The h Bar

nitsua60

00:12

@Sebastiano What's the point of the first two-thirds of the post? All the bit about how one might know that the equipotentials for a point-charge are perpendicular to the field? It seems to me it just delays a reader getting to your actual question about parallel plates. And it strike me as unnecessary, since anyone who can answer your question already understands fields/potentials around a point-charge.

Also, it seems that you need to be a little more specific about the charge arrangement. Are you talking about idealized infinite planes of constant areal charge density? Or how to figure out the field around an actual pair of (finite) plates?

(Hint: the way you mention a "beam of planes parallel orthogonal to the uniform electric field" seems to answer my last question, but it sure isn't presented in a way that makes me want to engage with the post. You don't demonstrate strong understanding of your question, so I--personally--don't have much interest in providing an answer.)

vzn

02:23

@JohnDuffield fluid paradigm (of spacetime) is new in the sense of not being widely or even narrowly accepted. maybe you are not really familiar with why it was thrown out over 1century ago. part of the reason was the michelson-morley null result on measurement of "relative ether speed" (utilized by einstein). anyone wanting to revive it must carefully delineate how its close yet fundamentally different than idea of ether. think it can be done, but havent really seen anyone do it yet...

Cows

03:06

Today was my first day of teaching programming. Went ok. Some guy kept trying to ask me to do things in ch 7. I was told to stick to the book earlier. The same kid asked me if I "just teach" or have actually done work before. Prepping chapter 3 notes for tomorrow

Should i tell him exciting signature cows responses or stay cool? hehe

John Rennie

04:12

@0celo7 fan bearings sometimes go, and they can make various weird noises. Often they make a kind of groaning sound. There isn't any way to repair the bearing so you need to replace the fan. This isn't mega urgent because fans will usually work for a while even after they start making a noise, but I wouldn't leave it too long.

0celo7

@JohnRennie it only makes the noise some of the time

John Rennie

In that case I'd ignore it unless it's annoying you. What fan is it? A case fan?

0celo7

gpu

John Rennie

Hmm, if it's a GPU fan I'd check the warranty as I'm not sure how easy GPU fans are to replace.

Rumplestillskin

04:42

Can anyone provide me with a sanity check. I have two vectors (in Cartesian coords) such that v^j . v^j is their dot product. Now I want to take the derivative with respect to v^i... Is the answer 2v^j or 2v^i or does it even matter if I replace the index?

Secret

04:57

SO TRUE

Secret

05:47

I wonder if there is a way to engineer metamaterial wires that redirect all incoming light along its length so that it will look pitch black when seen in any directions

Think a dirac string like configuration, except with light

advancedsciencenews.com/metamaterial-absorbers-a-review

17

Q: Can there be black light? I mean is it possible to devise a machine that outputs darkness?

I understand there are various colours that light can have. But i was wondering why there is no 'black' light. What is the logical explanation for this? I mean I am expecting an answer that goes beyond mentioning the spectrum details. All I could think of was a machine as powerful as a blackhole;...

visible-light

Once again, second law of thermodynamics ruins the fun

Having said that, in theory if the object can modify the electronics of the surrounding air molecules etc. so that they can only reemit or reflect the incident light in directions away from a certain specified direction, then said object can look like a dark emitter in that particular direction

because all it takes for an object to look dark is the reflected or emitted light from the object never be able to reach our eyes, so no active cancellation will be necessary

quora.com/…

Dawood ibn Kareem

07:05

@JohnDuffield I think you'll find that magnets work even if you believe in them.

John Rennie

07:24

@DawoodibnKareem I'm not convinced this is going to improve the signal to noise ratio of the chat room ...

Physics Meta

07:43

0

Q: Which best conserves the chemical energy of a person exerting a force: a time-dominant impulse or a force-dominant impulse?

Suppose we have an object acting in two scenarios. In the first scenario. The object has a particular mass and is travelling at a particular speed. A person stops this object (final velocity is zero) by exerting a force on the object. The first scenario: The person exerts a small force for a l...

discussion

Dawood ibn Kareem

If there's not going to be any signal, there may as well be noise. Besides, I got sick of shining my right-angle-traversing lights over Duffield's house.

Secret

If a chat room has too much noise, it will implode

John Rennie

@DawoodibnKareem every time anyone succumbs to the temptation to try and pursue a logical argument it always peters out into sophistry and just makes this chat a worse place.

Dawood ibn Kareem

Well, I promise you, you won't get any logical arguments from me.

Secret

[Random question out of nowhere]

Given the reputation of inefficiency and dehumanisation of bureaucracy, is there known ways to improve it and also put the human factor back in?

We all knew how adminstration staff often need to work long hours and deal with a lot of paperwork, but is there a way to help them?

Dawood ibn Kareem

07:59

Less paper. Better software.

Secret

make sense. How about the human factor. For example, often when going through a bureaucratic process, e.g. medical screenings in public hospitals in the east asian countries, there's almost no room for the individual context and histories of the patient to be taken account of, result in the prescription being symptomatic instead of focusing on the root cause of the disease?

Dawood ibn Kareem

Should a medical screening be concerned with root cause? A screening process is all about "do you need a doctor", and in my opinion, that should depend on symptoms.

Secret

Actually, I might have used the wrong words and am referring to that discussion about the need for efficient consultation at 6:55 result in dehumanisation in our current medical industry in Kurzgesalt's video:

Homeopathy Explained – Gentle Healing or Reckless Fraud?

►

It's unclear to me given such time pressure and huge number of patients, how we can put the human factor back in to have more effective diagonosis

Rumplestillskin

08:16

Is anybody familiar with the geocentric celestial reference frame?

Dawood ibn Kareem

I love this sentence in one of the comments under that video. "nearly masless objects like Photons cant exist unless they move very quickly"

Slereah

09:05

Wrong on many levels

Captain Bohemian

09:38

Now I found from a post in a forum it's like JEE is a test in India. How crazy it is that India has so many tests.

Rumplestillskin

@DavidHammen By any chance are you familiar with the GCRS?

Slereah

"Sistemi di equazioni differenziali con secondo membro discontinuo risperto all'incognita"

Mama mia

Dawood ibn Kareem

09:56

@Slereah And yet oddly correct. Photons that aren't moving quickly really don't exist.

Slereah

Well true

But 1) they aren't nearly massless and 2) nearly massless particles can move at 0 velocity

Dawood ibn Kareem

OK, you win. I still found the comment amusing.

Captain Bohemian

what happen to a photon if it stops moving at all?

John Rennie

@CaptainBohemian A photon cannot stop moving. Photons, indeed all massless particles, have no rest frame.

Captain Bohemian

10:22

so a phton stops to exist at the time it stops moving?

I recall the speed of light is related to the metric in gravitation theory.

Dawood ibn Kareem

These are actually really good questions. So I'm going to answer with a question. How would you slow a photon down?

Captain Bohemian

10:33

sorry, I made a grammatical mistake in the above. I mean "so a phton stops existing at the time it stops moving?

Anonymous

@CaptainBohemian The real question is: "Can a photon stop moving ?" :P

Secret

there is slow light, but that is a completely different thing

Anonymous

Yup ^

Slereah

11:01

Streater's book has a Lubos Motl quote in it

John Rennie

@DawoodibnKareem The only way to slow a photon is to make it only part photon. If you entangle a photon with a massive object then the entangled system can move slower than light. Under the right circumstances you get a pseudoparticle called a polariton that can move arbitrarily slowly. This is what happens in the experiments where Bose-Einstein condensates are used to slow or even stop light.

But of course you still aren't slowing a photon because the entangled object is not a photon.

Dawood ibn Kareem

Yep. I was trying to lead Captain Bohemian towards seeing why he/she can't stop a photon.

Just like Einstein reputedly imagined running alongside a light wave, or whatever.

Balarka Sen

What's the experiment you are speaking of here, @JohnRennie?

John Rennie

Now this is a novel use for the homework-and-exercises tag :-)

@BalarkaSen This sort of thing

Slow light

Slow light is the propagation of an optical pulse or other modulation of an optical carrier at a very low group velocity. Slow light occurs when a propagating pulse is substantially slowed down by the interaction with the medium in which the propagation takes place. In 1998, Danish physicist Lene Vestergaard Hau led a combined team from Harvard University and the Rowland Institute for Science which succeeded in slowing a beam of light to about 17 meters per second, and researchers at UC Berkeley slowed the speed of light traveling through a semiconductor to 9.7 kilometers per second in 2004. Hau...

Balarka Sen

11:16

huh

Secret

digitaltrends.com/cool-tech/chemistry-robots-twitter-experiment

lol chem bots

Tanuj

@JohnRennie Hi ! Good afternoon :)

John Rennie

@Tanuj Hi :-)

Tanuj

@JohnRennie Are you free ? I have got a few questions I have to ask.

John Rennie

@Tanuj yes, I'm around for half an hour or so. Problem Solving room?

Tanuj

11:25

@JohnRennie yea , thanks.

John Duffield

11:49

@DawoodibnKareem : you make it travel in a downwards direction.

@DawoodibnKareem : magnets work, but monopoles don't. There are no magnetic monopoles, they were proposed by people who elevated the desire for symmetry above the need to understanding electromagnetism.

Slereah

Damn lazy photons

"At the time that Fermat developed this principle, his justi fication was more mystical than scienti c. His justifi cation can be summarized by the statement that nature is essentially lazy, and these rays are simply doing the least possible work."

Balarka Sen

eNeRgY mInImiZaTioN

maybe physicists call what we call energy as action

John Duffield

@vzn : I'm familiar with the Michelson-Morley experiment, and how Einstein came up with SR. And how Einstein re-introduced the concept of aether when he was doing GR. But this aether was somewhat different, such that "The idea of motion may not be applied to it". Oddly enough LIGO is an interferometer.

@Slereah : see Einstein's 1939 paper on a stationary system with spherical symmetry consisting of many gravitating masses.

He said this: “it is noted that g44 = (1 - μ/2r / 1 + μ/2r)² vanishes for r = μ/2. This means that a clock kept at this place would go at the rate zero. Further it is easy to show that both light rays and material particles take an infinitely long time (measured in "coordinate time") in order to reach the point r = μ/2 when originating from a point r > μ/2”.

Slereah

12:12

Man O'neill doesn't discuss caustics

is there a good GR book that talks about caustics in details

It's one of those things that's only vaguely talked about in most GR books but then it pops up in papers

Penrose and HE briefly mention them

Secret

The word "caustics" reminds me of self intersecting curves for some reason...

Slereah

sciencedirect.com/science/article/pii/0003491677903177

that should do it

0celo7

12:59

Cigars fuck me up

I feel like death

Slereah

Don't smoke

Smoking ain't cool

0celo7

13:17

@Slereah don't all the french smoke

Future Historian

Well, I am back.

@0celo7? How would orbital mechanics affect a real life space battle?

Slereah

I do not

@FutureHistorian gravity

things fall down

0celo7

@FutureHistorian why are you asking me

Slereah

very important fact

Future Historian

Because....space battle tactics.

I want to know some possible tactics that a space force could use in real life.

Slereah

13:22

The corbomite manoeuver, obviously

Future Historian

@Slereah???? Come again?

Because I am not sure Star Trek is a reliable source for a real life space battle.

Slereah

He's doing a sci fi thing and he doesn't even know the corbomite maneuver :p

The Corbomite Maneuver

"The Corbomite Maneuver" is a first season episode of the American science fiction television series, Star Trek, first aired November 10, 1966, and repeated May 11, 1967. It is episode No. 10, production No. 3, the first regular episode of Star Trek produced after the two pilots, although it was aired later in the season. Written by Jerry Sohl, directed by Joseph Sargent, and created and produced by Gene Roddenberry, the storyline describes how the USS Enterprise encounters a massive and powerful alien starship and its unusual pilot. The episode features a young Clint Howard, brother of actor-turned...

Future Historian

Oh. Memory chip is back.

Sorry.

@Slereah. How is Star Trek a reliable source for real world space combat?

Alex K Chen

Is recommendation on history books on physcis on topic for this SE ?

Slereah

There are no reliable sources on real world space combat

Because there has not been any real world space combat so far

Future Historian

13:25

@Slereah. Except for probably Atomic Rockets.

Slereah

@AlexKChen No, ask hsm.stackexchange.com maybe

Future Historian

But I mean like....use real world physics to make a space battle work in real life.

Alex K Chen

OK, but I guess it's not bad to ask it on chat.

Do you guys have any good recommendations for this ?

Future Historian

As in: how would orbital mechanics affect a hypothetical real life space engagement once we DID get to space combat?

Slereah

that's a bit of a broad question

Future Historian

13:27

As in: say for example, a bunch of insurgents on Mars (classic example, I know) have established a relatively small space force with help from renegade Belters and UN forces want to smash the Martian rebels. How would a hypothetical engagement between both belligerents in orbital space be affected by orbital mechanics?

Keep in mind that both sides can deploy spacecraft, and fire at extremely large distances up to hundreds or even thousands of km.

Slereah

dtic.mil/get-tr-doc/pdf?AD=ADA600540

look this up, I guess

or look up documents on the topic

but what you're asking is too vague to really have an answer

Future Historian

Delta-v is up to 100 - 150 km/s on both sides, but the acceleration for their nuclear pulse ICF engines is....well, not that great, and they are equipped with a combination of nuclear missiles, short range lasers and railguns.

Just to make this example interesting.

Alex K Chen

@Slereah Wait wait wait... I have no clue how that's remotely relevant to my questions

Slereah

@AlexKChen not your question :p

you're not the only man on earth!

Alex K Chen

@Slereah Hah nice joke... isn't it blatantly obvious that I, Vladimir Jong Trump is the only man on earth ?

Secret

13:33

missing two more lunatics (there are 5 lunatic madman presidents you know...)

the viet guy and Xinjiping

(well, at least the media think they are mad that is)

0celo7

@Slereah I have to write a 1 page statement of interest for a summer school

on gr

Slereah

How many appendix pages will you add

Tell them that GR is pretty cool

0celo7

are you memeing my thesis

Slereah

Also what's the summer school's program

@0celo7 maybe

0celo7

math.mit.edu/programs/city-limits/2018/courses.html

Slereah

13:38

nice

Secret

Slereah

"We will then present results concerning the local well-posedness of certain equations describing relativistic fluids with viscosity, including their coupling to Einstein's equations."

neat

0celo7

I know Marcelo

he's pretty cool

Slereah

which one is Marcelo

0celo7

disconzi

Slereah

13:40

"it is due to a more sinister phenomenon, such as incompleteness due to lack of information for how to continue the solution uniquely (this is roughly known as the formation of a Cauchy horizon)."

spooky

0celo7

"GR is like crack for me."

Slereah

Maybe tell them you know Einstein and the evidence

0celo7

@Slereah these experts have probably heard of J. Duffield's work

Slereah

why did I chose to work in $n$ dimensions

it was my demise

everything is so much worse

Secret

I wonder if anything interesting can happen in nD+0T spacetime dimensions

Slereah

13:53

gregegan.net/ORTHOGONAL/06/GRExtra.html

this

0celo7

@Slereah smoking kills

don't do it

Secret

o wow, so that - sign in the metric is what allow black holes to be possible

0

Q: Propogation of waves across many worlds

If we accept the Many Worlds Interpretation literally, is it not possible there is propagation of waves directly between worlds? For example, given that ‘every eventuality exists’ in MWI, there should, amongst others, be infinities of only-minutely-different worlds in superposition. We can imagin...

quantum-mechanics newtonian-mechanics

But I think the point is those who inhabit one of the many sperpositions cannot really pereive each other, so there should not be any difference

Slereah

14:11

motls.blogspot.fr/2018/03/…

"And you should accept the subjectivity of the observations. Stephen Hawking died. Before he died, we could have used him for a nice experiment that makes the point because Hawking was a nearly perfect realization of a poker face. He was conscious and aware of things but you couldn't know."

"So we could have done experiments with him. For example, we could have used his eyes as the photographic plates in a double slit experiment. The photon or another particle propagates, the wave function spreads, we get a superposition of the particle at many points. When the particle hits Hawking's retina, the retina gets entangled with the particle."

Future Historian

News article appears describing "First Contact" with extraterrestrial life

And no, @JohnDuffield, do NOT get any ideas.

>:(

@Secret? Are you alive?

I am going to need you back in the Worldbuilding SE chat for a second.

Secret

mind you, I still knew nothing about orbital mechanics so don't ask me that

Future Historian

Meh. This is more of a Visitor series-related idea than what I was asking back there about the Planetverse.

Wait a minute.

@Slereah? That document refers to near-future space battles.

Aka: the ones limited to Earth orbit.

Slereah

Earth orbit and Mars orbit aren't very different mechanically speaking

Future Historian

I am referring to the context of more....interplanetary scales.

As in: with military spacecraft being sent from Earth to Mars, how would the approaching UN forces be able to handle the small insurgent force on Mars (supported by rogue Belters)?

Qmechanic

14:23

1

Q: Electrified Fences

On a chilling visit to Auchwitz-Birkenau saw the electrified fences, still intact; though, no longer live. The white insulators prevented the current running to earth, down the posts, but what happened to the current-flow when it rained?

electricity

^^ Phew. That's a dark theme. ^^

Slereah

@Qmechanic Streater's book on quantum interpretation starts with a chapter on dead babies

Literaly

Sir Cumference

Morning folks

Slereah

hey

Slereah

14:42

"[LeMaitre] wasn't Catholic. He pretended to be a catholic so he can deceive Christians into rejecting God. Same thing goes for theistic evolutionism."

Future Historian

@Slereah? What potential sources of energy could a hypothetical species of chemolithotrophic bacteria living beneath the Martian lava tubes use?

Slereah

more of a question for biologists

Future Historian

Still, they are not much into hypotheticals here anyway.

dmckee

@Slereah Hmmmm ... I'd argue that identifying the free-energy density of the environment is a pretty near the physicsy end of biophysics, no?

Slereah

@dmckee doesn't necessarily make them reasonable energy sources for bacterias

Future Historian

14:54

Especially the kind that could survive on a Martian lava tube.

Hmmmmmmmm.

Slereah

You know who else talks about caustics?

Synge.

I really need to get Synge

too bad the book is 460$ at least

Wait, there's a version for only two hundred

A bargain

why is it so expensive

Why is nobody publishing a new version of it

Synge lived to the ripe old age of 98

John Duffield

15:13

See his 1960 relativity: the general theory. Note that in the preface he said the principle of equivalence performed the essential office of midwife at the birth of general relativity, but should “be buried with appropriate honours”. That's because it only applies to an infinitesimal region, so it doesn't apply at all.

It's 34Mbytes.

0celo7

@Slereah i just got into another GR summer school

dmckee

@Slereah Well, yes, but then again no. One of the big surprises of twentieth century biology has been the diversity of extremophile life and the breadth of free-energy sources that they actually make use of.

My take on that has been that "Assume life runs on the free-energies that we're used to life using" makes less sense than "Consider free-energy as a prerequisite for life and wonder about how it converts it later."

YMMV.

Secret

@dmckee what does a free energy density of the environment even do?

o sniped

dmckee

Though I have to admit that finding life as we know it is a better defined problem than finding life without that restriction.

Secret

ok in that case, that will be quite a survey of all the chemical species that can be used as energy source in the area

dmckee

15:26

Galileo proved that we can detect large quantities of life as we know it.

@Secret Yep.

Secret

aywaym headign to sleep now, need to wake up at 7:00 tomorrow

Physics Meta

15:48

0

Q: Users that post every question in their homework/exams

Everybody who's been here for a while knows that the homework policy is not as advertised. If the exercise is sufficiently interesting, and the OP is sufficiently polite, the question often stays open and gets good answers. More sophisticated exercises also fare better: an interesting and nontr...

discussion

vzn

@JohnDuffield was reviewing Tenev + Horstemeyer last nite. while they have a brief section postulating matter/ particles as waves in the spacetime fabric. a careful analysis reveals that this is the basic difference with the classic ether theory. but they havent fleshed it out more/ much and how that would predict a null result for Michelson-Morley interferometer/ "ether drift" test. havent seen anyone else do so either. this analysis/ phenomenon is a key part of the massive paradigm shift.

Slereah

@dmckee I am aware :p

That doesn't mean you can expect life in any circumstances, either

@0celo7 huzzah

what will your next thesis be about!

Sir Cumference

16:08

@Slereah Wiki says "While a devout Roman Catholic, [Lemaitre] was against mixing science with religion, though he also was of the opinion that these two fields of human experience were not in conflict."

Seems he didn't care what Christians thought

Sigh I completely misread that

Anonymous

@JohnRennie The clock is synchronized with the Internet time, but still it suddenly changes to the UK time around evening and resets to Indian time around morning. Not sure how to change regional settings

John Rennie

@Blue Huh?

Anonymous

@JohnRennie I mean it is synced with windows.time

John Rennie

Press Windows-R and type the command control and click OK. That will open the Control Panel.

Anonymous

Yup done

John Rennie

16:21

At the top right click the View by dropdown and change the view to Small icons.

Anonymous

done

John Rennie

It should look like this.

Anonymous

I manually synced it around 5 mins back and now it is showing the correct time. However, pretty sure tomorrow it will again get back to the UK time :P

John Rennie

@Blue that syncs the system time, which is always in UTC.

Anonymous

16:23

@JohnRennie Huh, but it's showing the correct time now

Anonymous

I'm sending the snapshot

John Rennie

Windows always uses UTC time internally and it adds a regional offset whenever it displays the time to you.

Anonymous

See after manually syncing it it shows the correct time

John Rennie

In Control Panel click the Region link.

Anonymous

16:24

Done!

John Rennie

On the middle tab, Location, what is the location set to?

Anonymous

India

John Rennie

OK ...

In the Control Panel click the Date and time link

Anonymous

Ok

John Rennie

What is the time zone set to?

Anonymous

16:27

UTC + 5:30

John Rennie

Hmm, all is correct so far ...

Anonymous

Proof that I manually synced the time 5 minutes back :P

Anonymous

"6 hours ago"

Anonymous

chat.meta.stackexchange.com/rooms/89/tavern-on-the-meta

Anonymous

16:28

So I guess it removes the 5:30 offset everyday due to some bug...

John Rennie

I wonder if some other app is changing the time and is getting the time zone wrong ...

Anonymous

Umm, I don't have much apps other than Chrome and Visual Studio...

Anonymous

And the Anaconda/Python

0celo7

@SirCumference what

I’m a junior

Sir Cumference

Some people graduate as juniors

0celo7

16:31

@Slereah summer school

Like a workshop

Slereah

I dunno what a summer school is

I don't know if that's a thing in France

0celo7

see the second message

John Rennie

@Blue I could knock together a quick app to show the system time and the local time i.e. the UTC time as recorded by your PC and the time with the regional offset added.

Actually you could do that.

The point of doing this is that when the time next changes you'll be able to tell whether it's the system time or the regional offset changing.

Anonymous

@JohnRennie Okay, let's try that if you're free

John Rennie

@Blue I don't think I have Visual Studio installed on this laptop ...

Anonymous

16:36

Oh, nevermind. I mean this isn't a pressing issue. We could do it some other day too :P

John Rennie

@Blue you can write the app. Use GetSystemTime to get the UTC time and GetLocalTime to get the time with the offset.

Anonymous

@JohnRennie I see where you're going. I'll try that sometime this week/weekend and let you know. (a bit busy now because of a silly environmental science test tomorrow morning :P) Thanks for the help :)

John Rennie

Annoyingly my Mum's Internet is too slow for me to want to try installing VS here

Anonymous

Haha, slow net is good sometimes; enjoy at your mum's. :P

Abcd

17:08

@Blue Were do I see the Organic Chemistry Sylllabus from? I am so confused about which reactions are in syllabus, which aren't, which are supposed to be learnt.

Tanuj

@Abcd Go to the official JEE ADV site

Anonymous

@Abcd Check this

Abcd

@Tanuj Is Cope Reaction, pyrolisis of Esters, Pyrolysis of xanthates ECB in syllabus?

Tanuj

nope

Abcd

@Blue I have heard that sometimes they don't follow it :/

Tanuj

17:12

but you might still wanna confirm . I'm 95% sure they aren't in the syllabii

Abcd

"excluded R,S nomenclature"- lol...How can people study OC without R,S -knowledge

@Tanuj I am sure you must be knowing about R,S...

Tanuj

yea

Anonymous

Keep in mind that everything will not be from syllabus. They can ask questions based on extrapolation of the basic principles you're taught. So good to derive as many mechanisms as possible, on your own, from first principles (goc)

Abcd

Oh, I see.

Tanuj

@Blue how do I remember color of ions and coordination compounds ? Like I was solving past years from 2015 ig and they asked the color of a coordination compound. Where is the logic ?

Abcd

17:14

@Tanuj they have written, "excluded stereochemistry of addition and elimination"

dmckee

@dmckee I don't understand the voters on Worldbuilding. They seem willing to vote for anyone who uses technical sounding language no matter how factually wrong.

5

And it fosters a culture of not giving a $#!^ about good science among some of the posters as well.

Anonymous

That said, Etoos was really good, and covered nearly everything needed to be known. Pity that I discovered the website pretty late. :P (I know, I've advertised that site before)

Tanuj

@Abcd wtf ?

Abcd

@Tanuj see the syllabus.

Loong

@dmckee ups, I somehow edited your message

Tanuj

17:16

@Abcd nah , ADV is already complete shit . I'm sure they have messed up the syllabus too.

bolbteppa

Honestly, Bjorken-Drell is just incredible, what a book, even things that seem like bad things to do turn out to be good ideas

dmckee

@Loong And now it look really funny. You can't normally @-tag yourself

Loong

@dmckee something because of mobile :-|

Abcd

@Blue when did you find it?

Loong

sorry

Anonymous

17:17

@dmckee You can actually. Just edit in the permalink ID of your message after clicking the reply button

dmckee

Don't fret it. But I can't seem to undo it.

Nehal Samee

@Abcd ... When are you guys appearing at JEE ...?

dmckee

@Blue Ah. Never tried that.

Abcd

@NehalSamee 2019 May

Anonymous

@Abcd Mid 12

Anonymous

17:19

@Blue abc

John Rennie

I wonder if you can hand edit in a link loop ...

Nehal Samee

@Abcd ... Won't you guys appear in any board exam , like I SC ...?

Anonymous

@Blue See ^

John Rennie

@JohnRennie Here's a post. This now links to the post below.

Abcd

@NehalSamee yes, in March 2019

John Rennie

17:20

@JohnRennie here's a link referring to my previous post

Anonymous

Heh, it works :D

Abcd

@JohnRennie how did you do that

John Rennie

It works! :-)

Abcd

@JohnRennie mechanism?

dmckee

@JohnRennie Cool.

John Rennie

17:22

@Abcd the link is just :number where the number is the numeric id of the post

To get the numeric id for a post click the little arrow next to the post and select "permalink"

Without the angle brackets

You forgot the colon

Loong

Sandbox

Where you can play with chat features (except flagging) and ch...

3

Abcd

@Abcd efgh

John Rennie

It works! :-)

Abcd

yeah!

John Rennie

@Loong why would we use that when we have the opportunity to break the main chat room? :-)

Balarka Sen

17:24

@BalarkaSen This message is important, I direct it to everyone of high IQ

John Rennie

A closed timelike post

Anonymous

Nothing beats vzn's arrow :P

Abcd

@Blue How to make that?

Balarka Sen

@BalarkaSen To the future!

@BalarkaSen This is another message that is important, I direct it to everyone of high IQ

Anonymous

@Abcd I dunno. Ask the Copyright Owner

Balarka Sen

17:28

@BalarkaSen Loop-de-loop

Anonymous

←

Anonymous

↑

Anonymous

Ah, I copied it from the owner

Anonymous

chat.stackexchange.com/users/30568/vzn?tab=recent

Balarka Sen

@JohnRennie We did an experiment a few years back, by guessing the codes for future messages by writing down ":number" arbitrarily.

I think someone successfully predicted a message

John Rennie

17:31

And people have the cheek to accuse us of being nerds! :-)

Abcd

←

Balarka Sen

I ain't no nerd, I just like to break things

A few weeks ago I tried to break a couple chatbots by putting them in a loop of commands

It didn't work out well

(It's also more subtle than just setting a two-bot loop; there's a minimum timespan in which two messages are recognized as the same, so it has to be, like, five or six bots at once. A daring experiment)

Anonymous

"ain't no"....good use of double negative ;)

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