The h Bar

user116211

15:01

2

My nephew has been promoted to "Skunk Works" with Lockheed Martin. His specialty is aerospace engineering(primarily F-35) and will focus on that aspect in his duties. I am wondering if there is others with similar backgrounds and histories that he can reach out to. I would also like to see expe...

user116211

Are such things on-topic in meta; is it about the system? Maybe it's about the users in PSE; but still I'm not getting; so I'll leave that.

Physics Meta

2

Q: Looking for mentor(s) for my nephew

My nephew has been promoted to "Skunk Works" with Lockheed Martin. His specialty is aerospace engineering(primarily F-35) and will focus on that aspect in his duties. I am wondering if there is others with similar backgrounds and histories that he can reach out to. I would also like to see expe...

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2physics

15:18

@JohnDuffield well, you actually are thinking about "counting associated waves" ; that's why it results in such an issue. you don't need to "sit there and wait till the microwaves pass you by" and count them. YES it results in tautology. So you just can define if we consider the "n" number of transitions of cesium atom, the distance which light passes through that time , divided by that period of time(what ever it is) is supposed to be $1$.

John Duffield

@2physics : it isn't the number of transitions of a caesium atom. It's 9192631770 periods of radiation.

2physics

maybe scientists from other planets (or maybe our future technology) have more precise ways to measure that

0celo7

@ACuriousMind how tf does this integral work

ACuriousMind

@0celo7 by completing the square

0celo7

I don't know what that means

2physics

15:25

@JohnDuffield look It's the definition of 1 sec. I'm not talking about that. I'm saying the distance that light passes what ever it is, over the time the n number of transitions occurs (what ever it is) , is a fact of our world which can be considered constant and equal to 1 to define a unit system

Sanya

@0celo7 x² - ax = (x-a/2)^2 - a²/4

0celo7

How am I supposed to know how to integrate a Gaussian though?

Sanya

eh?

0celo7

You complete the square and you get a nasty Gaussian integral

How am I supposed to know how to do that integral?

ACuriousMind

@0celo7 Because it's a standard trick every physicist should know?

Sanya

15:29

you know how to integrate exp(-x²), right?

0celo7

@ACuriousMind One typically learns the trick in a first course on QM.

This first course on QM expects you to know it without refresher

What the hell is up with that

@Sanya nope

ACuriousMind

I'm pretty sure I learned it in mechanics/mathematical methods because I vividly remember that tutor demonstrating it

@0celo7 Do you really not know or are you playing dumb?

0celo7

@ACuriousMind Playing dumb

I learned the trick when I learned QM in high school

Sanya

>_<

0celo7

So I don't understand how one is supposed to understand this integral coming in without experience

Secret

15:31

Gaussian integral computation: Square the integral, label one of the x as y (so it basically look like a double integral). Change to polar coordinates, and integrate using invrse chain rule. After that take the square root of the result. The radial variable will ensure the $\infty$ to blow to zero

Sanya

@0celo7 define "no experience"

0celo7

@Sanya no prior exposure to QM

Sanya

I'd not expect someone in elementary school to get it, but that's kinda obvious

John Duffield

@2physics : but it isn't constant. That's the fact of our world. That's why we have that thing called gravitational time dilation. The second at one elevation is not the same as the second at another. However the (horizontal) metre is.

Sanya

well, you might have seen it in math lectures or other physics classes ... and if not, you'll probably have to do a bit of thinking, agreed

0celo7

15:33

@Sanya I'm sure you'll see it in calc 3, but to remember one specific integral is pretty impressive

and I certainly don't remember the value of the integral off the top of my head

Sanya

I dunno, there's just things that stick somewhere in the back of your head

0celo7

@Sanya Even QFT books at least give you the value of the integral!

Sakurai just expects you to know it apparently

Sanya

since class 8 in school I know that water has a c=4,19 kJ/kg/K at room temp ... just doesn't want to leave my head

0celo7

I don't even know what c is

Sanya

the heat capacity

0celo7

15:35

Oh right, that gladly left my head

Did stuff with that last semester in my thermo class

never again

(until my next one in two semesters)

Sanya

I like thermodynamics

0celo7

thermodynamics is terrible. too many signs

Sanya

^^"~

2physics

@JohnDuffield another question, is the gravitational field that surrounds us now is different from what it does in the next second (or next thousands of years)?

0celo7

@ACuriousMind also I'm not a physicist

where do the is go in that integral

2physics

15:38

of course it is.. you are right

Sanya

@0celo7 you just rotate the integration line in the complex plane

Secret

$$\int_0^{\infty}e^{-x^2}dx$$
Let $I=\int_0^{\infty}e^{-x^2}dx$,Consider "$I^2$"
$$\int_0^{\infty}e^{-x^2}dx\left(\int_0^{\infty}e^{-y^2}dy\right)$$
$$\int_0^{\infty}\int_0^{\infty}e^{-(x^2+y^2)}dxdy$$
Change to polar
$dxdy=rdrd\theta$
$$\int_0^{2\pi}\int_0^{\infty}re^{-r^2}drd\theta$$
$$2\pi\int_0^{\infty}re^{-r^2}dr$$
Use inverse chain rule $a_be^{-a(b)}db$
$$2\pi\int_0^{\infty}\frac{2r}{2}e^{-r^2}dr$$
$$\pi\left[-e^{-r^2}\right]_0^{\infty}=\pi$$
Therefore $I=\sqrt{\pi}$

0celo7

@Sanya Once again, I know that.

Sanya

>_<

0celo7

But how am I supposed to know that reading this for the first time?

Sanya

15:42

thanks x.x

John Rennie

@peterh If someone posts a question that is rubbish then you have to tell them it's rubbish. To do otherwise isn't fair to anyone involved. My point was that you should always be polite when offering criticism.

0celo7

@Secret You should do that integral in $n$ dimensions

Secret

I guess that might be possible, but I am not good at jacobians in n spherical coordinates

0celo7

I once did the computation

It was not fun

Secret

There's something interesting in the way integrals are computed. The issue is that unlike derivatives, that aren't as many theorems that simplify integral expressions, which is why integration is more frustrating

John Duffield

15:45

@2physics : no. But check out the Dirac Large Numbers hypothesis: "The strength of gravity, as represented by the gravitational constant, is inversely proportional to the age of the universe". I can't say for sure that gravity in the early universe was the same strength as it is now.

Secret

The reason this standard method of gaussian integral computation works is it exploit the symmetry of the integrand, and the rapidly decay property of the gaussian function to get rid of that infinity

John Rennie

@2physics: for us GR heads natural units normally mean geometric units. We take $G=c=1$ and don't really care about anything else.

Secret

Most nonelementary integrals that have analytic values for some intervals basically means there is some kind of symmetry being exploited at the integrand

peterh

@JohnDuffield Afaik it could be easily measured. The weight of the masses would decrease with time.

Secret

Having said that, I suck at integrals in general

especially any integrals that has rational function terms of the form $\frac{f(x)}{g(x)}$

peterh

15:48

@JohnDuffield Not very - maybe a change from $\frac{1}{1.37e+10}$ to $\frac{1}{(1.37e+10) +1}$ wouldn't be very big, but I suspect it would be measurable.

Sanya

@Secret any differential equation is better for numerics anyway :D

Secret

Numerical solutions are also interesting in themselves, especially when you see how it converges and diverges when using different methods, periodic oscillations and other behaviour

2physics

@JohnRennie if the world is expanding and the position of planets in the universe is changing doesn't it mean that the gravitational fields around us are changing? and if gravity affects the light , then how can we consider the speed of light as a constant fact of our world?

Secret

To me, most maths have a geometric feel, except for series

I can NEVER understand how series works

John Duffield

@peterh : the point is that our galaxy is gravitationally bound, so there's no local expansion, so the force of gravity on Earth wouldn't change.

Secret

15:50

let alone number theory

John Rennie

@2physics The speed of light is a local invariant. Any local experiment to measure it always returns the same value $c$.

Secret

A dream 5 days ago, however did caused me to google for a number theory lecture notes, thus I end up beefed up a little bit on number theory

John Rennie

This is because spacetime locally always looks Minkowski i.e. flat.

2physics

@JohnRennie considering what i said above, why is it invariant(locally or what ever)?

John Rennie

Any real experiment to measure $c$ would have to consider effects due to curvature, but in practice these are generally so small as to be unmeasurable. Not always of course, otherwise LIGO wouldn't have detected anything :-)

0celo7

15:52

@ACuriousMind @Sanya I legitimately do not understand how to complete the square.

Secret

That dream basically asked a potentially nonsensical question $$4 \mod 5 + 12 \mod 5 = n \mod m$$
and it asked to find n and m

ACuriousMind

Given your general problems with quadratic equations, I can't say I'm surprised :P

Sanya

@0celo7 I wrote it down EXPLICITLY up there

0celo7

@Sanya But I have a term in front of $x^2$

2physics

@JohnRennie so you mean there are effects, but very small

0celo7

15:53

@ACuriousMind Why is this so hard for me?

Sanya

@0celo7 ..... .... ....

Secret

Initially I suspect that question might make sense if m is a lcm of the two numbers after the mods, e.g. 12 and 5, because (if my memory serves) $\mathbb{Z}/12$ is a subgroup of $\mathbb{Z}/60$

0celo7

I'm not trolling, I really don't know what to do

John Rennie

@2physics yes, though very small is an understatment :-)

Sanya

@Secret can I say that your dreams are a bit interesting?

@0celo7 ax²-bx = a( x² - b/a x), right?

Secret

15:55

They are, but not all of them I can recall the math details accurately to do a reality check

0celo7

@Sanya sure

ACuriousMind

@0celo7 That mystifies me as much as it does you, I'm afraid

vzn

@DanielSank surely youre likely one of the top experts on that around here :|

0celo7

@ACuriousMind Perhaps the same reason why linear algebra is so hard

Sanya

@0celo7 aren't we done now?

2physics

15:55

@JohnRennie how about in comparison with the age of the universe

0celo7

@Sanya Maybe??

Sanya

we just complete the square inside the brackets and set z = (x-b/2a)/sqrt(a)

John Rennie

@2physics Eh?

Sanya

@Secret I have to admit that I dreamed solutions to problem sheets though ...

2physics

@JohnRennie I also have some other questions actually, I've just started to learn QM and relativity theories.. thanks for your help :P

vzn

15:58

@Sanya lol possibly the 1st positive endorsement here after many offerings

John Duffield

@2physics : it's locally invariant because of the tautology. We define our second and our metre using the motion of light, then use them to measure the motion of light.

ACuriousMind

What is it with all you people dreaming about math/physics?

Secret

@Sanya Well that never happened to me, most of the maths are nonsensical. The closest example is I dreamt of a way to finish a level from Super Mario 64

John Rennie

2physics

@JohnDuffield was it for me or @JohnRennie lol

John Rennie

15:59

Now this is what I call a Sunday lunch - bow down ye unworthy ones

vzn

@ACuriousMind what is it with all you people who dont dream about it? :P

Sanya

@vzn I have to admit my english is not up to your sentence

vzn

@Sanya hi what country are you in? undergrad? physics?

John Rennie

@2physics I'm not the best person to aask about QM, but I'm always happy to help with anything related to relativity - both flavours.

2physics

@JohnRennie enjoy your launch but I ask my questions :D

John Rennie

16:00

@2physics I've finished lunch now - very nice too :-) Feel free to ask any questions.

2physics

@JohnRennie my questions are kinda elementary . thanks

John Duffield

@2physics : for you. See what Einstein said here: "The theory of special relativity, therefore, applies only to a limiting case that is nowhere precisely realized in the real world".

Sanya

@vzn yep, I'm a 1st year homeopathy science from the moon

Secret

Complete the square: given $ax^2+bx+c$ which is not a perfect square, you want to think like an engineer and massage it into a perfect square. One obvious route is to use the do noting technique to do the following:
$$ax^2+bx+\frac{b^2}{4a}-\frac{b^2}{4a}+c$$
Now as an engineer, you can see that the first three terms look like a perfect square. Thus job done
$$(\sqrt{a}x+\frac{b}{2\sqrt{a}})^2+(-\frac{b^2}{4a}+c)$$

John Rennie

@Sanya 1st year homeopathy - the fewer lectures you go to the better you get at it :-)

2physics

16:03

@JohnDuffield alright, thank you. I'm convinced that it's not constant, but we can consider it as const for our practical goals :P

@JohnRennie do you believe in homeopathy?

John Rennie

@2physics do I look stupid?

Actually don't answer that :-)

Secret

Dealing with maths like an architect: In general, given a ugly mathematical object $M$, you want it to become $N$. Therefore your tools are the various axioms and theorems. Use your tools to massage $M$ into $N$

2physics

@JohnRennie lol no. but I've seen some cases who have been treated by Homeopathy

Sanya

@JohnRennie on a side note, I do actually believe in placebo effects for minor stuff like a headache, especially with kids

2physics

don't know if it really works or not

John Rennie

16:05

@2physics the placebo effect is a wonderful thing

John Duffield

@2physics : don't consider it as constant for your practical goals. Because it isn't constant. See this PhysicsFAQ article written by Don Koks.

Secret

Ever since a professor explained to me what the do nothing technique is and why it works, I started to have a hackerspace like attitude to maths

ACuriousMind

@Sanya There's nothing to "believe" in with the placebo effect - it's demonstrated that it exists in nice, repeatable studies.

John Rennie

@ACuriousMind which is why all trials have to be done double blind

Sanya

@ACuriousMind I was never curious enough to look for them :D

John Rennie

16:07

@Sanya pretty much every clinical trial demonstrates the placebo effect. People on the placebo treatment improve.

Secret

And the most ambitious of that hackerspace attitude is what I called "proof breaking", that is, you try to get something interesting form a proof by breaking it so that a counterexample pop up

ACuriousMind

@JohnRennie Sure. We physicists are pretty lucky particles don't exhibit the strange quirks of human psychology. All we have to deal with is QFT ;)

2physics

@JohnDuffield alright. it isn't but many people have considered it constant and it helped for their practical use..

Sanya

@JohnRennie they improve or they feel better?

2physics

@JohnRennie Homeopathy meds are not placebo actually

John Duffield

16:09

They aren't meds either.

John Rennie

@Sanya good question. They certainly feel better, but I believe there are measurable clinical benefits as well. But if you challenged me to provide hard evidence I couldn't.

@2physics yes they are.

Sanya

@JohnRennie I won't, because I didn't mean to annoy you - I was just thinking aloud

Secret

So, extremely hypothetically, if the notion of a continous transformation exists between logic systems, then it might be possibel for one to move the entire proof that the permenent is $#P$ into a logic system where it brekas down, compute the permenent and then tranform the result back to classical logic. This is simialr to how we change basis in linear algebra in order to do easier computations

John Rennie

@Sanya oops, did that come over as annoyed, it wasn't meant to :-(

2physics

@JohnRennie homeopathy is based on an old belief which what ever causes pain, you can find its treatment inside itself

vzn

16:12

← strong believer in placebo effect

ACuriousMind

@Sanya Good point, the improvements are mainly in "subjective" areas like pain sensation, and are not reliable - you can't predict the the effect at all, its strength varies wildly across different trials.

@2physics So what? An ancient belief doesn't make a sugar pill less of a sugar pill

Sanya

@JohnRennie nah, didn't; that was my choice of words

I'd thought I'd be annoying if I were to ask you for a scientific reference now though - even because I wouldn't follow it

John Rennie

I suppose at the end of the day if people like homeopathic treatments enough to want to pay for them then that's fine by me. I like beer enough to pay for it and beer is devoid of any clinical benefits.

Secret

So in a sense, I am an extreme person. I am willing to push a system to its limits in order for it to spit out an object I want (or die trying)

Sanya

@JohnRennie beer has a lot of valuable minerals :)

ACuriousMind

16:14

@JohnRennie No one is selling you beer claiming it has clinical benefits, though.

The usual selling points are that it's delicious and is alcoholic :P

John Rennie

@ACuriousMind Clinically proven to reduce levels of cortisol.

ACuriousMind

I...don't even know if that is a good or a bad thing

John Rennie

High cortisol levels mean you're stressed.

Secret

and stress can cause a lot of health problems

John Rennie

After a night on the beer I am highly unstressed.

In fact I'm generally so relaxed I can't walk :-)

Secret

16:17

I think it kinda make sense as alcohol is a suppressant of some sort

ACuriousMind

@JohnRennie That's an interesting way to look at it :D

Secret

in other news, vzn had turned dark red

2physics

@ACuriousMind I think just because it's ancient it doesn't make it worthless or reject its results. I trust in what science proves and I also don't say surely we can say that homeopathy has some convincing reason behind it but there are some issues which we can't interpret and explain them using science and our knowledge now. what do you think about them?

Secret

@2physics At least in science, homeopathy have been proven again and again for 50 somthing years that it is no better than a placeabo, and in some cases even harmful

2physics

whatever , leave homeopathy lol I forgot about my questions :D

ACuriousMind

16:19

@2physics I'm not saying it's worthless because it's ancient. It's worthless because it's not true. What are those "issues we can't interpret" you are talking about?

Homeopathy has been debunked again and again in controlled medical studies - it is no more effective than any other placebo.

Space Otter

A homeopath told me i was allergic to wheat gluten while my faveorite cereal was wheatabix. I've since become uninterested with the whole concept

vzn

← now seriously wondering if sanya has anything whatsoever to do with homeopathy or if it was a throwaway joke

2physics

@ACuriousMind well if you find many cases which has been treated using it, then what's the reason? who knows maybe that's the homeopathy is about !

John Rennie

Quickly, change the subject to something less controversial. LQG vs string theory anyone?

Secret

Unlike Electroconvulsive therapy which there is a growing evidence it is benefitial, but long terms effects are still active area of research

@JohnRennie I prefer them merged

Sanya

16:22

@JohnRennie anyone here for discussing material objectivity? :|

2physics

the effectiveness of placebos is also proved btw :D

vzn

@JohnRennie lol just found this feynman quote: "String theorists don't make predictions, they make excuses” (fighting words...)

John Rennie

I don't even know what material objectivity is ...

ACuriousMind

@JohnRennie I don't think I've ever seen an actual LQG proponent on the site...

Secret

Surely there should be some common ground between LQG and string theory (and any QG candidate that are still surviving)

Sanya

16:23

@JohnRennie something from continuum mechanics modelling ... it seems like a weird principle to me

invariance of material constitutive equations under general time dependent rotational coordinate transformations instead of under the Galilean group

Secret

ACM: I like both string theory and LQG, but I am a noob on both

2physics

who knows maybe homeopathy is true quantum mechanically , but in practice and everyday life it seems worthless :D

Secret

::Shoots anyone who dared to pass quantum mysticism as science::

ACuriousMind

@2physics ...what?

You're not making any sense

2physics

I didn'tttt

John Rennie

16:25

@ACuriousMind irony detection failure?

Secret

@Sanya So like if your object is rotating in a varying speed, its constituent properties remains invariant?

ACuriousMind

@JohnRennie perhaps? But then I must have missed a lot of irony further upthread...

Secret

@<--- this is a luxrious commodity, do not spam it

Sanya

@Secret no, the relationship between quantities, typically stress tensor and symmetric rate of deformation tensor, remain invariant, not the quantities themselves

vzn

@ACuriousMind spking of irony, another amusing factoid from feynman bio: he intermittently hung out at Esalen institute... as well as strip clubs... (etc) o_O

Space Otter

16:28

@2physics Homeopathy has been disproven by a lot of studies. Yet again it was also proven by a lot of studies that GMOs and Glyphosate were completely safe to eat and would have no adverse affects on the environment.

Secret

@Sanya Aren't tensors invariant under any coordinate transformations, thus that should include galien group transformations?

John Rennie

Good grief, I though we'd moved on from homeopathy. For the love of god someone change the subject.

Sanya

@Secret time derivatives have problems with time dependent coordinate transformations

Space Otter

What's that word when a scientist does an experiment and get the results they were looking for on purpose? I forget

Secret

@JohnRennie If you noticed closely, the topics in h bar are currently in a superposition

Sanya

16:29

the galilean group is fine, general rotations and accelerated systems are problematic

Secret

@Sanya So in that case material objectivity provide an invarience rule to some tensors in accelerated frames, which is not a common thing as far I knew

Space Otter

Hey there's an SE just for stuff like homeopathy discussions isn't there? It's called Skeptiks

Sanya

@Secret yeah, basically, and you stumble upon generalised derivatives, Lie derivatives that don't commute with the metric, stuff like that

2physics

@SpaceOtter alright; the same discussion exists about religion I think :D

vzn

@JohnRennie new subject: love + god :P

John Rennie

16:32

@kpv: hi

Secret

I think 0celo7 will be interested in the notion of material objectivity and its generalisations assumign he is interested in accelerated frames

kpv

Hi JohnRennie, this is KPV

John Rennie

@kpv hi. By the way, can you delete your comments on the Big Bang question now you've found me.

kpv

@JohnRennie deleted.

2physics

@JohnRennie I just read in a paper by Alden Mead (journals.aps.org/pr/abstract/10.1103/PhysRev.135.B849) that " it is impossible to measure the position of a particle with error less than planck length"

John Rennie

16:35

@kpv Thanks, though there is still one comment left. It's just that the comments are unrelated to th question so they make it look untidy.

2physics

my question is about this

John Rennie

@2physics true sort of. It's because to measure smaller and smaller lengths requires higher and higher energy.

To measure to less that a Planck length requires so much energy that it forms a black hole.

2physics

well wait plz

John Rennie

Though this is a somewhat hand waving argument.

@kpv all gone, thanks :-)

kpv

@JohnRennie OK, I have this question that was put on hold yesterday, I had a disagreement about it but it was put on hold anyway. Now I have totally reworded and tjhink the reason for hold should be gone. I have sent comments to the members who put it on hold. How can I get the hold removed.

2physics

16:37

does QM accept this argument ? (what that paper says)

John Rennie

This one?

-5

Q: Does this observation in a probabilistic experiment indicate presence of a balancing mechanism?

I will ask the question in terms of an observation on a hypothetical coin toss experiment. If you like, you may answer the question based upon the coin toss description alone. For little more curious and patient readers, I have provided link to a paper that I wrote about an observation on an ac...

quantum-mechanics entanglement probability

@2physics yes

2physics

I mean if it's according QM?

kpv

@JohnRennie Yes, can you please take a look also and see if the question is that bad.

John Rennie

@kpv OK, give me a few minutes to read it ...

@2physics yes

@2physics we don't have a theory of quantum gravity, so the argument is pretty vague but I suspect most physicists think it's basically correct.

kpv

@JohnRennie Yesterday, the objections were about the paper not being clearly written, which I think is not the case. Now, I have made the reference to the paper optional, so that objection should be gone.

John Rennie

16:43

I have to say it isn't entrirely clear to me what you are asking. You appear to be suggesting that if the same experiment is repeated then there might be different outcomes, but that difference is time dependent.

i.e. the coin toss probabilities vary with time.

Space Otter

How do we detect curvature from measuring CMB? Or should i go to Astronomy.SE?

Secret

@JohnRennie Well I guess the question might be boils down to basically, comparing a coin toss experiment with 28000 trials and 100 trials, the former found a 1:1 like ratio of head to tails while the latter found a bias towards tails compared to heads. Is this dependence of the probability with the number of trials suggest some underlying mechanism that is respnsibel for the bias?

Space Otter

Is that "on topic"?

ACuriousMind

@kpv 1. Your underlying question seems to be if the data you analyzed there is consistent with the data being random. This is a pure statistics question that should go to Cross Validated 2. It is unclear what you're asking because looking at data post hoc and then finding patterns in it is easy and such patterns, without any actual statistical analysis of their significance, mean nothing.

John Rennie

@SpaceOtter I'm sure there's already a question on this.

Space Otter

16:44

Ok one minute

ACuriousMind

5

Q: How/why can the cosmic background radiation measurements tell us anything about the curvature of the universe?

So I've read the Wikipedia articles on WMAP and CMB in an attempt to try to understand how scientists are able to deduce the curvature of the universe from the measurements of the CMB. The Wiki article on CMB explains merely the following: The peaks contain interesting physical signatures. T...

astronomy universe curvature cmb

^there

Space Otter

@JohnRennie yup thanks

John Rennie

@ACuriousMind Bingo. This time I waited to see if ACM would post first :-)

ACuriousMind

haha

I'm so predictable

John Rennie

@Secret this seems a meaningless question.

Secret

16:46

@JohnRennie Then I must have misinterpreted it

John Rennie

@Secret No, I agree with your interpretation, but I don't understand what is being asked.

The suggestion seems to be that one tried of 28000 tosses might be different to 280 trial of 100 tosses, but no suggestion is given for why this might be.

Secret

johnrennie: but anyway, is it in general possible for the experimental probability of the outcome of an experiment to depend on the number of trials, that is, the probability of the outcome can change depending on how many trials is being performed

John Rennie

Not if the trials are independent, no.

kpv

@ACuriousMind Well even if your statement is true, then just by looking for such patterns, I can not create consistent patterns. They do exist in data and that is what I have presented in a very clear way. The statistical significance is already mentioned, what is at question is same pattern in all 4 coins/setups, and then clearing of balance in all 4 at the same time.

John Rennie

@kpv if you have data showing an effect of the sort you describe this suggests the trials aren't independent. I can't think of any other way in which that data makes sense.

ACuriousMind

16:50

@kpv I don't see any mention of statistical significance anywhere in your question. Show that the patterns you see are highly unlikely to arise randomly and we have something to talk about.

kpv

@JohnRennie 280000 is just an example to make it clear that the bias survives for a long period.

Space Otter

nvm

John Rennie

@kpv noted. But the situation still seems purely hypothetical.

Space Otter

ok so that's not how citing works

Shing

would anyone be kind enough to tell me if the intersection set of x' and (x',x] equivalent to the set [x',x] ?

kpv

16:52

@JohnRennie Exactly, that is the point I am asking to confirm that this pattern indicate data that is not independent. This is an answer to my question which I had to work so hard to get.

Secret

I think it will be empty since $x' \notin (x',x]$

ACuriousMind

@Shing No, you've written down the union, not the intersection.

Shing

@ACuriousMind oh, sorry my bad. I mean union.

so basely, the union set of x' and (x',x] equivalent to the set [x',x] ?

Secret

yes

kpv

@JohnRennie I presented this hypothetical situation because there were objection about how the paper was written. The analysis in the paper on actual data from entanglement experiment.

ACuriousMind

16:53

@JohnRennie Only if all such experiments show the same pattern, and only if the pattern is statistically significant. Without strict notions of significance the LHC would be "detecting" new physics every day.

Shing

thanks, men

John Rennie

@kpv one eplanation is that the trials are not independent. I'm not sure I want to go on record as saying that's the only explanation. If I saw this in a a published paper I'd suspect an experimental error.

ACuriousMind

Especially when it comes to determining whether random data is truly random, it is important to do the proper statistics instead of looking for patterns that one feels are significant.

John Rennie

i.e. the correlation came from the meaurement system not nature

Shing

is this a axiom actually? I found it quite amazing.

ACuriousMind

16:55

@Shing Is what an axiom?

2physics

@JohnRennie I found this on a forum: "the gravitational length L=2Gm/c^2 associated with every electron or proton is 19 or 22 orders of magnitude smaller than the Planck length. Nobody seems to doubt either of the two statements. What is the exact answer to this paradox?"

Shing

@ACuriousMind the union set of x' and (x',x] equivalent to the set [x',x]

John Rennie

@2physics It means the gravitational length of an electron isn't a physically relevant quantity to compute.

Shing

I think it is called axiom of completeness?

2physics

what does he mean by "gravitational length"?

kpv

16:55

@JohnRennie The data was acquired from a published experiment. If it had errors, then other results that were published would also have been impacted and not have passed the review.

2physics

@JohnRennie what is gravitational length?

John Rennie

@2physics electrons aren't point particles. In fact there's a good argument that they don't exist in the usual sense in which we mean a particle.

ACuriousMind

@Shing It's not an "axiom", and I don't know why you find it amazing. By definition, $(x',x]$ is all numbers less than or equal to x and greater than $x'$. Adding $x'$ obviously makes this all numbers less than or qual to x and greater than or equal to $x'$, aka $[x',x]$.

kpv

@JohnRennie But I agree that is also one possibility and saying that there are two possibilities, is also an answer. But why it should remain on hold after the rewording.

John Rennie

@2physics the size of the black hole with the mass of the whatever. i.e. if you created a black hole with the mass of an electron what would be its Schwarzschild radius.

Shing

16:58

@ACuriousMind because it takes me sometime to think if there is some "gaps" between x' and (x',x]. and I can't think of a way to prove it in anyway.

John Rennie

@kpv well, it's not really a question about physics ...

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