The h Bar

enumaris

12:25 AM

@danielunderwood what was the name of the amazon service specifically for data labeling again?

I only remember amazon mechanical turk

danielunderwood

sagemaker is the one they recently announced I believe

Though one of the options for how the data is labeled is mechanical turk

enumaris

I see

vzn

1:37 AM

← feel its like a funeral around here sometimes when the "wrong" new science is announced, reminds me of this recent study ("new science!") :( The Polarization Of Society: Even Scientists Become Tribal acsh.org/news/2018/11/28/…

NormalsNotFar

3:28 AM

Is it possible to give the square root of the D'alembertian operator, $\sqrt{\square}$, a solid meaning?

IamAStudent

4:06 AM

https://news.stanford.edu/2018/12/06/shoucheng-zhang-obituary/
This news has been several days old, but I don't see many discussions regarding this on physics blog websites. On the other hand, there are many conspicracy theories abound, mostly from Chinese media.

4

vzn

4:23 AM

wow missed this Zhang contributed to... Stanford AI recreates chemistry’s periodic table of elements news.stanford.edu/2018/06/25/…

rob

5:11 AM

Fifty-five years old and died unexpectedly from depression. If you'll permit the use of strong language for emphasis: that's a fucking shame.

Yashas

6:22 AM

Any ideas how I can estimate the change in direction of a vector in 3D?

I need to come up with a quantitative way to measure change in direction.

I cannot simply use the change in vector as even change in magnitude along one direction is also a change in vector.

The deXYfied problem is I need to measure the randomness of a moving object.

John Rennie

7:18 AM

@Yashas Take the dot product to get the angle between the vectors?

Slereah

8:15 AM

morning folks

John Rennie

9:03 AM

@vzn we're all interested in new ideas - you can't sustain a career in science without an unquenchable conviction that the answer really is out there somewhere. But when you come in with your fanboi act for an idea that has some serious conceptual issues we feel obliged to take a more negative view just to preserve some form of balance.

Slereah

Not me

I'm just part of a conspriacy to cover the truth

John Rennie

@vzn In this case the idea requires the continuous creation of negative matter. OK, maybe that does happen but at the moment there is no physical motivation for it. Continuous creation of negative matter from nowhere? Huh? That's one of those extraordinary ideas that's going to need extraordinary evidence.

If all other avenues are exhausted then maybe people will start taking the idea seriously, but right now Occam and I think it's probably rubbish.

Slereah

9:22 AM

I mean

Technically the cosmological constant is already continuous creation of negative energy

Since it's a constant density over volume and the volume increases

But I'm guessing it's supposed to be more phantom field sort of stuff

which would be nice if true

Pretty easy to prop open wormholes with phantom fields

There's even exact solutions for it

It's just not very plausible

John Rennie

Huh? the energy density of the dark energy is positive. It just has a weird equation of state.

Slereah

Is it?

John Rennie

Yes

Slereah

I'm not big on cosmology I'm afraid

John Rennie

I answered a question this the other day ...

Slereah

9:25 AM

I like spacetimes but I'm not that interested in what actual spacetimes we live in

(SPOILER : it's a boring one)

John Rennie

1

A: How would we relate the cosmological constant to a dark energy distribution?

The easy way to see the relationship between the cosmological constant and energy density is to look at the second Friedmann equation: $$ \frac{\ddot{a}}{a} = -\frac{4\pi G}{3} \left(\rho + \frac{3p}{c^2}\right) + \frac{\Lambda c^2}{3} $$ where $\rho$ is the matter density. If we bring $\Lambda...

Slereah

Might as well be $\mathbb{R}^4$!

" also any positive cosmological constant violates the SEC."

I guess that's why I was confused

SEC ain't no NEC

Altho...

Lemme see

$$G + \lambda g = T \to G = T - \Lambda g$$

So if $\Lambda$ is positive... yeah that's positive energy term

Just negative momentum

What's $\Lambda$ for our universe?

Positive indeed

(lame)

Slereah

9:44 AM

Working with libraries is nice to avoid recoding everything yourself but jesus I hate dealing with library bullshit

John Rennie

Wow, I knew something about GR that Sam didn't. There's a first time for everything I guess :-)

Slereah

Oh there's plenty of stuff I don't know

I'm not very good at like

Astrophysics GR stuff

which is unfortunate because that's the stuff that they mostly give PhDs for

It's all gravitational waves and cosmology

John Rennie

I find the FLRW metric really unrewarding to work with. There's no closed form for it because it depends on exactly how all the "stuff" behaves, so you're left with an $a(t)$ that doesn't have a nice equation.

As a result cosmologists have come up with dozens of parameters to describe the geometry all of which have definitions I can never quite remember.

Slereah

well not too surprising

The universe isn't very orderly

John Rennie

In other news, I ordered some inordinately expensive chocolates from a company in Germany, which is the only place in the world you can get them. And [drum roll] they have just turned up!

Slereah

9:54 AM

is it a gift or are you just gonna gorge right now

John Rennie

Christmas present for my mother

Each chocolate costs two Euros! Fifty Euros for the box!

Slereah

you could probably get a box of chocolate for 2€

Well, not for long, now that you're leaving the EU!

gonna have to pay two bobs

John Rennie

Actually there's a good chance article 50 will be revoked and we won't leave after all!

The downside it that we'll all look like cnuts but that's a small price to pay.

11:07 AM

@vzn negative masses dismissed backreaction.blogspot.com/2018/12/…

Mostafa

12:43 PM

@IamAStudent This is really really sad

"suffering from depression" means death by suicide?

Slereah

That is usually the big morbidity factor of depression

Mostafa

I don't know what the Chinese media are saying but this guy had certainly played a significant role (along a few others) in helping Chinese universities become condensed matter physics research hubs

Secret

1:42 PM

> If you do this, you can produce particle pairs from a net energy of zero in infinitely large amounts. This fits badly with our observations.

boteppa, vzn: I think right now we cannot say much about that paper as the newtonian limit thing is not correctly computed and that there is still no experimental evidence for the existence of that creation tensor

but hopefully, we will soon find that inhomogeneous patches of expansions in the sky surveys that can give some support to them

Meanwhile, I wonder if there is a way to hide vacuum instability as that is a common feature of many negative inertial mass models

that is, the vacuum may be unstable, but hard to detect

> A creation term is also not a "magic fix by which you can explain everything and anything". That is incredibly misleading. It provides very exact and specific well-defined physical properties.

There is nothing wrong with putting fudge terms, as long they are expected to be physically observable, and hence generating experimental predictions for the experimentalists to check for

Mithrandir24601

@JohnRennie You're being optimistic, I think, but I really hope this happens

Secret

22 hours ago, by Slereah

since that kind of theory was developped in the 90's

12 hours ago, by vzn

← feel its like a funeral around here sometimes when the "wrong" new science is announced, reminds me of this recent study ("new science!") :( The Polarization Of Society: Even Scientists Become Tribal https://www.acsh.org/news/2018/11/28/polarization-society-even-scientists-become‌-tribal-13628

They are all part of The Plan. Looks like nature is finally taking the Fabricated World seriously ever since its creation 15 years ago

In other news:

I will say just crossing our fingers on this paper for the moment being. It is now up to the experimentalist to tell us whether negative mass can exist or not. Should they do, hopefully I will be informed first so I can bag them all up for my collection

John Rennie

2:25 PM

@Mithrandir24601 May's plan is definitely going to be voted down. The EU simply aren't willing to negotiate any further, so we're going to end up with the stark choice of either a hard Brexit or no Brexit.

And I can't believe parliament are going to vote through a hard Brexit. Maybe that's optimistic of me ...

Mithrandir24601

2:38 PM

@JohnRennie It's so hard to tell - I used to go by the BBC, until control over it changed to parliament :/ - There doesn't seem to be anywhere offering a really unbiased look at what may or may not happen

(In terms of the vote itself, that is)

Sid

@JohnRennie Ah, so, Brexit didn't quite work out for you guys, I see.

John Rennie

@Sid 48% of the UK thought it was a bloody stupid idea, and those 48% have been proved right.

Sid

What's a hard Brexit, btw?

Mithrandir24601

@JohnRennie nearly - 48% of eligible voters in the UK... :P

@Sid An even more stupid idea

Sid

Well, yeah. But, details? As to why it is more stupid?

John Rennie

2:45 PM

@Mithrandir24601 details, details :-)

@Sid British companies make lots of money by exporting to EU countries. They don't have to pay any tariffs or deal with any paperwork within the EU.

rob

Doesn't "eligible voters" include the ~20% who could have voted, but didn't?

source for image

John Rennie

@Sid With a hard Brexit they'll face tariffs on everything they export to the EU. That means the EU won't buy our stuff because it will be cheaper to get it from other countires still in the EU. So lots of British companies have a big fall in profits and have to fire lots of staff.

Mithrandir24601

@JohnRennie Or have just left the UK

Sid

@JohnRennie But then, they will sell it to the British, right? Surely, that's good for the British?]

John Rennie

Those companies that do survive will have to pay lawyers to deal with lots of paperwork when we're no longer in the EU, so even if they manage to keep exporting their profitability will take a hit.

Mithrandir24601

2:49 PM

@rob Aye, my bad :P

John Rennie

@Sid Suppose a company is used to making widgets for the EU - about 500 million people.

Suddenly their market shrinks to 60 million Brits i.e. a factor of ten smaller.

Not a great prospect, is it?

Semiclassical

@JohnRennie and even that assumes that the British represent a commensurate part of their part

going from selling to 500 million to selling to 60 million people isn't a problem if only the latter category were buying your product in the first place. but if none of them were, then you're utterly screwed

bolbteppa

@JohnRennie it is thought that about 20% of every country are authoritarians, and about 20% of the UK/US voted Brexit/Trump

Sid

@JohnRennie Ah, I get what you are saying.

So, as a whole, the companies will face losses. What about the people in general?

Semiclassical

companies facing losses means workers face losses as well

it presumably also means consumers losing access to certain good and services, or at least only having access to them at higher prices

John Rennie

2:56 PM

@Semiclassical My point is not to make a detailed economic analysis - I'll leave that to the economists to get wrong. my point is:

Well We're Boned!

►

bolbteppa

Maybe those numbers are off actually

Semiclassical

I find myself more in the mind of:

You maniacs!!! You blew it up!

►

bolbteppa

17/66 ~ 25%

In the ballpark

60/330 ~ 20%

vzn

3:13 PM

@JohnRennie it would be great if as a leader/ co-owner of this room you didnt refer to new ideas from reputable/ credentialed scientists as rubbish and found some other less dismissive/ devaluing way to refer to it. in short doesnt seem nice to me. am in agreement that "extraordinary claims require extraordinary evidence" but anyone familiar with the history of science will understand this is sometimes a very timeconsuming process... occasionally spanning decades and even centuries....

John Rennie

@vzn I wasn't going to comment at all. It's a perfectly good bit of phenomenology based on certain assumptions that may or may not be true. It's exactly the sort of thing theoreticians should be doing in the absence of any hard data to guide their work.

I responding to what seems to me unreasonable levels of excitement about what is a somewhat fringe paper that almost certainly isn't going to stand the test of time.

NB most papers are somewhat fringe and won't stand the test of time so I'm not criticising the author.

vzn

"rubbish" = trashtalking

"wont stand the test of time" → jumping to conclusions

John Rennie

I don't talk trash - I just sometimes employ my skills with the English language to make it clear how I feel :-)

rob

@vzn I think there's an important distinction between trash-talking an idea versus trash-talking a person.

vzn

← surprise! loses

rob

3:22 PM

@vzn I hope this chat room is not a contest with winners and losers.

vzn

lol depends on what you make of it doesnt it.

rob

I think that most new ideas are bad ones.

Certainly most of mine are.

Having bad ideas doesn't make me a bad person.

vzn

phds are trained to come up with new ideas. maybe theres a better way to respect that (around here). aka professional courtesy

oh look speaking of "unreasonable levels of excitement" even oxfords own press release announces it as a toy model ox.ac.uk/news/2018-12-05-bringing-balance-universe

John Rennie

My unreasonable levels of excitement comment was targeted at you, not the OUP.

vzn

am well aware of that JR

John Rennie

3:31 PM

The no. one cause of misanthropy in this chatroom is you telling us all we're wrong.

2

Mithrandir24601

@vzn I can come up with a new idea relatively easily. Coming up with one new idea that I can't disprove within five minutes, on the other hand is ridiculously difficult

Semiclassical

@Mithrandir24601 waving your hands and appealing to a 'new paradigm' without actually worrying about the technical details, by contrast, is very easy

vzn

@JohnRennie sounds like scapegoating/ putting words in my mouth. have never made such an accusation. there have been heated arguments about science over the years.

Mithrandir24601

@Semiclassical yup

John Rennie

@vzn It would be invidious to hold a poll, but I would be willing to bet most of the regulars here feel the same way that I do.

vzn

3:38 PM

@JohnRennie (feeling this is an extremely risky discussion for me...) you commented yourself the room was going better after prior designated scapegoat 0celo7 was removed for 1yr. thought things were going swimmingly lately.

Aug 22 at 4:22, by John Rennie

I have to say I think the room works a lot better now than it used to. We get some awesome discussions about physics and there hasn't been a flag for weeks. That is pretty much all you could ask of a physics chat room.

Semiclassical

just because something is better doesn't mean there aren't extremely tiresome moments

John Rennie

@vzn The issue I pointed out is that many of us feel you specialise in telling us how some pop sci article from the Daily Mail shows we're all wrong. I fail to see how your subsequent posts are relevant to this.

3

vzn

@JohnRennie feels like moving the goalposts. the latest contention is oxford phd science. understand your longrunning hatred of dailymail articles no matter what the contents.

Semiclassical

And you're shifting the goalposts in turn from your behavior to what OUP people have put forward

John Rennie

I've already said the paper we're discussing now is exactly the sort of thing I think theoreticians should be doing, and I fully support funding them to do it. As it happens I think the assumptions made are unreasonable but I'm only saying I believe that to be the case, not that it is the case.

vzn

3:44 PM

lol "rubbish" → "I fully support funding them to do it".

lol dailymail further covers rubbish dailymail.co.uk/sciencetech/article-6464245/…

John Rennie

Yes, I think the assumptions made in the paper are physically unreasonable. I've explained that in some detail. But I have never claimed to be omniscient and I think it's perfectly reasonable for a theoretician to make that assumption then see what happens.

vzn

right, except that its all likely rubbish

Secret

15 mins ago, by John Rennie

The no. one cause of misanthropy in this chatroom is you telling us all we're wrong.

John Rennie

99% of all theoretical papers are wrong. It's always been that way. Getting it wrong is part of the job for theoreticians.

Secret

no one beats me in terms of misanthropy

bolbteppa

3:48 PM

Found a good post on reddit

Secret

For example, a conspiracy theory on why this whole Brexit thing managed to get through back in 2016 is purely because one of my high school mates lived there failed to respond to a critical message in time

bolbteppa

egtheory.wordpress.com/2018/09/08/theory-norms

Semiclassical

"Rubbish" is too strong a word in my book; speculative and undermotivated, maybe

3

Secret

vzn: The gist of The Plan is that almost every catrosophe that occurred from 2015-2020 can be traced back to something between me and my high school mates. All of us humanity is going to suffer a bit more until 2020 when the universe itself is forced to solve every mess that is back in my high school year

bolbteppa

"Skinner wrote an interesting thread on how to distinguish good theory from crackpottery. He started with a trait that both theorists and crackpots share: we have an “irrational self-confidence” — a belief that just by thinking we “can arrive at previously-unrealized truths about the world”.

From this starting point, the two diverge in their use of evidence. A crackpot relies primarily on positive evidence: he thinks hard about a problem, arrives at a theory that feels right, and then publicizes the result. "

"A theorist, on the other prong, incorporates negative evidence: she ponders hard about a problem, arrives at a theory that feels right and then proceeds to try to disprove that theory. She reads the existing literature and looks at the competing theories, takes time to understand them and compare them against her own. If any disagree with hers then she figures out why those theories are wrong.

She pushes her theory to the extremes, looks at its limiting cases and checks them for agreement with existing knowledge. Only after her theory comes out unscathed from all these challenges does she publicize it."

@vzn remember your comment yesterday about me shooting down all these alternatives

vzn

3:52 PM

@bolbteppa post on what?

Semiclassical

I mean, I'm on record as at least being sympathetic to non-orthodox interpretations in QM

Secret

I do not call a model rubbish unless it deviates so much from the experimental data, or there are things that does not pass logical tests

bolbteppa

@vzn chat.stackexchange.com/transcript/message/47932801#47932801 read the above passage I quoted and compare to this and the fluid discussion we had

vzn

@bolbteppa fyi AK is a Theoretical Computer Science mod. chatted with him briefly yrs ago. lol it did not go well... maybe have commented on his blog a few times too :P

Secret

It is rare to have rubbish from theorist papers, and I am generally quite receptive though skeptical to weird ideas

Semiclassical

3:54 PM

but I don't consider non-orthodox modifications of QM to be terribly productive

vzn

@bolbteppa which comment? "needle in a haystack" :P

bolbteppa

Not sure what you mean

vzn

@Secret being pessimistic about humans is maybe not the same as misanthropy wink :P

Secret

"dies"

bolbteppa

@vzn I encourage you to entertain negative evidence basically, Descartes doubt and all that ;)

vzn

3:57 PM

@Semiclassical agreed on (occasional) "extremely tiresome moments" :P

Semiclassical

What I mostly find frustrating is the notion that talking in terms of a paradigm exempts one from producing specific details and models

Secret

Tbh, a paradigm is actually a lot more interesting when there are details on where to find experimental signs of it

Semiclassical

yep

vzn

@Semiclassical correspondingly find it frustrating that others dismiss new paradigms without looking at the produced specific details and models, turning a blind eye... claiming there are none.

Semiclassical

I'd take that complaint more seriously had I ever observed you actually furnishing such details.

vzn

3:59 PM

@Semiclassical oh now its personal. have produced/ furnished copious details in this room. very few care to follow them up.

Semiclassical

you're certainly willing to point to other people's work as providing details

bolbteppa

The one time details were furnished we discovered the paper wasn't claiming what you were claiming haha (Tenev paper)

Secret

@bolbteppa speaking about that one, while that paper basically reproduces everything in GR under a different set of postulates, I am wondering whether we can take the solid state analogy a lot stronger and define something like... er...:

vzn

@bolbteppa you guys are on record as rejecting the paper vociferously/ scathingly. dont really know what youre talking about. summarized it myself in a loose way at times. by the way it ties in heavily with the latest fluid universe ideas (by farnes).

Secret

Treating spacetime and its curvature as some condensed system, with the arrangement of light cones averaged throughout the region thus indicating some kind of "polarisation" in the arrow of time in spacetime

bolbteppa

4:03 PM

Here is part of the abstract:

Secret

for example, if under some frames of reference all the light cones point up in that region, then spacetime is basically flat and polarised towards some direction

bolbteppa

"We present an elastic constitutive model of gravity where we identify physical space with the mid-hypersurface of an elastic hyperplate called the "cosmic fabric" and spacetime with the fabric's world volume. Using a Lagrangian formulation, we show that the fabric's behavior as derived from Hooke's Law is analogous to that of spacetime per the Field Equations of General Relativity.

The study is conducted in the limit of small strains, or analogously, in the limit of weak and nearly static gravitational fields."

arxiv.org/abs/1603.07655

Secret

Hmm... I did not noticed this back in 2012 when I read the paper. I wonder what happens when the strain is large

vzn

@Secret 2 words black holes wink :P

bolbteppa

You can get GR equations from Newtonian mechanics if you allow for approximations

Semiclassical

4:05 PM

(I don't remember the Tenev paper, so I think I wasn't party to that. But in general I stay away from talking about GR stuff given my entire ignorance of it.)

Secret

I mean, if the cosmic fabric can potentially snap, that will provide a mechanism to change its topology

vzn

@bolbteppa farnes is further articulating the nature of the spacetime fabric that seems to account for dark matter/ energy. its revolutionary... an idea that has been on my mind lately... great to see it carried out... early stages!

@Secret have brought this up before in here. with elastic strain for small distortions its nearly linearly behaved, and becomes nonlinear for large strains. reminds me of renormalization in QFT! o_O

bolbteppa

Here is a Newtonian 'derivation' of the Friedmann equation astronomy.ohio-state.edu/~dhw/A5682/notes4.pdf

By this logic we could say we have found a non-Einsteinian way to show the universe expands and to ignore GR :\

Secret

Even though I am super hyped of Farnes paper since I am a big fan of negative mass and want an experimental evidence of it for 8 years, as the many papers he cited showed, negative mass cosmology is not really a new thing. What's really new in Farnes paper is the hypothesis that negative mass can be created at a rate slow enough to overcome the dilution problem as the universe expands

(And I will say I knew enough about negative mass literature since back in 2011, I spent weeks reading the literature just so I can use it as a major element in my scifi, and that page is realistic enough that it attracted some physicists in the field such as Richard Hammond)

bolbteppa

If we couldn't derive GR equations using Newtonian mechanics concepts in weak field limits/low energy approximations that would probably be a bad sign, it's really shocking to say this is a paradigm for a TOE

"relies primarily on positive evidence: he thinks hard about a problem, arrives at a theory that feels right, and then publicizes the result"

vzn

4:11 PM

@bolbteppa cool! p3 Evolution of Energy Density: The Fluid Equation...

bolbteppa

My god... haha

Semiclassical

I'm sure there's an idiom for this: saying "I'm not doing X" while doing X in the very next breath

vzn

@bolbteppa the difference between "negative evidence" and "puzzle pieces that dont fit yet" can be very subtle at times. (Kuhn talked about scientific "puzzles"...)

Secret

I took that one step further: I do X in a way such that others think I am not doing X

I also like negative evidence, because it tell us which models are dead ends

For example, I am still waiting for a negative evidence of Dirac monopoles

6

Q: Experiments or phenomenon to falsify the existence of monopoles?

This is a related, but opposite question to this one I have heard about a lot of things regarding elementary and GUT magnetic monopoles, as well the quasiparticle monopoles in spin ice Since there's like 50 years of non detection of magnetic monopoles, I started to wonder whether monopoles sear...

One of my most highly voted question asked in PSE

bolbteppa

Right, this is a case where you're using a well-defined puzzle (classical mechanics) to recreate an impossible-to-define puzzle (QM), even worse you're calling non-relativistic CM concepts a TOE because we could derive them from relativistic CM concepts in a static weak-field limit and so work backwards in this extremely special case

Secret

4:16 PM

50+ years of monopole research still end up nothing, though we have numerous quasiparticles that can mimic them

vzn

@bolbteppa any TOE formulation will be shocking to modern sensibilities, the search has been on ~½century, eluded einstein (at the height of his powers), and in key ways still coming up emptyhanded... aka thats not a bug its a feature™

bolbteppa

@vzn What you are claiming is literally no different to saying Newton was right all along because we can invert the fact that we can re-derive F = ma by starting from Einstein's $F = \gamma ma$ to re-obtain $F = ma$ in the limit of low velocities (since $\gamma \sim 1$), i.e. we can derive Einstein's $F = ma$ (with $\gamma \sim 1$) from Newton's $F = ma$, it's unbelievable tbh

Slereah

@Semiclassical it's the Gilligan cut

Semiclassical

hmm

Slereah

Example

vzn

4:20 PM

@bolbteppa did not say that. but urge you to think about analogues. there are many classical analogs that can be leveraged to work on the GUT/TOE. physics is full of analogues and an entire book could be written on the subj, wish somebody would, some are very deep! it relates to dimensional analysis studied in some corners...

bolbteppa

@vzn the Tenev thing "is conducted in the limit of small strains, or analogously, in the limit of weak and nearly static gravitational fields", they are using thermodynamics (and implicitly $F = ma$) to derive GR equations in "the limit", I've literally sent you a paper where the Friedmann equation is derived from Newton's $F = ma$ and the first law of thermodynamics in "the limit", this only holds because we are doing approximations - it's simply bizarre to call this Tenev stuff a TOE

vzn

@bolbteppa it seems bizarre by conventional wisdom. conventional wisdom also has failed to come up with a TOE. you have to break some eggs to make an omelette™ it only comes down to, which ones are you willing to break?

bolbteppa

@vzn If you call this Tenev stuff correct then you are forced to simultaneously say that GR can be derived from Newtonian mechanics

vzn

@bolbteppa its an analog and the dimensional analysis prj will help with that understanding. you can get F=ma in electrical circuits too did you realize that? it is rarely taught, found it in my undergrad mechatronics course.

bolbteppa

@vzn are you seriously going to claim Einstein was wrong and Newton was right, since you're so willing to break eggs

Secret

4:26 PM

I think it will be interesting if at very large strains, we get something more than black holes and nonlinearity

vzn

@bolbteppa its all about equations and they can be crosscutting across artificially contrived compartmentalizations, ie anthropocentric (bias)!

bolbteppa

I think that is a perfect contradiction, your TOE literally contradicts Einstein's GR haha, I told you months ago that you were using non-relativistic thermodynamics to end up with GR equations, I forgot the abstract literally says they are working in "the limit of weak and nearly static gravitational fields"

vzn

@bolbteppa ok agreed important point; its apparently "weakly relativistic" derivation and likely can be generalized to the ("more") relativistic case.

Secret

The Tenev paper is interesting to me not because it is a possible TOE as some groups claimed, but because of the idea of formalising spacetime as some elastic object

which there are some rooms to further expand upon this idea to get some more interesting cosmologies

bolbteppa

@vzn if you generalize to relativity then you get it without any thermodynamics

Secret

4:30 PM

To me, trying to look for TOE is way too hard thus I am content enough if some model suggest new physics to play with

vzn

@Secret note exactly farnes recent claims, spacetime as some elastic obj...

Secret

@vzn Nah, Farnes idea is that spacetime is filled with negative mass particles thus forming a fluid like structure. Far from being elastic

vzn

@bolbteppa its preliminary work, it needs work, its not complete yet, the pioneers will step up in the years ahead

bolbteppa

@vzn hopefully this is the end of your claims that Tenev is a TOE since even the abstract says it only holds in "the limit of weak and nearly static gravitational fields" and we know once we allow relativity we immediately get the results you thought they were getting by alternative means

vzn

@Secret (sigh!) fluid = elastic!

@bolbteppa they probably dont say TOE a single time in the paper...? have to look at it more closely. but they assert the idea can be extended. QED. :P

Secret

4:33 PM

fluid is not the same as elastic. There are numerous examples of fluids which is inelastic

vzn

@Secret its a new kind of elastic fluid

bolbteppa

@vzn are you really claiming they are saying/hinting we can derive GR from Newtonian mechanics, that's the only way we could end up with relativistic GR equations by 'alternative means'

vzn

@bolbteppa they seem to be working on a linear case and you are asking about a nonlinear case? aka curvature... think it can be worked out... am not saying its all done yet...! am saying its a (trailblazing!) path

bolbteppa

@vzn yeah, the solution is Einstein's GR

haha

vzn

@bolbteppa the basic idea/ analogy is that GR curvature is like fluid (spacetime fabric) density and this idea has been pushed very far in the Tenev + Horstemeyer paper and probably can be pushed substantially further as in the latest work of Farnes.

bolbteppa

4:36 PM

@vzn at least you admit you are now claiming it may be possible to derive GR from Newtonian mechanics, you hopefully know how off the map that is

vzn

@bolbteppa its Tenev + Horstemeyers idea, its implicit in their work. the devil is in the details™ o_O

@bolbteppa consider the concept of design patterns in software engr... such a concept similarly applies to physics analogies...

bolbteppa

@vzn "Definition of fluid - a substance that has no fixed shape and yields easily to external pressure" so space yields easily to external pressures, what's outside of space pushing on it?

vzn

@Semiclassical ps thats called science™ :P

@bolbteppa waves/ fields measure the spacetime fabric density. particles/ mass/ waves/ fields distort space (via "density"). etc... its the old ether idea reformulated/ revived in terms of a fluid with special properties. eg lorentzian contractions etc

bolbteppa

@vzn they are inside of space

It's definition is framed in terms of things outside of it

@vzn So if you want to pretend spacetime is a fluid you need to frame it in terms of th ings outside spacetime causing it to bend, and it's boundaries, not things inside of it, this casual use of technical words is really leading you down blind alleys man

You even took a massive jump into using fluid mechanics and calling it a TOE based on a paper using an approximation...

vzn

@bolbteppa the concept requires giving up the idea of "inside/ outside" or rather seeing it as an (anthropocentric) abstraction. its all just spacetime fluid. particles are high densities of spacetime fluid. solitons etc

bolbteppa

4:47 PM

@vzn so fluid is the wrong word to use then, maybe spacetime is the right word, hmm

vzn

@bolbteppa new words have to be constructed. they tend to be constructed out of old ones and given new meanings. this is a very timeconsuming process that Bohr understood/ helped out wrt QM, impressively but not entirely successfully/ accurately. hence the decades of angst/ cognitive dissonance over interpretations etc

bolbteppa

@vzn you may or may not be right, but one thing is for sure - "fluid" is an irrelevant word when discussing spacetime since it means something different that spacetime does not apply to

3

enumaris

just change the definition of fluid

bam

vzn

@bolbteppa lol guess you need to study Farnes more and then get back to us, understood its very recent and nobody has had time to do anything more than cursorily/ summarily/ authortatively/ definitively/ unequivocally reject it as rubbish yet :P

bolbteppa

FluiTenev mechanics

Those poor guys if they ever google their own paper

vzn

4:53 PM

it took ~2 decades for science to accept SR/ GR and einstein never even got a nobel for it (few realize that!)... humans/ speed of revolutionary paradigm shifts are not substantially different today... etc

bolbteppa

Right but what you're claiming is actually going backwards to getting GR from Newton's non-GR

vzn

@bolbteppa hey man its still GR that you know and luv its just a new... more correct derivation... that will explain dark matter + energy... not bad ("for a days work") eh? :P

danielunderwood

Quite the relaxed Friday, huh?

bolbteppa

Criticism of the theory of relativity

Criticism of the theory of relativity of Albert Einstein was mainly expressed in the early years after its publication in the early twentieth century, on scientific, pseudoscientific, philosophical, or ideological bases. Though some of these criticisms had the support of reputable scientists, Einstein's theory of relativity is now accepted by the scientific community.Reasons for criticism of the theory of relativity have included alternative theories, rejection of the abstract-mathematical method, and alleged errors of the theory. According to some authors, antisemitic objections to Einstein's...

vzn

> A collection of various criticisms can be found in the book Hundert Autoren gegen Einstein (A Hundred Authors Against Einstein), published in 1931.[4]

> According to Goenner, the contributions to the book are a mixture of mathematical–physical incompetence, hubris, and the feelings of the critics of being suppressed by contemporary physicists advocating for the new theory.

bolbteppa

5:00 PM

"mathematical–physical incompetence"

@vzn Why not give the Susskind videos a try without pre-judging theoreticalminimum.com to try get a sense of the actual issues?

"A number of years ago I became aware of the large number of physics enthusiasts out there who have no venue to learn modern physics and cosmology. Fat advanced textbooks are not suitable to people who have no teacher to ask questions of, and the popular literature does not go deeply enough to satisfy these curious people. So I started a series of courses on modern physics at Stanford University where I am a professor of physics.

The courses are specifically aimed at people who know, or once knew, a bit of algebra and calculus, but are more or less beginners."

vzn

@bolbteppa lol susskind is great have cited him in my blog when are you gonna ~~stop~~ start cherrypicking and read this one? citing 't hooft! how come susskind fans never cite it? maybe because most of em dont even know about it... :P The World as a Hologram arxiv.org/abs/hep-th/9409089

enumaris

"The primary reason that we use dark matter and dark energy to explain cosmological observations is that they are simple. Occam’s razor vetoes any explanation you can come up with that is more complicated than that, and Farnes’ approach certainly is not a simple explanation."

I don't like the phrasing here

Occam's razor is a rule of thumb kind of guideline, it certainly doesn't "veto" anything

vzn

@enumaris agreed. there is no simple explanation of dark matter/ energy so far after decades of searching and it seems unrealistsic to expect one.

enumaris

GR is certainly not "simpler" than Newtonian gravitation

and yet you don't get to "veto" GR via Occam's razor

bolbteppa

Being charitable I'd say she means his explanation "creates more problems than it solves" as she says at the end and so is not simple

enumaris

5:07 PM

You "veto" Newtonian gravity via experimentation

and only experimentation gets veto power

I AM THE SENATE

cough

@bolbteppa I might agree with the general gist of what she's saying, but that sentence just really rubs me the wrong way lol

bolbteppa

Yeah I cringe when I see this Occam stuff

It does read your way for sure

Semiclassical

@enumaris yep. it’s a heuristic, not an axiom

bolbteppa

It's usually quoted by people as if it's an axiom to ignore some irrational thing, the irony

Semiclassical

This goes to the broader point of it being hard to demarcate science vs pseudoscience

vzn

@enumaris occam razor came up sometimes in here & then vowed to look for some "refutations" (wrt science/ physics). came up with eg this. often those who cite it seem to be somewhat unaware of its actual history. Why The Simplest Theory Is Never The Right One: Occam's Razor Has A Double Edge scienceblogs.com/developingintelligence/2007/05/14/…

enumaris

5:12 PM

On a totally unrelated note...

John Rennie

I think you're misrepresenting Hossenfelder's use of Occam's razor. She's saying that when two theories are both consistent with the data you choose the simpler.

enumaris

Y'all seen Avengers: Endgame trailer??? UBER HYPE YALL

vzn

Jul 2 at 16:29, by enumaris

my philosophy is only, if two theories make the same predictions, use Occam's razor. If they don't make the same predictions, test it out, if it can't be tested...drink tequila

enumaris

:D

John Rennie

@enumaris is that Thanos 2 - the Avengers strike back?

enumaris

5:14 PM

@JohnRennie I think soooooo

It's happeningggggg

Hawkeye is Ronin in the Trailer daayum!

vzn

← lol drinks to that on quite the relaxed friday :P

John Rennie

Enumaris is overheating. Quick! Someone throw a bucket of water on him!

(I'm assuming he's not electrically powered)

Semiclassical

It’s probably worth keeping in mind the form in which Occam’s razor actually appeared in his writing: “Plurality must never be posited without necessity"

Which is not quite the same, in my book, as “simpler theories are better”

vzn

occam: pre-enlightenment 13th century monk en.wikipedia.org/wiki/Occam%27s_razor en.wikipedia.org/wiki/Occam%27s_razor#/media/…

Semiclassical

You can still propose complications, but there had better be a reason to do so

enumaris

5:18 PM

Based on the trailer, Occam's razor says Ronin is going to rescue us all, any theory more complicated than that is veto'd!

He's gonna use his katana and rip Thanos a new one while Cap grabs the infinity gauntlet off of him. :D

vzn

← (lol) ~~curses~~ mourns stan lee :P

Semiclassical

Bertrand Russell’s version of the razor is rather nice, I think: “Whenever possible, substitute constructions out of known entities for inferences to unknown entities."

vzn

@Semiclassical nice, right! exactly what Farnes is doing. :) :P

Semiclassical

(Of course, this presumes a clear distinction between known and unknown entities. Not sure how well that works when dealing with QM)

vzn

sorting out the known from the unknown is part of the epic struggle... aka terra incognita/ here there be dragons™ ... rumsfield also semifamously talked about it (wrt war!) :P

enumaris

5:25 PM

this discussion is gonna devolve into epistemology

vzn

aieee, run!

enumaris

There's some things we know e.g. Avengers: Endgame is gonna be awesome. There's some things we don't know e.g. When will Adam Warlock appear in the MCU?

bolbteppa

The Problems of Philosophy

The Problems of Philosophy is a 1912 book by Bertrand Russell, in which Russell attempts to create a brief and accessible guide to the problems of philosophy. Focusing on problems he believes will provoke positive and constructive discussion, Russell concentrates on knowledge rather than metaphysics: If it is uncertain that external objects exist, how can we then have knowledge of them but by probability. There is no reason to doubt the existence of external objects simply because of sense data. Russell guides the reader through his famous 1910 distinction between knowledge by acquaintance and...

Is really good

vzn

← coincidentally recently read Conquest of Happiness by Russell :)

enumaris

why aren't y'all more hyped about Avengers: Endgame???

danielunderwood

5:38 PM

I haven't watched any of the Avengers movies. Besides, everyone should know that Batman is the one true superhero

enumaris

oh my

No offense to Batman, but the recent movies have been atrocious

Nolanverse Batman was insanely good though

danielunderwood

I actually haven't watched any Batman since Dark Night Rises either

Though I don't even know if there have been Batman movies since then. I'm a bit out of the movie loop

enumaris

5:52 PM

Ben Affleck is batman

in Batman vs Superman

and Justice League

both of which were pretty crap

vzn

@enumaris how was the 1st one? heard kinda dark with lots dying o_O saw antman last summer, think all the physics geeks in here will like it, it has some QM weirdness :P

enumaris

@vzn Avengers: Infinity War? Or 1st avengers?

Infinity War was really good :D

vzn

@enumaris its not the 1st? uh oh geek cred wobbles precariously/ dangerously o_O

Semiclassical

Infinity War is the third avengers movie

(Though Civil War was pretty close to being one)

vzn

← shamefully out of the loop/ out of touch/ not keeping track of the latest comic book/ hollywood innovations/ outgunned! o_O

Semiclassical

6:00 PM

Infinity War is a weird example in that, while a lot of people got killed off

vzn

yeah gotta admire the chutzpah there...

Semiclassical

It seems far more likely than not that many of them will get revived, simply because their movies were so marketable

I don’t see them passing up the opportunity to make another Black Panther movie for instance

(And it’s got precedent in the comics: a lot of the characters killed off in the original Infinity War storyline were resurrected by the end of it)

vzn

lol understatement... oh black panther II is already in planning stages. did see it, liked it. (geek cred meter teeters up slightly...) got a chance to meet/ briefly chat with a stuntwoman at denver comiccon last summer. holy cow, talk about paradigm shift, never saw so many women in an action movie! o_O

Semiclassical

Nice

vzn

we should just all go watch a good comic book movie together & stop arguing & let bygones be bygones :P

@danielunderwood lego batman that is! + lobster thermidor :P

enumaris

6:40 PM

@vzn nope, Infinity war is 3rd lol. 1st is just Avengers. 2nd is Avengers: Age of Ultron

@Semiclassical I think pretty much every character killed off in the Infinity War storyline was resurrected...

in other non-related news, former Fox and Friends presenter being nominated for UN Ambassadorship

sounds legit

Semiclassical

Sounds right. Not sure that’ll be true for the movies tho

enumaris

@vzn then we can start arguing about movies instead :D

Semiclassical

@slearah looking more closely at that TV Tropes page, what I had in mind is this: tvtropes.org/pmwiki/pmwiki.php/Main/ImmediateSelfContradiction

vzn

← maybe some mixed feelings/ cognitive dissonance about superheroes called "avengers," with shades of vigilante justice... also all the focus on "wars"! o_O

@Semiclassical re that wasnt sure of/ following your reference. are you talking about AKs blog ref to crackpots taking into account only "positive evidence"?

Semiclassical

6:58 PM

No. I had something else in mind.

danielunderwood

@vzn I've actually never watched any of the lego stuff or played the games. I played the Harry Potter video games as a kid and have wanted something similar, but thought the lego games were too out there

vzn

@danielunderwood did you see last lego batman? hilarious! esp luved the lobster thermidor scene can relate lol

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