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2:21 AM
Hmm, might need to think about what it is like to live like a tachyon...
Do the accelerated frames of tachyons which tachyons are at rest in, contains indeterministic regions of spacetime
Other thoughts: Tachyon classifier:
Consider a pair of spacelike separates events A, B indeterminate causally (because it is A-> B in some frames and B-> A in others) correlated by a tachyon.
Let A,B be receivers with some initial binary value recorded, say 0, and 1
Upon emitting or absorbing a tachyon, a bit flip occurred at the receivers
Let $v_t$ be the velocity of the tacyhon
We also configure that A,B flashes a green pulse of light if it is 0 and yellow if it is 1
Now, in inertial frames $v < v_t$, A flips from 0 to 1 and emits a tachyon that travels faster than light to B, thus flipping B from 1 to 0
In inertial frames $v > v_t$ B flips from 0 to 1, retroabsorbs a tachyon, which travels to A to be retroemitted, and flips A from 1 to 0
Now suppose we have an event C that is in the future light cone of both A and B (hence C is timelike separated from A,B) which emits a blue light if it receives a green pulse of light from A, and stops emitting a blue light if it receives a red pulse of light from A
Then we end up with an interesting situation where depending on what $v$ is, C can switch from emitting blue light to not emitting blue light
Thus, because of the tachyon, a huge region of spacetime became casually correlated, and these events are related by a Lorentz transformation
In particular, for any timeline event that has a cause that involves events causally correlated by tachyons, the order of causality of the timelike event can be reversed when you overtake said tachyon, creating a scenario where basically, the whole configuration of events in the spacetime diagrams between different observers are related by a Lorentz transformation, not just events themselves
In particular, under such Lorenz transformation, the direction of causality of said events flips sign once it passes $v_t$
leading to a discontinuity in the direction of causality between two classes of reference frames
 
 
3 hours later…
5:48 AM
Tachyons don't have rest frames
 
@Slereah they are hypothetical only
There is only one thing faster than speed of light
 
Doesn't change the fact too much
 
It's time...... Wow
 
mathematically tachyons don't have rest frames
as can be checked trying to Lorentz transform them to rest
 
@Slereah How?
 
5:55 AM
things don't go well
 
@Slereah do they accelerate?
 
6:55 AM
@Slereah wow cool particle, thanks for sharing
June of this year, scientist will develop a Chip that can be implanted in human brain to make paralysed human beings to get normal :O
 
@AbhasKumarSinha Slowing a tachyon down via a Lorentz transform can only make it approach lightspeed, in the same way that speeding up a normal massive particle can only make it approach lightspeed
It won't get to lightspeed or lower, and hence won't get to zero velocity
 
mornin
 
how's life
 
At work
So could be better
 
7:49 AM
@NovaliumCompany I’d argue it does need evidence. And based on what we already know about nature, these things cannot happen.
 
@JakeRose I'm talking about something beyond our knowledge, reason, logic and understandings.
Just like a cat can't do certain stuff the human can, the human can't do certain stuff an enchanced human can...
Nvm it's messed up
But yeah, my main concern is that there may be things beyond our understanding, reason, logic and so on. If you argue that it does need evidence, you are still using logic and reason. Maybe some day we'll enhance the brain and be able to grasp other stuff.
 
8:40 AM
Ah right... thus the whole analysis above fell apart
 
9:11 AM
Wild thought, what happens if we can make gravitational waves to do that
 
@NovaliumCompany there very much is things beyond our understanding. And we have evidence they exist, or we don’t know about them yet (you can’t know what you don’t know!). But mysticism, we’ll there’s no evidence it exists. And when I say this, don’t conclude “oh science doesn’t understand it”. That’s not what is being said. What’s being said is that people have investigated these claims and found no good evidence any of it is more than quacks or just plain deception.
There’s a difference between not understanding and being wrong
And I’d be weary how far you take analogies in your reasoning. Just because a cat can’t understand mathematics doesn’t mean mercury has any effect in your life if you catch my drift
 
There are only ancedotes, and none of these are reproducible
There is also no way to prove whether they are real knowledge or just psychology meddlings
Even within mysticism, the notion of pure consciousness is controversial
 
@JakeRose That's my point. Mysticism doesn't need evidence/logic/reason to be true. People have investigated these claims but they are using logic and reasoning again.
 
Most of the time, the only describable thing in mysticism is the experience itself, and even that is not 100%
 
@Secret That would be technically rather difficult. According to this answer by Michael Seifert, the gravitational wave energy emitted by the Earth orbiting the Sun is about 196 watts. So good luck creating a gravitational wave spike of any significant power.
 
9:25 AM
Mysticism shares many similarities to the subjective experience when looking at artworks
 
@NovaliumCompany if you have no evidence then I’m afraid you cannot be true
 
@JakeRose You are again, judging using your reason and logic
 
The whole purpose of logic and reasoning is to investigate things such as this.
 
@PM2Ring I see, also, it is a bit hard to figure out what it will do without some pretty intense numercial calculation because gravitational waves are nonlinear thus they do not obey superposition
 
@NovaliumCompany you say as though that’s a bad thing. But in fact it’s the best method we have of investigating the world.
 
9:26 AM
@Secret excellent link
 
@JakeRose I totally agree, I support and follow reason and logic, but I'm just accepting the idea that there might be something beyond logic and reason.
 
I think you’re blindly saying these statements without thinking them through
Mysticism and all the other quackery voodo is not outside of logic and reason
It’s certainly not outside of experimentation
Experiment is the only true test of nature. Learn that, and respect it.
 
"As Alexandre Borovik notes, when schoolchildren work with units such as “apples” and “people” they are really working in a $\mathbb{Z}^n$-graded algebra, and one could argue that the study of homogeneous elements (that is, elements of the same degree) in $\mathbb{Z}^n$-graded algebras is the entire content of dimensional analysis."
 
Never knew one can think of kinds of objects that way
 
@NovaliumCompany FWIW, we had a few questions recently about the "theories" of quantum mystic Amit Goswami. physics.stackexchange.com/q/485049/123208 and physics.stackexchange.com/q/485056/123208 Amit Goswami has had scientific training, and he's trying to present ideas from ancient Hindu scriptures in a quantum context. But as you can see, he comes to some pretty bizarre conclusions, and is generally regarded as a crank by mainstream physicists.
 
9:32 AM
Ok, all I am saying is that there may be things that we cannot reach with our current cognitive capacities. Things that don't need logic and reason to be true, or most certainly, things we cannot currently imagine nor describe at all.
For us to imagine what those things are, will be like a worm trying to imagine what being human is.
 
I've been human
Wouldn't recommend it
 
same here
Actually, you don't know anything else from human, so you have no basis to say it's bad :D
If I start talking these stuff to the kids in school, I'll probably get bullied as hell
or at least be outcasted.
 
@NovaliumCompany Says you
 
ugh
it's 5:30am...
 
@Slereah Yes :D? I mean, I'm a human if that's what you're saying
 
9:36 AM
Another Indian scientist mystic is Subhash Kak, who claims ancient mystics were able to discover astronomical facts by yogic powers. One of his fans has been posting outlandish claims recently on Astronomy.SE.
 
Well, all I can conclude from our discussions with @JakeRose is that, there is quite a lot that we don't know yet. (or maybe not capable to know)
I mean, who knows, if the world was simple, it wouldn't be interesting to explore.
 
There are at least 6 types of unknowns:
 
@Secret You don't know how many unknowns there are, because your brain may be limited to what it can understand.
 
@NovaliumCompany there may be things that we cannot reach with our current cognitive capacities Sure, that's fair enough. And I agree that we can't simply dismiss mysticism just because it clashes with science. OTOH, we can dismiss claims that clash with empirical observation, and stuff that's not logically self-consistent.
 
@PM2Ring I agree with your first 2 sentences :D
 
9:43 AM
There are at least known known, unknown known, known unknown, unknown unknown, higher order generalisation thereof, known unknowable, unknowable known. Almost all unknown unknowns cannot be referred to by language, or even by experience

It is also unknown whether this model of the unknown is the correct one, by limitation of our biological minds
Many people said I am eccentric and with very unusual ideas, but I replied that the issue is I am not eccentric enough to transcend creativity
 
Everything is unknown :D
Maybe because it doesn't have to be known.
That sentence made 0 sense, but again, it doesn't mean it's not true just because it doesn't follow logic and reason :D
 
In the philosophy domain, I am researching on dialethia nowdays, thus "nonsense" is technically insignificant compared to that
It will be cool if cthulu pay a visit, as I need more eccentricity to figure out something
Everything is technically unknown. What we call an 'electron' may be something we simply cannot understand that behaves like an electron
 
The world is a f*cked up place dude...
 
But for that insane number of unknowns, it is surprising that we can make use of so many of them
I can imagine a world far more wild than that, where even things like "sense", "spacetime" etc. just makes no sense in there
Tbh, I think our universe is perhaps the most tame of the known worlds, assuming if there are indeed more worlds out there
 
 
1 hour later…
11:06 AM
What does the presence of homoclinic points indicates, in terms of dynamics of a system?
 
 
2 hours later…
1:03 PM
'Patterns That Eventually Fail' [link](https://johncarlosbaez.wordpress.com/2018/09/20/patterns-that-eventually-fail)

"$$\displaystyle{ \int_0^\infty \frac{\sin(x)}{x} \, dx= \frac{\pi}{2} }$$

$$\displaystyle{ \int_0^\infty \frac{\sin(x)}{x}\frac{\sin(x/3)}{x/3} \, dx = \frac{\pi}{2} }$$

$$\displaystyle{ \int_0^\infty \frac{\sin(x)}{x}\, \frac{\sin(x/3)}{x/3} \, \frac{\sin(x/5)}{x/5} \, dx = \frac{\pi}{2} }$$

where the pattern continues until

$$\displaystyle{ \int_0^\infty \frac{\sin(x)}{x} \, \frac{\sin(x/3)}{x/3}\cdots\frac{\sin(x/13)}{x/13} \, dx = \frac{\pi}{2} }$$
 
@Slereah I had a good chat with one of the big GR guys here
we should read the CK book
 
CK?
 
christodoulou klainerman
 
oh, the hamiltonian GR one?
 
what
global nonlinear stability of Minkowski
 
1:17 PM
ah, The Global Nonlinear Stability of the Minkowski Space
 
 
3 hours later…
4:15 PM
101
A: Does the new finding on "reversing a quantum jump mid-flight" rule out any interpretations of QM?

knzhouNo. All news stories about this result are extremely misleading. The "quantum jump" paper demonstrates an interesting and novel experimental technique. However, it says absolutely nothing about the interpretation of quantum mechanics. It agrees with all proper interpretations, including the Cope...

 
just upvoted the answer
 
4:32 PM
so what's the difference between dumb copenhagen and the usual copenhagen interpretations?
 
@thermomagneticcondensedboson I think @knzhou should answer that; I don't want to put words into his mouth. But from his answer: In dumb Copenhagen, everything evolves nicely by the Schrodinger equation, but when any atomic-scale system interacts with any larger system, its state instantly "collapses". That's a simplification.
 
I thought that was the usual Copenhagen
i.e. psi satisfies Schrodinger's eq except when a measurement is being done
 
@thermomagneticcondensedboson knzhou seems to be using the terms in the sense that "dumb Copenhagen" believes that any interaction with a large system leads to instantaneous collapse, while "actual (or modern) Copenhagen" posits collapse only for a measurement (though pinning that term down is probably also a bit hard) and is aware that it is not really "instantaneous" but rather itself a continuous process of decoherence.
Given that I don't think you can find a universally agreed upon definition of what the "Copenhagen interpretation" really is, that's a good a distinction as any other
 
4:52 PM
in The Restaurant at the End of the Universe, 13 mins ago, by Loong
@xkcd Sigh, yes, that's about how I feel. Admittedly, the TV series is aesthetically very well made and has many authentic details. However, there are suddenly so many people with a dangerously superficial knowledge again, but they don't want to hear what really happened because that would be too complicated.
 
how to maximize the value of line integral by choosing a appropriate curve within a domain in the given vector field ?
 
@AjayMishra a rather broad question
I’d suggest looking at some variations principles
@knzhou no idea if you delve into here often, but thoroughly enjoyed reading your answer!
 
5:16 PM
Hey I just learnt about Quantum eraser, why can't we make use of it and communicate faster than light?
 
There's a gazillion similar questions on the site already.
 
@Loong I tried to get this guy to improve his typography, to no avail:
BTW, can you please use proper typography on Stack Exchange sites. There should be a space after a comma. — PM 2Ring 6 hours ago
 
@PM2Ring and all these wrong "&" everywhere
 
5:31 PM
@Loong The ampersand abuse I can tolerate, but not the spaceless commas.
 
vzn
@PM2Ring thx for the ref (+1) but feel the new experiments actually do much more than refute strict copenhagen interpretation and not all knzhous analysis is seeing the bigger picture. theyre findings of subquantum effects that are outside the standard formulation of QM. there are few physicists brave enough to go on the record saying this, esp on this site given the policies. its no coincidence one of the coauthors of the paper is an expert on/ originator of an alternative QM formulation.
 
@vzn They don't refute the strict Copenhagen interpretation. Maybe it's the language barrier thing again. You never did tell me what your mother tongue is...
 
@vzn As knzhou says in the answer: "The authors themselves emphasize in their paper that what they found is in complete agreement with standard quantum mechanics. " Nothing "subquantum" about it.
 
@ACuriousMind I read a couple of questions, and none of them seem to answer it precisely or else I have some serious misunderstadning
@ACuriousMind A) if I give you 1000 photons, you will be able to tell whether they have wave properties or not by standard double slit experiment right?
@ACuriousMind B) I can control which photons you get are not collapsed and collapsed
 
@VARUN.NRAO Do you understand why the breaking of entanglement cannot be used for FTL communication in general, i.e. the no-communication theorem? If yes, then how do you think the eraser gets around it?
 
5:43 PM
@ACuriousMind Yes entanglement is measuring the values of spin. Here I am using not the values but collpasing of wave function itself
 
It's pointless to answer "Why can this particular setup not be used for FTL communication?" for every possible setup - we could do this for years, full-time.
 
vzn
@ACuriousMind the authors themselves say their experimental results support a newer interpretation that knzhous albeit highly upvoted answer doesnt cite whatsoever.
> Our findings, which agree with theoretical predictions essentially without adjustable parameters, support the modern quantum trajectory theory5,6,7,8,9
 
@ACuriousMind forget setup just please address my point A and B
@vzn do you have any idea about this?
@vzn I know I'm most probably wrong, but there is no convincing answer on the internet
 
@vzn I suspect "modern quantum trajectory theory" does not mean what you think it means. It does not refer to Bohmian mechanics, but to a technical approach to scattering theory that is fully derivable in the standard QM formalism.
@VARUN.NRAO I'm afraid neither your A nor your B make sense to me
If I send photons through a standard double slit, I will see an interference pattern. Nothing you can to do them beforehand can change that.
 
@ACuriousMind Why?
@ACuriousMind if measure their entangled pair am I not collapsing thier wave function?
if so how can you see interference patter?
 
5:50 PM
I don't know what you're talking about. What entangled pair?
 
vzn
> The authors themselves emphasize in their paper that what they found is in complete agreement with standard quantum mechanics. [REF NEEDED]
 
OK see, we have 1000 entangled pair of photons, one set is sent to you and me set is sent to me
I have one half of the entangled
Now I can choose to measure them or not measure them
 
vzn
@ACuriousMind never claimed it referred to bohmian mechanics. am not an expert in this but it looks like a semiclassical theory formulated mostly in the 1990s. would like to see an answer by someone on the site who has a good grasp of semiclassical theory.
 
@ACuriousMind based on which the wave function collapses on your end
 
@VARUN.NRAO How are they entangled? By their polarizations? Why would that have any effect on the double slit?
 
5:53 PM
no
 
0
Q: Traces of manifold-valued Sobolev maps

Ryan UngerLet $(M^m,g)$ be a compact Riemannian manifold with smooth nonempty boundary, and $N^n\subseteq \Bbb R^d$ a boundaryless isometrically embedded Riemannian manifold. For $1\le p<\infty$ we define as usual $$W^{1,p}(M,N):=\{u\in W^{1,p}(M,\Bbb R^d):u(x)\in N\text{ a.e.}\}.$$ Using the Euclidean tr...

I need upvotes
 
Also, the no-communication theorem precisely says that entanglement cannot be used to transmit information because I cannot experimentally distinguish a random assortment of "collapsed" states from an assortment of states that only "collapse" when I measure them.
So this is just generic "why is entanglement not usable for FTL communication?"
@RyanUnger I don't have an MO account :P
 
@ACuriousMind
I get that, but that's a little different from what I'm saying
@ACuriousMind look at this image
If you remove the lens which is acting as an arbiter and replace it with a mirror
 
@ACuriousMind how
 
how what?
 
5:59 PM
how has he made it this far in life without an MO account
 
@ACuriousMind that is the experimental setup I'm proposing
@ACuriousMind if we replace the lens before and A and B with mirrors, then the path information is always retained
Am I correct in this?
 
that...doesn't look like any setup I'm familiar with
 
@ACuriousMind oh, That's from pbs
I think is reliable, no?
 
I'm saying I don't know what it depicts, not that it's wrong.
 
@ACuriousMind Look at this image where its marked with yellow arrow mark
@ACuriousMind oh ok, as far I understand, the purple beam is the photon, which either travels in upper path or lower path
@ACuriousMind then there is a photon splitter placed after the photon passes through the slits which sends two photons which are duplicate versions of each other(which I wrongly called as entangled) in two different paths
@ACuriousMind one set ends with a screen and other set takes a path which meets a semi reflecting mirror, where half the times the photons are sent to A and B where the path information is retained or send them to mixer which "erases" the path info by mixing photons
@ACuriousMind it is the semi reflective mirror which decides whether the information should be erased or retained. This should be replaced by a complete mirror
so now its in our control
What is wrong in all this?
?
 
6:23 PM
That's not how a quantum eraser works. Since photons do not follow straight paths (that's the whole point!), just detecting a photon in A or B tells you nothing about "which slit" it took. You need to mark the which-path information differently, for example via polarizers.
 
@ACuriousMind "just detecting a photon in A or B tells you nothing about "which slit" it took"??
But the guy in the video says other wise
 
Then the guy in the video is wrong.
Or, put more kindly, he's oversimplifying because he doesn't want to saddle his layperson audience with details about how we actually obtain the which-path information in a quantum eraser experiment
 
If you click on the link he clearly states it
oh is he oversimplifying it? I thought pbs was reliable
@ACuriousMind so how exactly do we obtain which path information? and lose it for some?
Then the video is seriously misleading
 
@VARUN.NRAO Usually via polarizers and a different setup where you first split a photon into two entangled ones, send one of them through a double slit and then put different polarizers behind the slits
 
Yes correct
then the photon splits into half energy twin pairs right?
 
6:32 PM
Yes, the process is called SPDC
 
correct one goes to the screen and one goes to the detectors
fine now if I know the path info interference pattern should collapse
 
The interference pattern is destroyed because the photons arriving at the screen behind the slit carry which-path information in their polarization.
 
wait a second
so all the photons that split does not have which path information?
@ACuriousMind yes they carry the information in polarization, if that is maintained interference pattern is destroyed
But I can "choose" to mix it up and erase the information
I have the choice of the erasing the information right?
 
@VARUN.NRAO Actually, for a simple eraser, you don't even need the second photon: Yes, you can erase the polarization information by putting a third polarizer in front of the screen that's rotated at 45° to each of the polarizers at the slits (which are at 90° to each other).
After you put that third polarization filter there, the interference pattern reappears, because now all photons have the same polarization when arriving at the screen again
 
Now I'm making the choice
I can choose whether you see the pattern or not
 
6:42 PM
Sure - by putting the polarizer there or not.
 
then I can communicate with you
 
Yes - with the speed of light, since that's how fast the photons with their polarization travel from you (at the third polarizer) to me (at the screen).
 
damnnnnn
So I can do nothing with the detectors to communicate something to you
??
 
You can - but not faster than light.
 
dammmmn
I feel so bad
I thought for a second it was possible
Thank you for explaining me, now i understand it, the change is happening at the screen not at the detectors
 
6:46 PM
@VARUN.NRAO So you should feel good, because you now understand why it won't work. It's always good to have misunderstandings corrected.
 
Anyway now that I have understood it I am relieved, I was like why is no one seeing this, while all along I had misunderstood it. Yeah in that way I feel good, no more cognitive dissonance.
@ACuriousMind thanks again
 
There is actually a variant of the quantum eraser that look more like what your image showed in that it uses two entangled photons, but it's also about polarizations and only works if you "post-select" a certain subset of the photons you measure. I.e. it's more complicated but since the post-selection needs to communicate information between both the screen and what you're doing to the other photon, it is also impossible to be faster than light
 
@ACuriousMind particles are communicating super luminarly right? It's that we can't make use of it. This is what I understood
 
@VARUN.NRAO No
There is no "communication".
 
ok singalling?? no then how will we explain bell's experiment
 
6:52 PM
You can of course believe that they secretly send indetectable and unusable signals to each other, but it is not necessary to assume
 
@ACuriousMind the bell anomaly implies a communication, because the spin was not decided previously and had to be opposite, which as far as I can reason seem to be impossible without FTL communication
 
@VARUN.NRAO No, it only implies "communication" if you believe that "the particles" have meaningful and well-defined states all the way and so need to communicate to each other when one is measured so that the other can change its state before anyone sees.
That's the "realist, but non-local" option left by Bell's theorem
 
even if we assume they are in super- positional state
the result of measurement has to be opposite
how can this be explained?
even considering the idealist world view, the result must be opposite at the same time satisfy the stats
@ACuriousMind any way I am not in a position to assert these things as all my info comes from Youtube, I will try to study these things from scratch and then maybe try to understand it.
 
The "non-realist, but local" option is to simply stop trying to apply classical intuition at all. Provably, no information is transmitted between Alice and Bob, therefore there is no communication, period.
 
@ACuriousMind thanks for all your efforts
Good day
 
7:18 PM
@JohnRennie : and if that doesn't work, tariffs are next?
 
@PM2Ring kinda annoyed by that answer tbh. Not the technical side—that’s fine—but the polemic against Bohmians seems unnecessary
I mean, there are good reasons to be skeptical about the Bohmian account. But as someone who is sympathetic to it, I find the notion that “Bohmians want to turn every experiment into evidence for the theory” to be just rather silly
A basic appeal of BM, to me, is precisely that it does not “go beyond QM” in any experimental sense.
(There’s a bit of a “no true Scotsman” issue here—I’m sure that some people who would call themselves Bohmians would disagree with me. But to carelessly label all Bohmians with that, is rather irritating)
(I also think that referring to BM as “an ugly hack” is subjective; if anything I find BM rather elegant mathematically. So I always find that line of criticism just sorta silly.)
 
7:34 PM
@Semiclassical I think your kind of "Bohmian" has a publicity problem, since those who do think it goes beyond standard QM tend to be rather...vocal about it, rather similar to the publicity problem of "Copenhagen" where every pop-sci explanation claims to explain the "Copenhagen" interpretation.
 
@ACuriousMind yeah, I buy that
I remember the whole “pilot wave theory explains EM drive!!!” nonsense
One compliment I will give to that answer: it acknowledges that, while some people may want to locate some kind of classical mechanics underneath QM, the Bohmian interpretation is not an example of such
Just b/c you have trajectories, doesn’t mean it’s Newtonian
 
@Semiclassical I agree that he's probably being overly harsh in his anti-BM remarks. Perhaps he read an article by a strident Bohmian about that experiment before he wrote his answer... IME, many Bohmians do give the impression that they aren't happy about "quantum weirdness", and yearn for a return to a more classical foundation for physics. As did Einstein.
 
7:50 PM
Which is funny, given both Einstein’s lack of interest in Bohm’s work and the strong tension between BM and the relativity of simultaneity
BM isn’t the kind of answer which Einstein would seem inclined to endorse
 
I get the impression that both Einstein and Bohm had strong physical intuition, but that they would have had difficulty finding common ground regarding quantum matters. It's almost like they're speaking two different languages.
 
Bell + Einstein might have been an interesting conversation
(At the very least, having Einstein try to grapple with Bell’s inequality would have made for an interesting discussion)
 
8:06 PM
@Semiclassical Definitely! :D
 
’ll also note that I prefer Bell’s presentation to Bohm’s own. There may be good computational reasons to work in terms of the quantum Hamilton-Jacobi equation, but conceptually I prefer to put the guidance equation front and center
 
8:20 PM
@JohnRennie : well can you help me in understanding the implications of Homoclinic points (in a parametric space) in a dynamical system, please ?
 
 
2 hours later…
10:22 PM
0
Q: What's required for the lifting of a temporary question ban?

EdouardAlthough it has been in place for more than a year, the only question ban I've encountered on any Stack Exchange site was a temporary one that would have supposedly allowed me to ask one more question on the Physics Stack Exchange after it would've been in place for only six months, with subseque...

 

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