101

Flat Earth Theory / Re: About the conspiracy

« on: April 05, 2021, 07:33:28 PM »

The sub-atomic particles aren't going to use fudges of the laws or approximations to form atoms and molecules. If it can't be done based on a full simulation with the underlying laws then it can't be done.

That's right. Particle physics also has trouble simulating things with multi-body problems. You are arguing that because they can't simulate it that its theories must be nonetheless true. That does not follow at all. Since they can't simulate it or get it to work based on the underlying laws it means that the theories lean towards being false.

Does that same logic apply to your inability to account for the "Bishop's Constant".  (I have a hard time even typing that with a straight face)  You can't get it to work...so it must be false. 

Or how about all of UA?  You can't explain it based on the current underlying laws of physics...so it must be false.

102

Flat Earth Theory / Re: Is there anything that RET cannot explain?

« on: April 05, 2021, 06:12:14 PM »

Wrong. It clearly says that he is referring to both Newton and Einstein in the above quote.

Of course, GR assumes the equivalence of the gravitational and inertial mass.  That principle is the foundation of the whole theory.  But saying that GR assumes that is not the same thing as saying that GR doesn’t justify that assumption.  And since the whole book is about classical mechanics, there would be no reason for the author to explain that. 

Incorrect. That author does not say that the equivalency is not a coincidence. What you quoted merely says that Einstein proposed the equivalency.

What do you think “incorporates in a natural way” means?  By proposing that gravity should no longer be regarded as  “force”, removes the distinction between gravitational and inertial mass. It’s called drawing a logical conclusion.   But you know what they say...there are two kinds of people in the world.  Those that can draw a logical conclusion.

It is astonishing that it should be that way, yes.

And solving that astonishing fact was Einstein’s motivation (at least one of them) to develop GR.  Which he did.  The fact that you don’t realize that only exposes how superficial your understanding of the theory is.

You aren't a physicist, either. Your opinion is also of little value in comparison.

It isn’t  my opinion that a non-force can’t effect the motion of mass, it’s pretty much the foundational principle of all known physics.  Are you suggesting that a non-force can effect the motion of mass or are you suggesting that gravity is a force?

My explanation as to why GR solves the mystery  is of course very simplified.  If you want a further understanding you might try reading “The Evolution of Physics”, and get the full explanation directly from the person who developed the explanation, Einstein himself. (Only of course, if you consider him a reliable authority on his own theory.).

The whole book is basically an explanation as to why the equality of gravitational and inertial mass is not a coincidence in GR.   It is very reader friendly and targeted to the general public. 

In our world it happens that they are equal, but we can well imagine that this should not have been the case at all. Another question arises immediately: is this identity of the two kinds of mass purely accidental, or does it have a deeper significance? The answer, from the point of view o f classical physics, is: the identity of the two masses is accidental and no deeper significance should be attached to it. The answer of modern physics is just the opposite: the identity of the two masses is fundamental and forms a new and essential clue leading to a more profound understanding.  This was, in fact, one of the most important clues from which the so-called general theory of relativity was developed.

 A mystery story seems inferior if it explains strange events as accidents. It is certainly more satisfying to
have the story follow a rational pattern. In exactly the same way a theory which offers an explanation for the identity of gravitational and inertial mass is superior to one which interprets their identity as accidental, provided, of course, that the two theories are equally consistent with observed facts. p.36

The theory attacks the problem o f gravitation and formulates new structure laws for the gravitational field. It forces us to analyse the role played by geometry in the description o f the physical world. It regards the fact that gravitational and inertial mass are equal, as essential and not merely accidental, as in classical mechanics. (p.260)

Or try “Relativity: The Special and General Theory”.  Also, written for the general public, it is the closest thing Einstein wrote to a textbook on GR.

 

Guided by this example, we see that our extension of the principle of relativity implies the necessity of the law of the equality of inertial and gravitational mass. Thus we have obtained a physical interpretation of this law.p. 80

The theory of gravitation derived in this way from the general postulate of relativity excels not only in its beauty; nor in removing the defect attaching to classical mechanics which was brought to light in Section XXI; nor in interpreting the empirical law of the equality of inertial and gravitational mass; but it has also already explained a result of observation in astronomy, against which classical mechanics is powerless. p. 121

We then have the following law: The gravitational mass of a body is equal to its inertial mass. It is true that this important law had hitherto been recorded in mechanics, but it had not been interpreted. A satisfactory interpretation can be obtained only if we recognise the following fact: The same quality of a body manifests itself according to circumstances as “inertia” or as “weight” (lit. “heaviness”).  In the following section we shall show to what extent this is actually the case, and how this question is connected with the general postulate of relativity. p. 77

This guy, I think states it most succinctly.

In classical physics, it’s not clear why (passive) gravitational and inertial mass should be the same. In Einstein’s theory of gravity, general relativity, the situation is different. There, the reaction of small bodies to gravitational attraction is purely geometrical: Massive bodies will distort space and time, and moving bodies follow the straightest paths possible in such a distorted spacetime. The artificial distinction connected with the concept of a force – inertial mass on the one hand, gravitational mass on the other – is replaced by a law that has the equality of all bodies built-in at the lowest level: That, in a given situation, all bodies experience the same gravitational acceleration is due to the fact that their motion is directly governed by the properties of their spacetime environment; the object’s intrinsic properties play no role at all.

https://www.einstein-online.info/en/spotlight/inertial-and-gravitational-mass/

Frankly I don’t understand your resistance to the concept.  It fits right into UA.  In UA, there is no distinction between gravitational and inertial mass either.

As previously stated, a historian can be quoted on a point about physics, but if a physicist disagrees with him, that opinion is of little value. A historian isn't as credible as a physicist, sorry.

That doesn’t answer the question.  If you were of the opinion that physicists disagreed with him (which you should have been if you read and understood the paper) why did you quote him? Or did you quote him knowing that he fundamentally disagreed with your premise? To be clear, your choices here are "I didn't realize he disagreed" or "I realized he disagreed and cited him anyway".

EDIT: There is of course a third choice. "Physicists agree with him."

If you think his opinion is garbage, then you should remove the citation.  It leaves the impression that he agrees with your premise, which he doesn’t. And we all know you don’t want to be deceptive.

103

Flat Earth Theory / Re: Is there anything that RET cannot explain?

« on: April 04, 2021, 08:14:08 AM »

However, if a physicist disagrees with him, the historian's opinion is pretty much garbage. He simply doesn't have the required credentials to rebut a physicist, no matter how many times anyone calls him an 'expert'.

Now, when you have a qualified source for us on this, do let us know.

Physicists don’t disagree with him, not even the ones you quote. Is another one of your own sources qualified enough for you?

The guy who said “There is no a-priori reason why the quantity that determines the magnitude of the gravitational force on the particle should equal the quantity that determines the particle’s resistance to an an applied force in general”, also said, in the very same book you quote

“These observations led Einstein to make a profound proposal that simultaneously provides for a relativistic description of gravity and incorporates in a natural way the equivalence principle and consequently the equivalence of gravitational and inertial mass. Einstein’s proposal was that gravity should no longer be regarded as a force in the conventional sense but rather as a manifestation of the curvature of the spacetime”

Do you need to discredit him also now?

The book you quote by Ryan Martin is about Classical Physics so it is no surprise that he would describe the equivalence of inertial and gravitational mass as a coincidence.  In classical physics, it is.

If you read Einstein’s quote that Nigel Calder references, you’ll find that Einstein goes on to explain the “astonishing fact” of the equivalence of inertial and gravitational force.

You obviously didn’t even read the whole context of anything you quoted. Just cherry picked quotes you thought would support your point and not a single one of them does.  If John Norton is so unreliable why did you quote him?  You obviously had no idea who he is or what his credentials are, but he sounded good and that’s good enough for you.

You now have to resort to discrediting one of your own sources because you either can’t be bothered to actually read them or are incapable of understanding that he was contradicting the very point you were trying to make. It doesn’t matter if Norton is right or wrong, the smartest person in the world or a lunatic. You quoted him without the slightest idea of what he was talking about and completely missed the larger point I was making, which is your “wiki”, at least on this point, is the poorest excuse for “research” or “scholarship” I have ever seen.

Since you can’t be bothered with actually doing your own research, I’ll explain to you exactly why GR solves the great mystery. In GR, gravity is not a force, if gravity is not a force, then it can’t effect mass. A non-force can’t act on mass and mass can’t resist a non-force. The distinction between gravitational and inertial mass is a false one. They are the same thing...just “mass” whose behavior that we perceive as gravitational effects is determined by the spacetime curvature. 

When you see the term gravitational mass in the context of GR, it is referring to active gravitational mass, which is mass that gives rise to the gravitational field...which according to FE doesn't exist.

In General Relativity and in other geometric theories of gravity, the gravitational mass must always be taken to be the active gravitational mass, because in such theories there is no passive gravitational mass. A body in a gravitational field moves in response to the curved spacetime geometry, not in response to an impressed gravitational force; thus, the mass of the body is not a receptor of gravitational force, and passive mass is a meaningless concept—it is merely an artifact of the Newtonian approximation

https://arxiv.org/ftp/arxiv/papers/1010/1010.5557.pdf

Hans Ohanian studied physics at Berkeley and at Princeton, where he worked on relativity with John A. Wheeler.  He taught at Rensselaer Polytechnic Institute, Union College, the University of Rome, and the University of Vermont. He's written several physics textbooks and dozens of articles dealing with relativity, gravitation, and quantum theory, including numerous articles on fundamental physics published in the American Journal of Physics, where he served as associate editor for several years

Is he enough of a physicist for you?

104

Flat Earth Theory / Re: About the conspiracy

« on: April 03, 2021, 02:04:52 AM »

they would be "in orbit", and the weightlessness of UA must be identical to that perceived in the RET gravitational model (otherwise, the base principles under which RET operates break down, and you have a much bigger problem on your hands).

The problem is since the effects of UA are identical to gravity, how could weightlessness be achieved in a UA environment? 

There would have to be a way of neutralizing or cancelling out the effects of UA for the persons who are in orbit.

105

Flat Earth Theory / Re: About the conspiracy

« on: April 02, 2021, 01:24:53 AM »

Wow.  Right back where we started.  Mutually exclusive, no.  Your second statement is abjectly false.  Acceleration has nothing to do with whether one feels weightlessness or not.  It's all right there in the vomit comet.  You have weightlessness during deceleration, 0 acceleration, and acceleration all in the same pass

I've lost track of who is arguing what, but I don't think you guys really disagree. You're both just being a bit sloppy with your terms, especially "acceleration" and "free fall"

Acceleration is a change in an objects speed and/or direction.  Weightlessness is the result of free fall.  An object is in free fall when the only force acting on it is gravity. (or no force at all in relativity, since gravity is not considered a force).  Although an object in orbit changes direction and technically could be considered "accelerating", that "acceleration" is due only to the force of gravity, therefore it is considered in free fall.

An object that is truly accelerating cannot be weightless because changes in direction and/or speed require  a force other than gravity be applied because Newton's First Law. An object subject only to gravity will move at a constant speed and in a straight line unless acted upon by another  force.

Anyway, back to the question that started the whole discussion.  A person in a spacecraft will not feel weightless unless the space craft is in freefall.  If the flat earth is accelerating at 9.81m/s, the space craft must somehow be  accelerating along with it in order to "keep up" and maintain visual contact with the earth.  Any person in the spacecraft would have to accelerating along with the spacecraft, will not be in free fall and therefore cannot experience weightlessness.

Really, that's just another way of explaining the equivalence principle...acceleration and gravity produce identical effects.

106

Flat Earth Theory / Re: About the conspiracy

« on: April 01, 2021, 12:21:52 PM »

The same way anyone else perceives weightlessness, even when they are not truly in space.

That would violate the equivalence principle.  According to it, if you are accelerating upwards at a rate equal to gravity, away from any gravitational force, then it would feel like you are under the influence of gravity.

107

Flat Earth Theory / Re: Is there anything that RET cannot explain?

« on: March 30, 2021, 02:03:40 PM »

Physicist > Someone with a history and philosophy degree

And what shape do physicists think the earth is?
Your "appeal to authority" thing is very selective, you cherry pick bits and pieces from people you regard as authorities when you think their (often out of context) comments back up your beliefs.
But you reject their thoughts on gravity being a thing or the shape of the earth.

The level of cherry picking and hypocrisy is mind blowing.

Not only does he use an introductory quote from a paper written by someone he claims “doesn’t understand the physics” to support his position, the whole purpose of the paper he quotes is to contradict the very position he uses it to support.  If he’d actually read the whole paper without cherry picking, he would see that the whole paper is Norton (using the physics he doesn’t understand) explaining how and why Einstein ultimately “solved” the “coincidence” of the equality of inertial and gravitational mass...and that is the whole purpose of the paper.

Einstein's principle of equivalence asserted that the properties of space that manifest themselves in inertial effects are really the properties of a field structure in space: moreover this same structure also governs gravitational effects. As a result, the privileged inertial states of motion defined by inertial eff ects are not properties of space but of this structure and the various possible dispositions of inertial motions in space are determined completely by it. Space of itself is to be expected to designate no states of motion as privileged Einstein's principle of Equivalence 41 This principle guided Einstein to seek his general theory of relativity as a gravitation theory of which special relativity was a special case. There the principle found precise theoretical expression. The structure responsible for inertial and gravitational effects is the metric tensor. The space-time manifold itself has no properties that would enable us to designate the motion associated with any given world line as privileged, that is as \inertial" or \unaccelerated." This designation depends entirely on the metric and the and structure for space-time that it determines.

To claim that the equivalence of gravitational and inertial mass is considered a coincidence in GR shows a basic lack of understanding of it.  The solution to the coincidence, the existence of the gravitational-inertial field, is the very heart of GR.  Without solving that coincidence, there is no GR.

Moreover, the same paper he cites to support using the EP as evidence of UA, explicitly contradicts that it can be used to support UA, using Einstein’s own words.

He explained this to a correspondent in a letter of July 12, 1953, reminding him that the principle could not be used to generate arbitrary gravitational fields by acceleration:

The equivalence principle does not assert that every gravitational field (e.g., the one associated with the Earth) can be produced by acceleration of the coordinate system. It only asserts that the qualities of physical space, as they present themselves from an accelerated coordinate system, represent a special case of the gravitational field. It is the same in the case of the rotation of the coordinate system: there is de facto no reason to trace centrifugal effects back to a `real' rotation.19

Cognitive dissonance is a powerful thing.

108

Flat Earth Theory / Re: Is there anything that RET cannot explain?

« on: March 30, 2021, 03:35:10 AM »

He's not a physicist. He's a historian and a philosopher. It doesn't matter if he writes about it. He doesn't know the physics as well as an expert in physics. I have quoted multiple physicists. Physicists would know physics to a better degree than a historian and a philosopher would.

I would suggest getting better qualified expert sources than that paltry attempt

.

Paltry??? John Norton is one of the most respected academics on Einstein in the world and is cited in literally thousands of scientific works.  You obviously don't understand what "philosophy of science" means or the significance of the fact that he undertook the analysis of Einstein's Zurich notebook.  If you don't think that required an understanding of the physics involved...well, let's just say I am not surprised.

Telling a story is different than knowing the physics.

Philosophy of Science is "telling the story of the physics".  You can't tell the story of how Einstein came up with GR without understanding the physics.


Here's a few excerpts from his analysis.

Suddenly, without any warning of the transition, we find the basic notion of general relativity, the "line element" written at the top of the page.
line element
The coefficients Gμν enable us to compute the spatio-temporal interval ds between events separated by infinitesimal coordinate differences dxμ. If these coefficients assign spatio-temporal intervals that do not conform to a flat geometry, then we have captured the full range of gravitational effects in the manner of Einstein's general theory.

This is quite possibly the first time Einstein has written down this expression. The coefficients Gμν of what we now know as the "metric tensor" are written with an upper case G. Einstein shifted within a few pages to the lower case g, which remained his standard notation from then on.

The big project is to find how this quantity gμν, the metric tensor, is generated by source masses. These are the "gravitational field equations." That is this theory's analog of Newton's inverse square law of gravity. The lower half of the page is clearly making rudimentary efforts in that direction. There Einstein chooses a "Spezialfall" -- a special case -- in which the coefficients of the metric tensor revert to the values of special relativity, excepting G44 = c2. Einstein then tries to apply the gravitational field equation from his 1912 theory of static gravitational fields.

Einstein's analysis continues at this simple level on the facing page.There he asks beginner's questions. He looks at the coordinate divergence of the metric tensor and asks "Ist dies invariant?"-- "Is this invariant?" As the computation that follows immediately shows, it is not.

On this page Einstein sets up the equations for conservation of energy and momentum for continuous matter in general relativity. He starts with the equation of motion for a point mass--the geodesic equation--but now written in the form of an Euler-Lagrange equation:
5R snip1
He then applies this to a cloud of non-interacting dust particles in free fall to arrive at what we now recognize to be the condition of the vanishing of the covariant divergence of the stress energy tensor Tμν.
5R snip
However there is good evidence that Einstein's knowledge of tensor calculus is still limited. He does not know or is not sure that the operator acting on Tμν in this equation is a generally covariant operator. To check the operator, he replaces Tμν by the tensor gμν and sees whether the result is zero or a four vector ("0 oder Vierervektor"), as it should be if the operator is generally covariant. It proves to be zero and Einstein is satisfied. He writes "Stimmt"--"Correct".

http://www.pitt.edu/~jdnorton/Goodies/Zurich_Notebook/index.html

He literally goes through Einstein's private calculations on GR and explains them page by page, line by line and calculation by calculation. And this is just an informal commentary on his website. The actual textbook he wrote is introduced by

The notes documenting Einstein’s search for field equations for this theory take up the better part of the notebook. They start on pp. 39L–41R and continue on pp. 5R–29L and pp. 42L–43L. Our text is a detailed running commentary on these notes. 2 It provides line-by-line reconstructions of all calculations and discusses the purpose behind them.

Yeah, that's a guy who doesn't understand physics. 

Logunov rejected GR in favor of his own theory of gravitation...which has its own explanation as to why inertial mass and gravitational mass are equivalent.  So take your pick on either theory.  Either way, its not a mystery or a coincidence.

109

Flat Earth Theory / Re: Is there anything that RET cannot explain?

« on: March 30, 2021, 12:59:41 AM »

My source who says that it's still a coincidence is a physicist - https://www.queensu.ca/physics/ryan-martin

Your source who says the opposite is someone with a history and philosophy degree - http://www.pitt.edu/~jdnorton/jdnorton.html#Bio

Physicist > Someone with a history and philosophy degree

LOL, John Norton's creds are good enough that you cite him on your own wiki, multiple times.  All taken out of context of course.  He is considered one of the world's leading academics on Einstein and worked on the Einstein Papers Project. 

John Norton, an internationally recognized expert in the science of Albert Einstein, has published extensively on Einstein’s discoveries of general relativity, special relativity and the light quantum and also on philosophical aspects of Einstein’s work. He has been a contributing editor to the publication of Einstein’s collected papers and serves on the publication project’s advisory board. His most notable achievement was the analysis of the “Zurich Notebook,” which contains private calculations made by Einstein in preparation for his greatest discovery, the general theory of relativity

.

You might want to familarize your self with his CV.

http://www.pitt.edu/~jdnorton/homepage/cv.html

or his wikipedia page

Norton is considered an authority on the science of Albert Einstein and the philosophy of science. He has published on general relativity, special relativity, the relationship between thermodynamics and information processing, quantum physics, and the genesis of scientific theories. He is well known for his analysis of Einstein's "Zurich Notebook," a small, brown notebook which contains Einstein's private day-to-day calculations during a critical period (1912–1913) in his development of general relativity.[4] The trio of Einstein scholars, John Norton, John Stachel, and John Earman, have sometimes been jokingly referred to as John3 = John Norton × John Stachel × John Earman.[5]

110

Flat Earth Theory / Re: Is there anything that RET cannot explain?

« on: March 30, 2021, 12:16:14 AM »

The equivalency of gravitational and inertial mass, as seen in laboratory experiment, is a coincidence, even in GR - https://wiki.tfes.org/Equivalence_Principle

Not true.

Finally Einstein's reinterpretation eradicates an awkwardness of Newtonian theory. That theory had to posit that increases in gravitational mass in bodies are perfectly and exactly compensated by corresponding increases in inertial mass, so that the uniqueness of free fall can be preserved. Einstein's redescription does away with that coincidence and even the very idea of distinct inertial and gravitational masses. In his theory, bodies now just have mass, or, in the light of special relativity, mass-energy. For Einstein the primitive notion is the geometrical structure of spacetime with the curved trajectories traced out by all freely falling bodies, independently of their mass.

https://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/general_relativity/

111

Flat Earth Theory / Re: Water is always level?

« on: November 14, 2020, 03:52:36 PM »

If you disagree, and believe that your definition is correct - then please provide a demonstration in reality of level and flat ever differing.

It happens all the time.  I live in an 110 year old  house.  Put a carpenter’s level on the floors, they will be flat, in that, both ends of the level will rest on the floor, but I guarantee you that many places aren’t level.

Flat is a description of the surface of an object. A planar surface is flat.  Level is about the orientation of an object relative to some reference.

112

Flat Earth Theory / Re: Water is always level?

« on: November 10, 2020, 07:22:28 PM »

Let's imagine I'm on a flat Earth cliff edge in space, with two boxes at my feet, one "on the ground" and one "over the edge", with no upwards acceleration at all.  I'm sure we both agree that in this scenario, this is equivalent to free-fall on Earth.

No, only the box “over the edge” is in freefall.  The box on the ground is not.  In GR, freefall means there is no net force on an object.  More technically, it means an object moves unimpeded along a geodesic.  If an object is supported, then there is a normal force on it, and it can’t move unimpeded on a geodesic.
 

We have to consider in our experiment is that a rolling object down an inclined plane is not in free-fall. The inclined plane exerts some force on the object. The larger the inclination of the plane, the smaller the force exerted by the plane, and the closer the object will be to free-fall

https://www.racefitlab.com/Experiment hgAAAA8AAAAgwxxeAAAAAA==#:~:text=We%20have%20to%20consider%20in,will%20be%20to%20free%2Dfall.

Perhaps I'm completely missing something really simple, but another analogy here on Earth could be a wooden ruler held at an incline with a pencil rubber on it.  At some angle it will still stay put due to friction.  However, if I were to suddenly be accelerated upwards holding the ruler (creating my own "local UA" if you like) that rubber would appear to slide down the ruler from my perspective.

 

The problem is that in order for it to appear that the rubber “slides down”, the ruler would have to move horizontally to some degree, and UA can’t account for horizontal movement, only vertical.

The way I visualize it is an object suspended from the ceiling by a string, just touching a wedge.  If you raise the wedge straight up (creating your own UA, as you say), the object won’t slide down (the string would counteract gravity).  It would just stay where it is and rise up with the wedge.  In order for it to appear to “slide down”, while actually remaining stationary, the wedge would have to move up and either to the left or right (depending on the direction of the angle on the wedge).

I think that is the major fault with the concept of UA=gravity.  The effect that gravity has on an object will shift and change as the position of the object changes.  I don’t think UA can do that.  It has to always be exactly vertical and effect the whole object with exactly the same magnitude.

Anyway, I don’t pretend to have it all figured out, but I do know that the knee jerk reaction of “...but the equivalence principle...” on this site whenever someone raises a question about the effect of gravity is not justified.  It only applies to free falling objects and we see too many effects of gravity that have nothing to do with freefall...from saggy body parts to how plants grow. 

I found this page and video interesting though, and it pretty much sums up FET in a nutshell - takes existing science and facts, extracts the bits that fit, warps the rest and skews the consequences accordingly.  It does kinda' make sense why on the bigger scale the Equivalence Principle doesn't work in the flat Earth model interpretation of it:

Exactly, they take the bits and pieces of a concept that fits their narrative and ignore the rest.  Einstein’s concept of the EP and GR went through several iterations before the final theory was developed.  One of the last (maybe even the last) definition of the EP he made is

Principle of Equivalence. Inertia and gravity are phenomena identical in nature. From this and from the special theory of relativity it follows necessarily that the symmetric “fundamental tensor” determines the metric properties of space, the inertial behavior of bodies in this space, as well as the gravitational effects.

Einstein didn’t say that from the equivalence of gravity and inertia, it necessarily follows that the earth is accelerating upwards.  But that's exactly what flatearthers want to pretend that is what he said.

113

Flat Earth Theory / Re: Water is always level?

« on: November 08, 2020, 06:16:37 PM »

Honestly, I know it’s hard to wrap your head around, but if the Earth were constantly accelerating upwards at 9.81 m/s^2, neglecting all the other complications/contradictions that the Wiki tries to explain, you wouldn’t be able to tell the difference between that, and the attractive force of gravity on Earth as we know it.  Things would rise and fall and behave exactly as they do now.

Things if free fall would rise and fall exactly the same.  The EP is restricted to objects that have no net force on them, you can't assume that it applies to objects that have net force.

Stuff moving sideways is all explained by the same forces and vectors which have a direction and magnitude.  On a horizontal surface the box wouldn’t move.  On a slight incline, the box may or many not move depending on how much friction there is, but let’s say it does move, albeit slowly.  The steeper the incline, the faster the box slides.  At vertical, the box is in free fall.  UA would account for this because it’s directly analogous to gravity on Earth pulling us down

Perfect example...you can't calculate vectors the same way with UA as you do with gravity. Any object on a slope has a net force on it.  On a flat surface the normal force and weight from gravity cancel each other out so there is no movement.  That works with UA as well.

But on an incline, the normal force will always be some fraction of the weight/gravity/UA, so the forces are unbalanced.  When force are unbalanced, there is movement in the direction of the stronger force.  With gravity that would be downslope.  With the UA, the object would "fall" upslope because UA is the stronger force.

114

Flat Earth Theory / Re: Water is always level?

« on: November 06, 2020, 05:43:51 PM »

However, if the Earth were accelerating and changing its velocity over time, the car is free to move relative to the track which is fixed to the Earth.  Riders strapped into the car at the top would now effectively roll downhill.

The car is not in free fall. It's movement is constrained by the track and can only move with the track. If the track accelerates, the car accelerates with it. We aren't physically fastened down to the surface of the earth, either, but apparently we accelerate along with the earth according to UA. Its perfectly possible to stand on a steep hill and not "fall down".  That wouldn't be possible if the ground beneath us was constantly accelerating and we were not moving.  No matter how subtle the slope, eventually we'd end up at the bottom.  Again, the equivalence principle doesn't apply when an object is supported in any way.

Also, roller coasters generally don't move exactly vertically .  If the hill is at anything less than a 90 degree angle, there is some horizontal movement that UA can't account for.  Think of a box on any 45 degree inclined plane...in order for the box to "appear" to slide down the plane, the plane would have to move horizontally.

Anyway, that's the way I see it.  Maybe a flatearther can chime in.  Gravity is so ingrained into our everyday experiences, it's hard to visualize how things would behave without it.

115

Flat Earth Theory / Re: Water is always level?

« on: November 06, 2020, 03:15:32 PM »

@fisherman, maybe my understanding of UA isn't correct, but doesn't the Equivalence Principle go something like as follows:

• In a rocket in space, not moving, I feel weightless.  The equivalent to being in freefall on Earth.
• In a rocket accelerating upwards, I feel weight.  The equivalent to standing on the surface of the Earth with gravity.

Neglecting wind resistance and other complexities of where the ground is, in the first example, if I had a glass of water and slowly tried to pour it out, it would pretty much just stay in the glass or at least stay relative to my position.  In the second example, the water would pour out onto the surface beneath me.  If Universal Acceleration is considered actual constant upwards acceleration of the Earth (much like the rocket) wouldn't water in a sloping pipe just flow as we expect anyway?

Your understanding of UA is the same as mine...won't necessarily say it is correct, though.  I'll let a FEr weigh in on that.

The important point that the FE explanation misses is that the equivalence principle only applies to objects in free fall. .

Water in a pipe isn't in free fall (because its movement is constrained by the pipe) unless or until to flows out of the end of the pipe.  But there has to be a force that moves it out of the end of the pipe to begin with. Assuming there is no water flowing in from the other end to push it out, if you slope the pipe and there is no gravity to pull the water out of the pipe, it won't go anywhere. No force, no movement.

UA and the EP is an elegant alternative to gravity for objects in free fall, but there are countless effects of gravity that don't involve free fall.  Your feet swell when you are on them all day because blood returning to your heart has to work against gravity. Gravity is partially responsible for why plant roots grow down, trees can only grow so high because rising sap has to work against gravity.

The clearest example I can think of is a rollercoaster.  They are usually gravity driven. Keep in mind, the coaster itself is not in free fall.  It is (hopefully) attached to the ground so it is rising with the surface of the earth and the riders in the cars are rising with it.  If the earth, the coaster and the riders are all rising together as one system, what happens after the chain pulls the riders to the top of the first hill if there is no force to pull the riders down? Nothing.  The whole system will just continue to rise together as the earth rises.

As the whole system rises, there is no relative change in the distance between the top of the hill and the bottom of the hill.  If the riders are at the top of the hill, there is no reason why the relative distance between the riders and the bottom of the hill should change unless there is a force acting on the riders that is not also acting on the rest of the system.

116

Flat Earth Theory / Re: Inquiries about Flat Earth theory of the firmament.

« on: November 06, 2020, 01:59:52 PM »

Or are you just agreeing with that fact?

Just agreeing.

117

Flat Earth Theory / Re: Inquiries about Flat Earth theory of the firmament.

« on: November 06, 2020, 01:43:11 PM »

Speaking of void, empty space...  You're right, gravity is relatively weak, but all it takes is any amount of gravity for something to be "held down".  The weaker the gravity, the thinner the atmosphere, and the lower the pressure gradient.  The further you get from the surface, the lower the pressure to the point where there are no longer any air molecules.  It's a simple concept.  I have to question your understanding of the basic gas law and the 2nd law of thermodynamics though, because you say there CAN'T be an infinite sky vacuum above our heads.  Can't be...why not?  I've asked this before - what do you think a vacuum is?  Do you think it's a suction force, where space acts like one giant vacuum cleaner which would suck the atmosphere away from our surface?  The only reason vacuum cleaners on Earth work as they do is because they create a pressure difference between the surface under the vacuum cleaner and the air around it.  Same with a drinking straw - you "suck" the air out of the straw, causing the pressure on the inside of the stray to be lower than outside.  The positive air pressure pushes down on the surface of the liquid, in turn pushing it up the straw.  The very notion of "suction" is a consequence of having gravity and an atmosphere, and is a pushing force

People often think that someone will get "sucked out" of an airplane if the door is opened, when in reality, they would get "pushed" out by the rush of air moving from the area of higher pressure to lower pressure. But there is only so much air in the cabin and eventually, the pressure will equalize.

A nice video from a balloon ascent was release not too long ago. Lots of beautiful images, but more importantly, equipped with live streaming of temperature and atmospheric pressure data during ascent and descent phases. The balloon reached an altitude of about 38 km, where it burst, as the pressure had dropped to 0.003 atm (getting real close to zero there - not much of a gradient compared to the ambient pressure within the rest of the 'vacuum's of space!

)

Same sort of thing happens with a regular balloon on the surface.  Poke a hole in one and it will fly around the room as the pressure of the balloon pushes the air out.  Once the pressure between the balloon and the air in the room stabilizes, it stops.

118

Flat Earth Theory / Re: Water is always level?

« on: November 06, 2020, 01:27:44 PM »

Under FET, gravity (caused by UA) also has a vector always pointing directly down towards the surface of the Earth.  In this model, my understanding is that neither the Sun or Moon have the property of gravity, so given that the Earth doesn't rotate either, as Iceman2020 says, UA alone clearly does not explain the mechanics.  I couldn't find anything in the Wiki here, or much elsewhere to be honest so I'd be interested to know what those mechanics are.

It isn't just tides that are a problem for FET/UA model, but the behavior of water in general on earth's surface.  Whatever the force is that keeps things "pinned down" on the surface in response to UA (inertia?), it isn't enough to keep water from flowing downhill.

There's a reason why plumbers install pipes on a downward slope.  Water in a level pipe doesn't flow.  But when it is on a slope, it begins to flow.  Movement requires force, which suggests there is a force at work when a pipe is on a slope that is not present when a pipe is level.  The Equivalence Principle wouldn't account for this because (among other reasons), it only applies to objects that are in free fall.

119

Flat Earth Theory / Re: Let's start with "Burden of Proof"

« on: November 04, 2020, 09:36:30 PM »

For pascals law, which we aren't really discussing - see below.

P=Dw*h (where Dw is ; Density, weight)

I hate to break it to you, but any formula that include weight, takes gravity into account as w=mg.

So exactly which law of hydrostatics are you referring to when you say that water can't curve?

120

Flat Earth Theory / Re: Water is always level?

« on: November 04, 2020, 08:54:44 PM »

Flat is synonymous with straight
Level is synonymous with horizontal

Jack44556677 is 100% correct in this regard.  Something is considered level when it is either normal to a flat surface, or tangent to a curved surface.  Level definitely does not necessarily mean flat:

I 100% agree with that.  My point is that a static fluid cannot have shearing forces. So any force effecting the surface of water must be horizontal to it.  On a globe earth, gravity effecting the surface of water would follow a curve, so the water must also curve to remain horizontal to gravity.