The h Bar

I finally think I see a way to see how you would arrive at Fermat, Wilson and Euler in number theory without wanting to, it comes from wanting to analyze square roots in modular arithmetic, shockingly simple idea

Slereah

bolbteppa

haha

skullpatrol

clint ain't what he used to be :P

bolbteppa

12:14 PM

Also not far off:

Balarka Sen

naw

0celo7

I should call them Eastwood spaces

Balarka Sen

nobody has that killing hair

bolbteppa

Yeah without the slick hair

Balarka Sen

@bolbteppa Eh, to the rest of the normal human beings they come from trying to do modular multiplication

bolbteppa

12:15 PM

Slereah

also

Frank Frazetta

bolbteppa

Lion King - Communism will prevail.

►

Slereah

more Sobolev :

$user image$

Old Sobolev looks a bit like David Lynch, too

skullpatrol

that tie knot looks...over done

Slereah

Balarka Sen

12:21 PM

@Slereah again, not having that hair automatically disqualifies

Slereah

$user image$

skullpatrol

\o @Blue

Balarka Sen

Yeah I'm ENO who fucking cares

Tweeted by BrianEnoMusic on April 4, 2018 at 3:43 PM

wat

LOL WAT

why is Brian shitposting

Oh it's an emo meme

Yeah I'm EMO who fucking cares

Tweeted by Skrillex on March 31, 2011 at 5:43 AM

unbelievable somebody made a twitter just to make that joke

Slereah

12:42 PM

So

Where does Galileo/Newton actually talk about Galilean relativity

I'm looking around but it's hard to pinpoint it

short of reading the whole books

bolbteppa

Galilean invariance

Galilean invariance or Galilean relativity states that the laws of motion are the same in all inertial frames. Galileo Galilei first described this principle in 1632 in his Dialogue Concerning the Two Chief World Systems using the example of a ship travelling at constant velocity, without rocking, on a smooth sea; any observer doing experiments below the deck would not be able to tell whether the ship was moving or stationary. == Formulation == Specifically, the term Galilean invariance today usually refers to this principle as applied to Newtonian mechanics, that is, Newton’s laws hold in all...

Slereah

Already looked!

bolbteppa

'Galileo Galilei first described this principle in 1632 in his Dialogue Concerning the Two Chief World Systems using the example of a ship travelling at constant velocity, without rocking, on a smooth sea; any observer doing experiments below the deck would not be able to tell whether the ship was moving or stationary'

Slereah

btw calling one of your character "Simplicio" is a dick move

bolbteppa

I'd highly doubt they even used the word relativity until Einstein

Slereah

12:44 PM

It's like calling him Dumbass McGee

bolbteppa

Yeah

Slereah

@bolbteppa Already searched for the keyword "ship"

bolbteppa

I vaguely remember trying to read this thing

Slereah

not much!

bolbteppa

I can't read these wordy books, same with Einstein's popsci book, at the time they were good, but now looking back they are just a mess

Slereah

12:45 PM

they are certainly long winded

bolbteppa

The height of craziness is trying to read Aristotle expecting to learn freshman mechanics (without realizing that's what you were looking for :\ )

Slereah

Reading into it, it seems Galileo's dialong is ENTIRELY ABOUT MAKING SHIPS

So I guess I do need to read the whole thing

bolbteppa

Dialogue Concerning the Two Chief World Systems

The Dialogue Concerning the Two Chief World Systems (Dialogo sopra i due massimi sistemi del mondo) is a 1632 Italian-language book by Galileo Galilei comparing the Copernican system with the traditional Ptolemaic system. It was translated into Latin as Systema cosmicum (English: Cosmic System) in 1635 by Matthias Bernegger. The book was dedicated to Galileo's patron, Ferdinando II de' Medici, Grand Duke of Tuscany, who received the first printed copy on February 22, 1632. In the Copernican system, the Earth and other planets orbit the Sun, while in the Ptolemaic system, everything in the Universe...

Slereah

he's on some tangent about how ships of different sizes have different properties even though this should not be if all was geometrical

bolbteppa

Day 2 in the summary is where he talks about it apparently on that page

Slereah

12:49 PM

"My brain already reels. My mind, like a cloud momentarily illuminated by a lightning-flash, is for an instant filled with an unusual light, which now beckons to me and which now suddenly mingles and obscures strange, crude ideas."

Same

bolbteppa

Galileo's ship

Galileo's ship refers to two physics experiments, a thought experiment and an actual experiment, by Galileo Galilei, the 16th and 17th century physicist, astronomer, and philosopher. The experiments were created to argue the idea of a rotating Earth as opposed to a stationary Earth around which rotated the Sun and planets and stars. An argument that was used at the time was that if the earth were rotating, there would be detectable effects on the trajectories of projectiles or falling bodies. == Ship's mast experiment == In 1616, after Galileo had already become concerned that he was a target of...

Slereah

They didn't like equations a lot back then

bolbteppa

'Galileo's 1632 book Dialogue Concerning the Two Chief World Systems considered (the Second Day) all the common arguments then current against the idea that the Earth moves'

He probably goes on and on so its hard to find

Slereah

yeah the "argument" is probably like 3 bloody pages of text

bolbteppa

They quote the passages in that wiki below

Slereah

12:53 PM

"have with you there some flies, butterflies, and other small flying animals."

Quick where can I buy some butterflies

I really hope that Galileo really did that experiment

bolbteppa

JD would love this stuff

Slereah

Going on board with a bunch of flies, butterflies, fishes, jumping up and down in his cabin

Then you have some salty Italian sailor popping in

ARE YOU ALRIGHT MISTER GALILEO

bolbteppa

Curveball: the inquisition was just worried about him

Anonymous

@skullpatrol Hi

Slereah

"Various people had discussed the experiment in theoretical terms, and some claimed to have done it, with conflicting reports as to the result."

Galilean relativity is a fraud

"I have been twice as good a philosopher as those others because they, in saying what is the opposite of the effect, have also added the lie of their having seen this by experiment; and I have made the experiment -- before which, physical reasoning had persuaded me that the effect must turn out as it indeed does."

So yes, Galileo did jump up and down in his cabin

Galileo and the evidence

Slereah

1:11 PM

"That the force by which the moon is retained in its orbit tends to the earth; and is reciprocally as the square of the distance of its place from the earth's centre."

ZeroTheHero

Congratulations to @DanielSank for his recent paper just published in Science:
http://science.sciencemag.org/content/360/6385/195 (might be behind paywall).

7

dmckee

@JohnRennie Well, yes. But I want to put the focus on ideas and not on people.

Slereah

Do you mean author #27

pitt.edu/~jdnorton/papers/cosmological-woes-HGR4.pdf

Apparently Norton really hates classical mechanics

dmckee

1:33 PM

I was a little surprised, though, at how cool the reaction to that question has been.

Is it hard to understand? Too obvious to bother with? Or is it actually hard to answer?

Here I am wishing that I had taken more relativity. Again.

2

Slereah

If you want you might want to look up objections to Puthoff's polarized vacuum theory

It's the serious theory of GR as a variation of the speed of light

Polarizable vacuum

Gravitation can be described via a scalar theory of gravitation, using a stratified conformally flat metric, in which the field equation arises from the notion that the vacuum behaves like an optical polarizable medium. It was proposed by R. H. Dicke (1957) and then H. E. Puthoff (1998). Harold Puthoff (see also Bernard Haisch and SED) In theoretical physics, polarizable vacuum (PV) and its associated theory refers to proposals by Harold Puthoff, Robert H. Dicke, and others to develop an analogue of general relativity to describe gravity and its relationship to electromagnetism. == Description... ==

Emilio Pisanty

@ACuriousMind You're not the only fast gun in the West physics.stackexchange.com/questions/399600/…

Slereah

"A proposal in 1921 by H. A. Wilson to reduce gravitation to electromagnetism by pursuing the formal analogy between "light bending" in metric theories of gravitation and propagation of light through an optical medium having a spatially varying refractive index. Wilson's approach to a unified field theory is not considered viable today."

journals.aps.org/rmp/abstract/10.1103/RevModPhys.29.363

webcitation.org/65eR7W9tu?url=http://…

arxiv.org/pdf/gr-qc/0505065.pdf

looks interesting

Slereah

2:05 PM

@dmckee I think the real problem with what you're asking is the whole Reichenbach epistemology thing

dmckee

@Slereah I don't see how that dodges the naive paradox in my question though.

Slereah

that is, a theory needs to define how you perform measurements

Otherwise they do not say anything

So you need to define how you physically take measurements of the speed of light

and time and space

dmckee

Keep in mind that the "variation in the coordinate speed of light has absolute meaning" take is not my position, but one that is proposed and defended around the site and chat by others.

Slereah

Sure, but the point being that I don't think it matters much in the end

dmckee

But the claim as I understand it is that variation in the results resturned by a a basic there-and-back light clock should be explained by $c = c(\vec{r})$. rather than by varication oin the metric.

Slereah

2:09 PM

You can argue that, if you ask another observer to measure that speed, and he gets another answer, that the process by which he measures times and distances is also affected by the same thing

I mean maybe you could get a consistent theory out of that, I dunno (from what I hear probably not), but the point is more that GR has no problem with this

The problem with the whole coordinate speed thing is, how do you measure it?

How do you know in advance what the distance the light is going to travel is?

In SR that distance is defined by the light itself, so there isn't really much of a choice

That's why I try not to think too much about experimental GR :p

The theory affects how you define the measurements and it is fairly annoying

vzn

@Slereah thx, interesting! ps did you ever loo at tenev + horstemeyer? quite similar, very thorough survey arxiv.org/abs/1603.07655 btw what question are you guys discussing?

Slereah

I did not

2

Q: Equivalence principle and the meaning of the coordinate speed of light

Short version: Does the equivalence principle give us a means to tell if variations in the coordinate speed of light have absolute or only relative significance? Background In general relativity the local speed of light is a constant and has the usual value $c$, but the speed of light tha...

vzn

the theory was built on the idea that "local measurement of c" cannot vary. while valid and workable as a starting axiom, think it is an awkward pov wrt some measurements eg new ones by atomic clocks that can measure "time delay" wrt gravitational field. they are not really measuring an "infinitesimally local" region of space. it seems that some of the difficulty is in the language. also this en.wikipedia.org/wiki/Shapiro_time_delay

bolbteppa

If you view geometry as the art of reasoning from badly drawn figures, and want to reconstruct geometry by noting all that matters is the relative positions of the pieces making up a geometric object (e.g. a triangle on the plane still looks like a triangle when the plane is bent), then homology on a manifold seems to be the a way of talking about geometric objects on a curved space, or at least to Poincare it was, hmm

Balarka Sen

2:24 PM

poincare defined homology in a completely different way

chains being formal linear combination of submanifolds of a manifold

vzn

newsweek.com/…

Balarka Sen

he wanted to figure out how many times you have to cut a manifold along some specific sort of submanifolds to disconnect it

eg, at minimum how many circles to do need to cut along to disconnect a surface of genus g?

bolbteppa

There's so much going on in this stuff

Right now it seems like he was trying to generalize elliptic functions to fuchsian functions so he could solve more general differential equations, and wanted to generalize the link between elliptic functions and toruses to do this, so he's forced to face the problem of what a geometric object really is, and thinks up this 'geometry of position' idea (analysis situs) that what matters is just the relative positions of the component parts,

hence why it seems like he wants to define generalizations of geometric objects by merely saying their boundaries must satisfy this homology relation, but to define general geometric objects he needs to generalize the underlying space they live in, hence manifolds, but now he's forced to deal with connectivity questions and found Riemann did work on this so he used that,

then realizing he can define geometric objects like tori by chopping them up into pieces (a square with edges identified) he somehow naturally ends up at the fundamental group, but there's also a link to multi-valued functions, gah

Semiclassical

@BalarkaSen should be g+1 circles, shouldn't it?

Balarka Sen

@Semiclassical Right.

Semiclassical

2:36 PM

I imagine the challenge there isn't so much in guessing what it should be but in formalizing that into something tractable

Balarka Sen

Yup.

I mean, you have to formalize to even ask the question in a non-trivial way

You can take a small circle on a surface inside a chart

Cut along that and you have disconnected it

Take two meridians on a handle of any surface and cutting along them disconnects it

But these are "obviously" the wrong numbers

Semiclassical

Right.

vzn

re dmckee question, following from janssen. how does one express the following mathematically?

Mar 29 at 18:12, by Semiclassical

"Given this situation, in the presence of more complicated frames and/or gravity, relativity generally relinquishes the whole concept of a distant object having a well-defined speed. As a result, it's often said in relativity that light always has speed c, because only when light is right next to an observer can he measure its speed— which will then be c. When light is far away, its speed becomes ill-defined. But it's not a great idea to say that in this situation "light everywhere has speed c", because that phrase can give the impression that we can always make measurements of distant s…

Semiclassical

^ the discussion from the day should have a link/citation to the actual paper of Janssen

in case anyone wants the context

@BalarkaSen I feel like the more appropriate question is how many circles you'd cut on to get something equivalent to a sphere with some number of holes

in which case that's just the genus g

Balarka Sen

That's much better, yes

You can ask someone to prove that g+1 disjoint circles, no matter however arranged, disconnects a genus g surface

Semiclassical

2:42 PM

oh nice

Slereah

@vzn Parallel transport of the velocity

it is not unique

Semiclassical

@BalarkaSen hmm, wouldn't it be "at maximum" then?

Balarka Sen

@Semiclassical Only if I said "to not disconnect", no?

Semiclassical

17 mins ago, by Balarka Sen

eg, at minimum how many circles to do need to cut along to disconnect a surface of genus g?

vzn

@Slereah it appears the simple/ intuitive way to think about it is a "density of space" (eg proportional to gravity) but that seems to be verboten wrt convention/ conventional wisdom... on other hand its not much different than "curvature" :|

Semiclassical

2:44 PM

As you said, 'at minimum' it's two

But you can cut out at most g circles without rendering it disconnected

Balarka Sen

No, no, 2 (in fact 1) is the wrong number. You want homologically independent as an adjective

Slereah

@vzn well density would be a scalar, not a tensor!

Semiclassical

hmm

Balarka Sen

I mean 1 is the correct answer to the question as I said it but it's just wrong :p

vzn

@Slereah not an expert on this but think theres a natural (math!) relation between the two. btw it seems to come up in the new verlinde theory.

Balarka Sen

2:45 PM

I was just demonstrating how Poincare came up with the idea of homology

Semiclassical

Well, my point is that g disjoint circles aren't always enough to disconnect the surface, but g+1 of them are

Balarka Sen

I getchu

So g+1 is the minimum of the number of disjoint circles which always disconnects the surface

Slereah

also what do you mean by "density of space", exactly

Semiclassical

I guess the point is: You need at minimum g+1 circles to be sure that you'll disconnect the surface.

Slereah

Sounds like a not very coordinate invariant notion!

Balarka Sen

2:46 PM

'cuz g+2 circles also disconnects it.

so does g+k for all k>1

vzn

@Slereah it affects speed of light. am struggling to find a nice math descr somewhere, think someone has probably laid it all out.

Semiclassical

@vzn ...yes, it's called GR

0celo7

see my thesis

Balarka Sen

@0celo7 you're like Jake Paul rn

buy dat thesis

vzn

@Semiclassical as currently formulated it doesnt accept/ address the idea of density but thats part of the paradigm shift (tenev + horstemeyer et al)

Balarka Sen

2:48 PM

link in bio

0celo7

@BalarkaSen gotta get the hype machine rolling

I've already got someone who will use it for a class

Balarka Sen

I agree

Niiice

Semiclassical

well, it doesn't accept the idea of what you want density to mean

But this is really the danger of talking about physics without math.

vzn

@Semiclassical lol you dont nec know what am thinking of.

Semiclassical

I stay away from discussions of GR precisely because I know I don't know the math well enough to follow it

No, but I trust that Slearah does

In any case, though, there's only two logical possibilities

Balarka Sen

2:49 PM

vzn has been to the CHURCH OF PARADIGM SHIFT

vzn

am not claiming anything that is not already written down. it will be sound incoherent to anyone who doesnt want to look at new refs eg tenev + horstemeyer

Balarka Sen

he'll bring revolution to physics

Semiclassical

Either GR does contain your notion of density, in which case this is irrelevant

Slereah

who is horse mayor

Semiclassical

or it doesn't, in which case GR doesn't contain the notion of density as you desire it

vzn

2:50 PM

@Semiclassical double bind! sounds like totalitarianism o_O

Semiclassical

Considering I"m not forbidding you from leaving, I dont' see a double blind :>

Secret

pubs.acs.org/doi/10.1021/jp9058017

What is this article doing in chemistry???

Balarka Sen

go back to the church of paradigm shift, priest of revolution

Semiclassical

(I do actually know the definition of a double bind, so tossing that at me isn't going to impress me)

vzn

> if this library contains works compatible with the koran, it is redundant. if they are inconsistent, they are blasphemy. either way it needs to be burned

Slereah

2:52 PM

@Secret You can do SUSY in QM

It's not the superpoincaré group

Just a relation between bosonic wavefunctions and fermionic wavefunctions

Semiclassical

(a primary statement, a secondary contradicting statement which occurs at another level, an injunction forbidding one from resolving this contradiction, and the repetition of this as to form a reflexive pattern. without that third element it's just a single bind)

SUSY in QM is closer to stuff involving the Dirac equation IIRC?

Balarka Sen

@Semiclassical who needs a definition when you can namedrop?

pfeh pathetic

you disgust me

Semiclassical

lol

bolbteppa

You can susy up the harmonic oscillator for example

Semiclassical

yeah

and I know you get stuff like "you get two harmonic oscillator spectra, one starting at n=0 and the other at n=1"

But I haven't done any of the actual math in a while.

Slereah

3:02 PM

That was supposed to be the topic of my PhD

vzn

← trapped by logical technicality, sounds like double bind o_O :(

Semiclassical

No, just a regular old bind.

A single primary command is not a bind; there is no contradiction present.

Two conflicting commands, at different levels of communication, comprise a bind.

Balarka Sen

A wise man once said that if you ever loose in a logical argument then it's automatically because your opponent was using a double bind

Semiclassical

To escape this bind, one needs to be able to leave the field i.e. to declare at least one of them does not bear upon you

The third injunction is thus that you cannot leave the field. Hence you are prevented from resolving the single bind, and therefore are doubly bound.

A single command on its own cannot be a bind, since you can either obey it or not.

vzn

3:17 PM

the forbidding injunction, not given explicitly by you but by the scientific method, is that science demands that phenomena be explained correctly ie without inconsistency.

Semiclassical

The other thing that's problematic about the double bind terminology here is that, as per how it was defined by Bateson, the injunctions don't occur at the same level of communication

So a statement like "Either A is true, or B is true" doesn't strike me as very plausible for being a double bind in ordinary communication

it just strikes me as how logical statements work :P

vzn

> The parallel between Equations (3.9) and (3.11) confirms that gravitational waves are analogous to shear waves propagating in a solid material and that furthermore the speed of propagation, which is the speed of light c, is related to the shear modulus and density of the medium per c2 = μ/ρ. p18

skullpatrol

3:35 PM

@Slereah are you going to stay with that topic?

Slereah

@skullpatrol well it was 8 years ago

skullpatrol

are you still interested in it?

Slereah

I dunno, never looked much into it since I didn't get to do it!

It was non-relativistic QM on a Riemannian manifold, Atyiah-Singer's theorem and SUSY

Something about finding ground states

skullpatrol