The h Bar

Krishna

00:59

@FakeMod did you notice that I used two 's's for disappointment? Wonder why I did that. (Just ignore it, please)

Captain Bohemian

02:12

It's great to be able to see the sunshine when getting up every morning. When in a room where there is no window straightforward directing to the outdoor, I can't see the sunshine day or night and feel like being in a dungeon making me feel somewhat depressed.

Sir Cumference

03:06

excuse me what

changes to a numpy array apply to everything previously assigned to that array?

spent an hour trying to figure out what was wrong with my code, who would expect that

Manas Dogra

Yes "=" goes bothways..really makes things difficult in Python...
and this happens for many other objects other than numpy arrays too

8

Q: How does python assign values after assignment operator

Okay a very silly question I'm sure. But how does python assign value to variables? Say there is a variable a and is assigned the value a=2. So python assigns a memory location to the variable and a now points to the memory location that contains the value 2. Now, if I assign a variable b=a the ...

Sir Cumference

@ManasDogra whaaaaa....

Manas Dogra

happens for python list appending too :)

only way I saw to get around this is using deepcopy

Sir Cumference

03:22

why can't this language just be normal

Manas Dogra

@SirCumference ask Rossum :p

Sir Cumference

thanks for the link tho, good to know

Manas Dogra

@SirCumference code for what you supposedly wanted to achieve

Why What Where When How

Is that python? Ewww

Manas Dogra

@WhyWhatWhereWhenHow why "Ewww"?

Why What Where When How

03:38

@ManasDogra Because I only learned cpp and not python 😂😂😂 so I don't understand it.

abhas_RewCie

(removed)

yo coolio

Why What Where When How

@abhas_RewCie sup{}

@abhas_RewCie have you search 1s1k hunter in yt?

abhas_RewCie

@WhyWhatWhereWhenHow No bro... I searched youtube in youtube and twitter in youtube

Why What Where When How

hunter1s1k

abhas_RewCie

@WhyWhatWhereWhenHow I don't like music

Why What Where When How

03:47

@abhas_RewCie But hunter1s1k is also in youtube so search it in youtube then you go to youtube to search after you search on youtube then you search it okay

abhas_RewCie

@WhyWhatWhereWhenHow I searched Youtube for youtube to find hunter1s1k on youtube, but searching hunter1s1k on youtube lead be to even bigger youtube

Why What Where When How

@abhas_RewCie I have a feeling that whenever you talk in chat I hear him talkin by screaming.

@abhas_RewCie Then how you lead it to smaller youtube? Have you find any bound of youtube or is it boundless?

abhas_RewCie

@WhyWhatWhereWhenHow No, I'm silent

@WhyWhatWhereWhenHow Youtube is boundless when you have smaller youtube and bigger youtube together, but I only have smaller youtube, I don't give a damn to bigger youtube, because there is a youtube inside youtube that can youtube upto the youtube of the youtube youtube youtube youtube youtube

Why What Where When How

@abhas_RewCie abhas he has read entire bible in 9 hour without formally reading it.

abhas_RewCie

@WhyWhatWhereWhenHow coolio

Why What Where When How

03:53

@abhas_RewCie I said where is sup youtube and inf youtube search for it. I know youtube can create youtube where youtube is in youtube and all of it in single YouTube that goest to infinite youtube but in order to prove it is infinite we need to prove it is not bounded by a large or small youtube even you watching youtube there is youtube outside your frame of observation.

Susan Wojcicki is a true loop genius.

abhas_RewCie

@WhyWhatWhereWhenHow The frame of observation is infinite, see youtube when youtube is of the bigger or inf bounded condition youtube is the youtube best youtube o youtub o youtube coolio youtube coolio youtube

Why What Where When How

@abhas_RewCie what kind of frame is youtube? It is really becoming abstract.

abhas_RewCie

@WhyWhatWhereWhenHow It's rounda

Why What Where When How

@abhas_RewCie I have a conjecture that says youtube has uncountable sets of frame.

abhas_RewCie

@WhyWhatWhereWhenHow I've a even better conjecture that says that youtube has countable sets of frame

Why What Where When How

03:59

@abhas_RewCie I'd contradict your conjecture!

abhas_RewCie

@WhyWhatWhereWhenHow I'd contradict yours

Why What Where When How

@abhas_RewCie Then there is no cases left. So we need to define something that is uncountable and countable at same time.

It is similar to schrodinger cat.

abhas_RewCie

@WhyWhatWhereWhenHow No. We can assume it's true, rest is okay

Why What Where When How

@abhas_RewCie May be it has conditions of outcome! I can't believe in every outcome is uncountable and countable at same time.

Yes it has condition.

abhas_RewCie

@WhyWhatWhereWhenHow Nof

Why What Where When How

04:10

The condition was already held when we contradict each other.

abhas_RewCie

@WhyWhatWhereWhenHow no

Why What Where When How

@abhas_RewCie y,x,z?

abhas_RewCie

@WhyWhatWhereWhenHow x, y, z, t

xxx

yyy

zzz

ttt

Why What Where When How

(removed)

abhas_RewCie

(removed)

Madame Akira

05:46

Page 35 :- atomic spectral lines have discrete energy values.
Page 251 :- nooooooo. How can they be infinitely sharp, they have a width whyy ? due to **Heisenberg**
** Uncertainty Principle**

$\delta E \cdot \delta t \leq \frac{h}{4 \pi}$

Guru Vishnu

Wondering why formatting doesn't work?

Hint: Don't use Shift+enter

Madame Akira

of course I am

~~let's try you suggestion on strikethrough~~

---this time I'll use shift enter---
no it doesn't

@GuruVishnu very nice suggestion

user434058

Yo! I asked my first question.

Yuvraj

06:37

@JohnRennie hi

John Rennie

@Yuvraj hi :-)

abhas_RewCie

07:01

@JohnRennie Hello

John Rennie

@abhas_RewCie hi :-)

abhas_RewCie

@JohnRennie I asked you for a formula...

Angle of deviation of ray of light in curved spacetime

John Rennie

Light deflection in a gravitational field.

For light passing a black hole?

abhas_RewCie

I tried searching for it, but didn't find

John Rennie

Or any massive body?

abhas_RewCie

07:04

@JohnRennie No, not blackhole, just general

@JohnRennie general formula that can work for blackhole, massive body and normal body

John Rennie

8

A: Bending of light - photon's inertia instead of mass

In Newtonian gravity the acceleration due to gravity is independant of the mass of the object - a falling elephant accelerates downwards at the same speed as an accelerating gnat (ignoring air resistance). That means the orbit of an object does not depend on the object's mass (provided the object...

Also:

30

A: How can gravity affect light?

Newton's law does predict the bending of light. However it predicts a value that is a factor of two smaller than actually observed. The Newtonian equation for gravity produces a force: $$ F = \frac{GMm}{r^2} $$ so the acceleration of the smaller mass, $m$, is: $$ a = \frac{F}{m} = \frac{GM}{r...

@abhas_RewCie Were you asking where it is in a book?

Yuvraj

contradicting to what einstein believe

abhas_RewCie

@JohnRennie yes

I want to see how it was derived

John Rennie

What GR books have you got?

abhas_RewCie

@JohnRennie Schutz

John Rennie

07:08

Let me dig out my copy of Schutz ...

abhas_RewCie

ok

John Rennie

p293 in my edition

abhas_RewCie

@JohnRennie Oh okay, I'll find that

@JohnRennie Thanks :)

John Rennie

I need to work now for a bit. Back later ...

Captain Bohemian

07:59

the weather is so hot that walking outdoors feels like being broiled.

Madame Akira

08:14

@Yuvraj @FakeMod have you guys solved Irodov ?

user434058

08:38

@MadameAkira I have solved 90% of Mechanics (excluding SR), and a bit (20%) of Electromagnetism and about 50% of Waves and Oscillations.

Rudi_Birnbaum

Hi all, I came across a complex vector field $\mathbb R^3\to\mathbb C^3$ with an imaginary part with zero divergence and real part with zero curl. I wanted to ask if anyone knows any other such fields and what other properties to expect from that or where such things else naturally could occur.

Madame Akira

@FakeMod the electromagnetism is not differential right ?

I mean I have never read it so I am not sure to what extent it covers electromagnetism.

user434058

@MadameAkira You can solve it using both the forms. Though Irodov (Arihant version) has mentioned only the point form of Maxwell's equations in the short theory section preceding the questions...

Yuvraj

@MadameAkira yes not all but electrodynamics and mechanics

Madame Akira

@FakeMod hmmm

@Yuvraj you're in IIT right ? for engineering or physics ?

user434058

08:49

:54400064 which branch?

user434058

@Yuvraj oh, nice :)

ACuriousMind

@Rudi_Birnbaum That's what the "Faraday field" $F = E + \mathrm{i}B$ is when there's no magnetic field

But of course the proper formulation of combining $E$ and $B$ into a single object is to use the EM tensor, not this (decidedly not covariant!) construction. I've seen it in some places, though

In general, complex vector fields in physics will often be of this type of being combined from two real fields, since we measure real, not complex, numbers with most measurement devices, so it is unnatural for a (classical) physically relevant quantity to be complex-valued

Yuvraj

09:04

@ACuriousMind hi

It's just representation which makes working and visualizing functions

JingleBells

09:18

How is the image projected not too close for the user too see?

I'm was wondering the same for other AR devices

(Google Glass?)

For example, on the Hololens 2, isn't the projected image too close to the person's eyes and therefore blurred and hard to focus on?

ACuriousMind

@JingleBells When you focus on something in a well-projected 3d image (VR or not), you focus on the apparent distance of the object in the image, not on where the screen is.

John Rennie

@JingleBells the optics create a virtual image at a reasonable distanec from you.

Sha Vuklia

10:22

How can I see here that the right matrix $L$ is a Lorentz boost?

That $\epsilon$ stands for time reversal, and $Q$ for spatial rotations, is clear

Also, I'm unsure of the mathematical definition of a Lorentz boost. But I'm guessing it's just boosting a frame with a velocity in a fixed direction (for all boosts)

Rudi_Birnbaum

10:47

@ACuriousMind Thanks a lot, that is very interesting. I came across that when looking at the quantum mechanical "mechanical momentum density" of an electron in the magnetic field. The imaginary part is essentially the electrons current density, that is divergence free. But then there is this "odd" real part, that I fail to understand/give an interpretation to. Its curl-free and contains for example the gradient of the electron density. In non-spin zero cases its contains also some spin terms.

@ACuriousMind would you have any idea what that might be?

ACuriousMind

@ShaVuklia Apply $L$ to a vector $(t,x,y,z)$ and observe that it transforms the coordinates like a boost would do. Otherwise take this as the definition of a boost.

@Rudi_Birnbaum Why would a momentum density be complex and not real?

Are you just talking about the wavefunction in momentum space?

Rudi_Birnbaum

The Quantum mechanical momentum density is complex in general.

$\psi^*\hat{\pi}\psi$

ACuriousMind

And $\pi$ is just the momentum operator?

Rudi_Birnbaum

with $\hat{\pi}=\hat{p}-A$

no

its the "mechanical momentum" in the the magnetic field

ACuriousMind

but what is that supposed to be?

Rudi_Birnbaum

10:54

$A$ the vectir potential

ACuriousMind

i.e. what physical relevance do you think this term has?

Rudi_Birnbaum

this is called "mechanical momentum density"

and its used to define the probablility current density

$J=\Im\{\psi^*\hat{\pi}\psi\}$

some call it also "kinetic momentum density"

and I have heared the name "kinematic" as well

ACuriousMind

I have never had any reason to worry about this quantity at all, I'm afraid

so I can't tell you anything about it, sorry

Rudi_Birnbaum

Well I am not really worrying. but since $\hat{\pi}$ is a good old gauge independent operator, there is no reason not to regard its density distribution

OK but thanks that Faraday density thing is already quite helpful

Is it possible that its something about "forces"

?

like virtual forces?

ACuriousMind

there aren't really any forces in QM

Rudi_Birnbaum

11:02

:-(

Sha Vuklia

@ACuriousMind do you recognise this instantly as a Lorentz boost?

this is a general expression I found on stack

I am willing to believe that if one does the calculations, it turns out alright

but

hm, I'm a bit scared to just claim it's true without checking it (but the calculation seems aweful)

ACuriousMind

@ShaVuklia No. Note also that (I think) the "velocity" $\lambda$ in that expression is really a rapidity

bolbteppa

12:09

@ShaVuklia quora.com/…

Sha Vuklia

12:38

@bolbteppa A thanks, might have a look at that later!

abhas_RewCie

13:04

@ShaVuklia What is lorentz boost?

PM 2Ring

13:28

@SirCumference That's because of how name binding works in Python. It can be confusing if you've already done some coding in languages that use a different data model. There's a great article about this: nedbatchelder.com/text/names.html

That link's in a comment on the page linked by Manas, but I reposted it here, just in case you missed it. ;) For a TL;DR see here

@SirCumference I should also mention that assignment operators, eg += can be a little surprising when operating on mutable objects, so if foo and bar are (the names of) lists, foo += bar extends the existing list bound to the name foo, but foo = foo + bar creates a new list, and binds that to foo.

abhas_RewCie

@MadameAkira Completed, (Including QM)

:-P

But, QM not full.... (around 60% of part), will take a shot on SR Part

abhas_RewCie

14:12

@FakeMod Zinda hai ki marr gya?

Madame Akira

@ACuriousMind so it's like those 3d spoons on paper we see ?

@abhas_RewCie keep bluffing :-p

user434058

@abhas_RewCie Main Schrodinger's Mod hu...

abhas_RewCie

@MadameAkira I'll do more... I'm getting bored :P

@FakeMod Glad you told me, I need a microscope to see your profile clearly

user434058

@MadameAkira I eat all my meals on one of those...

ACuriousMind

@abhas_RewCie English, please.

abhas_RewCie

14:17

@ACuriousMind sorry...

ACuriousMind

@MadameAkira I don't know any 3d spoons, I'm afraid

abhas_RewCie

translation: alive or dead?

@ACuriousMind Have you ever been to China before?

ACuriousMind

Before what?

I'm not in China now, either!

user434058

@ACuriousMind before he asked you :P

abhas_RewCie

@ACuriousMind before this text?

@FakeMod Wanna take a course on bathroom singing?

user434058

14:20

@abhas_RewCie I am a pro...

abhas_RewCie

@FakeMod Have you recorded before?

Krishna

@MadameAkira There is nothing worth reading anyway

@FakeMod, is there anything like close flag?

user434058

@abhas_RewCie who the heck records bathroom singing man!!!

user434058

@Krishna what?

abhas_RewCie

@FakeMod Parallel lines have so much in common. It's a shame that they never meet...

2

ACuriousMind

14:21

@Krishna What? I think there are much more things worth reading than one could ever reasonably read in a lifetime!

Krishna

@Fakemod, when did I talk about bathroom singing?

abhas_RewCie

lmao

Krishna

@ACuriousMind I was talking about Fakemod's profile picture

user434058

@Krishna oh, I un-pinged you

user434058

@abhas_RewCie they do meet in private, don't you know? :D

abhas_RewCie

14:23

@FakeMod lol...

user434058

@ACuriousMind yo, ACM! How's life?

Krishna

By the way, as I asked, is there any close flag?

ACuriousMind

It...lives.

abhas_RewCie

@ACuriousMind How not to get bored in lockdown?

ACuriousMind

@Krishna If you add enough context so that we know what you want to flag to close, you might get an answer to that :P

user434058

14:25

@ACuriousMind Nice

Krishna

No, I was just asking. There is a deletion flag, so I imagined...

user434058

@Krishna are you talking about answers?

ACuriousMind

Do you mean on the main site or in chat? On questions or on answers?

Krishna

Questions

user434058

@ACuriousMind I have raised 0 flags in chat :(

Krishna

14:26

Main site

ACuriousMind

Sure, if you have less than 3k reputation, you should be able to raise a flag suggesting to close a question. Can't you see it in the flag dialog?

@FakeMod Why would you be sad about that?

user434058

@Krishna there is no flag for deletion... There is a flag for "not suitable" and "needs clarity" and "needs focus" and "duplicate" allo of which result in a closure...

ACuriousMind

I'd take it as a good sign that you haven't encountered anything flagworthy in chat, since that's usually rather unpleasant.

user434058

@ACuriousMind sad about the fact that I haven't yet tried that out...

user434058

@ACuriousMind yeah, I know. Let's drop this.

ACuriousMind

14:29

Again, please do not discuss piracy sites explicitly here.

abhas_RewCie

which liberary?

library

ACuriousMind

→ 8 messages moved to Trash

Yuvraj

@ACuriousMind ok

abhas_RewCie

@ACuriousMind quick tho

Yuvraj

I was not aware that it is pirated site

abhas_RewCie

14:30

@ACuriousMind It is a pirated website?

user434058

@ACuriousMind alright.

user434058

@abhas_RewCie yes

Yuvraj

@abhas_RewCie @ACuriousMind without disclosing the name ,can you say?

abhas_RewCie

@FakeMod Ah okay... Home page had it...

ACuriousMind

@Yuvraj As a general rule, any site that allows you to download copyrighted media for free is very likely to not be legally allowed to do that.

abhas_RewCie

14:31

@Yuvraj I use archive.org, it's fully legal with lic on each book you see, usually CC if they have purchased copyrights

@ACuriousMind archive too?

Yuvraj

what should i do i have downloaded some books @abhas_RewCie

Madame Akira

@ACuriousMind those youtube video with people drawing spoons on paper with specific shading in diff. areas just to make them look if there was an actual spoon on the paper.

ACuriousMind

@abhas_RewCie Archive usually only offers material that's in the public domain or otherwise legal to be offered.

abhas_RewCie

no idea

Yuvraj

@abhas_RewCie ?

Madame Akira

14:34

@Yuvraj you are in your bachelors and still don't know sites to get books without buying them ? I ain't buying this.

ACuriousMind

@MadameAkira I don't spend my life on youtube and therefore have no idea what you're talking about :P

abhas_RewCie

@Yuvraj no idea, never tried that website, so delete after reading them

user434058

@MadameAkira meh, I wasn't talking bout that...

Madame Akira

@ACuriousMind yes your REP speaks for itself.

abhas_RewCie

@ACuriousMind Your childhood was not awesome :P

Yuvraj

14:35

@MadameAkira i never visited such site before we usually use the library for books, lockdown make me stuck

@abhas_RewCie delete?

what?

abhas_RewCie

@Yuvraj first read and complete the book, then delete it

user434058

BTW, I just notice that the "Trash" chatroom is a gold-mine of entertaining messages :P

abhas_RewCie

if you've downloaded

ACuriousMind

@abhas_RewCie It was pretty awesome, actually.

abhas_RewCie

@FakeMod same here

@ACuriousMind How?

did you ever hard friends?

user434058

14:36

@abhas_RewCie he played video games

user434058

@abhas_RewCie wot?

Yuvraj

@abhas_RewCie it will take some days to finish them off

ACuriousMind

Given past experience of talking with you about my personal life, I'm not really interested in going into detail.

abhas_RewCie

Ah, Neither I

Yuvraj

@abhas_RewCie actually site has millions of books

abhas_RewCie

14:38

Ah, I see it, thanks

@Yuvraj aarey! Read, enjoy, complete then delete, is that too hard to understand?

@FakeMod had*

user434058

Now it's of no use

Yuvraj

@abhas_RewCie means not to forward them

abhas_RewCie

@Yuvraj Okay

@Yuvraj yes

Was that deleted?

Yuvraj

yes

abhas_RewCie

Good then

Yuvraj

14:40

and i made images do you want to see them

warmhole?

@abhas_RewCie

abhas_RewCie

@Yuvraj Okay, I'll see later.

Bye

user434058

@Yuvraj how did you do it?

Yuvraj

@FakeMod what?

user434058

@Yuvraj how did you create the image of a wormhole?

user434058

Software?

user434058

14:42

Code?

user434058

How?

Yuvraj

just a rough sktech

user434058

@Yuvraj ah, ok.

Guru Vishnu

A chemistry question: Which coloured IUPAC book is meant for nomenclature rules? I know gold book is for terminologies.

Blue, red, green or something else?

Especially I'm looking for nomenclature of coordination compounds.

Or if anyone knows: Which is the recommended IUPAC name for the ligand (NH2 CH3) - 'methylammine' or 'methanamine'?

user7951

15:02

@GuruVishnu red

"methylamine" if you mean something like dichloridobis(methylamine)copper(II)

Guru Vishnu

Fine. That was my choice too. My book said used "methanamine" and that's why I got confused. A small clarification, shouldn't we use "ammine" instead of "amine"?

That was for the complex - [Pt(NH3)2Cl(NH2CH3)]Cl (book's name: Diamminechlorido(methanamine)platinum(II) chloride) whereas I took (methylammine).

Captain Bohemian

The weather is so hot, even at night 11 pm.

30 C indoors. don't know the air temperature outdoors.

user7951

@GuruVishnu The Red Book also has diamminechlorido(methanamine)platinum(II) chloride

It's not clear in the Red Book when they use methanamine or methylamine. Both were correct names in organic chemistry when the Red Book was printed.

Later, however, the Blue Book clarified that methanamine is preferred. But that's for the organic compound, not necessarily for the ligand.

Guru Vishnu

15:18

Ok. Got it. It was in the page 164 (here). I thought for NH3 they used "mm" instead of "m" so expected the same here. It seems it doesn't matter.

Thank you very much for your help :-)

user7951

Yes, the mm is only used for NH3 ligands.

Guru Vishnu

Ok :-)

user7951

@GuruVishnu You also might want to get this one: doi.org/10.1515/pac-2014-0718

And the supplementary material: degruyter.com/supplemental/journals/pac/87/9-10/…

Yuvraj

@CaptainBohemian it is almost 47 in day

and in night 35

feel like burning always

Captain Bohemian

@Yuvraj I feel like to eat two bowls of ice within a day.

Yuvraj

15:25

indeed

we face a huge scarcity of groundwater during these months , which make us understand the value of each water drop

@CaptainBohemian extreme summer is always harsh to spend

Guru Vishnu

@user7951 Thank you for sharing. I like the brief version in particular. It's just 4 pages and it'll definitely be helpful :-)

Captain Bohemian

@Yuvraj I think we don't lack water. What most people lack is probably money.

Yuvraj

lol;'

Captain Bohemian

15:40

water is mostly free when you rent a house

you can get as much water as you like to drink from water machine freely.

JingleBells

16:16

@ACuriousMind What do you mean?

Jake Rose

Why for a bound orbit is $\frac{du}{d\psi} = 0$ where $u=1/r$ and $\psi$ is the angle?

JingleBells

@JohnRennie What do you mean? The Google Glass and some other AR devices seem to put the image pretty close to your eyes

Jake Rose

Oh never mind

It's just really bad wording I think

It specifically means at the apoapsis and periapsis

@aaronstevens Why the hate for Ve?

@BioPhysicist

BioPhysicist

16:43

@JakeRose It just doesn't make much sense to me. If you're going to try and abbreviate things, why not just do "+" and "-"? Also, "+" isn't "positi" and "-" isn't "negati".

user434058

@BioPhysicist I am waiting for your post on Meta. I didn't star that message for nothing :P

user434058

It seems like @Loong also anonymized himself (though he was already anonymous, but now he's even more anonymous...)

Sebastiano

17:05

Good afternoon from the Sicily island everybody into chat. My question

0

Q: How can I calculate the emf-induced with a non-planar surface?

Just this question is only for me because I have given any clarifications on the Faraday-Neumann-Lenz for my students of an high school. We know that the magnetic flux, where $\:S$ is a regolar surface, (with all the hypotesis of regularity, $B\in\mathcal C^1$, etc.), is given by the formula: ...

calculus integration derivatives physics surface-integrals

is coherent in Math.SE or in Physics.SE?

Jake Rose

@BioPhysicist I quite regularly use them. For me a simple '+' is more likely to get confused with an operation. Where '+Ve" is a good way of showing theres no operation.

There's no way to get the solution without a $\Phi$ term is there?

ACuriousMind

17:35

@JingleBells When you focus on something in an image, your eyes focus at the distance of the virtual image of that thing, not on the distance of the screen

ZeroTheHero

17:51

@JakeRose ... would very much as an instructor like to know the source of this problem/question

Jake Rose

18:10

@ZeroTheHero wdym?

ZeroTheHero

18:48

@JakeRose well this looks like a textbook problem or a problem from some lecture notes or something. I'm kinda curious as I'm always on the look-out for sources of problems.

bolbteppa

@ZeroTheHero p.8

JingleBells

@ACuriousMind Sure but the virtual image can't be that far, can it? I mean, it's basically the display rotated 90 degrees?

ZeroTheHero

19:12

@bolbteppa Thanks

JingleBells

ACuriousMind

@JingleBells why would it be rotated? Have you read e.g. the mirror example in the Wiki article I linked?

Physics Meta

0

Q: Why is this question actually off topic, how should it be modified so it is reopened?

I had asked: A game of boxes with rotating gears which was closed due to it being a "homework/check-my-work" question. The question is NOT homework, it's an original question I had come up with. Moreover the question itself isn't "check my work" since part it is completely unclear to me how to a...

vzn

19:32

in theory salon, 58 secs ago, by vzn

Einstein Wrong, Nature Does “Play Dice” – Unknown Mechanism Leads to Quantum Interference in Simple Reaction / scitechdaily

JingleBells

@ACuriousMind I don't mean rotated, look at the image I posted

As far as my intuition goes, this is what the user should see (the virtual image)

ACuriousMind

@JingleBells I don't understand how you came to the conclusion that "the image" should be there

JingleBells

@ACuriousMind Yeah, me too. I'll watch some vids on virtual images and optics and come back.

ACuriousMind

You can't conclude where the virtual image is just from the geometry of the screen

JingleBells

What's wrong with the image I posted? I've done the experiment with a phone and plexiglass and it reflects and it's like a hologram

ACuriousMind

19:40

Where the virtual image of "things" from a digital display is depends entirely on how the display emits the light. If it emits the diverging light rays at the right angle, the virtual image can be kilometers away

@JingleBells What experiment? This isn't about how the non-active screen reflects light, it about how it emits the light when it's turned on.

JingleBells

Oh, so on the picture I sent, the reflective glass is actually bent which makes the image appear further?

it acts as a lens, not a flat surface?

ACuriousMind

I don't know what technique these glasses actually use to achieve a distant virtual image, but yes, that's one possibility.

JingleBells

This is what I was talking about

JMac

I've actually tried a holo-lens along with some building model software. It was pretty cool. They had this cool thing where you could overlay models over what you were actually seeing and match it to your location, like for construction it could show you approximately where stuff went, based on 3D models, while you were walking around an unfinished building.

Secret

Random geometric symbol:

Looks like some kind of futuristic lab logo

something something accelerator quantum gravity research center

PM 2Ring

20:09

@JingleBells FWIW, there was a question about thus stuff a while ago, but unfortunately it still doesn't have an answer.

0

Q: Can we use regular glasses with inlaid display to display images to a wearer?

Object (virtual) (distance: d) <---> Glass with some display + Human Eye Would it be possible to display something onto a regular glass covered with a display (preferably transparent) to give the viewer the illusion that there is an object at distance d? An example would be Augmented Realit...

optics geometric-optics

Sha Vuklia

20:42

What is a good introductory text that treats flat pseudo-Riemannian manifolds?

I only want to understand the basic notions so that I can read simple proofs about Minkowski spacetime (considered as a flat pseudo-Riemannian manifold)

basically I want to be able to follow this proof (here $M$ is Minkowski spacetime)

ah, I see Lee has written a book on Riemannian manifolds

Physics Meta

22:06

0

Q: Asking if the following post could be suitable for the main site Physics Stack Exchange

I would like to ask if the following questions can be potentially interesting for the main site. The problem is that I've asked a similar question in past months (with an account now deleted) on the main site Physics Stack Exchange and was not well received (if I remember well I included some dis...

discussion questions specific-question

Why What Where When How

22:33

Greetings !@ACuriousMind

Today is my last time I am being online this week.

So goodbye for like 5 to 6 days!

Why What Where When How

23:23

Holy sht! No one in the history of humankind who is an autodidact has ever won nobel prize in physics or chemistry lol.

looks like there is no hope for any autodidacts in modern society.

Looks like there are less than 10 autodidact physicists on the earth alive right now. May be 0.

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