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12:19 AM
@dmckee I was trying to be silly dammit
I was confused (and still am) about what they were talking about
@BernardMeurer your favorite, bob, likes to say "proper planning prevents piss poor performance"
@0celo7 He's right
@dmckee sigh
that's supposed to be "wasn't"
was not trying to be silly
1:09 AM
@BernardMeurer / @0celo7 / @dmckee plz +1 this meta.physics.stackexchange.com/questions/7426/… ... BM just dug up 3 good refs on reddit AMA & may post later as the need arises. the basic idea (eg as stated on wikipedia) is that its like a press conference. so how does one "prepare" for a press conference? ofc there is "room" for different povs on this, but chat rooms are only "rooms" in a very abstract sense... am not at all rejecting preparation...
@vzn People prepare for press conferences I think :v
@BernardMeurer the pt is efforts toward "preparing" like one does for a real world "talk" may not translate well into cyberspace/ cyber chat room etc. ... eg it would work better if theres a specific topic etc
@0celo7 BM == Bernard Meurer
aka me
1:23 AM
mind = blown
@vzn I don't see why it wouldn't translate well into an online chatroom, it's basically the same as a real chat just with text instead of voice
@BernardMeurer in a "real world" talk, look at all the perceptual cues, not present here. eg, speaker stands, audience sits, maybe has podium, is introduced, audience quiet until end, speaker may have visual aids, they face each other, etc
@vzn That would suggest that in an online room where such cues don't exist preparation would be even more important no?
In DS's case he has to know with Google what are his boundaries first, and that's a must preparation
@BernardMeurer its not up to me/ us to figure that out, ofc respect his boundaries on that, he already said google stuff was off limits, maybe this could be problematic without clearing w/ employer, assuming he understands the basics of his NDA etc... figured he might talk in a general way...
anyway if you guys want guests, plz upvote the meta post, "cant get hung for trying"
> its not up to me/ us to figure that out

What are you referring to here?
1:29 AM
@BernardMeurer DS has to get clear on what he "can" say, we cant do it for him, thats the NDA angle. dont really think it could be that complicated, but hoo boy, maybe thats mistaken. (ofc lawyers might say so, & dont know how many pages his NDA is...) o_O
@vzn Yeah, that's exactly my point, he needs to know the scope of what we may be going into so that he can do his research on what he can and can't say on those subjects
@BernardMeurer no disagreement. the other angle is like "preparing for a talk" eg rehearsing the topic/ speech etc ie the more conventional stuff. but its not a speech/ presentation (unless someone wants to volunteer for that). its more like Q/A, AMA etc
@vzn I just think you're getting the idea of preparation wrong that's all, he's not going to be rehearsing a speech, but he may be taking a look at his thesis to make sure his memory is fresh and so on
@vzn no
you're right about one thing
1:35 AM
@vzn Hey, we can always agree to disagree :) I'm just trying to present you what I think might be DS's point here
I can't speak for him obviously, but at least this is what I've understood from the who situation
everyone has good pts. am not discrediting any of them
and hey, thanks for the effort for putting this thing together :)
@BernardMeurer o_O ?!? (shock!) lol wow maybe will not give up then :P
@vzn Shock? I always thought this was a nice idea, just think if we're going to be doing this as a community we need to go though the details of it as a community too :)
@BernardMeurer "we" is a very slippery/ capricious concept sometimes
1:38 AM
and specially respect the guests' effort and desire to a limit
@vzn True
@BernardMeurer DS doesnt wanna be rushed & wants this to be a bigger/ more structured deal than maybe can be sustained in this environment
@vzn I agree with that, we shouldn't rush this. Something done well is always preferable to something done fast. And I do think this chat structure may prove to be an obstacle, but I think theorizing on that before we even do our first AMA is a waste of time. We take our time and organize a nice thing in the chat here, if that fails we start to look at alternatives
sure. did you +1 the meta ad?
@vzn First one to do so :)
thx man luvya
1:48 AM
@vzn No worries mate
2:02 AM
The answer to this question doesn't seem satisfactory to me. I'd like to hear more about how general relativity (or something similar) plays a role and more about how gravity itself works, not the effects
What do you guys think? I'm considering bountying it but if there's not a better answer then there's not much of a point
It has nearly 20k views and only a few votes on the answer, which is a pretty low ratio
2:47 AM
@vzn: We need to think how we would take questions; whether that would need another chatroom or not; how people would interact with the guest etcetera.... the question is when would we do that? Any idea in your head?
3:22 AM
@MAFIA36790 contrary to some assertions, am open to ideas. think an open forum is better to start & 1st guest can help with ideas on the format/ etiquette. when would we do what? discuss the format? think discussion in here is fine until the mods complain or if someone has a better idea. have been thinking about opening another room for chat guest coordination but am not sure it can be sustained yet... maybe ppl just wanna have some big drama instead :|
(did you upvote the ad yet?)
@DanielSank Started a spreadsheet for beers :v
You have poisoned me dan
3:40 AM
@vzn ^^^
@BernardMeurer You've to take a loan to deal up with ACM and Dan ;P
@MAFIA36790 I didn't get the scholarship :/
@BernardMeurer WHHHHHAT T__T
Sending assassins to kill those fanatics
3:42 AM
I'll be going to bed now
@BernardMeurer ookay.... I can't say anything... o/
@MAFIA36790 what?
@vzn I've upvoted already ;_;
I've seen Emilio's comments although.
@MAFIA36790 votes are anonymous. thx man. :)
3:47 AM
@vzn ;P
@MAFIA36790 yes, everybody will now see his/ DSs comments, there was no chance to negotiate 1st before the objections line up under the ad, making it harder/ more distracting to get upvotes, now it becomes symbolic of any anticonsensus
have been thru all this before/ recently in another SE milieu
4:41 AM
@BernardMeurer The point is that @vzn doesn't know what the guests need to do in preparation and needs to re-adjust his/her perspective to account for this.
@BernardMeurer That's a good example.
Hello @JohnRennie.
@vzn I'm going to outline what I think the considerations for this AMA thing are in a Google doc. Do you have a Google account?
I'm also going to redo the add image because I have a better idea for it now.
@DanielSank Morning - well, it's morning here in the UK :-)
@JohnRennie Very good. Evening here.
Going to work on a bit of a write-up on what I think the goals and structure of @vzn's proposed hbar AMA's could be.
Will turn bits of it into meta posts.
I think it's a very good idea, but I'd like to solicit feedback regarding how to actually run it.
I have to say I'm not sure about the idea ...
Most AMA's (e.g. on reddit) use comment posts, but not in real time. I'm not sure if this can work in a chat room.
@JohnRennie What reservations do you have?
Although I would be fascinated to hear you talk on what it's like to work at Google.
4:48 AM
@JohnRennie Be happy to, if I can clear it.
Should be able to do.
Quantum computing I can read up for myself, but experience of working at Google isn't something I can easily get at :-)
@DanielSank to be fair I've never taken part in a Reddit session, so I can't really judge. But i worry that (a) we may get too few people, and just the usual crowd. (b) we may get too many people and it all gets confused.
@JohnRennie Yes this is of course the concern.
I have no idea how this can work in a chat room if everyone is firing off questions all at once.
I'm thinking when we do the test run, if I'm the guest, I might just put everyone on ignore while I'm typing answers.
Plus a good session requires lots of interaction i.e. informed questions. Right now what I know about quantum computing you could tattoo on a flea's backside, so unless I go read up on it I'm going to find it hard to make a useful contribution.
@JohnRennie The point of an AMA is that you can ask stuff not necessarily part of the physics discussion.
You can ask where I went to school, how I liked it, what kind of pizza is my favorite...
You know, anything.
It won't hurt to try, as long as people aren't hurt if their expectations are dashed. And if it raises the profile of the PSE that's good.
It puzzles me why we aren't deluged by excitable school kids wanting to know cool stuff about physics.
That's what I would have done if the PSE was around in the 70s :-)
4:54 AM
@JohnRennie Well, it's because we require questions to be good
Asking good questions is remarkably difficult, as you know.
That's why people write entire essays about it.
True, but if I feel an OP is genuinely interested I'll usually try to be charitable and maybe prompt them to join the chat.
@JohnRennie Also, what would you have asked as a kid that wouldn't be a duplicate?
@JohnRennie Dat rep minimum tho.
It's not hard to get 20 rep if someone is really interested.
@JohnRennie Perhaps via edits.
I think for a "kid" it's hard to get votes.
For example take:
Q: Proportional Acceleration Due to Changing Density of the Earth

Bob ZhaoMy question has to to do with a recent video minutephysics posted about the time it takes for a person to fall through the earth, found here https://www.youtube.com/watch?v=urQCmMiHKQk At around 4:05, he mentions some "mathemagical dust" that nets him the answer of 348 seconds. I was attempting...

I'm still debating with myself if and how best to answer this.
4:59 AM
@JohnRennie To be honest, that question is pretty low quality.
OP needs to put the calculation they're referring to in the text and not require readers to go to a video link. It's vague.
This is why kids have trouble :)
But it's a sincere question from (probably) a pre-calculus school kid who is genuinely interested.
@JohnRennie So what? It's a bad question by site standards.
I'm not sure a rigorous answer is appropriate, but maybe an answer explaining how you go about doing the calculation.
I think we all decided long ago that interest isn't enough.
@JohnRennie Yes, that would be appropriate, but when I see questions like that the first thought in my mind is "train this person to ask better before they have bad habits reinforced by getting good answers".
The problem is that it can be hard to know what to ask. You have to understand a certain amount to know how to phrase the question.
I agree it's a tricky judgement. How do you know you're not encouraging the lazy end of the "gee whiz" crowd rather than a potential future physicist?
5:04 AM
@JohnRennie Yes but they didn't even put the relevant info in the post. They direct to a video
@JohnRennie That's just not the issue, I think. Online groups have to enforce good communication practices lest their communities turn into spaghetti.
I think the proper approach is to politely and positively point out how to ask properly at the very beginning, and be generous with help once the improvements are made.
See my comment on the post in question.
That's a really good comment :-)
@JohnRennie Thank you. I've learned by example from you guys and from a very wonderful person who runs a python project called Twisted.
The guy's name is Glyph, and he is very polite and encouraging while always maintaining very high standards for contributors to the project.
It's one of my long term concerns that as a community we're a bit too quick to condemn. Only a mild concern as overall I think the PSE does vastly more good than harm :-)
But we could be kinder sometimes.
@JohnRennie Another thing that helped me was learning what works and what doesn't work in code reviews in my lab. Harsh rejection of bad code results in people going to others for review, and then the crappy code winds up going through! If I'm nice, people keep asking me for reviews and the code is better in the end
@JohnRennie I think there are surprisingly few mean users. There's only one who comes to mind... 'though I really do wish he would shut the f--- up.
I can't think who you mean :-)
5:12 AM
@DanielSank: Good morning.
@JohnRennie I can't tell if you're being coy or serious.
@MAFIA36790 o/
I'm guessing you mean CuriousOne
@JohnRennie He is GENIUS.
@MAFIA36790 I think he does know his stuff, but he specialises in comments that are at best only marginally helpful
@JohnRennie Emotion dominates in his comments.
5:16 AM
@JohnRennie I'm going to say one thing and then stop because this can get out of line easily. CuriousOne knows a lot, but IMHO he makes more incorrect or confusing comments than helpful ones. It is particularly annoying to me that he almost never writes answers, but is content to write unhelpful and too often wrong comments, or even to comment on people's intelligence rather than contributing to the site.
For the record I agree 100%
I once spent an entire evening convincing him that his entirely uninformed opinion about quantum mechanics was demonstrably (i.e. experimentally) wrong. It took all evening because he preferred to side track the conversation by saying things like "I don't believe in faeries dancing on needles" rather than to actually discuss physics.
Thanks @JohnRennie! As I have a Ph.D. in physics and studied at an Ivy League university, I understand the hate. :) — Astrophysics Math 8 mins ago
I think I'm beginning to admire this troll's persistence :-)
@JohnRennie WTF ;(
For whatever it's worth, I think CuriousOne drags the site down a lot, and I wish something were done to correct it.
@JohnRennie Oh god, another one?
5:18 AM
@DanielSank he was banned once.... you can't do it much.
@MAFIA36790 Can't do what much? Ban?
The guy insulted a user this morning.
@DanielSank This is usual.
What really annoys me is that he comments on well-written posts by users who know enough to be fooled by his bs.
@DanielSank Bring it to mod's attention if you feel it violates the BNBR policy by flagging it...
@MAFIA36790 I think I did.
So @JohnRennie, what is it you do?
5:25 AM
Q: Alternating current in a R-L circuit

ADITI SAINII am having some problem in a numerical. But my answer didn't match. The question is here- An electric bulb is designed to consume 55 W when operated at 110 volts. It is connected to a 220 V, 50 Hz line through a choke coil in series. What should be the inductance of the coil for which the bulb...

He has not changed his behaviour even after his suspension... I'm taking it is his natural way to interact with others. I've acclimatised with this quite long ago.
@PhysicsMeta This is really annoying ;((
Even in the main site it would be closed.
5:45 AM
Everyone interested in the AMA idea, please take a look at this
@vzn, @DavidZ, @Danu @BernardMeurer
I'm really a physical chemist. I did my PhD on the solid state photoreaction between metallic silver and germanium selenide, then I left academia and worked for Unilever as a colloid scientist. About twenty years ago I lost interest in industrial research and became a computer nerd, then about ten years ago I quit full time work and now work part time as a contractor.

I was fascinated by GR, black holes, time warps, transdimensional interfaces, etc, etc as an eleven year old so when I had the time I decided to attempt to learn GR and see what it was actually about. And now here I am :-)
For the record, if your interest is in applying science to everyday life colloid science is absolutely fascinating. It touches on numerous aspects of things we take for granted.
@JohnRennie Cool! I never learned anything about colloids.
Is "colloid science" a fancy word for a milk scientist
@Slereah Milk is indeed a colloid, but so are many things found in nature. Blood for example.
5:56 AM
milk, blood, what's the difference
They all go well on cereals
Colloid science is generally taken to include solution properties of polymers and also surface adsorption effects.
the one thing I know about polymer science is that you can use path integrals for it :p
For example Unilever's two in one shampoos work by using a polymer that is solubilised by high surfactant concentrations. When you rinse off the shampoo the deceased surfactant level reduces the solubility of the polymer and as a result it flocculates the silicone droplets in the shampoo. The flocculate sticks to your hair, then as the hair dries the silicone droplets spread over hair and condition it.

The spreading works via a silicone monolayer that forms at the air-water interface. It's all absolutely fascinating :-)
6:22 AM
> Chemistry is physics for dummies.
We all smile at statements like that, and it's true that physics can be stunning in its elegance and purity (e.g. GR) while the real world is messy and confusing. But at the end of the day people want to buy two in one shampoos and somebody has to make them.
6:40 AM
Dear @MAFIA36790, one of your users CuriousOne is constantly accusing Brian Greene of "lying to children" in his posts. Whenever one brings up what Brian Greene said, CuriousOne states that Brian is "Lying to children." This is very impolite to everyone involved. Is the management aware of this slander? — Astrophysics Math 11 mins ago
Keeping scientific arguments aside, you can't behave like a childish immature, CuriousOne ;((
6:56 AM
@JohnRennie i don't
(I have no haiiir)
@Slereah What? T__T
@Slereah well, the thing is that CuriousOne is correct in this case. Brian Greene is an enthusiastic populariser of physics and I support him wholeheartedly in this. However like all popularisers (including me) he sometimes has to be generous with the truth to make things comprehensible to non-physicists.
Though CuriousOne is, as usual, making no attempt to be diplomatic.
If any high rep users are watching, please, please vote to delete that question before it sullies the reputation of the site any further:
Q: Do Logic and Reason lead us to the Fact that the Fourth Dimensions is moving at c relative to the three spatial dimensions?

Astrophysics MathThis is a vastly shortened version of a similar previous question: Firstoff, in his general relativity Einstein showed that dimensions could bend, curve, and move. This is an experimentally proven fact. Dimensions can, and do, move. In an earlier post we logically prove that the photon remai...

@JohnRennie OP seems to be arrogant. He needs to get cooled down ;(
@MAFIA36790 the OP is just a troll - don't feed him any further
1 hour later…
8:22 AM
Accusing someone of peddling lies to children is a very JD move
8:39 AM
Then again, what else are you supposed to do
You can't explain string theory to a layman
But if they don't feel like they do the interest of the public for science goes down
And then where is the funding
I think Brian Greene generally does a good job of explaining things that are fundamentally hard.
I have been to his talk in sydney this year, where he talked about LIGO, String theory, time travel and the multiverse
8:55 AM
Crowd pleasing topics
I wish had had some more technical talks, such as the various technical details of string theory. That would be a good learning experience
Where is Lumo?
Don't focus too much on learning fashionable theories, I'd say
Start with basic physics
String theory is pretty far off, skill-wise
@Slereah We ARE not laymen ;((
We don't require fancy sci-fi books for getting theories like that...
8:59 AM
We would wait for the correct time to conceive these....
after all, we are people of physics and not laymen !!
@Slereah That's what I am doing now during the break, trying to get my quantum mechanics more solid via massive reading. In particular want to solidify my understanding on von neumann measurements
I probably know way more of string theory than the average internet "I love science" nerd
Yet I wouldn't say I know string theory
It's a complex topic
2 hours later…
11:01 AM
@Slereah hahahaha
11:30 AM
Hi all
12:16 PM
12:27 PM
Q: Why did big bang occur?

Anubhav GoelWhy did big bang occur? Why did it expand from singularity? Was there an alien who disturbed uniformity of universe to start a chain series to expansion?

Primarily opinion-based?
The 3 of them are, however quickly closing their gaps now

Maple 2015 started to stretch to the data analysis region that is the domain of matlab
Maple 2016 strengthen it's symbolic domain by including noncommutative manipulations, fixing some errors in series simplifications. It also has a few databases inbuilt for a vaerity of purpose, such as the 971 solutions of EFE

Matlab started to extend towards symbolic in 2015 via the symbolic toolbox. It also introduces simulink to extend to the model based design region that is the domain of maple. It strengthen's it's domain of caompability and
Q: Why many users have 1 score?

Anubhav Goel Why is John's score 1?😵 I have seen a few similar other users.

12:43 PM
Holy shit JD got suspended
Ohhhh shit boy till June 19
@DavidZ @dmckee @Qmechanic gg
@0celo7 RIP JD
@Qmechanic Hmm, I'm very dubious of this user.
@Qmechanic or just not about physics, if you ask me
@DavidZ damn good point ;(
12:51 PM
@0celo7 btw I noticed what DanielSank was telling you a while ago about asking the mods for explanation - I didn't respond at the time since I'm on vacation, but basically he's right
In short:
1. Maple is symbolic king, especially in differential geometry (atlas 2 still fall short of that). It has a slightly more diverse model based design system than matlab

2. Matlab is numerical and data analysis king. It also has sophisticated machine learning algorithms and the most easily compatible to other programming platforms and device integration

3. Mathematica has the largest number of centralised database to supply data from (think wolframalpha). It also have unique capabilities such as geometric computation and entity based code (imgine coding by sticking an actual image
so perhaps this can be shorten as
Maple=Symbolic king
Matlab=Numerical king
Mathematica=Geometric object king
1:16 PM
Hey...can someone explain this?
why is Aij(Xi +Yj) != AijXi +AijYj ??
in tensors...
@Sidarth Why not use mathJax?
dunno how to use it
i and j are indices ....
@Sidarth okay, do you know what mathJax is?
1:18 PM
its a thing for writing math here right?
@MAFIA36790 should i just get the pluging for my browser?
Q: MathJax basic tutorial and quick reference

MJD To see how any formula was written in any question or answer, including this one, right-click on the expression it and choose "Show Math As > TeX Commands". (When you do this, the '$' will not display. Make sure you add these. See the next point.) For inline formulas, enclose the formula in $......

@Sidarth ^^^^
@JohnDuffield I'm sorry you fell victim to the mod's abuse
Lord knows I've suffered under them too
@MAFIA36790 cool...ill check it out..thanks...
so..how abbout my doubt guys...anyone?
What is it
1:26 PM
why is Aij(Xi +Yj) != AijXi +AijYj ??
in tensors...
That's not a valid tensor equation
its a non identity
im asking why is it true
why is aij(xi+yj) not equal to aijxi + aijyj ?
why cannot i expand aij(xi+yj) ?
i and j are indices
lower indices
Something that doesn't make sense cannot be true
Xi+Yj has no meaning
1:30 PM
why cannot i expand aij(xi+yj) ?
This is why physics math is terrible
oh sorry
its a question on the einstein summation
Xi+Yi has meaning
forget tensors
the right question is , in einstein summation,
why cannot i expand aij(xi+yj) ?
What do you think it is
1:32 PM
i believe that it would simply be aijxi + aijyj
is it wrong to think like that?
Einstein summation is usually in the context of tensors, but that's not a tensor, so I don't know what you want. You can of course invent some new Einstein summation that has nothing to do with tensors, but that's your definition and you're on your own.
im sorry....please forget it...
It's like asking if the addition of cows is associative
but is the addition of cows distributive?
@Sidarth write out in full what that expression means
You're mixing free and dummy indices
1:42 PM
what do you make of aij?
i dont know how to write it out
but ill just tell you
aij(xi + yj)
i and j are indices
@0celo7 you have a roommate, right? how is it like to have one?
because I have to decide in a few days.
do you understand?
@Sidarth I know what you think you're writing but I'm telling you if you write it out in full you'll see it doesn't make sense
I've seen my fair share of tensors...
@3075 depends on if you like to run around naked in your room
Can't do that anymore
reminds me, what is the layout of the apartment you share?
do you have your personal room?
and do you share a bathroom/shower?
Why do you care
1:48 PM
because I want to know how it's like.
I have no idea how it works.
Just make sure you don't have a communal shower
The rest will work itself out
@3075: You're going to Waterloo, right?
@0celo7 bad thing is that the best residence has a communal shower and bathroom -.-
@MAFIA36790 yes.
Then it's not the best...
@0celo7 best in terms of rooms, accessibility, and food.
it's the only one with a single room option.
@0celo7 will you live off residence next year? because I heard upper year students don't live on residence.
I was considering living off residence.
but it's expensive af
~$300 more.
2:08 PM
Hello to those of you propping up the h bar. I have a question that I'm not sure is legit for Q&A. I have made a browser game based on quantum mechanics, but I'm self taught in this subject so would like to reality check it with some more knowledgeable peeps to check I got the physics right, before sharing elsewhere! Anyone keen? :)
You're right that wouldn't fit on the main site, but it does go well here in chat
I don't have time myself, unfortunately
Q: Wolves To Humans

Destinee TowerzHere´s the question that everyone has asked scientists can they some how change wolves to where they look and act as if they are humanand the answer is if we have the right machines we could transform a living wolf to a human but the thing is we would need a human willing to turn into a wolf so t...

Best thread
^^^ Lol despite the tag I can assure you that is not mine!
Thanks @DavidZ well if anyone does have a moment there is a blog post describing the physics here, and the game is linked from the post: linkingideasblog.wordpress.com/2016/04/25/…
To run this you will need to the latest version of Java.
Unfortunatly Chrome has stopped supporting Java altoghether.
In other browsers you may need to enable it.
Cool idea though. The Java/chrome situation sucks
Yup. That happened since I started making it - with hindsight Java was a bad choice, though I do have a friend interested in porting to Javascript so that may happen at some point. Still I would hope most geeky types have a way to use Java at hand.
2:31 PM
I've had similar regrets about code choices. You think something will be portable and around for a while, then...
@davidz can he put forward an advert suggestion here?
You mean like a community ad?
Anyone can suggest an ad
@SideshowBob you can put forward an advert for your game on that meta page. If it's a popular idea, it'll be advertised here.

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