[Gulliver]

I thought it'd be enlightening to critique EnaG a part at a time. I'll try to critique a paragraph or several (up to a page), roughly in order, each day or so.

IF a ball is allowed to drop from the mast-head of a ship at rest, it will strike the deck at the foot of the mast. If the same experiment is tried with a ship in motion, the same result will follow; because, in the latter case, the ball is acted upon simultaneously by two forces at right angles to each other--one, the momentum given to it by the moving ship in the direction of its own motion; and the other, the force of gravity, the direction of which is at right angles to that of the momentum. The ball being acted upon by the two forces together, will not go in the direction of either, but will take a diagonal course, as shown in the following diagram, fig. 46.

This page fails quickly. Momentum is not a force. There is only one force acting on the falling ball. It's caused by gravity. Furthermore, R. forgets to specify vital assumptions. For example. he assumes that the ship's velocity is constant. And there's yet another level of error in this one paragraph. The observer's position (and motion) influences what path he (or she) perceives the ball takes. So this first page is riddled with errors. One has to start to wonder why FEers refer to this book at all.

[Tom Bishop]

This page fails quickly. Momentum is not a force. There is only one force acting on the falling ball. It's caused by gravity.

Was momentum often spoken of as a force as the typical lexicon in the 1800's? Newton spoke of momentum as a force.

Furthermore, R. forgets to specify vital assumptions. For example. he assumes that the ship's velocity is constant.

Why can't he assume the ship is traveling constantly in his own thought experiment? 

And there's yet another level of error in this one paragraph. The observer's position (and motion) influences what path he (or she) perceives the ball takes.

Rowbotham is talking about a moving ship, and provides illustrations from an observer looking at it from the outside. The implications of what was meant is clear.

Next time please try to make your threads more interesting.

[Gulliver]

Newton spoke of momentum as a force.

Please provide objective, verifiable evidence of this outlandish claim.

ETA: Even if Newton made the same mistake, it's still a mistake invalidating this entire chapter. Are you really sure about referencing EnaG as accurate?

[Gulliver]

Furthermore, R. forgets to specify vital assumptions. For example. he assumes that the ship's velocity is constant.

Why can't he assume the ship is traveling constantly in his own thought experiment? 

You're not paying attention. I've said nothing about R's inability to make assumption.

[Gulliver]

And there's yet another level of error in this one paragraph. The observer's position (and motion) influences what path he (or she) perceives the ball takes.

Rowbotham is talking about a moving ship, and provides illustrations from an observer looking at it from the outside. The implications of what was meant is clear.

Next time please try to make your threads more interesting.

How can you tell the position, motion, and acceleration of the observer? Surely a good scientist would provide those details as they influence his experiment.

[Gulliver]

The ball passing from A to C, by the force of gravity, and having, at the moment of its liberation, received a momentum . from the moving ship in the direction A, B, will, by the conjoint action of the two forces A, B, and A, C, take the direction A, D, falling at D, just as it would have fallen at C, had the vessel remained at rest.

It is argued by those who hold that the earth is a revolving globe, that if a ball is dropped from the mouth of a deep mine, it reaches the bottom in an apparently vertical direction, the same as it would if the earth were motionless. In the same way, and from the same cause, it is said that a ball allowed to drop from the top of a tower, will fall at the base. Admitting the fact that a ball dropped down a mine, or let fall from a high tower, reaches the bottom in a direction parallel to the side of either, it does not follow therefrom that the earth moves. It only follows that the earth might move, and yet allow of such a result. It is certain that such a result would occur on a stationary earth; and it is mathematically demonstrable that it would also occur on a revolving earth; but the question of motion or non-motion--of which is the fact it does not decide. It gives no proof that the ball falls in a vertical or in a diagonal direction. Hence, it is logically valueless. We must begin the enquiry with an experiment which does not involve a supposition or an ambiguity, but which will decide whether motion does actually or actually does not exist. It is certain, then, that the path of a ball, dropped from the mast-head of a stationary ship will be vertical.

No. the ball does not receive its momentum from the ship, or at the moment of its liberation. The ball has its horizontal momentum when it "went on board".

Since the ball, the top of the mine (or tower), and the bottom of the tower all are traveling horizontally at the same velocity (Technically the top of a one-mile-high tower travels 0.00000160868 mph faster) RET agrees with reality.

Finally, R. makes his all-too-typical error in reasoning. If he can't find evidence of RET, especially failing to do the math involved, RET must be false. Failing to find evidence to support a thesis does not disprove the thesis.

With yet another page destroyed with such little effort and demonstrating R.'s failure to reason, I increasingly have to wonder why FEers reference this text.

[Rama Set]

Failing to find evidence to support a thesis does not disprove the thesis.

This is not always true. A null result is what effectively disproved the luminiferous ether hypothesis.

[Gulliver]

Failing to find evidence to support a thesis does not disprove the thesis.

This is not always true. A null result is what effectively disproved the luminiferous ether hypothesis.

You're half right. If a theory makes a prediction and an experiment can measure whether it does or not, then a theory may be disproved by running that experiment. M&M did a great job of accounting for all the possibilities, such as seasonal and dragging. R. doesn't show that his experiment fits that category. He fails.

Confer: http://www.statisticalmisconceptions.com/sample2.html

[Gulliver]

It is also certain that, dropped down a deep mine, or from the top of a high tower, upon a stationary earth, it would be vertical. It is equally certain that, dropped from the mast-head of a moving ship, it would be diagonal; so also upon a moving earth it would be diagonal. And as a matter of necessity, that which follows in one case would follow in every other case, if, in each, the conditions were the same. Now let the experiment shown in fig. 46 be modified in the following way:--

Let the ball be thrown upwards from the mast-head of a stationary ship, and it will fall back to the mast-head, and pass downwards to the foot of the mast. The same result would follow if the ball were thrown upwards from the mouth of a mine, or the top of a tower, on a stationary earth. Now put the ship in motion, and let the ball be thrown upwards. It will, as in the first instance, partake of the two motions--the upward or vertical, A, C, and the horizontal, A, B, as shown in fig. 47; but because the two motions act conjointly, the ball will take the diagonal direction, A, D. By the time the ball has arrived at

No, a ball dropped from the masthead of a uniformly moving ship would NOT move on the diagonal, but in an arc prescribed by gravity's acceleration on the ball Through this page, R. fails to understand the difference between acceleration and uniform motion. Furthermore, R. fails to separate instantaneous acceleration, as in throwing the ball and constant acceleration when dropping a ball. So...no diagonal paths here, but plenty of R. failure.

Why do FEers revere this book?

[Gulliver]

By the time the ball has arrived at D, the ship will have reached the position, 13; and now, as the two forces will have been expended, the ball will begin to fall, by the force of gravity alone, in the vertical direction, D, B, H; but during its fall towards H, the ship will have passed on to the position S, leaving the ball at H, a given distance behind it.

The same result will be observed on throwing a ball upwards from a railway carriage, when in rapid motion, as shown in the following diagram, fig. 48. While the carriage or tender passes

from A to B, the ball thrown upwards, from A towards (2, will reach the position D; but during the time of its fall from D to B, the carriage will have advanced to S, leaving the ball behind at B, as in the case of the ship in the last experiment.

The same phenomenon would be observed in a circus, during the performance of a juggler on horseback, were it not that the balls employed are thrown more or less forward, according to the rapidity of the horse's motion. The juggler standing in the ring, on the solid ground, throws his balls as vertically as he can, and they return to his hand; but when on the back of a rapidly-moving horse, he should throw the balls vertically, before they fell back to his hands, the horse would have taken him in advance, and the whole would drop to the ground behind him.

Well, this page just continues the physics mistakes from the start of this chapter. But I can't help but point out that there's only one force and it's not "expended". Gravity still acts on the ball, even after it come to rest on the deck.

How can FEers reference EnaG when R. continues to make such sophomoric errors?

[Rama Set]

I totally appreciate what you are doing but perhaps you could critique larger passages at a time or even make each new critique a new post rather than a new thread?  This is a little spammy.

Thanks!

[Pete Svarrior]

I totally appreciate what you are doing but perhaps you could critique larger passages at a time or even make each new critique a new post rather than a new thread?  This is a little spammy.

Thanks!

Good point. I've merged the threads. Gulliver, please try to contain your critique of ENaG to a single thread. Thanks.

[Tom Bishop]

It is pretty well known that the usage of the word "force" was used differently in prior eras.

Thermal-Fluid Sciences: An Integrated Approach, Volume 1:

"Parenthetical material has been added; in the mid 1800s, the word force commonly meant energy [4, 5]"

Per falling in an arc, Rowbotham describes that the ball moved diagonally from point A to point B, which it does even when falling in an arc. Moving diagonally is an accurate description. A ball can fall in an arc diagonally. The subject of the ball's motion is not in scope of the text, or pertinent.

Yawn.

[Gulliver]

It is pretty well known that the usage of the word "force" was used differently in prior eras.

Thermal-Fluid Sciences: An Integrated Approach, Volume 1:

"Parenthetical material has been added; in the mid 1800s, the word force commonly meant energy [4, 5]"

Per falling in an arc, Rowbotham describes that the ball moved diagonally from point A to point B, which it does even when falling in an arc. Moving diagonally is an accurate description. A ball can fall in an arc diagonally. The subject of the ball's motion is not in scope of the text, or pertinent.

Yawn.

So you're arguing the someone else made this mistake, so it's okay that R. did too. You really should choose your "scientist" better. If R. didn't study _Philosophiæ Naturalis Principia Mathematica_(first published in 1687, 196 years before EnaG), then I don't see why you'd rely on his understanding of kinetics in the first place. Oh, and remember you claimed that Newton used "force" incorrectly. We're still waiting on your answer to the challenge to provide evidence of your claim.

From a grade-school level text:

A straight line inside a shape that goes from one corner to another (but not an edge).

[pilot172]

wouldn't it be instead of the ball falling in an arc it would fall straight and the ship would move giving the appearance of the ball falling on an angle

[Tom Bishop]

It is pretty well known that the usage of the word "force" was used differently in prior eras.

Thermal-Fluid Sciences: An Integrated Approach, Volume 1:

"Parenthetical material has been added; in the mid 1800s, the word force commonly meant energy [4, 5]"

Per falling in an arc, Rowbotham describes that the ball moved diagonally from point A to point B, which it does even when falling in an arc. Moving diagonally is an accurate description. A ball can fall in an arc diagonally. The subject of the ball's motion is not in scope of the text, or pertinent.

Yawn.

So you're arguing the someone else made this mistake, so it's okay that R. did too. You really should choose your "scientist" better. If R. didn't study _Philosophiæ Naturalis Principia Mathematica_(first published in 1687, 196 years before EnaG), then I don't see why you'd rely on his understanding of kinetics in the first place. Oh, and remember you claimed that Newton used "force" incorrectly. We're still waiting on your answer to the challenge to provide evidence of your claim.

Words change meaning over time.

From a grade-school level text: A straight line inside a shape that goes from one corner to another (but not an edge).

One can move in a diagonal direction, or diagonally, without necessarily traveling in a straight line.

The prases 'moving diagionally', 'diagonal', and 'diagionally' != 'diagonal line'

For example, we have an empty chess board. If we place a rook on it, and use its L shaped moves to travel from one corner of the board to the other, it can be said to be moving diagonally across the chess board.

These arguments are incredibly weak. I would suggest coming up with something stronger, lest it further besmirch your character.

[Gulliver]

Words change meaning over time.

Yes, some do. But Newton wrote in terms that the scientific community had agreed upon, 200 years before EnaG. Also from context. R. clearly considers the ship motion's as imparting a force just like gravity.

One can move in a diagonal direction, or diagonally, without necessarily traveling in a straight line.

The prases 'moving diagionally', 'diagonal', and 'diagionally' != 'diagonal line'

For example, we have an empty chess board. If we place a rook on it, and use its L shaped moves to travel from one corner of the board to the other, it can be said to be moving diagonally across the chess board.

These arguments are incredibly weak. I would suggest coming up with something stronger, lest it further besmirch your character.

So, if you're right about R. just using the term imprecisely, why did he draw straight lines and not arcs in his diagrams?

[Tom Bishop]

Yes, some do. But Newton wrote in terms that the scientific community had agreed upon, 200 years before EnaG. Also from context. R. clearly considers the ship motion's as imparting a force just like gravity.

Newton was speaking in the language of his day, just as Rowbotham was.

So, if you're right about R. just using the term imprecisely, why did he draw straight lines and not arcs in his diagrams?

Rowbotham did not draw anything in the book. They were provided by an illustrator for the publisher. This is indicated on the title page.

[Gulliver]

Yes, some do. But Newton wrote in terms that the scientific community had agreed upon, 200 years before EnaG. Also from context. R. clearly considers the ship motion's as imparting a force just like gravity.

Newton was speaking in the language of his day, just as Rowbotham was.

So since Newton won the community over with Principles and clearly define the scientific terms in his day, then R. failed by using sloppy terms. And you still want to listen to this guy? Heck,m he didn't even know that, as according to you, the FE has two poles.

So, if you're right about R. just using the term imprecisely, why did he draw straight lines and not arcs in his diagrams?

Rowbotham did not draw anything in the book. They were provided by an illustrator for the publisher. This is indicated on the title page.

Are you saying that R., who was instrumental in publishing EnaG, did not review and approve the illustrations? If so, then you're impugning every illustration in EnaG as corrupt, right?

[Tom Bishop]

So since Newton won the community over with Principles and clearly define the scientific terms in his day, then R. failed by using sloppy terms. And you still want to listen to this guy? Heck,m he didn't even know that, as according to you, the FE has two poles.

Understandable, as the South Pole was not yet discovered.

Are you saying that R., who was instrumental in publishing EnaG, did not review and approve the illustrations? If so, then you're impugning every illustration in EnaG as corrupt, right?

As I recall, the old publishing monopolies (and many current ones) wouldn't publish your work unless you give them ownership of it, and accept their terms on residuals. The illustration, editing, marketing, etc, is provided by the publisher.

The extent Rowbotham worked with the publisher is unknown. But when he sent in his work to be published and signed the contract, it was no longer his decision. Even if Rowbotham made corrections or criticism to any part of it, the publisher had ultimate authority on whether it was within budget or time tables.