@JohnRennie You are talking about string theorists, right? ;)

@AaronStevens "This is my last attempt to make things right..... I will not be trying to contact you anymore."

I gave him a last chance, he didn't take it, then be it. If he prefers to destroy bridges, instead of building ones, then be it.

@JingleBells But ACM already requested you didn't ping him again if he didn't respond, yesterday. Then you pinged him again.

@ZeroTheHero no, on the whole it's people who aren't string theorists blabbering on about string theory.

@JMac hi

how are you ?

Not too bad, you?

not good

@JingleBells ok then, there you go. Let it be then

@JMac in lockdown i lost my concentration from my

studies

everyday i cry

that i am not able to devote my much of time in studies

Why are you crying? @YuvrajSingh...

frustation of not giving anything to my studies

ok

@YuvrajSingh... then you have nobody to blame, but yourself

@skullpatrol that isn't being helpful

yes

thst, my friend, is the essence of independent study

you have to do it alone

yes

thanks pal .

:-)

@JohnRennie hi ,sir long time

@YuvrajSingh... hi :-)

I'm working I'm afraid. This are rather busy this morning :-(

I'll be around later though.

Have your servers been extra busy, Sir?

@skullpatrol yes, lots to do this morning.

The lockdown makes eternal September look like a slow period

@JMac Correct, but I wanted to give Slereah a last chance.

@JohnRennie I'm sorry, Sir, I didn't mean to sound so blunt.

I was replying to this:

studies

I think Sir Newton was given plenty of opportunities to practice his powers of concentration before the Black Plague put him into isolation. @YuvrajSingh...

> As described in Gale Christianson's Isaac Newton, a few months after acquiring his undergraduate degree in the spring of that year, the 23-year-old retreated to his family farm of Woolsthorpe Manor, some 60 miles northwest of Cambridge.

@YuvrajSingh... It might not be possible, but if you focus on something else for awhile you might feel more refreshed when you come back to the studies.

It's just so weird when someone you thought was your "online friend" just suddenly stops responding to you, no explanation, nothing. Slereah has been such a good person to me, always polite and helpful. It makes me wonder, what in the world have I done... was it my fault...

When you first came into this chatroom you used to talk about "real life" friends, remember? @JingleBells

If not, please search the transcript for those days :-)

@JingleBells your comments look silly now! you yourself have closed this, while ago.

@JMac thanks .

@JohnRennie are you free now?

Hi @YuvrajSingh... Of course I haven't forgotten you!

:54120328 I'm busy writing about the early history of relativity right now. But I'll be available in a while. Do you have a physics question? If so, just ask it. You know the rules here.

there are presheaves and sheaves

but

what are postsheaves

the great mystery of our time

@skullpatrol Yes, I remember

@YuvrajSingh... closed what?

gr only applies to freely falling body!, does gr explains about the momentum of the bodies?if there is collision between the planets would gr agree with the impulse that will be produced?

@JingleBells

then this

chat.stackexchange.com/transcript/message/54119517#54119517 @JingleBells

You've been told this so often. Please stop trying to get random individual users to answer your questions, just ask your question to the room.

so sorry!

just don't do it again

yes

Saying "sorry" every time you ignore a rule does not grant you leave to keep ignoring it

oh!

man i said sorry

@YuvrajSingh... So I've closed a message?

it was by mistake

you are converting point into a line!

@JohnRennie To be fair, that is because they see a for their point of view disproportional amount of attention (scientific, public, monetary) going into it. The string theorists don't need to keep talking about it to others, they can just keep writing papers.

@ACuriousMind well yes. My objection is that they long since ceased saying anything new.

I'm not attempting to defend or criticise string theory. My point is merely that if people don't have anything new to say they should keep quiet.

If this was a factual debate I'd agree, but it's a political one - as long as what they perceive as injustice exists, they won't shut up about it

And, at least in the abstract, rightfully so. People shouldn't shut up about injustices just because they don't have any new arguments against them.

Guys, can you give me advice on how to improve myself in terms of online communications? I feel like a lot of people here don't like me and I want to change that. I don't know if I am the problem, but I might as well be. As a start, I will stop chatting in other languages and I will stop pinging users who do not wish to chat with me.

@JingleBells hi :-)

I think you are misinterpreting people's reactions.

For example suppose you pinged me wanting to talk about potatoes. I probably wouldn't reply, not because I hate you but because I'm not interested in potatoes.

(Actually I am interested in potatoes if they are fried and served with ketchup :-)

I should probably feel offended that you are not interested in the Great Potato

Actually, now I think about it, virtually all forms of potato are of interest provided you avoid the elementary errors in preparation.

Our school used to serve mashed potato with no added butter or cream, and it was remarkably good as an adhesive but remarkably bad as a meal.

@JohnRennie Yes, what bugs me is that I don't know what types of potatoes Slereah is disgusted by. I have a lot of potatoes and I can't find which one has repulsed Slereah, that's my issue, so I can stop mentioning that potato.

@JohnRennie hi :--)

Like any other conversation you should talk about what you want to talk about, and see if anyone replies. If they don't it means they aren't interested and you should probably talk about something else.

If you post something and slereah is interested he will reply. If he doesn't reply you may assume he isn't interested. That doesn't mean he is offended.

So he doesn't want to get into unnecessary drama and smelly potatoes?

You don't need to ping us as the chat room shows when new posts have appeared.

Hmm, I guess I'll have to figure out what potatoes Slereah likes

You seem very keen on chatting specifically with slereah and I have to wonder why?

Why him particularly?

@JingleBells You should probably stop obsessing over getting specific users to reply to you.

I would ping him if I wanted to ask about GR, or about something else that I think he would have special knowledge of e.g. things happening in France.

But otherwise why would I ping him?

Well, I assumed he is offended by something that I've said, and I just wanted to figure out what, so I can stop saying it. Maybe he doesn't like the way I "debate". My father told me yesterday that I very regularly start arguing on some topic just for the sake of arguing. Maybe it's true.

why not ask your father for advice, pal

Because he is not the one offended

Your assumption is probably wrong.

I am trying to understand DIY spectrometers, I don't quite understand!

@JohnRennie He said it just like that, he is not offended

I do not understand the photosensor part. does it need to be moved to capture the full spectrum? or does it need a lens so that all the spectrum falls into it?

Maybe let's stop discussing other users in this chat room as if they're not here, it's a bit rude and definitely weird. Sometimes people on the internet don't want to talk to you, and that's fine. If they want you to know why, they usually have no trouble telling you.

@ACuriousMind Okay

then, people use normal usual cameras as photosensors, but aren't cameras bad in that they try to mimic human vision and so they detect about 3 times more green light than red light? if so, does a software unbias the reading?

I'm not into DIY spectrometers, but I'd imagine there are different designs?

another question I have is why is it necessary to have both a slit and a diffractometer (commonly they use a CD surface for that)

isn't the slit enough to diffract the light?!!!!

lastly, how does a software translate a spectrogram into a spectrum?

I've checked many websites, many confuse a spectrograph instrument with a spectrometer and so on

I haven't found a useful website so far

for DIY spectrometers

@thermomagneticcondensedboson I'd imagine it just integrates over the time component?

You don't even necessarily need software for that, you can do that in hardware

no. I mean, the camera "sees" an image of violet---green----red then from what I understand this image is translated into an intensity/count spectrum plot

how is this done? certainly not by integrating over the time component

@ACuriousMind does the fact that his avatar is listed as "currently in room" make it any less "weird?" :P

chat.stackexchange.com/rooms/info/71/the-h-bar

@thermomagneticcondensedboson Well, that's not a spectrogram :P A spectrogram is a 3d graph of time-frequency-amplitude

lol ok

spectrum I guess then

or, well, I guess the sequence of camera images would be a spectrogram

each image is a frequency-amplitude graph and the time axis is time

if the position of the frequencies in the image is fixed, I see no problem with mapping positions to frequencies and just integrating the amplitude over time here

the result is a frequency-total intensity graph, i.e. a spectrum

@JingleBells have considered experimenting with the "ignore this user (everywhere)" option?

chat.stackexchange.com/faq#mute

@skullpatrol Who do I ignore?

anybody who ignores you; you can ignore them back

@skullpatrol he is not chatting to me why would I ignore him :D

I indeed ignored him today but it was pointless so I unignored him

ok

Finally, xkcd clarifies "Garbage In, Garbage Out"

"N pieces of statistically independent garbage" is pretty good

How appropriate in this age of coV stats from around the world

Garbage Math

(—Garbage)^1/2 = imaginary garbage

that^ is the worst

they missed irrational garbage also

...you realize the comic is about interpreting "garbage" as "imprecise" or "uncertain", yes?

Nothing of what you just said relates to precision or uncertainty in any way

...fun fact: the "ea" in "tea" and "pea" are silent

that would make "ueue" in "queue" sad :'(

touché

also, "eee" in "tepee"

Loong for the win!

*silence comes with a price

That's why they say it's golden

Almost $1700/ounce thnx to coV

pff it's so hard to find a cheap 3D printer here in Bulgaria. The only two options I found are Ender 3 and Mega Zero and I prefer the Ender 3 but they keep delaying the delivery time :\ ... some Austrian company

@ACuriousMind Trying to learn homotopy theory

I don't really get the point of the chain groups

Why do we need integer factors to the simplices?

$\pm 1$ seems like it would suffice

You can do homology with whatever coefficients you want

But the integers are the best choice because the universal coefficient theorem says you can determine all other homology groups from that

What do the integers of a simplex correspond to, though?

What's the difference between a line and 2 line

The chain groups do not represent geometric objects

unfortunate

They're just formal combinations of chains "with multiplicity"

Is there a motivation for them?

If you want more geometric (co)homology, you need to do something like cellular homology

I guess maybe it helps relating them to $k$-forms later on?

There is indeed the $\mathbb{R}$-valued version too

I need to remember about +130 geographical points and names on the map for Geography class, any tips?

We gonna have a test on some of them at the end of the year :(

how am I supposed to remember +130 geographical locations with their corresponding names...

Anyways, I just want to pass, I believe I can do that

@FakeMod Do you, in fact, know that this question would be on-topic at Earth Science?

The question is not off-topic here because it's earth science, but because it asks about human institutions rather than anything scientific. Please don't direct users to other sites like that unless you are very sure that the other site will accept the question

@JingleBells That's ridiculous, IMHO. But you gotta do what you gotta do, if you want to pass. You can code, right? So make a game of it. FWIW, I learned the locations of all the states of the USA & the names of the state capitals from a fairly simple game (that I didn't write). But I must confess that some of that knowledge is a little fuzzy, 30+ years later.

FWIW, if I had thought that they'd want this question, I'd have migrated it there

step up your game, then :P

@PM2Ring Well, I only want to pass, so I just have to sit a few hours and pump that info into the hippocampus

Anyways, Imma watch Sherlock Holmes (2009) now

that was why, it seems

@Vivek If silence comes at a price try free speech.

The amount of work...

How can I use the symbol $\Bbb R$ in overleaf? Can't seem to get it to work

$\mathbb{R}$?

that produces a kind of stumpy looking one

it's not a big deal, just wondered if there was a way to get the slightly nicer looking one that can be used on SE

ah I have it, ty