12:00 AM
If you have very very large $\beta$ then you can approximate via Laplace's method
$\int_a^b h(x) e^{Mg(x)} dx \approx \sqrt{\frac{2\pi}{M | g''(x_0)|}} h(x_0) e^{Mg(x_0)}$
$x_0$ is the global max of $g(x)$

@psa The idea is that the difference between successive terms gets smaller as you make $\beta$ bigger
For large $\beta$ it very closely resembles a continuum

1:02 AM
@JakeRose @SirCumference OK, so if that's the case, $\beta$ is inversely proportional to $T$ (I'm talking about thermodynamic $\beta$). We were told that this approximation is accurate in the classical limit, but doesn't the classical limit correspond to large $T$, small $\beta$?
Sorry, I meant $\sum_{j=0}^{\infty}$ in the infinite series, not $j=1.$

1:13 AM
I've forgotten most of my thermo in preparation for the Part II maths cours I'm taking on it.
But I don't have any notion of my head of a classical temperature being high or low?
The thermodynamic temperature can't (usually) be below 0 but that's the only major restriction
Where does the integral come from?

@JakeRose The integral is an approximation of the partition function for a rotating diatomic molecule.
The series is the exact form, but I don't think it's easy to solve (doubt there's any closed form solution).
The spectrum has degeneracy $\Omega = 2j+1$ and energy $E = j(j+1)\epsilon$
QM tells us we should only count every second $j$ for a diatomic molecule, but I'm ignoring that.
What I mean by high/low temperature is that the classical limit is valid assuming we have sufficiently high temperatures.
So high $T$ gives low $\beta$, and apparently that approximation is only useful in the classical limit.
So there's either something awry with my physics or I'm doing something wrong with the math.
it's weird, this seems accurate for low $\beta$ when I use matlab to calculate the integral and the series for $n = 100$
oops
I think I'm just tired, pretty sure it makes sense now

1:44 AM
@psa wait, right, i was thinking the other direction
$\beta$ is thermodynamic coldness so lowering it should make the series resemble the integral

right, nice
the average energy should fall off like $\frac{1}{\beta}$ then I think?
hm wait no

3 hours later…
4:55 AM
I don't know if anyone has seen the news but universal cancer treatment might be coming. I hope it's not just unnecessary buzz

2 hours later…
7:11 AM
Should a tag wiki excerpt describe what tag to use other than the given one. For example .
Newtonian mechanics covers the discussion of the movement of classical bodies under the influence of forces by making use of Newton’s three laws. For more general discussion of energy, momentum conservation etc., use classical-mechanics, for Newton’s description of gravity, use newtonian-gravity.
And tag except of says "Questions related to the perception and measurement of light (primarily in the visible range), its mathematical description, the reproduction of colors by different means, color combinations, etc. Please use the tag [electromagnetic-radiation] if you want to refer to the general form of light." But I don't think questions related to the perception of light are answerable using physics (without residing to biology).

2 hours later…
9:13 AM
@skullpatrol I missed you pal

Composing music is very hard when you have a anti-motif bias
You end up with numerous chunks of completely distinct melodies and you struggle to glue them together into a song

9:27 AM

10:10 AM
My cousin is in Heidelberg Cement in Logistic department and he says that doing a job is a very difficult thing, there is a lot of pressure from upper officials and colleagues don’t exchange their shift duty no matter how sick you are (my cousin is in shift duty, means his duty time changes every 2 days)
Is doing a job really a difficult thing? I know do what you like rule, but I’m asking about the job in corporate sectors, is it really challenging?

10:32 AM
@Knight I've never found problems like that, but then I've always done jobs I like.

@JohnRennie Are you in corporate sector?

@Knight I worked for 12 years for Unilever, which is a huge multinational company. Then I worked for a number of small IT firms.

@JohnRennie Wow!
@JohnRennie Why do my cousins (almost everyone of them) feels so much pressure of the work? They say that if the someone from the other country who wants something from you (for job purpose, means if he wants some details or what not) then he generally calls at his day time (which is most of the time night in my cousins’ time zone)
How true are these things for a general public.
?

I don't know. I've always worked in skilled jobs i.e. first as a scientist then as a network engineer.
If you work in an unskilled job where you could be easily replaced then I guess you would feel a lot more pressure.

10:52 AM
Sir I think they are semi-skilled . assistant manager in logistic department, software engineer class 2 , officer in HR department.

I think it depends on the company, and on your immediate manager.
I wouldn't immediately jump to the conclusion that the whole of your working life will be hell :-)

So, in general what can we conclude? Or is it not possible to conclude anything?

I don't think it's possible to conclude anything.
Most of the people I know are happy with their jobs. That's in the UK of course, and it might be different in other countries.

Are you saying this only to keep me happy about the future ? 😀
@JohnRennie Are you angry?

No, that was meant to be a joke - obviously not a very good joke :-(

11:00 AM
Oh God!
Please don’t do that again, it just blew me off.
🥶
My GOD! I thought I lost you.

deleted

Sir I almost became ...
As ACM always say that chat is a very hard thing to keep up, you made a joke and here it struck me like a gold bullet in my brain.

@Knight sorry :-(

Don’t say sorry, I’m a subset of yours.
Teachers never say sorry to their good students (lol)

@Knight they are bad teachers then.

11:08 AM
@JohnRennie Sir what do these symbols mean in music?
Yesterday there came a advertisement on TV where Star Trek Discovery music was shown an composer showed his notebook which was full of those symbols 🎶

You need to read an introduction to musical notation.

It’s very hard to learn from beginning (especially without a teacher)

That link seems a pretty good introduction.
I wonder is there is a web site where you can put notes on the stave and hear what they sound like.

11:15 AM
Yes it was a very nice. But I don’t even know what does bass, beam means.
Have you ever read T.S. Eliot? Your countrymen poet?

@Knight No, T. S. Eliot is hard work to read.

@JohnRennie I thought you could explain me few of the references that Eliot make in his poems.

You'll have to Google for those. Entire academic careers have been made form trying to figure out what T. S. Eliot meant.

Wow! I don’t why whenever I read him my inner self says to me “ he is trying to say something but you’re too materialistic man to understand it”

Or of course he could just be talking nonsense then laughing about how seriously everyone is taking it.
2

11:25 AM
Yes, and it’s philosophy to differentiate.
What’s the truth

12:12 PM
hey hey

12:23 PM
Can any moderator can help me in viewing my deleted question please!
@ACuriousMind @DavidZ @rob
I ping you because you are moderators!

1:01 PM
@ACuriousMind Makes so much sense, thanks! My hold up was on interpreting $\text{ad}_X$ as a matrix, but of course that makes sense, as it's just a linear map $\mathfrak{g}\rightarrow\mathfrak{g}$. Cheers :)

1:13 PM
@YuvrajSingh... if you go to your user profile and in there you go to the list of questions, then at the bottom there should be a link that says "deleted recent questions"
@JohanLiebert in general, on this site, the answer to "should the tag wiki (/excerpt) for tag X be improved?" is always "yes"
the answer to "... and who's willing to put in the work to improve said tag wiki?", on the other hand, has proved rather more elusive over the years
but if you're willing to jump in, by all means do so
@SirCumference that answer plays a bit fast and loose with AC. Given AC, yes, every vector space admits a Hamel basis. But without it, no.
50

If $V$ is given to be a vector space that is not finite-dimensional, it doesn't seem to be possible to exhibit an explicit non-zero linear functional on $V$ without further information about $V$. The existence of a non-zero linear functional can be shown by taking a basis of $V$ and specifying th...

... is at least one relevant thread.
I'm not sure whether that one has a proof that the axiom "every vector space has a basis" is equivalent to AC, but I'm fairly sure there's one in MO

1:39 PM
That result is due to Andreas Blass, a reference is also given in the Wikipedia article: Basis (linear algebra).
And of course, the same reference can be found in many other places. Mathematics: Vector Spaces and AC, MathOverflow: Axiom of choice and bases of vector spaces over a fixed field.
Blass, Andreas (1984), "Existence of bases implies the axiom of choice", Axiomatic set theory, Contemporary Mathematics volume 31, Providence, R.I.: American Mathematical Society, pp. 31–33

1:54 PM
@EmilioPisanty thanks sir but it only provide recent question link!

Can someone explain what anti-de sitter space and de sitter space are?
Are they simply landscape and swampland?

2:12 PM
@quallenjäger landscape and swampland? I'm not even going to begin to figure out that metaphor. No, they are exponentially contracting and expanding universes respectively

@Jim Apparently it's an actual thing en.wikipedia.org/wiki/Swampland_(physics) I googled it because I thought they were using a very weird metaphor or translation.

@JMac like almost everything else about string theory, that metaphor makes little sense, is overcomplicated, and probably is based on something stupid

@Jim I don't think it's a metaphor, is my only real point. It's a terminology that string theorists use. If it makes sense to use in this context, or if people should really care at all, is another question entirely.

it must be a metaphor unless they are talking about literal swampland. Since that would be ridiculous, I'll lean towards it being a metaphor

@Jim Not really, in my opinion. They are talking about a physical concept that people refer to as "swampland". Although there are probably metaphors that led to that naming convention, it doesn't really imply that using that terminology is itself a metaphor. They aren't trying to compare it to actual swamps, they are trying to ask about "swamplands" as defined in the string theory context.

2:27 PM
you're saying that although the etymology may have been a metaphor, it is now a separate term that has its own definition and no longer is a metaphor?
I can get on board with what you're saying, but I'd probably still personally rather lump it in as a metaphor, if only under my own internal definition

@Jim Yes. It's not being used as a metaphor, so it's not a metaphor in this case, even if it's etymological origin is metaphoric, the way I see it. I guess my point is that the person using the term "swampland" is not themselves (necessarily) trying to connect the concept with actual swamplands; they are just using terminology which would be understood. To me, the difference is in the intention.

@JMac Yeah, I see what you mean. Although any newcomer would initially see it as a metaphor because they don't know better, someone needing to use the term would not do so with any intent of comparing the two concepts. In that case, I change my stance to criticizing the etymological origin, rather than the standard usage

@Jim Yeah, that's really what I was getting at. We can blame the people who made the convention; but once the crappy metaphor becomes incorporated into the terminology, it doesn't seem fair to assume that everyone is actually using it metaphorically.

I completely agree. The people that made the terms were to blame. It's awful

2:49 PM
Well people get bored at work. I used to give stuff very weird names to make these dry written papers bit interesting.
But yeah, in string theory, landscape and swampland are actually classifications of physical theories, whether it is compatible with string theory.

3:12 PM
I feel like I should know this, but...
If I consider entangled pure states of 2 electrons, then the only spherically-symmetric state is the singlet. If I allow for 3 electrons, then there aren't any spherically-symmetric states because the total spin must be 1/2 or 3/2. But if I allow for 4 electrons once more, then there should be a spin-0 state.
Which, I guess one would still call a singlet?

A good song is always a good song!
One who watch it please share his view what they feel!

I guess the point is more-or-less this: If I entangle two electrons to get a singlet, and then tensor that with another singlet, then the result is still spin zero. But I could also achieve spin zero by first entangling two pairs of electrons as two-electron triplets and then entangling these.
But then I don't expect to get nice symmetries across all four particles.

3:47 PM
those are very different states, right?
they don't evaluate to the same density matrix

yeah, by singlet I just mean "has total spin zero" since the only possible Sz is zero.
I think this comes down to saying that, if you want to insist on having spherical symmetry for a state with at least three particles, then you're going to have to give up on some other nice symmetry considerations.

helo mai frends
velcam

velkommen
...and that exhausts my knowledge of norweigian

Здравстуй.

4:03 PM
@YuvrajSingh... how old is this deleted question?
and why do you want to see it?
The system only shows you a limited depth of deleted questions (60 days, if I understand correctly) for a reason

@EmilioPisanty the idea is to see if the deleted questions can be improved enough to be undeleted.

@Semiclassical the spin-0 ones

i have offered to help with the editing.

@JohnRennie then that does require moderator help
Is Yuvraj in, or at the edge of, an automated question ban?

@EmilioPisanty yes. Annoyingly the SE won't let you see even your own deleted questions if your rep is < 10K.
And above 10K you can only see your own deleted questions, so I can't find them and give Yuvraj a list.

4:09 PM
Random question just to make sure I am not going crazy: Normally a population that just grows due to its own reproduction is described by $dP/dt=kP$. If we want to also include immigration at a constant rate $r$, then the differential equation becomes $dP/dt=kP+r$, right?

890

I would really like to see all of my questions and answers on the profile page, even if some of them were deleted, and I don't have enough rep to see them on the site. (Note that some questions are automatically deleted after 30 days or 1 year, and the author might be oblivious about what happen...

I mostly agree with the rationale
I'm not bitter, I just understand how human beings work. I guess that's sort of the same thing. But loss aversion is huuuuge and showing people their deleted content, every day, on their user page is pretty much the textbook definition of it. "Gee, remember your deleted question with allll those upvotes? Look at it every single time you go to your user page. That'll remind you of what you lost, and how much you miss it. Have you considered complaining about the unfairness of that deletion today? How about tomorrow? Maybe next week? Just think about it. Every time. Forever." — Jeff Atwood Apr 6 '13 at 8:04

Which is the most famous stackexchange post?

Right, but the SE issues a ban on asking new questions if you have too many deleted questions, then it makes it impossible for you to find an undelete them. That seem suboptimal to me.

@JohnRennie agreed
@AaronStevens yes
@NovaliumCompany this chat comment right here
(... or, otherwise: define "famous")

@EmilioPisanty I was tutoring someone, but they said the online assignment marked it as incorrect. I just wanted to make sure I wasn't making some dumb error. They were probably entering it in incorrectly or something. Thanks

4:12 PM
Which stackexchange post has the most views on the website?

@NovaliumCompany which site?

srsly?
dude...

@NovaliumCompany you know that there are multiple SE sites, right?

Don't they share a single database?

if you want answers to your questions, asking ill-defined unanswerable questions is not really the way to go about it
"the website" is never used on SE to describe network-wide statistics

if you want on all the sites, then you ask for the most views SE-wide

@JohnRennie thank you.

@NovaliumCompany this satisfies you? wow.

@NovaliumCompany I'm guessing that SO has the highest voted question since it's by far the busiest site.

@NovaliumCompany Have you tried being clearer instead of getting frustrated when people want you to be clearer?
8

4:14 PM
so instead of the most views on the whole of SE, you were actually looking for the most votes on SO only?

@JMac it seemed pretty clear to me

that was a rather weird way to phrase it

@JohnRennie I assumed he was talking about Physics SE, so to me it wasn't that clear.

Guys, let's stop this here. Sorry if I was unclear.
I'm pretty sure all of you have better ways to spend your energy.

@NovaliumCompany to answer this question: not really. They all have databases on the same server, but it's not that easy to combine queries into all of them simultaneously

4:18 PM
@NovaliumCompany This one's pretty famous, with 2.7 million views, and countless links on & off the network: stackoverflow.com/q/1732348/4014959

@NovaliumCompany if it's views you want, then it's easy to query for on SEDE, Posts by ViewCount
I'm providing you that query since I was already halfway through writing it when you decided to attack me for helping you

Thanks!

but since all I got in return was spit in my face, I'm not sure I'll be doing that again

@EmilioPisanty My apologies.

have a nice day :-)

4:19 PM
Sometimes I wish I could down vote comments

@AaronStevens Don't you think it will bias people before they have even read the comment?

@AaronStevens like starring them, but with the opposite meaning :-)

@EmilioPisanty I don't know what happened. I'm sorry if I have insulted you in any way.

@NovaliumCompany Not anymore than it would for actual posts on the site. I am not actually proposing this though... that was more of just an aside comment

@NovaliumCompany What gets me though is that if you ask a question, and someone wants you to clarify, it's very rare that they are trying to just frustrate you and cause more work. Often times, people clarify because they want to make sure they actually answer what you ask. Instead of getting frustrated when they ask, understand that they are most often asking so that they can help you better than answering something they aren't clear about.

4:22 PM
@JMac I realized my mistake and I apologized. Lesson learned.
Let's not cause unnecessary drama.

@JMac to me Emilio's reply looked critical rather than encouraging. I would have got annoyed as well.
> if you want answers to your questions, asking ill-defined unanswerable questions is not really the way to go about it
Is that friendly and encouraging?

@JohnRennie that's well past the point in which the conversation got snarky and insulting on the other end, in response to a reasonable query from my side.

So you thought you'd abandon the high ground as well?

@EmilioPisanty it is around 6 month old!

@JohnRennie by the second insult, I stopped seeing the point for a bit
in any case, there wasn't a real apology or any clear evidence of actually understanding what the point is, so I'm just gonna hit the snooze button on messages from that source.

4:30 PM
@NovaliumCompany This query on the Stack Exchange Data Explorer shows the most viewed questions.
Ah. I missed that someone had already posted it. Whoops

For those who have a gold tag badge, do you have to be careful when going through the close vote queue to not close a question with that associated tag too quickly?

@AaronStevens yes
and when browsing the site in general, as well

If you are going through the queue do you just skip the question then?

@EmilioPisanty can I post my question link here I need edit suggestions!?

92

We've already had people ask if they can decline the ability that comes with a gold tag badge to insta-close-as-dupe questions in their tags. I did this by accident today myself. On reflection, I decided not to reopen, and my asker thanked me for finding the dupe, so that question is staying clo...

@AaronStevens this is the object of a fair amount of complaining, and of at least one browser extension which (mostly) works to alert you when the dupehammer is active

4:33 PM
@AaronStevens luckily you can single handedly reopen question if it turns out you've been too heavy handed :-)

@AaronStevens I do a run-through of duplicate CVs on the tags I have a gold badge on first
using the filter functionality

@JohnRennie I wasn't saying his comment was necessarily perfect either. I was specifically referring to Nova's comment about it being exhausting to talk to people here. I was actually trying to hint at the fact that the feeling of exhaustion isn't necessarily one sided in those conversations. People get exhausted with vague questions too.

makes optimal use of my CVs and my time in clearing the queue

@JohnRennie Ah ok, thanks.

then the rest is safe from over-strong closure ;-)

4:34 PM
@EmilioPisanty You can filter in the queue?
2

I then also do a run for off-topic questions tagged homework
helps me focus my CV reviews on the stuff that annoys me the most

Oh wow yep, I see the filter option. For some reason I never saw that haha

and it's easier to review when all the tasks are similar, instead of swinging wildly through concept-space
@AaronStevens I agree it's not very discoverable at all
I only found it one or two years ago

I just realized that you can edit "Your Communities" this morning -_-

@EmilioPisanty Yes that makes a lot of sense. Thanks for the tips. I just realized I am close to getting the gold tag for newtonian mechanics, so I just wanted to make sure I didn't abuse its power once I have it.

4:37 PM
@AaronStevens what on Earth is the point of having power if you don't immediately abuse it? :-)

@JohnRennie I suppose I should have not asked about it here and then just said "oops, I didn't know" when someone first flagged my power abuse

:-)
Just say "Who? Me?" :-)

@AaronStevens here, I'll do some edits for you.

@EmilioPisanty ?

@AaronStevens you should have that gold badge already, if I understand things correctly
it just needs some time to shake out

4:42 PM
@EmilioPisanty What magic did you just do?

it seems that there some questions that you answered earlier which were incorrectly filed and were missing some tags

Lmao it just took that 1 question to set him over, didn't it?

@EmilioPisanty Ah lol. pretty sneaky

@JMac well, two
@AaronStevens no comment.

@EmilioPisanty Well, thanks for that. Now I can actually get my work done I guess :P

4:59 PM
Hello everyone! I learnt that moment of inertia is a measure of distribution of mass around a given axis. So is it possible to get the original distribution of mass (or at least shape) by the knowledge of moment of inertia around different axes?

@JohanLiebert You could give it a shot -- draw some simple shapes and come up with some masses for them and calculate the moment of inertia
Then try to go backwards -- given the moment of inertia, can you invert the equations and find masses?

@JohanLiebert I'm thinking that makes sense if you have knowledge of an infinite number of axes; but I feel it falls apart completely with a finite number, though that's just my intuition.

I don't know why I got muted for 30 minutes considering that I apologized for anything wrong that I did and excluded myself from the situation.

@NovaliumCompany It was an automated mute. Someone had flagged your comment (I saw it but didn't vote on it because I was involved in the conversation) meta.stackexchange.com/questions/86479/…

@JMac Oh, alright.

5:14 PM
Well I assume it was an automated mute because I saw the flag around the time it happened. There's always a chance that it wasn't; but it seems likely the case here.

It was automatic

Just wanted to make it clear that I'm technically guessing
Oh okay, there we go. someone who actually knows could confirm it

It means either 6 people agreed it should be flagged and removed/muted, or a moderator somewhere on the network agreed it should be removed/muted. I don't know how to tell which is was. My guess would be a moderator somewhere

@tpg2114 Alright, thanks

Annoyingly, chat flags don't appear on the mobile view. That's not relevant for me here on the chat.stackexchange network, but it is on chat.stackoverflow

5:22 PM
The mobile chat is a pain to use

@tpg2114 thanks.
@descheleschilder I bring up relativity because it blurs the lines a bit between position and time and, therefore, between conservation of linear momentum and conservation of energy. I meant to argue that, despite relativity treating position and time in a similar way, they remain distinct, so that conservation of linear momentum and conservation of energy maintain different characters even under relativity. This was just an aside. — WaterMolecule yesterday

Sigh... it's only time:30 but it feels like it's (time+4):30 and I want to go home.

But ACM sir says:"You tagged your question [tag:newtonian-mechanics]. In Newtonian mechanics, time and space are not related at all.
And beyond Newtonian mechanics, i.e. **in relativity, time and space are not separate concepts, so neither are energy and momentum.** " These two statement (one by ACM and other by WaterMolecule) look quite opposite of one another. Why so?
@ACuriousMind sir what do you think about the comment made by WaterMolecule as compared to yours? (I'm a bit confused)

@tpg2114 Same here. I feel like it is (time + 6 months):30 and I want to graduate and move on :P

@AaronStevens Better than (time + NaN) I suppose. You have a number in mind ;)

5:37 PM
@tpg2114 I have a goal in mind. With each passing day that goal feels more and more unobtainable though

Pretty standard phase to be in. I know that doesn't bring any consolation, but it means you're getting closer to the end.
For the longest time, the only goal was survival until you felt you could set a goal of a date right? Well, you survived and you can at least put a number out there.

@JohanLiebert They really aren't opposites. Do you know about four-momentum?

@tpg2114 True. Definitely been trying to survive ;P. I still feel out of place going into biophysics, since my undergrad was just in physics and mathematics without any biology. I feel like I am still just scratching the surface as to how physicists really think about biological systems, how they tackle various problems, etc.

Multi/cross disciplinary fields are hard. It amazes me sometimes how two different groups may be doing the same exact thing, but the language and math they use to describe it are so different that it is unintelligible
Also, I'm not a physicist, but my view of biological systems: they are squishy and gross.

@tpg2114 I agree. That is why I have been doing modeling work instead :P
A post-doc that just left our lab had gotten turned down for a teaching job precisely for what you just said though
They said his physics was "too squishy"
Our lab and a biology lab we collaborate with does laser ablation studies of fruit flies though. So it at least can sound appealing to people other than biology
I just tell people we shoot mutant fruit fly babies with lasers

5:49 PM
... why...
Although, a laser-firing, fruit-fly-killing home robot would be awesome

@tpg2114 We are looking at how tissues know that a wound is present, and how they know what to do to heal the wound. Lasers are a way to make easily reproducible wounds
Plus we have the laser ablation system go through the microscope we use to image the system, so it is easy to wound and then watch what happens

6:05 PM
its exciting, maybe a genuine (future) breakthrough! conventional wisdom has been that there can be no such thing as a universal cancer cure and there is a lot of science pointing in that direction. alas, it can take very long (years minimum) to move these types of discoveries into human treatments, if it indeed carries at all. am optimistic. also, it again indicates the human immune system is wondrous and still not that well understood.
https://www.bbc.com/news/health-51182451

@vzn hmm...
I hate "click bait" titles like that

the fact that it's a SciAm headline doesn't do wonders for their credibility

@AaronStevens !?! lol! the original word for "clickbait" decades ago was "headline"... it would be so nice if ppl would actually click on articles before dissing them... asking way too much around here...

The cancer thing sounds cool though. Seems too good to be true though... I think it shouldn't be this hyped until more tests are done
@vzn I didn't say anything about the content of the article. I only commented on the title

@AaronStevens not in the mood for a debate but think its a genuine breakthru which ofc cynics will blithely dismiss as "hype"
@AaronStevens right. exactly.

6:14 PM
@vzn I am not critiquing the science.

@AaronStevens ofc there is some "hype" incl even from original researchers but the writeups are balanced. choose your news source. some are like tabloids full of hype, others are not. there is such a thing as credible journalism. although its increasingly vanishing...

That's an announcement that I'd place firmly in the "tell me where it's at in a few years" category

@JohanLiebert The distinction can be made within a fixed frame, but not coordinate-independent. You can also play different games in relativity to get "an energy" (e.g. find a timelike Killing vector and call its conserved quantity along a geodesic "energy"). Bottom line is, the notion of energy and whether it is conserved simply isn't straightforward in relativity.

@Semiclassical meanwhile millions of people will die of cancer around the world. maybe nobody in your family. someone in mine just died of it last summer, an agonizing death. the family is still paying off the high bills.

@vzn I didn't say anything about "hype", tabloids, etc. it looks like you think I am making points that I am not actually making

6:16 PM
4 mins ago, by Aaron Stevens
The cancer thing sounds cool though. Seems too good to be true though... I think it shouldn't be this hyped until more tests are done

...and? if it's a useful discovery, it'll save lives. if it's not, it won't.

@vzn Sorry, I thought we were still on the atom wave article

and there's no way to know for sure until this reaches the stage of actual medical testing rather than basic research
which, unfortunately, takes years

@vzn Waiting for more tests, data, etc. doesn't mean we think it is not important

its already a breakthrough in animal research. such breakthroughs are rare. the animal models of cancer are rather sophisticated and in many cases highly correlate with humans.

6:18 PM
except when they don't...

right. it could all turn out to be nothing (wrt human cancer). anyway billions are spent on cancer research per year, its one of the top killers of humanity. etc...

@vzn You are right, it is very exciting. But it still needs to actually be shown to work in humans and cure as much cancer as it claims.

is there a possibility this will prove significant? sure. is my being 'hyped' about it going to affect whether it is, and how rapidly that will happen if so?

yes. work remains to be done. its a milestone.

@Semiclassical Reminds me of this Twitter account that just cites other posts talking about research an adding 'IN MICE' when, in fact, they are talking about mice :P

6:20 PM
@vzn Indeed. And even if that exact "therapy" doesn't work, perhaps something can still be learned.

@ACuriousMind yep

@ACuriousMind Haha, that is hilarious.

on the note of scientific humor on twitter: twitter.com/scienceshitpost?lang=en

Anyone know of specific instances where a conclusion was drawn in mince but it was invalid for humans? I am sure they exist, but I have never looked into it.

@Semiclassical there is not being hyped about [x], and not being hyped about anything at all...

6:22 PM
Given that we're talking about [x] and not \forall, I don't see your point.

@Semiclassical Spherical Dog!

@Semiclassical seems nobody in here gets hyped about anything at all sometimes... seems to be a general cyber malaise, dont know what else to call it...

I have a book about mathematical models that has an instance of a spherical lizard too :)

the sheared sheep is what got me

Yeah that is a good one
Ok last one
This is gold

6:25 PM
yup

a joke about suicide of a scientific luminary, yeah.

@AaronStevens the thread on the wildebeast is the stuff of nightmares

>13. Physicists laugh a lot
Not only is the humour of physicists arcane, but almost anything unexpected can provide a jocular moment. Theirs are the ultimate inside jokes, which are often not obviously funny. But laugh along anyway — even if you don’t find the humour, they won’t know the difference.

seems to be a joke about the low status or ...? of thermodynamics + statistical mechanics, also. a not unheard of sentiment around here.

"Others doing X have experienced terrible fates. So let's go do X ourselves." that's the joke
has nothing to do with the standing of statistical mechanics as a subject

6:31 PM
understand theres some joke there (its been quoted in here before). also understand there isnt. its a kind of zen joke there. even though nobody here is into zen. lol
@Semiclassical its easily interpretable as alluding to the standing of the subject.

if you choose to, yes
"X studied Y, and killed himself. X' studied Y, and killed himself. Now we get to study Y."
that's pretty much all that's there, and the joke would be the same regardless of X,X',Y

yes. X1 and X2. top scientific luminaryS, both virtually inventing the subject...

1 hour later…
7:36 PM
Hey all! Can someone please let me know how Witten in this paper (arxiv.org/abs/hep-th/9802150) went from (2.14) to (2.22)? I get the integration by parts, where does the limit come from? to cancel infinities?

8:04 PM
yes please.

1 fortnight = 2 weeks. It's a common term in British & Commonwealth English, but very rare in American English.

There are 7 days in a 1/2 fortnight... :D anyways, I was talking about this
minecraft is better tho
much much better

8:26 PM
My favorite bit of science humor was when a physicist put his cat as co-author of a paper because he wrote in the plural the entire article and didn't want to change it to the singular

9:07 PM
lets make a keyboard thats a mouse. Like, you literally move the whole keyboard as a mouse.
lol

9:25 PM
@NovaliumCompany People typically lean towards lighter mice... so I'm gonna opt out of that one

10:00 PM
@Tesseract mine probably still has to be this legendary example: improbable.com/airchives/paperair/volume12/v12i5/…

10:33 PM
@JMac "mice"

@SirCumference ?

never heard that used for a computer mouse :P

@SirCumference Really? Computer mice is the term I always see for plural of computer mouse. "Computer mouses" doesn't sound right to me.

10:58 PM
Water mass and gravity. In a V shaped cylinder verses a right angled cylinder, both with the same volume. Is the water pressure larger than the other at the bottom of the cylinder?

@xtrchessreal You mean like a cone vs a cylinder? If they have the same volume, then that would depend on the area of the base and the depth it's submerged. If they had the same base circle area and were submerged so that the bottom was at the same depth in each, pressure would be the same\
Wait, area doesn't matter for pressure, so just the depth. I was thinking forces

So the cone would have more depth to make up the same volume as the cylinder.
Assuming the top opening was the same radius

@xtrchessreal Or you could just have the top of the cylinder submerged further than the top point of the cone, and have their bases at the same depth still.

I am trying to relate the water pressure of the Oceans at their lowest points would have increased pressure as the oceans volumes rise over time.
In a sense acting like a wedge or a knife point and perhaps breaking tectonic plates where they meet as the pressure increases, causing shifts, under water landslides, earthquakes more often.
Or perhaps just larger events