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Messages - 9 out of 10 doctors agree

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21
Flat Earth Theory / Re: Clock the Sky
« on: April 26, 2019, 08:54:14 PM »
The time a star or the Sun takes to move 15 degrees is exactly 60 minutes, or, 4 minutes per degree, EXACTLY.
Nope. A star near Polaris will move significantly slower, and a star on the equator will move slightly faster.

And for the record, clocks were never set based on the speed at which stuff moves in the sky; they were historically set by a standard pendulum length and "sun at due north/south = 12:00 PM".

22
Flat Earth Theory / Re: Solar Light Composition
« on: April 26, 2019, 06:31:56 PM »
I hope you realize that the power from the sun isn't actually even.

Of course, radiation burst and solar flares make it radiation fluctuating, this is why we use average measurements.
No, I mean it's not even across the Earth's surface. Sunlight coming at an angle is less radiance than sunlight from directly overhead.

This is exactly why we use "average" of 1kW/m².   The same average I used to calculate the energy within the cone from the flat earth sun.
That average was probably calculated based on spherical area. You can't use it as a reference for flat area.

23
Flat Earth Theory / Re: Solar Light Composition
« on: April 26, 2019, 03:58:38 PM »
I hope you realize that the power from the sun isn't actually even.

Of course, radiation burst and solar flares make it radiation fluctuating, this is why we use average measurements.
No, I mean it's not even across the Earth's surface. Sunlight coming at an angle is less radiance than sunlight from directly overhead.

24
Flat Earth Theory / Re: Solar Light Composition
« on: April 26, 2019, 02:53:10 PM »
I hope you realize that the power from the sun isn't actually even.

25
Flat Earth Theory / Re: Size of planets
« on: April 26, 2019, 02:51:44 AM »
There is nothing inherently wrong with moons orbiting planets in FET. Jupiter already moves irregularly compared to the stars, so other stuff near it with even more irregular movement isn't out of the question.

26
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 24, 2019, 04:13:27 PM »
There is no way to do it. The motions of the bodies are unpredictable.

From the above:

Quote
Such solutions do not exist because motions of the three bodies are in general unpredictable

Look up chaos theory, which directly spawned from attempts to solve the three body problem. Neither an analytical solution or a numerical solution can solve chaos theory.

The fact that we claim the official orbiting model is defined by very specific laws and mathematical formulas.

The official round earth model is not even a 3 body problem. It's like a 90 body problem.


The fact that the three body problem has not been solved, and the official model is a 90+ body problem is something that definitely weakens some aspects of the official model and should be kept on the wiki.
Once again, solvability has almost nothing to do with veracity. There are solvable models that are inaccurate, and there are unsolvable models that are accurate.

27
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 24, 2019, 04:00:25 PM »
There is no way to do it. The motions of the bodies are unpredictable.

From the above:

Quote
Such solutions do not exist because motions of the three bodies are in general unpredictable

Look up chaos theory, which directly spawned from attempts to solve the three body problem. Neither an analytical solution or a numerical solution can solve chaos theory.
It's not a numerical solution, it's an approximation. It has a known error bound. Nobody ever called it a "solution".

28
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 24, 2019, 03:18:20 PM »
The position of the article is entirely contradictory to what you, the OP, and QED are "skim-reading".
Huh? I was just opposing your point that the paper set all the masses to the same value.

29
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 24, 2019, 02:54:16 PM »
You think that an equation would only have one mass referenced to describe three bodies?

Separate masses != All masses are the different

I would recommend that you guys do more than a "skim-reading".
If the masses were assumed to be the same, then the paper would use a single variable for mass instead of 3 variables.

And this is still besides my main point (in the OP) that a model doesn't need to be solvable to be accurate.

30
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 24, 2019, 02:39:32 PM »
Very funny. First you admit to only a cursory glance at the articles, as it only took you '15 minutes' to find them, and now you claim to have read them and that it's abstractly 'in the equations' and never stated anywhere,
Here's an equation from the paper showing that they have separate masses. This took me less than a minute of skim-reading.

31
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 23, 2019, 11:51:02 PM »
The "Euler method" is shown in the article:
Then why were you claiming that we didn't know how to simulate it?

I don't see a simulation of the heliocentric sun-earth-moon system. Do you?
Universe Sandbox is mentioned in the article.

The restricted three body problem also assumes that one of the bodies, the moon in this case, is massless. That's the best they can do.
Is that restriction necessary for an approximation though?

Quote
Also, the simulation in the image doesn't use the orbit that the Moon has.

Do you think that they were trying to simulate an incorrect model of the moon's orbit?
Funny thing, I looked up the orbit listed on the image, and it turns out it's not even an orbit for the Moon at all.

32
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 23, 2019, 11:06:48 PM »
The "Euler method" is shown in the article:
Then why were you claiming that we didn't know how to simulate it?

Also, the simulation in the image doesn't use the orbit that the Moon has.

33
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 23, 2019, 10:27:48 PM »
If the three body problem is unsolved then there is no working model. The idea that it "might" be solvable doesn't mean that there is a working model. There likely are no good solutions, since they have been searching for a way to simulate it for 400 years. The few available solutions and scenarios are extremely sensitive look nothing like heliocentric astronomy.
We haven't been searching for a simulation method for 4 centuries, we knew how to the whole time.

34
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 23, 2019, 10:07:40 PM »
If no one has solved it, it means that they don't have a working model.
You're quite obviously conflating terms.

This is an example of a model (actually, most are second order, but this one is first order):



To solve this model means to find the set of functions that comprise solutions for any initial conditions, like so:



A working model means that the differential equation matches observations.

35
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 23, 2019, 09:37:46 PM »
Quote from: 9 out of 10 doctors agree
Quote
Now add a third body, and everything falls apart. The problem goes from one that a smart undergraduate can tackle to one that has defied solution for 400 years.

An unsolvable differential equation can still describe reality. Is there a point to the quote?

"An unsolvable differential equation can still describe reality"

An interesting string of sentences, but I don't really see anything to discuss on the matter. Is there an argument somewhere? If you want to know what the three body problem is and its goals then I would suggest you do some research on the matter.
Well, the argument seemed to be that since nobody has solved it, it can't be a working model. Which is wrong.

36
Flat Earth Theory / Re: The three-body problem wiki article
« on: April 23, 2019, 09:10:02 PM »
No one has solved the three body problems of astronomy.

"It actually simulates the Sun-Earth-Moon system quite well" is not evidence, or an argument. Your opinion is not an argument.

The Three Body Problem remains unsolved. See: https://wiki.tfes.org/Three_Body_Problem
Tell me, what do you think "solve" means in this context? Hint: it has nothing to do with testing the equations against reality.

37
Flat Earth Theory / The three-body problem wiki article
« on: April 23, 2019, 08:53:43 PM »
This is altogether a terrible article. Here's a breakdown of everything it gets wrong:

Quote from: wiki
which has its roots in the unsuccessful attempts to simulate a heliocentric Sun-Earth-Moon system.
The model isn't wrong—in fact, it actually simulates the Sun/Earth/Moon system quite well.

Quote from: wiki
Due to the nature of Newtonian Gravity, a three body system inherently prefers to be a two body orbit and will attempt to kick out the smallest body from the system—often causing the system to be destroyed altogether.
The keyword there is attempt—it's not guaranteed to break the system. The Earth and Moon have far more binding energy than can be supplied by tidal forces from the Sun.

Quote from: wiki
There are a limited range of scenarios in which three body orbits may exist. It is seen that those configurations require at least two of the three bodies to be of the same mass, can only exist with specific magnitudes in specific and sensitive configurations, … The slightest imperfection, such as with bodies of different masses, or the effect of a gravitational influence external to the system, causes a chain reaction of random chaos which compels the entire system to fall apart
The differential equation has unstable equilibria. Shocker.

Quote from: wiki
"Describing the motion of any planetary system (including purely imaginary ones that exist only on paper) is the subject of a branch of mathematics called celestial mechanics. Its problems are extremely difficult and have eluded the greatest mathematicians in history." — Paul Trow, Chaos and the Solar System (Archive)
Eluded the mathematicians, but not the physicists.

Quote from: wiki
Now add a third body, and everything falls apart. The problem goes from one that a smart undergraduate can tackle to one that has defied solution for 400 years.
An unsolvable differential equation can still describe reality. Is there a point to the quote?

Sections 2-3
The important thing to remember is that, for a long time—maybe a billion or two years—the solar system was unstable. If a body had a close encounter with a much larger mass, it had 3 possible outcomes: colliding with the larger mass, deflection into a more eccentric orbit, and acceleration into a larger orbit. Eventually most bodies either hit a planet, get too much eccentricity and falls into the Sun, or get ejected into the Kuiper Belt, resulting in the modern set of planets in orbits too far apart for any close encounters.

Also, minor gravitational interactions between planets are observed as slight orbital changes over decades or centuries. Even if a planet had enough energy to eject an adjacent planet (I haven't done the math yet but I doubt it), it would take hundreds of millions of years or more for perturbations to lead to encounters.

Quote from: wiki
The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits).
Again conflating unsolvable equations with bad models.

Quote from: wiki
This is precisely the issue of modeling the Heliocentric System, and why its fundamental system cannot exist.
This issue relies on the assumption that there are no setups that can last long periods of time without being the equal-mass solution that I've already dismissed as irrelevant.

Quote from: wiki
Programming students participated in the New Mexico Supercomputing Challenge to simulate the solar system and found issues with creating basic orbits:

Simulation of Planetary Bodies in the Universe (N-Body) (Archive) (Source Code)
I recognize that algorithm, having used it myself. One thing I can say is: this algorithm leaves out a key invariant, and that can cause instability in close encounters between objects, or even just over time.

Quote from: wiki
It has often been claimed that this simulation provides evidence that the Sun-Earth-Moon System and the Solar System are able to be simulated with Newtonian Gravity.
Universe Sandbox doesn't use Newtonian gravity. It uses general relativity.

Kidding. While it isn't technically using the Newtonian model, it's close enough at the scale of the solar system that it might as well be. Anyway, the quoted passage goes into how the simulation uses a set of 2-body problems between bodies and their main attractors. The bolded phrases seem to be cherrypicked to indicate that the simulation uses this alternative model because using the normal model would reveal the inherent instability of an incorrect system. This is entirely wrong, it's a problem of time complexity.


In conclusion:
Every part of this article is either wrong or irrelevant, and it should be deleted.

38
Flat Earth Theory / Doppler shift in stars
« on: April 22, 2019, 08:56:27 PM »
The search for exoplanets, whether you believe in them or not, uses measurements of Doppler shift (spectral lines moving) to precisely measure the radial velocity of stars. For example, I found this data for 51 Pegasi:



The line connecting them is a sinusoid model for it. I can integrate that model to get a function for how far away the star is at any given time:



If I plug the function stats in the graph into the antiderivative, I get a range of 6.5 million meters, equivalent to about sixty degrees of latitude along a meridian. This would obviously mean huge movement in the sky that isn't observed.

Quote from: Counterclaim
What if stars just normally got hotter and colder periodically? Wouldn't that shift their spectra and create the appearance of radial motion?
Sure, but it wouldn't change the spectral lines—specific wavelengths that are observed in smaller portions because they're absorbed by the atmosphere of the star.

Quote from: Counterclaim
Why can't the spectral lines also change?
Because they're determined by chemical properties, and as such only change when there's a chemical change. This also means that they can never continuously move; they can appear or disappear, but not shift.

39
Flat Earth Projects / Better explanation for FAQ on UA/speed of light
« on: February 05, 2019, 08:13:35 PM »
The FAQ in the wiki has the following reasoning for why the Earth will not exceed the speed of light:

Quote
Due to special relativity, this is not the case. At this point, many readers will question the validity of any answer which uses advanced, intimidating-sounding physics terms to explain a position. However, it is true. The relevant equation is v/c = tanh (at/c). One will find that in this equation, tanh(at/c) can never exceed or equal 1. This means that velocity can never reach the speed of light, regardless of how long one accelerates for and the rate of the acceleration.

While the science used here is correct, it seems like someone reading it would still have trouble grasping the argument, or why it works this way. So I wonder if we could change it to something more like this:

Quote
Unfortunately, that's only half of the truth. You're probably thinking of an object that accelerates at a constant rate, then abruptly stops accelerating when it reaches the speed of light. The problem with this idea is that it violates relativity. The real reason that we say that the speed of light can't be exceeded comes from the Lorentz factor, calculated as (1-v2/c2)-1/2. This factor is used in special relativity for many different purposes, but most notably for time dilation. Essentially, while a moving object feels the same force regardless of speed due to the principle of relativity, the rest frame will see it accelerate progressively less and less according to the Lorentz factor. Since it approaches infinity as the object approaches the speed of light, that speed is never exceeded to the rest frame.

40
Flat Earth Theory / Re: Production of solar panels near sunset
« on: January 07, 2019, 10:58:36 PM »
During sunrise and sunset I can look at the sun. I always thought that this is because the sunlight has to go to much more air to hit my eyes regardless of the shape of the earth.
Weird, I've only found that possible when there's smoke (usually from far-away wildfires) on the horizon.

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