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Messages - garygreen

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1
Flat Earth General / Re: Anyone for a public discussion?
« on: November 13, 2017, 04:32:43 PM »
imagine you bring a pebble inside and drop it from some height.  you make a plot of its position over time (its lateral motion, let's say) and you get a straight line.  neat!  there is a mathematical function that describes straight lines.  you have an analytic solution for the object's position with respect to time or displacement or something.

now imagine you bring a leaf inside and drop it from some height.  you plot its position over time, but now the plot is all messy, like graph #2 from my previous post.  damn.  there is no analytic solution that describes this motion.

where did the failure of physics happen?  you didn't do any physics.  you just plotted the position of an object over time.  one of them happened to be describable by well-known analytic functions.  the other did not.  nothing failed at anything.  it's just that lots of stuff can't be described analytically.

now imagine that i have a phd in fluid dynamics or something, and i simulate your leaf-dropping in a computer.  i tell it how to update the position of the leaf over time using equations of motion from physics.  if my code makes correct predictions, then it's asinine to say "your solution isn't analytical therefore it's wrong and/or meaningless."  the opposite is true.  i've used the laws of physics to get a numerical solution to an analytically unsolvable problem.  that's a success, not a failure.

In the article you linked the authors basically created a scenerio where three bodies moved around each other and decided that they solved the three body problem. When you make a graph with a function you are computing a pattern.

Solving the three body problem is actually much more complicated than that; it's providing a solution that will allow us to solve the problems in space and physics, where we do not know the exact "function" that brings the scenerio to its conclusion. You admitted yourself that the solution of the page was not very useful.

you are completely misunderstanding both what this paper is saying, and what an analytic solution represents.  and what a function is, if i'm being completely honest.

also i did not say that the solution from that paper is not very useful.  i said that there do exist analytic solutions to 3bp, but they are not useful.  numerical solutions are useful and make accurate predictions.  numerical solutions are computationally expensive (you're iterating lots of tiny time-steps, for example), but they're not less useful/accurate/valuable than analytic solutions.


2
Flat Earth General / Re: Anyone for a public discussion?
« on: November 13, 2017, 05:46:36 AM »
At no point do they actually come up with a solution to the three body problem. They think that they can create a 3D model of moving bodies, run it a few times, see the pattern, and therefore they can predict future occurrences from the pattern and the three body problem has been solved.

you're severely misunderstanding two things: 1) what the paper is saying, and 2) what an analytic solution means.

first, the paper is not describing patter recognition.  the parts you're describing are meant to demonstrate that the code does what it's supposed to do by asking it to find numerical solutions to problems for which there are known analytic solutions.  the author starts by demonstrating that it correctly solves two-body problems.  then he shows that it correctly solves a special case of the three-body problem.  and so on.

second, you're conflating "does not have an analytic solution" with "cannot be solved."  that's not what it means, though.  here's an example:

suppose you make a graph of an object's position over time and you get a graph like this.  there's a function that will tell you the value of the graph at any arbitrary point along the horizontal axis.  this "motion" has an anlytical solution.  it can be described by functions we know.


now suppose you see this graph.  there is no function that will tell you the value of the graph at any arbitrary point along the horizontal axis.  it's just a bunch of random chaotic movement.  it's hardly a failure of physics that mathematics does not have analytic functions to describe a graph like this.


the only reason two-body problems can be solved analytically is that it's circular/elliptical motion, and we have lots of functions for that.  if two-body motion were like the second graph, then we wouldn't have analytic solutions for them, either.  it's not a coincidence that the special cases for which there are analytic solutions to the three-body problem all involve circular motion.

ironically, these simulations are exactly about using geometry and physics to solve a problem that has no purely mathematical solution.

3
Flat Earth General / Re: Anyone for a public discussion?
« on: November 13, 2017, 12:37:35 AM »
They should be embarrassed because it is seemingly a simple problem on its face, but they don't have the tools to do it.

why do you believe that this is a simple problem?

Read through the first PDF. They are running a simulation of three bodies, tracing the patterns of its movement, and then making a prediction on the pattern they saw. This is not a real solution to the Three Body Problem.

can you point me to the passage you're referring to?  i'm not seeing anything about pattern recognition.

numerical integration is not a process of finding patterns.  it's literally just using a computer to solve equations of motion derived from newton's laws.  it's not pattern reognition; it's geometry + calculus + computers.

4
Flat Earth General / Re: Anyone for a public discussion?
« on: November 13, 2017, 12:19:01 AM »
a general three body problem has never been solved.

See: Three Body Problem on Wikipedia

it's only accurate to say that no analytic solution has been found.  it's still more accurate to say that no useful analytic solutions have been found.

numerical solutions are most definitely available and are used regularly.

http://ccar.colorado.edu/asen5050/projects/projects_2013/Brown_Harrison/Code/Brown_H.pdf
https://arxiv.org/pdf/1508.02312.pdf

5
Philosophy, Religion & Society / Re: Trump
« on: November 06, 2017, 05:04:53 AM »
https://www.icij.org/investigations/paradise-papers/

well this is an interesting development

6
Philosophy, Religion & Society / Re: Trump
« on: November 05, 2017, 04:47:28 PM »
on fox news sunday this morning paul ryan basically said the tax bill is net-neutral for most middle class families.  they'll get a higher standard deduction and lose a bunch of itemized deductions. 

but don't worry; paul ryan is "convinced" that we'll pay for the revenue loss with growth.  lol ask kansas how well that shit works.

The republicans could literally say "We've decided to make murder legal if it's a liberal" and they'd god damn cheer.

sure, there's a core group of folks on both sides who are like that, but if the party were a monolith, then obamacare would've been repealed.

this is just 2008 all over again, but it's republicans this time.  they win all the branches on a populist tide, and then suddenly they're faced with the reality that populism doesn't actually help you govern anything.

7
Philosophy, Religion & Society / Re: Trump
« on: November 05, 2017, 03:33:19 PM »
one thing i was super wrong about is how interesting this tax reform bill is gonna be.  less than a week ago i'd have said the odds of the gop passing any tax reform were literally 0.

and now democrats are running a slew of but mah national debt! ads.  this is weird.

8
Arts & Entertainment / Re: Just Watched
« on: November 05, 2017, 12:06:09 AM »
watched 2/3 of passengers last night.  i'll write up some thoughts on it when i finish, but for the moment i'm kinda surprised at how much hate this movie got.  i think it's pretty good so far.  it's a really fun "what would i do/how would i handle this" watch.

now to be sure, i'd have directed this movie way differently.  but that's not really a criticism of the film.  my only real beef with it is the manufactured tension in the climax.  it goes on for way too long.

i'd have shot this movie from aurora's point of view.  she wakes up, has no idea what's going on, and suddenly this mysterious guy shows up and the story goes from there.  she doesn't know what his motives are, if he's telling the truth about anything, what he's been up to all alone on the ship for so long, etc.  then maybe she gets some clues that he's lying to her about stuff, maximum tension ensues.  could've been a sweet thriller-ish scifi flick.


9
Flat Earth Q&A / Re: FE orbit of planets
« on: November 05, 2017, 12:02:42 AM »
Back when geocentricism was all the rage - they ended up with more and more complex explanations for the orbits of planets that became SO insanely complex that it was eventually abandoned in favor of the much simpler heliocentric system.

Do you know where I can find these equations, I could do an animation for the wiki.

the equation of motion in this case would be a series of plane waves (think sine wave).  each wave gets some scaling factor, and the sum of all the waves is a single path that describes whatever planet you're talking about.

something like this: 

interesting historical side-note: epicycles weren't really abandoned because of complexity.  modern tables of planetary positions, for example, are computed from equations of motion that may contain thousands of terms.  it has more to do with the arbitrariness of the epicycle model.  any path can be described as a sum of plane waves, so epicycles don't end up telling you anything physical about why a planet moves as it does.

10
Philosophy, Religion & Society / Re: Trump
« on: October 30, 2017, 05:43:17 PM »
Literally me. After all, it's okay if Republicans do dodgy shit.

fwiw i wasn't taking a shot at you

even though you're a freedom-hater who hates freedom.  i bet you're not even american.

11
Philosophy, Religion & Society / Re: Trump
« on: October 30, 2017, 03:19:23 PM »
wapo reports republicans paid fusion for oppo research on trump: i sleep.

wapo reports democrats paid fusion for oppo research on trump: REAL SHIT.

12
Flat Earth General / Re: How Hard is it to Realize Earth is Round?
« on: October 24, 2017, 02:40:14 PM »
i've been on .org since the split.  the idea that anyone is using this forum to make money is totally absurd.

round earth dudes and dudettes: chill out a little bit.  lol i think science can survive a few polemics on a web forum.

13
https://mises.org/library/misess-non-trivial-insight

btw this article has a ton of super interesting shit to say, and one of them is right on point:

Quote
This stands in sharp contrast to the method of the positivists, a camp that includes most of today's practicing economists. In their opinion, economics can only be "scientific" if it adopts the procedures used by the natural scientists. Roughly, the positivists feel that economists should form hypotheses with testable implications, and then collect data to measure the accuracy of their predictions. Those tendencies that enjoy the most success in this sense are then deemed to be better "laws" than conjectures that do not fit the data so well.

laboratories are not required by the scientific method.

14
Suggestions & Concerns / Re: Renewed FES merger talks
« on: October 24, 2017, 02:26:17 AM »
Quote from: John Davis
No, our two groups will coexist, but this forum will be shifted in its usage as the new platform gets integrated to be more of a social hub. This is a long term project, so it will come when it comes. I will say I have a good amount of the backend work done to this end.

speaking of things that will never, ever happen...

also, i'm with the others.  tbh i don't really care much either way, but it seems silly to "merge" without merging the forum.  i feel like we gain nothing.

15
If you are trying to contradict Earth Not a Globe you need to read the source material to know what you need to contradict.

this cuts both ways.  you're right that a necessary component of any criticism is a demonstration that you fully understand the position you are criticizing; and, you consistently demonstrate that you do not understand what astronomer claim to know, how they claim to know it, and the assumptions they make in the process.  your descriptions are wildly inaccurate.

as an example, astronomers do not assume all stars are the same; they assume stars are made of atoms.  everything else follows from that.


16
Philosophy, Religion & Society / Re: Trump
« on: October 18, 2017, 03:04:36 PM »
Everyone I've ever met from Texas seems nice, racist.

i feel like you should be commending us for how polite we are about our distaste for brown people.

17
Unless you can put all aspects of celestial phenomena under controlled conditions, observation alone does not cut it.

Astronomy does not follow the Scientific Method. Observe --> Interpret are the steps used in pseudosciences such as Astrology. It is not science.

as rama rightly points out, the scientific method does not require laboratories.  they're useful for conducting experiments, but they're not fundamental to the method.

it's worth noting that the bedford level experiment is methodologically identical to the practice astronomy; the experiment does nothing more than record the brightness of an object.  in this case the brightness observation is binary (did we collect any light from the bridge or didn't we?), but the method is fundamentally the same as observing stars.  you didn't put the bedford level in a giant laboratory.  nor the surface of the earth.  surely you don't think those observations worthless, do you?

an old analogy, but i'm here, so fuck it: suppose i'm a taxonomist.  i've studied the biology, physiology, and anatomy of all manner of plants and animals, and my field is obviously based on empirical laboratory and field research.

now let's suppose two odd things: 1) suppose that i've never seen a racoon before.  never even heard of one.  i have no idea that they exist.  2) suppose that someone could somehow take a photo of 100,000 different raccoons at a particular instant in time and give it to me on a flash drive.  so now i'm a taxonomist who has never seen a raccoon before, and i have 100,000 images of different raccoons all at different stages of life and death.  some are infants.  some are dead and rotting.  some are giving birth.  some are eating.  some are banging, jumping, running, fighting, hunting, scavenging, etc.  you get the idea.

having never handled a raccoon before, i could nevertheless tell you a lot of true things about raccoons by relating what i see to the animals and plants that i have studied.  i could correctly classify them as mammals, describe their internal structure, fit them on the tree of life, and tell you a shitload else about their characteristics. 

sure, there are plenty of questions that will be difficult to answer without getting my hands on a raccoon, but i'm still doing good science just by collecting photons.

18
what experiments

virtually all experiments in astronomy measure one of two things: 1) how bright an object appears across all wavelengths of light, and 2) how bright an object appears at specific wavelengths of light.

the op is also an experiment, but it measures distance between two points on earth.

20
Philosophy, Religion & Society / Re: Trump
« on: October 14, 2017, 03:51:10 PM »
why is anyone pretending trump gives a shit about the flag code

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