opened the blinds one day to find one of the dolls hanging from a noose outside the window. We got to go back to playing dodgeball or whatever instead.

That sounds like a TV show

@xnor how can anything move in "literally no time"?

6:15 PM

We never had to do crap like that

@skillpatrol quantum mechanics :P

@ChrisWhite lol

Do fluctuations happen in a time span?

@ACuriousMind how long does a quantum fluctuation last

@skillpatrol it isn't, or rather just an infinitely small distance

I was just using his "reasoning" with infinities applied to time

user54412

How many angels can dance on a quantum fluctuation?

So, what are you saying?

6:18 PM

oh right, quantum tunneling, isn't that instantaneous?

@ACuriousMind can an entangled quantum fluctuation tunnel faster than light

there was this experiment where they claimed FTL communication with quantum tunneling, but it was actually just the phase or group velocity

@ChrisWhite don't be silly, Angels don't exist

if a fluctuation can create something like our universe then a helluva lot of angels, even if they are fat

superluminal tunneling by Nimtz, that's the experiment

and one response. arxiv.org/abs/0709.2736

@ACuriousMind what if all the quantum fluctuations we see every day are just subfluctuations on a bigger, underlying fluctuation

what if the universe is a quantum fluctuation

omg

6:34 PM

@ChrisWhite do you think there would have been a public outcry if the doll was "of color"?

you mean black?

There are other colours pal :P

user54412

@skillpatrol Definitely. Even if color had nothing to do with it. Fortunately, we hung a white baby, because as long as you're racist against whites or Asians, you're covered in the US.

sure but the reaction would have been biggest

Aaah ha so it was you! :P

user54412

6:39 PM

@skillpatrol Be careful. That statement can be seen as trying to appropriate black struggles as your own.

all whites are racist and there is no such thing as reverse racism or racist blacks, don't you know? :D

ok, story time

I was in the fort one night

there was a lot of alcohol and...other substances

and apparently I got schooled in racism because I kept claiming blacks can be racist and that's wrong

dunno

Let's just be civilized here and stop.

why can't we just make fun of JD or something

this is perfectly civil

6:42 PM

He left

or discuss the ramifications of the universe being a quantum fluctuation

see, there's a quantum field

the MASTER FIELD

and we get UNIVERSALONS

and the universe is such a thing

fleeting

it will last only as long as the uncertainty principle allows

we're all doomed :O

@0celo7 it's only racist when whites do it, don't you know? :P

@xnor someone told me that society is subconsciously racist

user54412

@0celo7 Good story. Leaves the reader wondering the important questions. Like "what substances? superfluid helium perhaps?"

@ChrisWhite it's hard to debate when coughing

user54412

6:45 PM

(Yes, I've been to parties where LN2 was the party substance.)

@0celo7 of course, because if it is subconscious then you can always play the victim card

reminds me of modern feminism and patriarchy

if society is so racist where are all the racists

/me shudders

if you're a racist you get put on the news and shamed

furthermore, where are the racists with power?

time to pack

user54412

11

Q: How to explain to a student that it is common to include a supervisor as a co-author

In my field of research, it is common to include a supervisor as a co-author of a student's PhD research related papers. A supervisor mainly contributes by helping to improve the writing of a paper, such as emphasising its contribution or clarifying the content etc... Which means that a superviso...

authorship supervision

user54412

6:49 PM

sigh

sigh?

political correctness will be the end of us all

user54412

so glad I'm not a biologist

what's the issue??

user54412

that's got to be the worst field for "grad students are slaves and owe their lives to their professors"

6:51 PM

why

user54412

just the whole idea of "I direct this lab, so I deserve authorship on all papers produced by it. I don't have time to even know what the papers say." Really disgraceful.

sounds like the kinda thing I want to do

how do you know this is biology

user54412

If I were a student in that situation, I'd put the lab director on the paper and then also put the university president and the director of the NSF on the paper too. After all, Important People deserve Recognition.

ctrl F shows no hits for biology

user54412

@0celo7 It might not be, but that's definitely a thing in bio more than any other field.

6:54 PM

@ChrisWhite Well usually it does have its merits as well in the sense that those labs are usually big and individuals don't have to worry about funding. Not that I think it is academically appropriate, but yeah. And it is not at all only biology, even though there maybe more than elsewhere.

Welcome back :-)

user54412

The top people in the hierarchy in those fields aren't even scientists anymore. Sure, what they do might be valuable or even necessary for stuff to get done, but so is the janitor who cleans my blackboard or the landlord who puts a roof over my head. I just can't respect bureaucrats who take credit for others' work.

@ChrisWhite Well, they're managers and responsible for the operation of the unit. Like a CEO.

user54412

@alarge I'm not sure I've ever met a CEO in person, but I suspect I wouldn't like them much either.

user54412

I guess my opinions of people are inversely proportional to their opinions of themselves.

7:01 PM

@ChrisWhite It takes a lot of skill to manage people, to win grants etc. It's just not science, which is the problem. But the phenomenon is largely due to how science gets funded.

And undefined if they have no opinion of themselves :P

What I find sad though, is how these lab managers have never ever studied management. And I've asked several professors leading large labs. Many seem to be of the mindset (at least subconciously) that management is a soft science at best and therefore easy, and there is no reason for a Scientist to study it, as for a smart person it all comes naturally.

user54412

@alarge I can see how funding is at the root of it all. But what I don't understand is why some fields (astronomy) have dodged this sort of master-slave hierarchy. We have a much more egalitarian feel.

I should emphasize that nobody's actually said it out loud, but that's just how I've felt talking with these people.

user54412

Perhaps it's just an issue of scale. Biology >> astronomy when it comes to funding.

7:05 PM

I guess it's due to scale but also long held tradition and culture in the field.

Halp

what do I need for a three day trip

In biology you've been winning Nobels for a long time without doing the actual work (Crick/Watson for DNA for example)

Although I'm sure in physics as well there are many students whose names never got mentioned.

user54412

36

Q: What to do without underwear on a 4 day trip?

Ok, this might be a ridiculous question/situation but it's my situation. I'm at a football camp in boston until Friday, and I've realized I forgot to pack any underwear (I wear boxers), I have the one pair I came with. I'm going to be pretty active for these days, so far my current strategy is ...

tips-and-tricks clothing hygiene sports-equipment

user54412

take heed

I have 4 pairs + the ones I'm wearing

7:09 PM

TMI

:D

how is that too much

I'm wearing underwear, big deal?

I have 4 pairs packed

I own more

user54412

@0celo7 conformist

@ChrisWhite caltech did a number on you

imagine how bad Berkeley is

I have: pants, shirts, underwear, socks, tooth cleaning supplies, deodorant

seriously people what do I need???

What are you going to do there?

no clue

7:20 PM

How many other people will be there?

er, 10?

I need my laptop for homework purposes

Take your favourite textbook(s)

I'm taking the math 307 lecture notes that Denzler gave me

I have to read those

I think we have 16 hours of driving in total

user54412

16 hours? You could get to NJ with that.

8 to 8 back

16 is probably enough to see ACM

11 hours from here to Frankfurt

maybe 2 hours to Hberg?

then an hour to hunt him down

user54412

7:26 PM

Might be difficult to find, since he's on the Mun.

::checks Steam::

not even online :O

he died D:

that's the only reason he could not be playing that game

Mun?

user54412

Or rather, I envision him on some sort of crazy Lissajous orbit that's gone too far, attempting a last-ditch retrograde burn to try to lower the periapsis. But he was thinking in categories and got the idea to just "reverse all the arrows" and is now careening out of the solar system with no fuel left.

user54412

@skillpatrol Mun

@ChrisWhite thanks

8:02 PM

@0celo7 : you could always try. But there again, I could always make fun out of you:

user image

I still don't like Landau's derivation of the nonrelativistic lagrangian...

Of a free particle*

It just seems really imprecise.

@NeuroFuzzy how so? How does he do it

@JohnDuffield I don't know what that's supposed to mean

wtf

8:19 PM

You should go check it out pal

And I am not implying anything with that suggestion. Remember I am just some colorless stranger on the internet :P

I don't understand how this statement:

2 hours ago, by skill patrol

There are other colours pal :P

Can justify this warning:

2 hours ago, by Chris White

@skillpatrol Be careful. That statement can be seen as trying to appropriate black struggles as your own.

user54412

@skillpatrol Saying there are other colors is halfway to saying "there are disenfranchised white people" or "there are male rape victims" -- it's just something you can't get away with today. No, it doesn't make any sense.

Yellow for Asians or red for communists are examples of "other colours" who did not have the same struggles as the blacks, correct? @ChrisWhite

user54412

8:36 PM

Exactly. Or even brown/dark (which is a whole other story, because somehow Hispanic, Middle Eastern, and Indian got grouped with the same color, and which of them is a minority or just a version of white depends on the situation).

user54412

Though I wouldn't say red for communists applies here. Like, it is, but colors as stand-ins for race are orthogonal to colors as stand-ins for politics.

user54412

Otherwise communist China would be... orange?

I believe the red came from the ussr.

user54412

@DanielSank There were more signal-processing-on-a-sphere papers on astro-ph today, like this one (by the same people I mentioned at some point in the past). I tried to get people excited about using wavelets and taking into account tensor-valued functions correctly, but no one seemed interested :(

user54412

The paper even used $\eth$ and $\bar\eth$ for operators!

user54412

8:43 PM

Not often I have to look up a latex symbol anymore.

Do you use the color code in your LaTeX? @ChrisWhite ;-)

"The center of SO(8) is Z2, the diagonal matrices {±I} (as for all SO(2n) for 2n > 2)"

Why only even?

What's the center of SO(3)?

is it bigger

user54412

::tries to remember what the center is::

The elements that commute with all other elements

user54412

then what's the centralizer?

8:50 PM

Isn't that George Bush

@Slereah Casimir?

or is that the Cartan thing

user54412

@Slereah commute... commune... communism. I see where you're going with this!

Casimir elements are part of the center, yes

user54412

@Slereah Perhaps they just mean -I is not in the center of SO(2n+1) (since it's not even in the full group)?

Isn't it?

user54412

8:59 PM

det(diag(-1,-1,-1)) = -1?

@ChrisWhite I've never seen those symbols before.

Paper looks interesting.

Oh right

That makes sense

I guess it's only part of O(n)

user54412

"ð is the only Latin alphabet letter faithfully representing delta's phonetic value."

user54412

"A capital eth is used as the currency symbol for Dogecoin."

user54412

9:35 PM

High resolution image of Pluto (warning: > 50 MB) -- this picture has a linear resolution of about 170 m, which is about 2000 times better than what we had a few years ago.

8

It should be blue.

:(

did you do the problem set

also post it again

9:51 PM

@ChrisWhite thanks for sharing pal :-)

@0celo7 i'll do it on the weekend.

I have a lot of other work.

2 hours later…

user54412

11:38 PM

2014-11-30 22:23: Question posted.

user54412

2014-11-30 23:38: Qmechanic removes computation and adds homework-and-exercises and numerical-method.

user54412

2015-09-24: OP removes homework-and-exercises and numerical-method and adds computational-physics.

user54412

Someone really needs to write a query that tells us how often the OP undoes @Qmechanic's edits, and moreover what the distribution of delay times is.

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