2:42 AM
@ACuriousMind I recommend studying economics before disparaging it. Economists do indeed study bounded rationality, and there’s a whole subfield called behavioral economics.

3 hours later…
5:52 AM
@ACuriousMind My problem is that, I've plenty of skills, but no idea...
:-(
How to deal with such?
@JingleBells you've some idea? How do you get those?

2 hours later…
8:10 AM
@abhas_RewCie I don't lol. No one knows how to come up with genius ideas. I think it's more important to pinpoint customer pains and needs and then come up with a solution.
@ACuriousMind Hmm, I did some research and it's true that there's the inequality of rich kids being able to start companies much easier than poor kids but I'd say they are as blessed as they are cursed. When you start poor, you're forced and pushed to your limits. You learn more and gain valuable insights and experience that a rich kid cannot get.

My phone can persist for a whole day long without needing to charge midway.
But my laptop can only persist for a handful of hours.
is it because my laptop is bigger and heavier and thus needs more power to sustain?

8:35 AM
how long will a full-charged tablet persist without charging?

9:18 AM
is a quantum circuit composed of charged carriers which are in quantum entanglement?

1 hour later…
10:32 AM
Looking to get into more books, is the Lord of the Rings series worth reading?

yes
The Hobbit is really good too

I will propose a counterpoint
No, Lord of the Ring is a giant slog

10:56 AM
@user76284 Yes, of course all of this is much more nuanced than I put it in those few messages. I'm sorry if that was insulting, if it's any consolation, I also talk about generic "physicists" like that when I really mean "many physicists, which I disagree with" ;)
@Slereah I concur!
LotR might still be "worth" reading because it's a touch stone for much of modern fantasy - most common fantasy tropes can be traced back either to it or to D&D :P
On the other hand, reading some of the more unconventional modern stuff without always comparing it to LotR internally might not be a bad thing, either

I will disparage economics a bit :
If you are a good economist, a virtuous economist, you are reborn as a physicist. But if you are an evil, wicked economist, you are reborn as a sociologist.
--An Indian economist, quoted by Paul Krugman

@JingleBells People heroically growing with hardship happens all the time in stories, but in reality hardship often just makes them miserable.
This isn't an RPG where you get experience points for completing the "Don't starve to death" quest, it's real life.

It's not too easy
I hope you can wait 5 generations

11:11 AM
Hunger is really a problem difficult to solve as it recurs so soon.
Is economics hard? I found it too boring to study when I first touched it in junior high school.

I'm not too interested in it's effects on literature

@SirCumference The LOTR books are very slow moving. I tried reading then aged about 12 and quickly got bored and gave up.

@JohnRennie Really?
I thought you were into it
Dec 28 '16 at 7:09, by John Rennie
WHAT! YOU'VE NEVER HEARD OF ME ... err, Sauron I mean

I did eventually succeed aged about 18, but I can't say I greatly enjoyed the experience. It was more a case of reading them so I could say I had.
@SirCumference I love science fiction and fantasy, but within the genre there are all sorts of books and some are long and tedious.

@SirCumference I personally wouldn't read them for enjoyment, but many people (at least claim they) enjoy the worldbuilding so much they're not bothered by the poor pacing of the story itself

11:23 AM
Have you read any fantasy books? If so what sort of book do you like? Lots of action? Lots of philosophising?
As ACM says LOTR is all about the complex world Tolkien constructs - there isn't much action.

The deepest fantasy I've read was Harry Potter as a kid
So in other words I've read very little

Harry Potter is excellent fun! I've read them all.

Thanks for the advice tho. Maybe I'll at least read the hobbit and see if I'm into it

That's a pretty good list of the most enjoyable fantasy books.
The Hobbit is a children's book so you may find it a bit over simplified.

Oh, I was under the impression they were all adult books

11:27 AM
I think Name of the Wind is the first on that list that I'd recommend without reservations

I read TNOTW and enjoyed but though that Kvoth was a bit of an idiot who seemed expert at getting himself into trouble through his own stupid mistakes.

American Gods is excellent but Gaiman's sense of humour definitely isn't for everyone

Then I started The Wise Man's Fear and immediately Kvothe started getting himself into trouble through his own stupid mistakes.

I would say that your description of Kvothe is entirely accurate :)

That was about 50 pages in, out of 800 pages, so I gave up and haven't revisited the book since.

11:30 AM
But yeah, I'm not sure I'd recommend the second book as much. But the first is enjoyable even if you don't read the rest :P
Also, why does that list recommend Color of Magic of all the Discworld novels :(
I mean it's the first one but really not the one you should recommend to people if you want to show them how good Pratchett could be :P

It is a list of the books most popular with Goodreads members, not best!
Though actually I like The Colour of Magic.
I think I read it first of Pratchett's books. Was it the first published?

It's not that it's bad, it's that it's very unlike most of the later entries in the series
@JohnRennie Something like Strata or the weird ones about the boy getting sucked into a video game might have come first but it was the first Discworld novel

I read it shortly after publication in the early 1980s, and I think you have to put it in that context.

For fantasy I recommand the Amber cycle
By Zelazny

At the time it was a big departure from the rather staid fantasy books of the time.

11:35 AM
@JohnRennie It's extremely...slapstick-y, for lack of a better word, compared to the later books that still poke fun at cliches but at the same time are also interested in telling a coherent story about something

The first Pratchett books I think are different because they used to be written for like

@ACuriousMind yes, but at the time it seemed really new and different.

Magazines
A few pages at a time

Again, it's not that it's bad - it's still pretty funny - but I feel it's a poor representant of what the Discworld eventually became

Maybe watch the extended LOTR and Hobbit, and then read His Dark Materials which is often compared to it

11:36 AM
I remember that the Colour of Magic appeared in the White Dwarf

@ACuriousMind Agreed, but lots of Goodreads members will be wrinklies like me who have fond memories of the book because it was the first Pratchett book they read.

Dave Langford reviewed The Colour of Magic for White Dwarf #64, and stated that "It's one of those horrible, antisocial books which impel the reader to buttonhole friends and quote bits at them. My ceiling is covered with brown spots from when I tried to read Pratchett's jokes and drink beer at the same time. Only native sadism makes me recommend this disgraceful work."
:D

Ugh, that list reminded me of a few books I'd rather have forgotton

There are some crimes against literature on that list! :-)

@bolbteppa By watch do you mean see the movies?

11:40 AM
I recommend the Eye of Argon
Also why is Watership Down in the list

Yeah

It's about bunnies in rural England
Not the most fantastic of places
They do have religion but that's true of many book characters

@Slereah third in the noble gas series.
(oops :-)

@Slereah I don't know about France, but bunnies around here typically don't talk and live through war allegories

The movies are good enough that I feel guilty for never having watched all 3 extended ones in one go

11:43 AM
They do, they just talk in bunny language

Then again, if we're going that route maybe Kafka was a fantasy author, too, what with the polymorphing into an insect and all

Or Animal Farm

@bolbteppa Just, whatever you do, don't try to watch the three Hobbit movies in a row

@ACuriousMind I think what doesn't kill you makes you stronger if you manage to pull it through.

I haven't seen any of them yet, that's not a terrible idea haha
The Simarillion strongly put me off going any deeper into Tolkein

11:46 AM
See, at least the Silmarillion is honest about being a lore dump
LotR is a lore dump dressed as a story :P
@JingleBells That phrase was coined by Nietzsche as part of his philosophy and isn't actually true in many cases: Starvation doesn't make you stronger, it just leaves you with stunted growth. Lack of education doesn't make you smarter or more resourceful, you just know less. Lack of medicine doesn't make you magically resistant to disease, it just kills you sooner.

I am for capitalism (with government intervention where there needs to be) and I agree that being born into a wealthy family unfairly gives you the advantage of starting a business easier and faster than someone who has to take loans and work his ass off. I'm totally FOR wealth and income inequality but against babies being born and having a business advantage without working for it but by simply being born into a wealthy family.
@ACuriousMind Don't interpret it literally lol, I just said it like that

Maybe think about why you're saying it if you don't actually believe that it's true

@ACuriousMind By saying "what doesn't kill you makes you stronger" I reflect on my bad experiences and what I've learned from them. What mistakes to not repeat... not literally starve and then be proud about it

But "making mistakes and learning from them" wasn't what we were talking about, it was people with less advantageous starting positions just having it harder even before having the chance to make any mistakes!

Well, then I apologize for that context-irrational saying. What I'm trying to say is sure, it's unfair (as I said above) but the poor kid will make more mistakes and generally learn more how to start a business from the ground than a rich kid that just gets money from Dad, hires people and starts the business. The poor kid will experience first working for someone, seeing what the business culture is from inside a company, will have to learn to build relationships, etc.

12:01 PM
Have you ever worked in a company?

People learning about business from a benevolent employer is also something that happens in movies, but very rarely in real life
I think you have a very romanticized view of what the working world is like

I have stated only a few reasons why the poor kid will gain insights about the world that the rich kid won't. I believe you get the idea. There are so many things that the poor kid will experience that the rich kid will not.

Working in a company feels boring.

@JingleBells Oh, I fully get the idea - I just think that you're mistaken that these "insights" confer a significant advantage or are even insights they should gain. (E.g. there's plenty of states of affairs they shouldn't have to learn about because it shouldn't be like that in the first place)

12:11 PM
Okay, instead of sitting around and complaining about how unfair it is for rich kids to have an opportunity that I don't, I decided to see what opportunities do I have that the rich kid does not and that I can turn into something positive and strong, that can help me forward. Sure, it's unfair, but I chose to not pitty myself and fight through it.

I'm not asking you - or anyone, really - to pity yourself.

Some people are prettier, some are more athletic, others are smarter, others are born into rich families. People are difference and the world is unfair. People have different opportunities at different times. Some get the greatest ideas, others do the greatest executions. The world is inherently unfair and unequal. Nevertheless, I've decided to focus on what I can do, rather than what someone else can or can't.
@ACuriousMind Yes, I know, it's nothing personal. I'm just expressing my motivation to achieve my goals despite unfairness and inequality.

@JingleBells I just don't believe that all these inequalities and injustices are inherent qualities of the world. They're features of a human-made system that has evolved and changed over time, not eternal and unchanging. Sure, there is little chance of one single person changing them on their own, but there is no chance of ever changing anything if we all acquiesce and just accept that the world will always be like that,
so I try to be wary of rhetoric that presents very particular aspects of human systems like natural law.

I recall my childhood, feeling l grew up in a dilapidated home compared to others.

@ACuriousMind I respect your views on socialism and communism and I'm not anti-socialist nor anti-communist. I'm also not here to start a debate on capitalism vs socialism, there's plenty of that on the net already. Let's agree to disagree. No hard feelings from me.

12:23 PM
But I always made sure I managed well in schoolwork.
I just didn't know how to manage laundry, so my clothes always looked dirty before I entered university.

@JingleBells It's fine if you disagree with me :) But if you come here and start asking questions about how to make a great business or how to be successful I can't help but reflect on the nature of business or success, just like I start to reflect on the nature of knowledge and science when someone starts asking which quantum interpretation is true ;)

@ACuriousMind I get ya, no worries. Thanks for the help anyways :P

@Slereah But was it really written for that? It would explain the vignette style, for sure

@ACuriousMind not sure
It's a bit more scattered than the more recent books, certainly
just going from one wacky location to the next

Well, that might also be because it's wasn't a fleshed-out world with lived-in places yet
so every location was essentially a series of jokes and nothing more

12:35 PM
mb

2 hours later…

3:25 PM
Becoming an Entrepreneur is sooo hard! First find a problem yourself then find a solution yourself... :-( @JingleBells

@abhas_RewCie Not necessarily. You can always start a business doing something that another company already does, and try to compete with them.
It's not possible in every industry, but there are definitely areas you can start your own business by just doing things well.

@JMac Works when entry barrier is low... When there are lesser companies in the market, then Entry Barrier is unnecessarily high... example, I can't come up with a Search Engine that competes google.

@abhas_RewCie It all depends on what you're doing. You're going to have a hard time competing directly with leading multi-million dollar international tech companies; but starting small local businesses can be very viable in some fields if you can manage the company well.

@JMac These local companies need a very higher capital to start and growth potential is pretty low
If I need something very big to do, then I really need to find problems and ideas.
No alternatives to it.

@abhas_RewCie Local companies need a lot less capital than starting a large international company... Growth potential also starts low, but if you make a place for yourself and are able to both operate and scale well, you can grow a small business over time; and it's actually possible for "regular" people without pre-existing wealth. If you want to do something very big, you basically either need to work your way up to it, or start off rich to begin with.

3:37 PM
@JMac okay...

Just saying, sometimes thinking you need to come up with some special unique idea to make a big company seems like the wrong way to look at it. Ideas are a dime a dozen, and you need a lot more factors than just the good idea to actually make something huge and successful. It seems a lot easier and less risky to take something proven to work and show that you can run even a small company before you try to compete with major companies.

3:58 PM
hooooooooooo boy, is that ever a rabbit hole
researchgate.net/publication/… in case anybody wants to fast-forward
> Fortunately, there are a few persistent localized (PL) microseismic sources on the Earth that continuously radiate strong seismic signals and which are useful for synchronizing seismic networks (the 26 s PL source in the Gulf of Guinea,the 7–15 s PL source on Kyushu Island, and the 26 s PL source near the Vanuatu Islands).
> The PL microseismic sources are similar to the Omega navigation stations in having fixed locations and a monochromatic signal, narrow frequency band, and strongly radiated signals that can be identified at very distant receivers.

@EmilioPisanty So, how many theories that it's ancient Atlantean tech or whatever am I going to find if I go looking? :P

Let's check on vixra
Nothing
Too niche perhaps

@ACuriousMind The Atlanteans pay good money to suppress those articles.

here's an intruiguing theory though

@Slereah Is that like numerology... but with words?

4:31 PM
@Slereah nothing's going to turn the vixra croud off faster than "26s PL microseismic source"
it's quite close to sounding esoteric enough that you could build a conspiracy theory around it
but I don't think it's really there

I mostly think that they don't know about it
but now that it was on xkcd
Just gotta wait a bit

5:11 PM
hm, 26 s sounds too fast for a natural nuclear fission reactor; Oklo had about 3 hours

@FadedGiant it's a couple of orders of magnitude
surely that can be accommodated
I mean, what's the range of possible periods for geysers?

if we could find some natural uranium zirconium hydride 🤔

what is it about zirconium that has all the nuclear engineers orbiting around it to no end?

high melting point (1845 °C) and low neutron cross section (0.185 barn)
so it's nice for fuel cladding
Magnesium alloys were used in early gas-cooled reactor types because of the low cross section (0.063 barn), but the lower melting point of 650 °C doesn't give much safety margin, especially if cooling water leaks in.
Zirconium alloys are passivated in water, so they can be used for reactors that are cooled and moderated with water.

5:33 PM
Don't really see any TOE's on vixra among the recent ones :(

But the fun thing about uranium zirconium hydride is that it has a big negative fuel temperature reactivity coefficient and that you can have fuel and moderator in one material.
So you can make fast and strong pulses.
You can make a reactor safely go prompt critical with that.

user434058
6:40 PM
@ACuriousMind That's not really a positive statement, but idk why, it's eye candy to me. I find it really beautiful... Maybe I am too dark... ::resumes watching Breaking Bad::

An argument for $R_{33} = \sin^2 \theta R_{22}$ in Schwarzschild I haven't seen is from $R_{22} - \frac{1}{2} r^2 R = 0$ and $R_{33} - \frac{1}{2} r^2 \sin^2 \theta R = 0$ we have $R_{33} = \sin^2 \theta [\frac{1}{2} r^2 R] = \sin^2 R_{22}$

@FakeMod I don't really know what you're trying to tell me...how can a statement be "eye candy"?

user434058
@ACuriousMind Idk, it looks good/pleasing to me. Well, I should've said something like a literary candy to my brain...

8:16 PM
@abhas_RewCie wut? ok

Kamala babay

1 hour later…
9:19 PM
Can we always reach every element of a lie group through the left/right translation maps? I feel like this has to be related to it being connected in the topological sense but I can't see this explicitely stated anywhere

@Charlie By "left translation", do you just mean the maps $f_g : G\to G, h\mapsto gh$ for some $g\in G$?

I feel like since they're both diffeomorphisms they are therefore bijections and so have to hit every element
yeah that's what I mean

In that case, exactly what you said - they're bijections

sweet
ty

9:34 PM
I was actually also wondering earlier why we go to the trouble of defining a connection in order to map between different tangent spaces if all we need to do is define the push-forward map
It's still a bit confusing to me that we can define the Lie derivative without a connection by defining the flow of vector fields and using the push-forward map
I guess I don't see what advantage there is to using a connection based derivative as opposed to one that just uses the push-forward/pull-back maps to connect tangent spaces
I still see the push/pull maps as literally just "moving" a (co-)vector to another (co-)tangent space, maybe naively

@Charlie What do you mean "all we need to do is define the push-forward map"?
Are we still in the context of Lie groups here and you're pushing forward by the translations?

hmm
ah no I mean on general manifolds

So what do you want to push forward by, there?

as in along what map?

yeah

9:45 PM
hm
can we not always find a section that allows us to generate a particular flow which allows us to take the lie derivative in the direction we want?
I feel like that was a theorem given in the book i'm on

but the Lie derivative doesn't give you a notion of parallel transport

I guess what's strange to me then is that we can even define a push/pull map that puts "the same" vector/covector at another point if we don't have a connection to define what we mean by "the same"

I still don't know what you mean by the "push/pull map"
Are you pushing forward along some flow?
Then you need to choose a flow there

hmm

The notion of parallel transport/connection does not require any additional choice - I can hand you a vector and a path and say "please transport this vector along this path" and you can just do it

9:50 PM
maybe push/pull operator is more accurate, I'm not sure how to be super precise about what I mean there
but when we transport the vector along the path, we have no notion of whether it is "the same" vector at the end point?
Maybe I'm mistaken in thinking that defining the push-forward of a vector along a map "maintains" the vector in some sense at the resulting tangent spaces we're moving it through

@Charlie It doesn't

because in my head that is the whole point of the connection
ah

A map just acts on vectors through its Jacobian
There is no requirement that this action be bijective, or that it should preserve anything
Parallel transport, on the other hand, is an isomorphism between the tangent spaces
Just take, for example, the map that maps every point on a manifold to a single fixed point. Since it's "constant", its derivatives are all zero and its action by pushforward on vectors is just to map every vector to the zero vector
That doesn't preserve anything useful

I don't see why they necessarily map to the zero vector in this case

Because the action on vectors is the Jacobian matrix, and the derivatives of this map are zero because it's constant, so the Jacobian is the zero matrix
Just do it on $\mathbb{R}^n$ if you have trouble thinking abstractly: The map $\mathbb{R}^3\to\mathbb{R}^3, (x,y,z)\mapsto (3,4,5)$ acts like I said, you can just explicitly compute that it does.

9:58 PM
ok I definitely will need to cover the jacobian in more detail
it's taking me a while to just process what's being said atm sry lol

In coordinates it's just the matrix of all partial derivatives, it's nothing fancy

yeah
I hadn't given any thought to the intrinsic meaning of the Jacobian
like in coordinate free language
I don't feel like it has any meaning there

It's the pushforward :P

hmm

Matrices are linear maps, and the Jacobian at a point $p$ is the linear map $T_pM\to T_{f(p)} N$ induced by a map $f: M\to N$

10:01 PM
oh
I didn't realise it had that special role

And what I just said is also just the definition of the pushforward. We just usually use "Jacobian" for the concrete matrix on some $\mathbb{R}^n\to\mathbb{R}^m$ and "pushforward" for the abstract map $TM\to TN$, but they're really the same thing semantically

so the jacobian is an endomorphism on the tangent bundle
oh wait no
not necessarily at least

It's an endomorphism if your map is a map from the manifold to itself, otherwise it's just a homomorphism between two different tangent bundles

yeah
ok I think I have gathered enough intel to just go and think this through ty

Anyway, I suggest re-reading the definition of "pushforward" until you see it's really nothing but the Jacobian

10:05 PM
yeah I definitely remember seeing it in the definition, I didn't give enough thought to how important the jacobian is as a map I guess
push-forward wasn't explicitely done "with" the Jacobian it was done in coordinates using the chain rule and the big reveal was that the jacobian appears

10:50 PM
If you're doing differential geometry you'd better get the pushforward down because you're gonna be eating a lot of them for submanifolds

Does GR involve a lot of work on submanifolds?

It does!

I've only met the timeslices in the schwarzschild geometry idk if that even counts lol
ok I will definitely revisit that then :P
It actually makes it feel a lot clearer just knowing the Jacobian has this general purpose