The h Bar

ZeroTheHero

02:02

@JohanLiebert did you get your answer on moments of inertia?

Johan Liebert

@ZeroTheHero no

ZeroTheHero

the answer is no: it is not possible.

Johan Liebert

@ZeroTheHero yes I concluded that by making a counter example. What you did for getting the answer?

ZeroTheHero

as an example the cube and the sphere have the same principal moments of inertia so moments about any other axes will be the same.

(if I understand your question correctly).

In fact shape is related multipole expansion of the surface, not to the moments of inertia.

There is some fancy word around solids with same moments of inertia... it has the word “similarity” in it but I don’t remember right now...

”rotationally similar” or something like this... I just don’t remember...

Johan Liebert

@ZeroTheHero yes in my case I did it with a solid and a hollow sphere (both have the same inertia). So I concluded that there must not be a unique solution. Though I would like to see a mathematical treatment of the case.

Shootforthemoon

06:56

Hey, can I spam this group with a question of mine (boutnied since 5 days, no new answers from reputable source...)? XD

Yuvraj Singh...

No, you can, t advertising the question is not allowed in the room. @Shootforthemoon

Shootforthemoon

I know, I was kidding @Yuv

But at max I would advertise knowledge >:P

John Rennie

07:12

@Shootforthemoon hi. This question?

Shootforthemoon

@JohnRennie yep

John Rennie

@Shootforthemoon I'm not sure why you're ignoring the battery.

When a battery is present electrons don't travel round the circuit. Inside the battery a chemical reaction produces free electrons at the anode and they travel round the circuit back to the cathode where the reaction consumes the electrons.

If you don't include the energy of the reaction in the battery then it does look as if the energy isn't conserved, but why would you ignore the energy change in the battery?

Shootforthemoon

Yes, it's quite obvious that a battery is non conservative XD. But in general an emf can be any work that creates a separation of charges, so I don't get why it needs to be conservative

sorry, non conservative

Especially my problem is that closed integral

I don't see how the emf is present all around the circuit, or in some cases (electromagnetic induction) even delocalized

Yuvraj Singh...

07:46

@Shootforthemoon emf is not a mechanical force like you are comparing it.

Electromotive force, abbreviated as E.M.F and denoted by ε, is not a force. It is defined as the energy utilized in assembling a charge on the electrode of a battery when the circuit is open.

Emf is not f it is $E$, it very confusing to me too when I first saw that word and from the user of this website only I got know emf is not a force.

Shootforthemoon

You are right (in fact I said mechanical work :p)

Yuvraj Singh...

So can I paste this as answer.

Shootforthemoon

I saw that also in the comments or answers of some users, that's one reason why I did not consider them reputable sources

@YuvrajSingh... ?

No wait, when I talk about a force in the question I put it in latin to underline that a work (EMF) is done by some hypothetical force and that force must be non conservative as well

Yuvraj Singh...

@Shootforthemoon I ask are you OK with answer like that.

Too extended my above answer , emf a is a measure of the amount of energy added to a coulomb by something. If a battery has an emf of 2V, then it adds 2J to each coulomb flowing through it. If the battery is perfect, then that also means that the potential difference between the two ends is also 2V. If the battery is imperfect, then some of that extra energy may be lost again in the internal resistance of the battery.

Changing magnetic also produces emf.

it is almost always measured in volts in both metric and imperial systems.

Shootforthemoon

@YuvrajSingh... Unfortunately that I already know, maybe I formulated the question poorly, as English is not my mothertongue.

@YuvrajSingh... that's true, emf is a work per unit charge

Yuvraj Singh...

07:56

@Shootforthemoon same here.

But that work in, t simple as f. Ds

@Shootforthemoon rennie sir can help you.

Shootforthemoon

Thanks @Yuvraj

@John do you know any reference or source I could use to address the topic under 360 degrees?

John Rennie

@Shootforthemoon I don't understand what you are asking.

If an EMF is nonconservative then either energy is being supplied or consumed by sme external force, or we have a violation of energy conservation.

With induction we get non-conservation if you look only at the circuit because the external magnetic field does work on the electrons in the circuit.

In a circuit with a battery there is no external agent acting, so if the EMF was non-conservative we'd have a violation of conservation of energy.

Yuvraj Singh...

But sir that violation of energy is not define?

This one sir.

Shootforthemoon

@JohnRennie ok, in the question I make a strange example and say if there was gravity acting on a single side of the circuit say to move electrons downwards towards the cathode (protons fixed), would gravity be nonconservative?

John Rennie

08:12

@Shootforthemoon that's not a physically realistic example. You can't just say gravity only acts on half the circuit.

Shootforthemoon

ok, but emf only acts on half the circuit, no?

John Rennie

If you create physically unrealistic situations you're going to get physically unrealistic rsults.

@Shootforthemoon In a battery the electrons start at the cathode with a higher energy than they have at the anode. That higher energy is supplied by the Gibbs free energy of the reaction in the battery. As the travel round the circuit they gradually lose that initial energy.

Shootforthemoon

That's right, I see that emf provides electrons with more potential energy, but this is done along a single side of the circuit, not on the whole path. If the emf were present on the whole circuit then it would be ok to evaluate the work done by the battery as a closed integral

I don't see instead why we can do such procedure

@John Consider gravity in general, not on a circuit, we can create gravity at a single region in space. if our path is closed but goes outside of that region where gravity is, the work done by gravity may be nonzero.

John Rennie

@Shootforthemoon there are two ways you can look at this. Strictly speaking in a circuit the electrons don't move in a look. Take for example a circuit with a zinc-copper battery. At the anode the reaction Zn -> Zn2+ + 2e generates electrons. Those electrons travel round the circuit and end up at the cathode where the reaction Cu2+ + 2e -> Cu consumes the electrons.

So if you consider a single electron it doesn't complete a loop. So integrating round a loop doesn't describe what actually happens to an electron.

Shootforthemoon

Aha, thanks

John Rennie

08:26

What we'd actually expect is that the integral of the EMF from the anode to cathode is equal to the free energy difference between the electrons in the zinc anode and the electrons in the copper cathode. Which of course it is.

But ...

We tend to ignore this detail and treat the circuit as electrons flowing through the battery.

Shootforthemoon

But so what does integrating mean in this context?

John Rennie

In that case the battery is treated as acting like a pump, and in that model there is an EMF acting inside the battery to pump the eletrons from the cathode to anode through the battery.

@Shootforthemoon potential is the integral of EMF.dx

Or equivalently E = -dV/dx

Shootforthemoon

When we define potential as the work done per unit charge we consider however that each electron completes a loop after an undefined period of time

no?

John Rennie

That's the point I was making above. Rather than worry about what exactly happens in a battery we just assume the electrons flow through it i.e. that they do move in a loop. This isn't actually what happens, but it works fine for doing circuit calculations.

In that case we have to assume there is a potential gradient inside the battery.

There is a sense in which this does exist, because it's the difference in the free energies of the electrons in the zinc and copper (or whatever the battery is made from).

Shootforthemoon

@JohnRennie Ah, so we could demonstrate that the two situations are equivalent via such gradient, right?

John Rennie

08:33

Yes.

@Shootforthemoon Have you studied electrochemistry?

Shootforthemoon

@JohnRennie Thanks very much! I would like to know the proof, but your words already reassured me a bit

@JohnRennie General electrochemistry

John Rennie

I ask because the fundamental equation is the Nernst equation and it works precisely by equating the free energy of the reaction in the battery to the EMF developed across the battery.

Shootforthemoon

We've mentioned it, but never defined it in such way, so I'll take note of that, thanks!

And instead, is motional emf delocalized on a circuit?

John Rennie

To summarise I think the confusion is that in real circuits with a battery electrons don't flow in a loop so integrating the EMF round the loop is inappropriate. In our model circuit electrons do flow round the loop (through the battery) and in that case our model circuit does have a potential gradient inside the battery.

Shootforthemoon

Thanks very much! @John

John Rennie

08:40

@Shootforthemoon do you want me to try and put all this in an answer to your question?

Shootforthemoon

@JohnRennie That would be great! if you have time, of course.

Also if there's some reference you would suggest me for that, I'll follow your advice

user129412

I have a silly question... What happens if I cover a loop of area A with a thin (thicknes << penetration depth) superconducting film, and apply a perpendicular magnetic field? Will I thread a flux through that loop?

John Rennie

@Shootforthemoon actually, rereading your question you're asking something slightly different to what I thought.

Shootforthemoon

09:44

@JohnRennie Ahh, I felt the discussion of before was related but somehow I missed some relationships. Thought it was just me lol

@JohnRennie But still would you suggest something for that?

John Rennie

@Shootforthemoon rereading your question it looks as if you are saying that the electrons have no force exerted on them once they leave the battery. And if there's no force there cannot be any EMF. Is that correct?

Shootforthemoon

10:08

@John Ohh, I see, so that force from the battery continuously works also on the outer electrons (the ones on the wire)?

John Rennie

The electrons in the wire behave much like a gas. In fact there is a model for electrons in metals called the free electron gas.

Shootforthemoon

so isn't it that once a separation of charges have been created and continuously kept by moving electrons at the cathode what happens outside is a result of coulomb's interactions between charges?

John Rennie

In this model what the battery does is compress the gas so the "pressure" is higher at the anode than at the cathode.

So along the wires between the anode and cathode we get a pressure gradient.

The electrons in the wire feel a force because the pressure is higher on one side of them than on the other, and they move towards the lower pressure i.e. towards the cathode.

Shootforthemoon

ohh, wow i see

and that would also explain why an induced emf is eventually delocalized on the circuit?

1010011010

12:19

Howdy, I'm studying Matsubara frequencies again

I have the case where I do have poles on the imaginary axis

Shifting my integration parameter by a small $\varepsilon$ shifts the poles of my weighting function and the pre-existing poles in opposite directions

I'm just a bit confused what the integration path is

Guru Vishnu

13:42

Hi. Some time ago, I saw a question about the possibility of refractive index of red being larger than that of violet such that the spectrum gets reversed in its order. I tried different queries - `spectrum reversed`,`refractive index red`, etc., but couldn't get close to the question I'm looking for. If possible, can someone help me find that question?
Thanks!

Jim

14:09

@GuruVishnu can you give any more specifics because a cursory google search comes up with nothing

Guru Vishnu

@Jim I actually made a search using the search box on the main site and not Google.

I think in addition to the queries I used, you might need to use answers:1 to eliminate duplicate tuples.

Jim

I figured that, but the site's search engine is not nearly as good as google. So I use that when I need to find something specific

Novalium Company

To make video games more relatable and immersive, let's put the player's face as the main character. In that way, the player will feel like he is literally in the game.

Guru Vishnu

Thanks for letting me know that. Do you use site:physics.stackexchange.com while searching on google for searching questions within this site?

Novalium Company

Let's make a local social network. An app that uses GPS tracking to allow other users nearby to rate your look, comment on you and so on... it's an anonymous way for people to know how others feel about them in real life.

Let's make a contact lens mouse. It tracks where you look and moves the cursor there.

Guru Vishnu

14:19

@Jim, I'm looking whether is it possible for the refractive index of red colour in a medium is more than that of violet colour, so that the order in which the colours in the spectrum appear get reversed.

I'm sorry if I'm disturbing you.

Jim

@GuruVishnu I'm not a materials scientist, but generally, the answer is no. That said, some materials have been engineered with various "magical" properties. I wouldn't be terribly surprised if it were possible to create such a material. But my best guess is that one cannot

Guru Vishnu

@Jim Thank you for your help. I was also thinking of the same thing but was unsure of the other possibility.

Guru Vishnu

14:38

@Jim: Just now, I came to know (from your profile) that you did your undergrad in rocket science (aerospace engineering?). I'm also interested to do a career in a space agency. If possible, could you provide any guidance?

To be more specific - which is the best choice amongst - aerospace, electrical, computer science, etc..? I find all of these fields to be related to space sector?

PM 2Ring

@GuruVishnu That's called anomalous dispersion. You might find something useful to you in these questions: physics.stackexchange.com/search?q=%5Bdispersion%5D+anomalous+

Novalium Company

Can we automate automation?

Guru Vishnu

@PM2Ring Thank you. I didn't know that keyword. That query gives a bunch of stuff to read about. It would also help me learn more from google :-)

Johan Liebert

Avoid pen aper scree shot of the answers, try write it, and for more information use meta! — Yuvraj Singh... 4 hours ago

Novalium Company

It's the decade of putting AI everywhere people can find. Why not make a machine that will randomly automate things... donno?

Jim

14:47

@GuruVishnu If those are your only options, aerospace is the one to go with. You will have to do a master's degree to specify your studies in space systems, but that's standard for everyone. I was lucky enough to have the option to do an undergrad in space engineering (none of the aero nonsense, just space stuff), which meant that I technically didn't need a master's degree, although most of my colleagues still went for one

PM 2Ring

@YuvrajSingh... Also, what does "pen aper" mean?

Pᴀᴜʟsᴛᴇʀ2

@ACuriousMind @Chris @DavidZ @rob @Qmechanic - Would you all be interested in the following:

0

Q: What is the angular velocity limit and maximum bank angle of a standard road curve?

I'm trying to declare some simple test conditions for a loaded vehicle where the test will output the maximum limits for that state of the vehicle. In order to calculate the maximum safe velocity, the following parameters must be taken into account: Height of present center of gravity (CG) of...

PM 2Ring

@JohanLiebert I suppose that Yuvraj means that Jujhaar can learn on Physics meta why we don't like screen shots of text & equations.

Jim

@GuruVishnu space engineering, or aerospace if that's what's available, will give you plenty of training in electrical and computer systems. It's the most relevant for working in a space agency, although the other options can provide a path to such a career.

PM 2Ring

Jan 11 at 15:04, by ACuriousMind

> Don't advertise your recent questions. If you just posted something on the main site, give it some time, and don't tell people to go there and look at it. Particularly by pinging people. That's rude. Those who can answer are already watching the queue on the main site!

Guru Vishnu

14:51

@Jim Thank you for you reply. There are still a lot of options which I need to search after my exams. Here there are no courses like "rocket science". Only things are "aerospace" and "avionics" where the latter deals with the electronics part.

Especially, some people say aerospace is slightly modified version of mechanical engineering.

Pᴀᴜʟsᴛᴇʀ2

@PM2Ring - Not sure what that has to do with the price of tea in China?

Jim

@GuruVishnu That's common most places. "Space engineering" is still a new field and most areas do not offer undergraduate programs in it. However, a master's degree will let aerospace students specialize in space systems

Guru Vishnu

@Jim Thank you very much for your time and reply. Are you working in the Canadian space agency? I like the Canadarm's function on the ISS :-)

Johan Liebert

@PM2Ring yes you are. Initially I misinterpreted it but as soon as I realised this I removed question.

Pᴀᴜʟsᴛᴇʀ2

@PM2Ring - Not my question I'm asking about. I'm asking if Physics would be interested in a question which doesn't belong on Mechanics.SE. As a Moderator of Mechanics, I try to give common courtesy before arbitrarily moving questions.

Jim

14:54

@GuruVishnu No, after my undergrad, I decided to leave the space industry and go into physics. I still have strong ties to the industry and many of my former peers and close friends are working for the CSA or in the space industry, but I work at a university.

PM 2Ring

@Pᴀᴜʟsᴛᴇʀ2 I realise that it's not your recent question, but it's still a very new question. ACuriousMind is a moderator & an owner of this room. I was just posting that link to let you know the room policy on linking recent questions.

Pᴀᴜʟsᴛᴇʀ2

@PM2Ring - You still do not understand.

Jim

Incidentally, the Canadarm was a contribution by private company MDA, not the actual Canadian Space Agency itself. In Canada, most of our space industry is privatized with the CSA only managing the front-end/astronauts

PM 2Ring

@Pᴀᴜʟsᴛᴇʀ2 Fair enough. I'm on my phone, so I didn't realise that it wasn't a Physics site question. Sorry about that.

Pᴀᴜʟsᴛᴇʀ2

@PM2Ring - No worries.

PM 2Ring

14:56

Phew! :)

Guru Vishnu

@Jim That's great! If possible, I'd like to discuss some more after all my exams with you. Thank you :)

@Jim I didn't know that. But the mechanism with which it grabs resupply vessels for berthing is brilliant!

Yuvraj Singh...

15:20

@PM2Ring I just said that it is better if we use math Jax and other options on site rather than posting screen shot!

@JohanLiebert does that make sense posting my comment here because I wrote that comment for the OP and he understand that we'll!

Knight

@JohanLiebert What happened here ?

Johan Liebert

@YuvrajSingh... I don't know. I just came now.

Knight

@JohanLiebert It was I who asked it, please click on the arrow (on the left of my message) to see to which of your message I have replied to.

PM 2Ring

@YuvrajSingh... Ok, but I stiil have no idea what "pen aper" means. Is that a typo, or another language?

JMac

@PM2Ring Avoid pen and paper screenshots of answers.

Knight

15:32

May I please know on what topic the discussion is going on?

Johan Liebert

@Knight ah sorry I pinged the wrong person. Actually I was trying to say sorry if it hurt him (the act of posting his comment here). I just wanted to clarify.

PM 2Ring

@JMac Ah! So it was a typo. Well spotted!

Knight

@JohanLiebert When that comment was made and to whom and where ?

LOL

Yuvraj Singh...

@PM2Ring actually I was writing 'pen paper'

PM 2Ring

@Knight Click on the timestamp of the comment. It's a link.

Johan Liebert

15:34

@Knight thats there in the chat above.

Novalium Company

Ra Ra Rasputin Russia's greatest love machine

Johan Liebert

@YuvrajSingh... Sorry. I didn't mean anything wrong. I just wanted to clarify what it means.

Knight

@JohanLiebert Today I talked to that @AbhasKumarSinha

Johan Liebert

@Knight where? FB?

Knight

Yeah

Johan Liebert

15:42

@Knight So you made an FB account or you have one?

Knight

@JohanLiebert I made it

I didn't use social media much

Johan Liebert

@Knight neither do I.

Knight

@JohanLiebert But that guy looks like a kid.

A kid who doesn't know some of the rules.

Johan Liebert

@Knight no he doesn't look like a kid from his photo though!

Knight

@JohanLiebert HAHHA he seemed a thin kid to me

Johan Liebert

15:47

@Knight It's hard to imagine what the other person looks like on the other side just by talking. I used to imagine you as thin guy. (Aren't you?)

Knight

@JohanLiebert Yeah I'm LOL

Doesn't he look like a kid?

Someone 12 or 13 years old?

Johan Liebert

@Knight please delete his photo. He has not given his consent for this.

Knight

@JohanLiebert I want him to come ask me "Why you have posted my image without my permission?" I want him to come here and argue with me

Guru Vishnu

@PM2Ring Usually when I search using the SE search engine, I'd get both questions and answers occupying the results and so I'd use answers:1 to eliminate duplicate entries. Now it seems, if I use that query none of the results turn out. I think, similarly, I could have missed a lot of posts. So could you tell what exactly "answers:1" in the query does? I know it gives >=1 answers but it seems to eliminate some.

Johan Liebert

@Knight don't make him angry and neither it is right.

@Knight yeah! Though his height makes a difference!

PM 2Ring

15:57

@GuruVishnu Sorry, I don't use the internal search very much. I suggest looking at the search help page: meta.stackexchange.com/help/searching

Knight

@JohanLiebert ROFL

Guru Vishnu

@PM2Ring No problem. Thank you for the link :)

PM 2Ring

You're welcome.

Johan Liebert

@Knight are you ready to go to college?

Knight

@JohanLiebert I have applied the application forms

@JohnRennie Thank you for telling me about Tom Waits,

@JohnRennie I'm listening this , it is acting both as comedic and a tragic (his voice seems comic but in actuality the song is tragic)

John Rennie

16:04

@Knight hi :-)

Knight

@JohnRennie Hi

I will practice to talk to everyone in the voice of Tom Waits (there is a very high probability that people will stop talking to me after that)

John Rennie

:-)

I like some Tom Waits. I have his album Swordfish Trombone. But I'm not his biggest fan

Knight

Have you ever tried to speak like him?

John Rennie

No, why would I do that? :-)

Semiclassical

trying to speak like Tom Waits seems like a good way to get laryngitis

Knight

16:10

@JohnRennie Sir have you ever read Leo Tolstoy?

John Rennie

Tom Waits is paid to speak like Tom Waits. I am not! :-)

Semiclassical

also, Tom Waits doesn't need to try to sound like Tom Waits

John Rennie

@Knight I haven't read War and Peace, if that's what you're asking.

Knight

@JohnRennie Yeah, that's very true. I will also get paid for singing like Tom Waits (they will pay me for stopping it)

John Rennie

@Knight :-)

Knight

16:11

@JohnRennie Not necessarily War and Peace but any of his work?

Semiclassical

the two bits of Tolstoy I've read are "The Grand Inquisitor" (from The Brothers Karamazov) and "The Death of Ivan Illych"

both of which I consider quite good

John Rennie

I can't remember. Possibly at school though if I did I have since forgotten it.

Semiclassical

they're each pretty short, so yeah

Knight

@Semiclassical @JohnRennie I read Anna Karenina (my version had 1700 pages and I read about 1400) but the problem is I'm not able to tell why I liked it, but when now I move to some other novel I don't get that feeling which I got from Anna Karenina

Tolstoy's writings are just prolific, but what makes it prolific. The content of Anna Karenina is infidelity (google search says so) but it is everything except infidelity.

In one of the chapter Tolstoy writes "Levin was reading the work of Mr. Tyndall on scattering of light but was disappointed due philosophical mistakes"

Why everyone has become quiet?

John Rennie

@Knight I'm eating lunch.

Knight

16:21

@JohnRennie What is it today?

John Rennie

Chicken

Knight

WOW!

John Rennie

I would have said Tolstoy was prolix rather than prolific.

Knight

yeah! But his first line of Anna Karenina say "All happy families are alike but all unhappy families are unhappy in their own ways"

It contains really really a deep message

JMac

@Knight I'm not sure I really see the "depth" there... That just sounds like a baseless assertion to me. What's special about happy families that makes them all alike, while unhappy families are different?

Semiclassical

16:32

wikipedia has a whole entry on this, heh:

Anna Karenina principle

The Anna Karenina principle states that a deficiency in any one of a number of factors dooms an endeavor to failure. Consequently, a successful endeavor (subject to this principle) is one where every possible deficiency has been avoided. The name of the principle derives from Leo Tolstoy's book Anna Karenina, which begins: All happy families are alike; each unhappy family is unhappy in its own way. In other words: happy families share a common set of attributes which lead to happiness, while any of a variety of attributes can cause an unhappy family. This concept has been generalized to apply...

whether or not it is correct, is another matter entirely. (it supposes that all marriages aim to achieve the same goal, and are to be judged on that criterion.)

John Rennie

@JMac Yeah Tolstoy - CITE YOUR SOURCE!!

JMac

@Semiclassical Yeah, that still seems like a weird as hell perspective to me. "In other words: happy families share a common set of attributes which lead to happiness, while any of a variety of attributes can cause an unhappy family. " What about happiness limits it to a smaller set of attributes than unhappiness? Seems so baseless to me.

John Rennie

There are many roads to happiness (grasshopper)

JMac

@JohnRennie Plus, is happiness really the destination, or the road itself?

Semiclassical

they cite a quotation from Aristotle in that regard. personally, i'd quote the whole of Kierkegaard's "Purity of Heart Is to Will One Thing"

JMac

16:40

@Semiclassical Aristotle's perspective seems to be more based around "good" than happiness. "Purity" also sounds like "good" opposed to happiness too.

Semiclassical

well, "good" and "happiness" are rather closer in Aristotle than they might seem

both being synonymous with "living well"

JMac

@Semiclassical It seems like if you substitute "happiness" for "success" in his argument, and "unhappiness" for "failure", it falls apart completely for me

Although success may be narrowly defined compared to failure, the same doesn't really hold for happiness and unhappiness; which seems to be the whole basis of that line of reasoning.

Semiclassical

sure. i'm just saying that his perspective is very much bound up in what he takes good/happiness to mean in the first place

as for kierkegaard, a relevant quote:
"The person who wills one thing that is not the Good, he does not truly will one thing. It is a delusion, an illusion, a deception, a self-deception that he wills only one thing. For in his innermost being he is, he is bound to be, double-minded. Therefore the Apostle says, "Purify your hearts ye double-minded", that is, purify your hearts of double-mindedness; in other words, let your heart in truth will only one thing, for therein is the heart's purity (p. 25)."

which both indicates the relevance of "the Good" and the fact that he's writing it within an emphatically Christian context (which Aristotle is of course not)

JMac

I don't actually see any reasoning in that Kierkegaard quote... It seems like a religious assertion, but I don't really see how he's connecting that to this topic. Does he establish somewhere else why a "person who wills one thing that is not the Good, he does not truly will one thing" besides the assertion that all are good inside inherently?

Semiclassical

it's very much a religious text, yeah

if one wants to under-gird that with philosphy, I know a good book relating Kant and Kierkegaard in that regard

but, to quote one of the sources i know of, "Kierkegaard, as with several of his edifying discourses, specified that this work be read aloud, since it was intended as a private preparation for public confession." So it's definitely within a religious context and not intended as an abstract philosophical argument.

JMac

17:01

@Semiclassical Well that I can accept. I think I was a bit aggressive here because it's the second time I've seen a Tolstoy quote like that here, where it sounds deep; but it's expressing something as if it's factual when it's just an opinion (the other quote was "In all human sorrows nothing gives comfort but love and faith.")

Semiclassical

what I wonder about is how much is lost in translation there, both in the literal sense but also in the cultural sense

which is part of what I was getting at re: Aristotle and Kierkegaard, where I do know a bit about the relevant philosophical background

that said, I am tempted to agree with the following statement: "All correct solutions to an intro physics problem are alike; each incorrect solution is incorrect in its own way." :P

which may not be literally true, but boy does it feel like it when I'm grading

ACuriousMind

@Semiclassical Well, the space of incorrect solutions certainly is much larger than the space of correct solutions!

@Pᴀᴜʟsᴛᴇʀ2 Probably not, it would likely be closed as 'engineering' here.

John Rennie

I just Googled TeVeS and the first hit Google offered me was the Wikipedia page on Carlos Tevez.

bolbteppa

@Knight Anna K was incredible, Levin's parts are like 3 page philosophical inquiries

John Rennie

ACuriousMind

17:14

I think that tells you something about the relative popularity of physics vs. football :P

JMac

As a Canadian I get a hockey player

Semiclassical

weird, I just get the theory

ACuriousMind

I get a German entrepeneur

@Semiclassical Are you on a university network?

Semiclassical

yeah

JMac

That actually makes a lot of sense. Though you would think the google overlords would know that I actually care more about physics results than hockey ones

ACuriousMind

17:18

Would explain it, I'm sure Google has enough data to see that people from university network more often request sciency stuff than random people and tailor results to that

Semiclassical

right

also, it's a Canadian hockey player

ACuriousMind

@JMac Your IP is likely dynamic and shared by other people, so that they're not tailoring the results uniquely for you

JMac

@ACuriousMind I'm also logged in, so I figured google would know better.

ACuriousMind

Hmmm, true

JMac

darn, the advertisers don't know enough about me personally /s

DanielSank

17:27

Hi, everybody.

Knight

17:38

@bolbteppa Thank you so much for replying. Let’s discuss about it more (if you don’t mind)

@JMac Come on let’s discuss through Q & A about why you find that quote baseless

@DanielSank Hello and welcome to the h bar

JMac

@Knight I feel like I already did discuss why I found it baseless.

Knight

@JMac Would you mind it discussing it once more?

JMac

@Knight I guess? I just personally don't find the quote that deep. It seems over-generalized to the point that it's just blatantly wrong.

Knight

@JMac Well if you find something personally defective then I cannot do anything.

JMac

@Knight Well I think statements like "All happy families are alike; each unhappy family is unhappy in its own way. " should be obviously flawed. It's the same issue I took with your other Tolstoy quote. They might be good observations about typical human nature; but it doesn't mean they can be applied to everyone, as these quotes do.

Knight

17:52

@JMac Nothing can apply everywhere, the thing is that they apply to comapringly more number of people.

bolbteppa

Up next: how poetry is actually just a bunch of untruths :p

JMac

@Knight And yet the Tolstoy quotes you give do choose to use words that apply to all cases (the other example was "In all human sorrows nothing gives comfort but love and faith"). If you're willing to say "nothing can apply everywhere", then shouldn't it be obvious why I find those quotes problematic?

bolbteppa

@Semiclassical PF isolated off all the interpretation stuff to a separate forum, full of Bohm stuff

JMac

(also note that "nothing can apply everywhere" might lead to a bit of a paradox; if "nothing can apply everywhere" you can apply "nothing can apply everywhere" everywhere... which is a bit of a pickle)

Knight

@JMac No it’s not obvious, you find QM logical but it’s doesn’t give any ressonable output in many cases (for example it’s not possible to solve QM equations to study psychology, we have to do it in a different way)

@JMac No it’s not paradoxical, to make it paradoxical you have to use induction and as you know induction can never be made strong

JMac

18:07

@Knight I actually know next to nothing about QM, so I wouldn't really say I find it logical. I know it's a very useful scientific model in some domains; but I wouldn't be able to say it is a true representation of everything. As far as I know science doesn't say that either; there are things that QM doesn't explain AFAIK, and science isn't really about truth claims as much as it is "fits best with what we currently know"

Knight

“Fits best with what we currently know” that’s exactly the matter with those quotes.

JMac

@Knight Not really. I disagree with the notion that it fits best with what we currently know, because I would argue those don't apply to everyone who currently exists or has existed; which goes against the wording of the quotes.

Semiclassical

@bolbteppa yeah, i can't blame them

I may be sympathetic to interpretational questions, but they really don't fall under the same heading as other physics problems

@JMac a relevant quote: "Two sorts of truth: profound truths recognized by the fact that the opposite is also a profound truth, in contrast to trivialities where opposites are obviously absurd." -Niels Bohr

Knight

@JMac It applies to those who exists and have existed.

JMac

@Knight That's where I disagree, again. I don't think either of those quotes can be shown to apply to all those who exist or have existed. In general, it may follow for most; but just because it applies to most, it is not the same as a claim that it applies to all.

That's especially true when you're dealing with personal emotions (happiness and comfort in these examples). There's no objective measure, and people are quite obviously different emotionally.

Semiclassical

18:18

personally I find the question of "is Tolstoy correct" as less interesting than "why did Tolstoy think that"

JMac

@Semiclassical I agree with that; but I still think it's problematic to state things like that without pointing out the flaws in the wording. I think they are interesting ideas and there's probably reasonable motivation behind them; but I'm being presented with them as is. I feel the lack of accuracy obscures any depth by speaking too authoritatively about something which is anything but.

bolbteppa

@JMac the famous works of literature must be very tough to read, they are full of these statements

Semiclassical

an easy response to that would be that "it's a novel, it doesn't have to be literally true." but that assumes people -don't- treat such pronouncements as literal

(as I think is evident even in this conversation)

JMac

@Semiclassical One issue that is biasing this conversation for me is that Knight did try to use one of those quotes as literally true in a conversation with me the other day. My other issue is Tolstoy's strange choice to add in the words like "all" and "each" when omitting them would have still pointed to the same things without trying to paint everything with the same brush.

bolbteppa

@vzn you might find this interesting

Semiclassical

18:27

@JMac for the latter, I'd respond with "it's a novel" (though I appreciate that it may be stylistically distracting). for the former...yeeeep

JMac

@Semiclassical True, it's a novel. But I still think the observation would feel a lot "deeper" to me if it didn't try to over generalize. I guess it's just personal, but for me that overstating often ruins the depth, even if it's presented in literature and not as some philosophical fact. It appears to be presenting itself as a fact in the literature... and at what point do you draw the line between a story and the authors actual philosophical beliefs?

Semiclassical

this is a hyperbolic comparison, but that complaint feels like the equivalent of getting into knots over someone saying "I am lying."

people say overly-general stuff all the time

but it does go to matters of taste/preference and in that regard is not up for debate

bolbteppa

@Slereah Tong has new gr lectures, likely going to replace Carroll as the usual reference given online

Semiclassical

@jmac also: smbc-comics.com/index.php?db=comics&id=1903#comic

bolbteppa

These GR notes look amazing tbh

bolbteppa

18:51

"3.1.4 A Sniff of Hodge Theory"

Knight

@JMac Okay, I’m getting you, your main problem is that Tolstoy made it a general satement and according to you no one should ever say anything for general, ha?

That’s same as no “no decision is perfect but some are better”. So, since those quotes apply better in some situations therefor I tend to use them.

JMac

@Knight You can say things about people in general, just when you add "all" to it, it weakens the point quite a bit for me. Especially because you used a similar Tolstoy quote when talking to me a few days ago and acted like it did apply 100% to everything because of Tolstoy's word choice.

Semiclassical

personally, I want to believe in the literal truth of Bad Lip Reading

Knight

@JMac Question 1: Where (if ever) should we use the word all ?

Question 2: Whenever a man acts on something he acts on some principle to which he thinks is true. On that day you thought that that didn’t apply to Abhas, didn’t you acted on your belief which you assumed to be true?

JMac

19:08

@Knight When you can justify that it actually applies to all cases. I don't think it does for the things Tolstoy talks about, that's why I disagree with it. He's talking about human emotions, which are quite complex and not nearly so easy to universally distill into rules like that.

@Knight I literally have no idea what you are trying to say with this question 2.

Knight

“When you can justify that if actually applies to all cases “ give an example of that.

@JMac On that day you assumed that “In all human sorrow...” doesn’t apply to Abhas, that’s the same thing as I assumed that it applied to him.

JMac

@Knight In science, you can say things "apply to all cases" when it's been reasonably shown that there are no known exceptions or reasons to be exceptions. Now obviously that could change if an exception is found, so it's implied that it's all known cases. If we apply the same reasoning here, I would argue that there are cases where Tolstoy's quotes do not apply, so we can show they are wrong for all known cases.

@Knight No, I actually said I didn't understand how that quote applied to our conversation, and I disagreed with that quote in general because it was trying to make a statement about every human that I felt was incorrect, in the same way as this other quote.

Knight

@JMac For Tolstoy it applies to all known cases, for me it applies to all known cases.

@JMac I have found it to be valid in all cases.

JMac

@Knight Okay, well I find comfort in a lot of things that are not love or faith (assuming you don't stretch those definitions until they are vague and meaningless). Unless you are only willing to believe I'm lying, you should now have reason to suspect that quote is actually wrong.

Knight

@JMac Then I must say that you have never been in sorrow.

Semiclassical

19:22

I’m just gonna leave this here...

en.m.wikipedia.org/wiki/No_true_Scotsman

ACuriousMind

Denying all evidence for exceptions to a rule is certainly one way to make the rule apply to "all known cases".

2

Knight

When I said “you have never been in sorrow” that’s a very logical point as for me the state in which you don’t find comfort from love and faith is really not a sorrow from my perspective.

Semiclassical

(“No person who had experienced sorrow would deny X.” “I’ve experienced sorrow and I don’t believe X.” “Then you didn’t truly experience sorrow.”)

Ah, and now I have a reason to cite this: en.m.wikipedia.org/wiki/Persuasive_definition

Checking a lot of boxes today

ACuriousMind

The first rule of tautology club is the first rule of tautology club.

JMac

@Knight You used sorrow in the context of someone leaving the hbar/Physics SE. You're moving the goalposts a lot here. I have no way of knowing how much "sorrow" he experienced due to that... but based on events in my own life I feel it's only fair to assume I've experienced at least some equivalent amount of sorrow how I understand the word.

Semiclassical

19:30

@ACuriousMind tbf, modus tollens is a valid inference...so long as the implication is valid in the first place, of course

Knight

@JMac See we have reached where we assume things

Semiclassical

An argument does generally rest of assuming that the participants are rational beings, yes.

Though this conversation is making me question that.

JMac

@Knight Yes, and I think you saying I've never been in sorrow is a really really bad assumption that is basically just ignoring evidence based on personal preference.

Knight

@JMac “You have never been in sorrow” because love and faith doesn’t comfort you.

JMac

7 mins ago, by ACuriousMind

The first rule of tautology club is the first rule of tautology club.

Semiclassical

19:37

@Knight Good lawd this is condescending

JMac

@Knight If you define sorrow to be that which love and faith comforts, then sure, that quote is right, but that is just a tautology.

Semiclassical

“You don’t accept my viewpoint of what sorrow is, so you can’t have sorrowed.”

JMac

No true sorrowsman.

2

Knight

@JMac Yes, and to prove that the definition of sorrow is not that you need to assume few things.

And people have different assumptions and mine was “love and faith” one.

Semiclassical

Why is it our job to prove your definition wrong?

Knight

19:41

Not your job.

JMac

@Knight No, I just need to pull up a dictionary to see how people usually define sorrow and see that it is not specific to love and faith in any common use of the word. Then it's up to you to connect those dots.

Knight

“How people define sorrow” aren’t you using generalisation?

JMac

@Knight Are you trolling or actually trying to have a discussion right now?

Knight

@JMac How am I trolling?

JMac

@Knight I assume people are using words the way they are meant. Can you point out at least where Tolstoy defines "sorrow" as "love and faith" besides that quote. If not, I have no reason to assume he isn't also using an English definition of the word. If he's not using the English definition, it again goes back to it being a bad quote, because it's very misleading.

The same also goes for changing the words love and faith until they fit with sorrow, twisting the definitions.

Knight

19:46

@JMac If I use my definition of sorrow for understanding that quote then I find it true, if you use your definition of sorrow then you’re finding it wrong. How to get agree on what sorrow is?

Semiclassical

As poetry, it’s a fine enough quote. As a definition, it’s rather silly. As grounds to define away other peoples’ experiences of sorrow, it’s reprehensible.

JMac

@Knight How is your definition really a definition and not just a circular assertion denying the practical use of the word? Why bring it up in the context of Abhas? Were you not assuming he was in sorrow based on the traditional definition?

Knight

@JMac I can define things anyway I like.

Semiclassical

You’re free to try, I guess.

ACuriousMind

Communicating badly and then acting smug when you're misunderstood is not cleverness

2

Knight

19:51

Just the same way we defined $W = F d$ as it was very useful

ACuriousMind

(there's an xkcd for everything)

When you use common language words people will assume you are using their common definition. Insisting on your own definition without explaining it up-front is a bad communication strategy at best and intentionally misleading at worst.

JMac

@Knight Well there's no point in talking to you if you are going to define words your own way, instead of an English definition; without first making it clear how you are using those words. Especially if we relate it to the context you used it. You tried to make a point by saying "In all human sorrows nothing gives comfort but love and faith." By your definitions, you said "In all human things which can be comforted by love and faith, nothing gives comfort but love and faith."

Even with your own definitions you didn't really say anything.

Aaron Stevens

I just got here... but I am experiencing some deja vu

Knight

@JMac Why I cannot define sorrow the way it is useful to me and apply to people whom I know?

Semiclassical

Because sorrow is intensely personal and you’re treating it as some sort of word game

JMac

19:57

@Knight chat.stackexchange.com/transcript/message/53302134#53302134 Please look back on the context you used the quote. You were communicating nothing and saying it was your grounds, if your definition of "sorrow" is that which can be comforted by love and faith.

Aaron Stevens

@Knight When you use words in a way no one else knows you are, then no one will be able to understand you

Knight

@JMac Yes because I believed that Abhas was in sorrow (the way I feel sorrow) because I talked to him with love and faith he felt comforted.

JMac

@Knight Well then like I mentioned, there's really no point in trying to talk to you if you're going to be using your own secret definitions of words all the time that don't comply with common English.

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