The h Bar

9:47 AM

3

A rare day

(there usually is a yellow flag indicator up there)

10:09 AM

@ManishEarth -1. Redundant arrows.

Ironically, I starred it.

redundancy is a feature

Rajath Krishna R

Is intelligence an important factor for becoming a good physicist?

Crazy Buddy

1:46 PM

@ManishEarth Nice... Well, you guys did that (made the community handle stuff all by itself) ;-)

And Crazy is back :D

Alright people...

I am in ~~deep shit~~ a tank filled with kerosene and water...

Help me out...

I know I have to use Bernoulli's equation...

$$P_o + \rho_2 g (h_2 + h_1) + \frac{1}{2} \rho_2 v_2^2 = (P_o + \rho_2 g h_2 + \rho_1 g h_1) + \frac{1}{2} \rho_2 v_1^2$$

right?

Pressure at the hole will be $P_o + \rho_2 g h_2 + \rho_1 g h_1$ right? [$P_o = \text{Atmospheric Pressure}$]

@ManishEarth?

@CrazyBuddy?

2:21 PM

Post this as a question maybe @ShuklaSannidhya

2:37 PM

@PranavHosangadi Naah... It's trivial...

3:00 PM

Cmon h-bar...

So here's how I would do it:

\begin{equation}
P_bottom = P_atm + g * (\rho_1 * h_1 + \rho_2 * h_2)
\end{equation}

Applying Bernoulli's equation just before and just after the orifice

\begin{equation}
\frac{\rho1 * v_efflux^2} = P_bottom - P_atm = g * (\rho_1 * h_1 + \rho_2 * h_2) \\
v_efflux = \frac{2g * (\rho_1 * h_1 + \rho_2 * h_2)}{\rho_1}
\end{equation}

Crap... isn't MathJax enabled in chat?

For those whose chat is MathJax challenged

Please check for errors, this is a half-asleep calculation

3:21 PM

@PranavHosangadi All it says is "Image not found"

Try this link: i.stack.imgur.com/8sLro.png

Did the link work?

Something's wrong with my DNS.

http:// i. stack. imgur. com/ 8sLro.png

remove the spaces

3:25 PM

@ShuklaSannidhya works for me

1 min ago, by ShuklaSannidhya

Something's wrong with my DNS.

Q: MathJax in chat (ChatJax offshoot)

There's a bookmarklet from which you can run mathjax

Nov 5 at 19:15, by ManishEarth

4

This is an offshoot of ChatJax, which enables MathJax along with mhchem on chat. Copy the text below: javascript:(function(){if(window.MathJax===undefined){var%20script=document.createElement("script");script.type="text/javascript";script.src="https://d3eoax9i5htok0.cloudfront.net/mathjax/lat...

OpenDNS has blocked imgur because it has Pornographic Images.

@ManishEarth So what do you think about this

1 hour ago, by ShuklaSannidhya

Pressure at the hole will be $P_o + \rho_2 g h_2 + \rho_1 g h_1$ right? [$P_o = \text{Atmospheric Pressure}$]

yes

So this relation is right-

1 hour ago, by ShuklaSannidhya

$$P_o + \rho_2 g (h_2 + h_1) + \frac{1}{2} \rho_2 v_2^2 = (P_o + \rho_2 g h_2 + \rho_1 g h_1) + \frac{1}{2} \rho_2 v_1^2$$

isn't it?

3:35 PM

wait, why?

Rajath Krishna R

hello everyone please give me an answer......Is intelligence an important factor for becoming a good physicist?

@RajathKrishnaR Well, yes.... One needs intelligence to be good at any career that involves thinking. And the academia involve a lot of thinking.

@RajathKrishnaR lets philosophize: what is intelligence?

@Manish Gone through very many comments yet?

no, studying

3:40 PM

@Manish Good. Want a nice queue?

@ShuklaSannidhya This is correct @ShuklaSannidhya

I offered it to the dba people, but they don't seem to want it.

Bernoulli's expression for the top of the tank - $P_o + \rho_2 g (h_2 + h_1) + \frac{1}{2} \rho_2 v_2^2$ and that for the bottom will be $(P_o + \rho_2 g h_2 + \rho_1 g h_1) + \frac{1}{2} \rho_2 v_1^2$

@Undo sure, but I may not handle it

3:43 PM

@Manish That's fine.

@Undo Does that flag all of them from the app?

@ShuklaSannidhya ah, yes, true

No... I'm too lazy to try to dissect the post request. And it's actually a webpage.

But I want to make it do that!

@Undo Easy-peasy, have it accept the fkey and then just generate forms in iframes and click them

@Manish First I want to make it work :). Anything about the mod queue that really helps processing?

As in?

Well, if you flag individual comments it's ridiculously easy to blow them off

3:47 PM

Mechanics - what happens to flags after buttons are clicked, button location, etc.

Individual comment flags are one-click handled. Custom flags are annoying as mentioned in the meta post of mine

However, you have a flag throttle so just flagging individual comments may not work so well.

So maybe make it cast a custom flag on the post itself?

Wouldn't that scale badly?

@Undo as in?

Umm... your meta post?

Hard-to-delete comments?

For one comment, flag the comment. For two comments, your choice. For more, custom flag.

@Undo I'm talking about custom flags on the post making it hard to delete comments

Most flags give us a list of posts with an expand arrow next to them. We can carry out mod actions from within the queue.

3:51 PM

Ok.

Yeesh, the dba people seem to not understand that I want to run this myself for a while.

Anonymous

Chem.SE seems to be performing pretty badly. If it fails, will it also be merged into Physics.SE ?

Whoa whoa what?

It's doing great.

Anonymous

@Undo It's full of "Okay"s, and only one "Excellent".

@DIMension10 That's actually very good performance. Look at the other betas

@DIMension10 Yes - the colors aren't anything to be worried about.

3:54 PM

It only becomes a matter of concern when the q/day or the visits are really, really low.

(q/day less than 1)

Which they absolutly aren't.

Anonymous

Oh, ok.

But yeah, they freaked me out on my first beta too :)

Anonymous

But what if it does fail, eventually ? Will it be merged into Phys.SE ?

@DIMension10 We'll cross that bridge if we come to it. Probably a split between biology and phys.

Anonymous

3:57 PM

That's scary.

Failing sites are scary. But chem isn't even close to failing.

Anonymous

Huh, how could it be merged into partially biology? It's also into beta.

Oh, forgot about that.

The comms team would figure it all out.

So probably primarily physics.

@DIMension10 No, it would have some posts migrated to Phys and some to Bio, because we (Chem) have some biochemistry too

And some posts would be just preserved in the dump

When Gamification was closed some posts were migrated to Cognitive Sciences. Being a beta doesn't change that.

As long as it's only some posts and not all.

The cogsci comminuty picked the posts that they wanted.

In the case of a site merge, they would have to discus it further.

Note to self: always use a LIMIT statement when fetching stuff from a 50,000 row db for displaying in an html table.

4:04 PM

yep

Or run it on a webserver

@Undo Is this a PHP app?

@ManishEarth Yup.

Right now it's on my local machine.

Gimme. Or GitHub. I may be able to add flagging abilities.

Let me make it work, please :)

ah, ok

note that flags can only be submitted once per 5 seconds

Yup. I know that by heart.

By 'make it work', I mean make the queue at least show up.

After that, you can do whatever you want with it.

4:07 PM

To make it be able to flag, have it create an iframe on the same domain, with the contents being a form that has all of the correct hidden input elements. Then, use Javascript to submit the form. Of course, you need the user to add the fkey beforehand.

Although I would like for it to be a little centralized, so that there aren't problems with deleted comments showing up.

Maybe we could both draw from my DB?

Sure.

Ok, great. Almost done with the queue part.

Make sure that using the app clears the item from the db or marks it as "flagged" so it won't show up

That's what I'm planning to do.

4:09 PM

yayz

I have a handled field, along with a wasObsolete, handledBy, and wasValid. So it's pretty fine-grained.

handledBy? Hmm, you going to implement a login?

For future expandability.

And you and me could have races to see who can handle the most :)

hah

Except we couldn't do that with Phys. wouldn't be fair.

4:12 PM

Stack Overflow. Tons of comments to be had

Yup. But SO has soo many that I want to start smaller.

once I make it work on Physics, I can just make a new SO table, populate it with comments, and point the app at it.

@Undo Another thing is that maybe you might want to fetch context or something. Some way to see the comments around it, and queue flagging for them as well

@ManishEarth Thinking about making that a javascript thing - that would be an awful lot of stuff to store server-side.

Like you press a context button and it fetches the comments for that post.

Nah, there's a better way:

Ooh?!

4:14 PM

@Undo Basically, have a full copy of the comment table, and use a JOIN statement to list them underneath the main comment. You collapse them under it, with a small expandyarrowthing to show them all. Each has its own flag option.

@ManishEarth There are 140,000 comments on Phys alone. Forget about SO, with it's 24m.

And I don't have a very big server :)

You run the LIMIT query first and then the JOIN so that you save CPU.

It's an AWS t1.micro server.

@Undo Hmm. I could run it then. I have DigitalOcean.

With all of 8gb of memory :)

Oh, well, let's see where this goes.

Current progress:

4:18 PM

> 2065392 kb is what I have

That's just 2GB. Huh?

For what?

Well, not my server, but I sysad the server of our institute's coding club and as such we don't mind running other projects on it

I'll try to run it as much as I can on my end, I don't really want it to cost anyone else money.

How do I import a JS script into a .php html file again?

@Undo <script src=...>

Ah, ok. I'll memorize that eventually :P

Woohoo! Made jQuery work!

4:26 PM

yay

It appends 'Hi!' to every div when I click on a div!

So nothing useful.

Yeah, this isn't desired behavior.

@Undo hah

Rajath Krishna R

5:17 PM

@ManishEarth Sorry sir for debating with you about the homework policy when I first came into this site. Now, I understand why you discourage homework questions.This is a great site......

7:15 PM

While you're at it, nuke this. I made it associated to the wrong site.

→ 46 messages moved to Comment purging and stuff

7:37 PM

Is the answer 42 related to Feynman's "42 zeros" comment?

@Transmissionfrom Hitchhiker's Guide to the Galaxy

@ManishEarth Yes (I know), is that inspired by Feynman's comment?

dunno. What's the comment?

don't think so though

"Isn't nature wonderful to make something with 42 zeros!"

ah

7:41 PM

gravity vs strong interaction

The comment is from a newspaper, so possibly it was only uttered to the journalist (and did perhaps not appear in one of Feynman's books or lectures).

it's possible that Adams copied it from Feynman, but I'm doubtful

@ManishEarth So, where on SE is the question: "Where does 42 come from?"

heh

Science Fiction & Fantasy

@ManishEarth Hmm, ok. So, I'll ditch the theory.

@ManishEarth Something else. How much of India (in % over all areas) would you reckon knows who Sachin Tendulkar is?