« first day (3120 days earlier)      last day (145 days later) » 

1:19 AM
0
Q: Is the new activity indicators in PSE main page really useful/necessary?

acarturkI currently use both physics.SE and math.SE, and one difference I noticed was the new activity counters and notifications on PSE, which were absent in its math counterpart. Now, in my experience so far, these labels and notifications, albeit not intrusive, make it harder to concentrate while brow...

 
 
2 hours later…
vzn
3:24 AM
@SirCumference thomas carlyle called economics "the dismal science" in 19th century... but wrt justification of slavery... lets note physics was a rather "dismal science" pre Galileo. econophysics is a very young new science being born before our eyes. maybe/ hopefully its future form will be far more sophisticated/ evolved than anyone can imagine right now.
 
 
2 hours later…
5:10 AM
what does "non-thermal energies" means? I see it in "I am mainly interested in the investigation of the processes that may be responsible for the energization of particles to their non-thermal energies in astrophysical environments and for the propagation of such particles in the interstellar and intergalactic medium. ...
... These topics are central to our understanding of the origin of Cosmic Rays both in our Galaxy and in extragalactic sources and are crucial in order to interpret the wealth of data from radio to gamma rays that are becoming available in recent years."
 
 
1 hour later…
6:14 AM
@ACuriousMind Armed with knowledge of equivalence classes and invariants, pretty sure mathematicians understood the principle of family resemblance a lot better than most wizards :P
 
 
1 hour later…
7:43 AM
"Econophysics" isn't a thing
Econophysics is just "economics with methods from physics"
aka "math"
 
Quantum finance is an interdisciplinary research field, applying theories and methods developed by quantum physicists and economists in order to solve problems in finance. It is a branch of econophysics. == Background on instrument pricing == Finance theory is heavily based on financial instrument pricing such as stock option pricing. Many of the problems facing the finance community have no known analytical solution. As a result, numerical methods and computer simulations for solving these problems have proliferated. This research area is known as computational finance. Many computational...
 
I know quantum finances
 
The problem of these quantum inspired inter discipline models is that the dynamical equation, if it exists, is too complicated to write down
 
You might as well call physics econophysics because it uses additions, which was invented for accounting purpose
 
nah that's too extreme
 
8:10 AM
In other news
in Mathematics, 55 secs ago, by user 170039
https://chat.stackexchange.com/rooms/pingable/36
turns out there is a pingable list
 
 
2 hours later…
10:02 AM
yo
so say we actually had exotic matter
will we be able to actually construct a worm hole?
or is it still out of out scope
and for that matter, do we even know how to construct one by bending space time or do we just say stuff in theories that we actually have no way of doing?
 
10:17 AM
@MartianCactus I'm not sure of the details, but you need to construct a pair of entangled black holes, which are the mouths of the wormhole, using the exotic matter to stop the wormhole from collapsing. Then you need to move the mouths to where you want them. If you want a time difference between the mouths, I think you need to do that movement at relativistic speed, to get some time dilation.
You need a fairly large amount of mass / energy to create black holes. Although in theory BHs can have small mass, we don't know any way to achieve the required energy density apart from getting a few sun's worth of mass to collapse.
Even if we found some way of applying enough pressure to compress an Earth-sized chunk of matter smaller than its Schwarzschild radius, that wouldn't be much use for transportation, since the radius of the mouth of such a wormhole would only be a few centimetres.
I suppose you could charge up your wormhole mouths, so you can drag them around electrostatically. Of course, moving anything that massive will chew up a lot of energy.
 
10:34 AM
Define "wormhole"
 
worm·hole
/ˈwərmˌhōl/
noun
a hole made by a burrowing insect larva or worm in wood, fruit, books, or other materials.
PHYSICS
a hypothetical connection between widely separated regions of space-time.
 
Then you're gonna need more than exotic matter
Since that also requires topology change
You can do a bag of gold spacetime with just exotic matter though
 
hmm...
Suppose the AdS/CFT formulation also holds for our universe and that spacetime is really a tensor network of entanglements, it seems to dig a hole requires modifying the network topology somehow so that there will be regions where the network is less densely packed with edges
Problem is it is not clear if the thing that is entangled are even quantum states as we knew it, or something more exotic
I had a feeling whatever that makes up spacetime is something more weird than wave functions
and also "very small" otherwise we would have noticed it already in low energy experiments
Might look up one day to see what the tensor network corresponding to some wormhole like geometry in AdS look like
Ok so if there is a way to unitarily evolve these states, then it may be possible to modify which of the pairs get entangled and hence the connections of the mouth of the wormholes
But to create a wormhole when previously there isn't any, seemed to be more challenging
 
11:07 AM
In the many worlds theory in QM, whenever we observe anything that is in a superposition, "reality splits" into different worlds each observed each of the possible outcomes. So my question is when something is in a superposition? I mean, my book gives example with the PETE box (50% chance a ball to be black, 50% to be white) and reality splits and there are 2 identical observers, each observed each possible outcome.
 
11:35 AM
in Theory of Magic, 2 mins ago, by Geo
@Secret Maybe that is because the magic is never investigated and understood. We can cause it to happen repeatedly, but no one ever exploits that to actually figure out why it happens.
Science is when given two events A and B, A and B are connected by a chain of causal events which is simpler than A or B
Magic is when the above is not true
That is, an event is magic if its causal relation cannot be decomposed into a transitive chain of causal relations using the same relation operator R
 
@PM2Ring So if you move the mouths to where you want them then you cant travel between galaxies instantly? As popular belief says. Then that means you can only travel to a place you already have been..
 
12:01 PM
@MartianCactus Once the mouths are where you want them, yes you can travel almost instantly through the wormhole. But it will take you 2.5 million years (relative to Earth) to transport a mouth to Andromeda, if you can do that near light speed.
But I defer to Slereah on this topic, since they know far more about gluing spacetimes together than I ever will.
 
12:57 PM
@Slereah yo
so are you guys positive there is no other way to do it which does not involve major things like making 2 black holes?
 
1:14 PM
@MartianCactus No. As Secret said, there's the possibility that at the ultra-small scale spacetime already has an existing network of naturally-occuring wormholes, we just have to figure out a way to expand the mouths to a useful size, and then use exotic matter to keep our chosen wormhole open. But I have no idea how you could select where the other end of such a wormhole is. And that expansion operation probably needs a huge chunk of energy.
 
Well
Send some negative energy through it
It expands
Go to the other side
and hopefully it's not too far away
then you can move it around using the usual tricks
But that's making a lot of assumptions
 
3 hours ago, by Secret
But to create a wormhole when previously there isn't any, seemed to be more challenging
The mechanism of a topological change interested me more, but I guess it will be very energy intensive to do that
though practically speaking, if there are already a lot of naturally occurring wormhole networks, then perhaps this existing set will always have the correct pair to do the job
thus all that boils down is the huge energy requirement, as well assumptions that gravity still behave in a predictable way at that scale, which we don't know since we don't have a quantum gravity theory yet
 
1:43 PM
Can we close stuff like this as non-mainstream? The OP thinks it's mathematical physics, and IME such people don't take kindly to being informed that it's nothing of the sort.
 
2:02 PM
@PM2Ring I wouldn't close it as non-mainstream personally. I can't even tell if what they are asking is based on mainstream physics, or something else, so I chose unclear what you're asking
 
@JMac They're mashing together various numbers from physics & looking for matches. When they find one, they see it as evidence for some hitherto unexpected connection. Generally, the match doesn't need to be very close. Here's an example from XKCD. forums.xkcd.com/viewtopic.php?f=18&t=108599
I'm tempted to close as unclear. It is clear to me what they're doing, but it sure ain't physics.
 
2:24 PM
Numerology is some of the most boring knowledge in existence. Even when reading New Thought stuff for entertainment reasons, I skipped all the numerology sections
 
@Slereah what's up with these intel security vulnerabilities
 
Because frankly, it is meaningless given the insane number of mathematical coincidences possible, thus numerology is not even not even even wrong in revealing connections it claimed to reveal
 
do I have to torch my PC?
 
@Secret Hey, it can give you Jenny's Constant and that made the BillBoard top-ten!
 
@dmckee ok, that's one hell of a surprise...
> Despite all the mythology to the contrary, I actually just came up with the 'Jenny,' and the telephone number and the music and all that just sitting in my backyard. There was no Jenny. I don't know where the number came from, I was just trying to write a 4-chord Rock song and it just kind of came out.
@RyanUnger screen get flooded with a huge number of gs
 
@Secret "not even not even even"?
 
Just my attempt to make something more intense than "not even wrong" but is heavily restrained by the language used
The same phenomenon happens whenever one tries to talk about any of the unknown categories
Put it another way, what I want to say up there is numerology is generally worse than "not even wrong" because given the huge number of mathematical coincidence, the chance that a coincidence is meaningful is virtually zero, thus numerology does even worse than astrology
 
@Slereah uh no, as of last week
we all need to disable hyperthreading
 
Well i don't know the specifics
But I know the culprit
BACKWARD COMPATIBILITY
 
2:51 PM
millennials
 
Oh god
Have you ever read x64 specs
It's a giant mess
you still have bullshit from the 70's in that processor
just because changing it would make some programs not work anymore
 
Well, these hypertreading issues make me happy that I cheaped out my build with an i5
 
@PM2Ring reasonably certain we close numerology questions as non-mainstream
 
Ranking pseudophysics subjects:
Astrology > anything that is not a globe > Orgone > ... > Quantum woo > Numerology
Astrology actually get the measurement part on the position of planets and stuff pretty close, but any effect it proposed are debunked out of existence already
 
3:09 PM
@KyleKanos Thanks
 
@JMac I have an i9 9900K so ironically I'm fine
My laptop needs to be updated though
no hyperthreading will impact my very heavy latex sessions
 
"very heavy latex sessions" could be misinterpreted
 
that's the joke.jpg
@Slereah do you have the Deligne books
They're not expensive for AMS members
 
3:35 PM
@RyanUnger whomst
 
@Secret i dunno, quantum woo bothers me more than astrology does.
 
@Secret so you give the same ranking to flat Earth, hollow Earth and concave Earth?
man, there's a steep gradient in imagination between those three
 
Believing that the universe could have an unknown influence on people's personalities and actions, vs. people's personalities and actions having an unknown influence on the universe
 
@RyanUnger that's what draft is for, no?
that, and splitting your document up into files and only including the ones you're actively working on
 
3:45 PM
they're both nonsense, but the direction of causation in the latter seems more absurd than the former to me
 
@Semiclassical No, my ranking is on how internally consistent it is, thus quantum woo is almost as random as numerology
 
Astrology is actually pretty rigorous in the way they do the planetary measurements, it is the event predictions that it get wrong
 
yeah, that's fair. astrology is in principle rather rigid (if not necessarily in practice)
 
@EmilioPisanty Well, I just don't bother to rank between them, though I think the concave earth is the most absurd of them all. You can still fit some real life evidence to flat earth if you tried hard enough, but concave earth throws everything out of the window
Also Semi, you brought out a good point here:
> people's personalities and actions having an unknown influence on the universe
Pseudoscience that falls into this category tend to be much less internally consistent due to egotism, banum effect, dunning Krueger phenomena and other principles
 
3:52 PM
I guess i'd put the ranking as hollow earth > flat earth > concave earth
hollow earth acknowledges that the earth is spherical, and "only" quibbles with the interior of said sphere
 
yup
 
flat earth, while absurd when faced with sufficient evidence, is a good enough model for most everyday experiences
 
yeah, there is a surprising number of ways to fit evidence to it
 
Concave earth, on the other hand, is in conflict with both everyday experience and detailed investigation
 
yup, especially in that video when there's that crystalline pyramid thing floating in the middle of it
 
3:57 PM
(Until you actually have such detailed investigation, of course, flat earth / concave earth / spherical earth are not so easy to rank.)
 
@EmilioPisanty I do everything in one file
 
As for quantum woo, it is very absurd and it even contradict itself in various ways (e.g. compare New thought, New Age and <insert healing scam>
 
It's fine if you don't have many figures
 
What is funny is that there are examples of "concave earth" in fiction. Specifically, in space colonies
 
3:58 PM
yup, dyson sphere stuff
 
no joke my laptop does seem slower now
 
yeah, or a space colony inside a tube
 
Interestingly, Having knowledge of both quantum woo and proper understanding of quantum mechanics makes me realise one important thing: Magic as depicted in folklore and in fictional works are actually very powerful because they are basically superluminal signalling
 
there's 5 pictures in my thesis
 
well, magic basically has no rules save narrative convenience
 
4:00 PM
the cover, 3 that @Semiclassical generated, and one depicting a spherical capping off
 
@Secret part of it, i suspect, is that I consider myself at least somewhat an expert on QM and therefore more liable to be annoyed by bad interpretations of it
I mean, I find "magnet woo" annoying but not to the same degree that I find "quantum woo" annoying
 
well it does not help that since the birth of quantum mechanics, people keep using "quantum" as a buzzword
thus the annoyance is understandable
 
In other news, just flagged that Adam troll for thinking you and I are the same person
 
i've had them on ignore for a while now
 
4:08 PM
good idea
 
@RyanUnger mite b cool
 
4:29 PM
so
my journal of choice took all my \hats and changed them to \widehats
$\widehat{\mathbf u}$, $\widehat{\mathbf e}$, $\widehat{\mathcal G}$
do I risk the wrath of the gods if I revert them to \hats at first-proofs stage?
 
depends on the journal format requirements...?
 
@Secret they definitely didn't go that deeply into the detailed finesse of mathematical typesetting
 
In that case, as long you are consistent, nobody will yell at you
 
@Secret I mean, I already submitted my .tex using \hats
then they re-keyed it to whatever system their back end runs
the proofs has a web app that allows me to edit the tex
which has all the \hats turned into \widehats
I've reverted them all
but I'm starting to feel like this
 
Hmm... if their backends don't like you reverting it, it will just automatically revert it again some time later. Thus just carry on and leave it be if it does revert back
 
4:40 PM
@PM2Ring So if there are naturally ocurring ultra small wormhomes, are there also naturally occurring ultra small black holes that make these wormholes or do they form by some other mechanism?
 
@Secret yeah, that's the plan
they also changed $\mathrm{SO}(2) \cong \mathrm{U}(1)$ to $\mathrm{SO}(2) \approx \mathrm{U}(1)$, which I'm mildly ticked by
man, proofs stage always gets me
 
@MartianCactus Kind of, but they're quantum-stabilized micro black holes, so they don't radiate, and they're too small to swallow anything. But I'm no expert in possible quantum gravity theories, so I May Be Totally Wrong. ;)
@EmilioPisanty I'd be more than mildly ticked by that. It's distorting what you're saying!
 
@PM2Ring eh
I get it
it's a physics journal with an experimental bent
their typesetters don't see a lot of math, are not specialized in it, and muck the details once in a while when it comes up
hence the mildness of the tickedness
proofs always require super-careful scrutiny, and this one needs plenty of corrections, but all things considered it's quite OK
definitely nothing on the level of substituting $$\operatorname{arcsinh}(\gamma)$$ with $$\operatorname{arcsin}h(\gamma),$$ which PRA once pulled
still annoys me to this day, five years later ¬¬
 
@EmilioPisanty Fair enough.
I sometimes see argsinh, which reduces that problem a bit.
 
4:59 PM
OMG $\mathrm{SO}(2) \cong \mathrm{U}(1)$ and $\mathrm{SO}(2) \approx \mathrm{U}(1)$ are NOT even the same thing, I will not be just mildly ticked off by that
 
@EmilioPisanty lol, that's bad... Wonder if that was an automated "fix" or manually done (assuming it wasn't just a mistyped entry)
 
@KyleKanos I have no idea. The TeX-to-internal-system conversion in phys rev is meant to be super streamlined and automatized, so who knows what happened there. Also it was ages ago, so it's mostly lost to time. But it still annoys me.
@Secret to be honest I'm more annoyed by the consistent mis-alignment of equals signs in equation arrays
but I've seen what a terrible galley proof looks like, this is fine
 
@Secret If A is congruent to B, then A and B are approximately the same structure. That's physicist maths for you. :D
 
$(\mathrm{SO}(2) \cong \mathrm{U}(1)) \implies (\mathrm{SO}(2) \approx \mathrm{U}(1))$
just don't do the reverse implication and logicians will still be happy
(but I knew physicists fail that, not that it really matters lol)
 
5:23 PM
whomst'd've
 
5:56 PM
whomst'd've'll's
Ahh, that book Q is for Quantum is a bit sketchy. I guess I'll have to read it a second time some day.
The book uses weird terms like "real state", "rocky state" wtf is this...
 
vanilla state, strawberry state, chocolate fudge state...
 
6:13 PM
@PM2Ring soo do they attract stuff?
i mean obviously they do if they are called black holes which means light cant escape
they must attract stuff..
but we dont stuff randomly being pulled around
 
6:47 PM
@MartianCactus I repeat, I'm no expert in possible quantum gravity theories, so I May Be Totally Wrong. But anyway... We're talking about really tiny BHs, down at the Planck scale, forming the structure of spacetime itself. So in this picture, spacetime is an almost perfectly uniform field of these micro wormholes / black holes. They don't pull anything around, because any particle is being pulled equally in all directions.
But I guess you can "blame" them for stuff like inertia, and the actual value of the speed of light.
 
I don't think the picture of a lot of micro black holes all over space(time) is remotely mainstream :P
 
I don't claim this theory is true, and I may have messed up the details, it's been years since I read about this stuff. I'm just saying it's a possibility that's been kicked around.
@ACuriousMind Agreed. OTOH, I remember a few decades ago it wasn't considered totally crazy to speculate that fundamental particles are quantum-stabilized micro black holes. So using them as the components of quantized spacetime isn't much more crazy. ;)
 
I won't pretend to gauge the "craziness" of the idea, just saying it's not close to being accepted physics.
 
not to mention the so called "aether" :-)
 
@ACuriousMind This discussion started with building wormholes, and stabilizing them with exotic matter. We were never within calling distance of mainstream. :)
 
7:02 PM
Apart from the existence of exotic matter, that sounds perfectly mainstream ;)
 
Ok, constructing entangled black holes and lugging them to where you want is mainstream, just extremely technically challenging. ;)
 
I seriously think whatever is being entangled ,are not blackholes, but something more weird than that
 
@PM2Ring We leave the practical implementation to the engineers!
"Spacetime engineer" would be a dope job title, though
5
 
from the department of quantum spacetime engineering
 
25 mins ago, by PM 2Ring
@MartianCactus I repeat, I'm no expert in possible quantum gravity theories, so I May Be Totally Wrong. But anyway... We're talking about really tiny BHs, down at the Planck scale, forming the structure of spacetime itself. So in this picture, spacetime is an almost perfectly uniform field of these micro wormholes / black holes. They don't pull anything around, because any particle is being pulled equally in all directions.
This non mainstream thing is quite intuitive though, because any black holes has entropy proportional to its horizon area, which under that formalism, can be explained as the tensor network of micro black holes
It also explain nicely why black holes will merge and expand their horizon area, because what is happening is that an ensemble of micro black holes interact and then they became entangled, adding to the bulk and creating an anisotropy which is felt as gravity
but again, I don't think even quantum fields make sense in quantum gravity, thus this intuitive picture is likely to be way off
 
7:30 PM
@skullpetrol go raiders
bub rubb
 
 
2 hours later…
9:16 PM
@NovaliumCompany any none mathematical book will be ‘sketchy’ :)
 
 
1 hour later…
vzn
10:32 PM
In physics, there is a speculative notion that if there were a black hole with the same mass, charge and angular momentum as an electron, it would share other properties of the electron. Most notably, Brandon Carter showed in 1968 that the magnetic moment of such an object would match that of an electron. This is interesting because calculations ignoring special relativity and treating the electron as a small rotating sphere of charge give a magnetic moment that is off by roughly a factor of 2, the so-called gyromagnetic ratio. However, Carter's calculations also show that a would-be black hole...
 
11:08 PM
@RyanUnger WOO WOOOO
 
you posed to be up cookin breakfast
 
:-)
 

« first day (3120 days earlier)      last day (145 days later) »