[edby]

Get onto a merry-go-round that is rotating at a 'constant speed' and see if you can throw a ball up straight into the air and get it to fall back into its same position with you.

The ball has a tiny gravitational attraction to the merry-go-round.

[edit] Also, you are changing the subject. Rowbotham's examples are of objects moving with a constant velocity, and with no rotation. He seems to think you can tell whether you are on a moving earth or not just by throwing objects up in the air. This is entirely false.

[Tom Bishop]

Get onto a merry-go-round that is rotating at a 'constant speed' and see if you can throw a ball up straight into the air and get it to fall back into its same position with you.

The ball has a tiny gravitational attraction to the merry-go-round.

Now we are just introducing more things.

If the merry-go-round was in space, and the floor of the merry-go-round was as attractive as the earth would be, I don't see how the ball would behave any differently.

The merry-go-round is spinning beneath the ball. Why would the ball follow the spin rather than going in a straight path? The ball is equally attracted to the floor of the merry-go-round if it just travels in a straight path.

[edby]

I repeat, please do not change the subject. Happy to discuss merry go rounds somewhere else, but R does not mention merry go rounds in that chapter.

Rowbotham's examples are of objects moving with a constant velocity, and with no rotation. He seems to think you can tell whether you are on a moving earth or not just by throwing objects up in the air. This is entirely false.

Again:

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.

He does not say the horse is accelerating.

[Tom Bishop]

I see. Changing the topic when you have backed yourself into a corner on "rotating bodies don't cause acceleration." Good idea.

Horses can accelerate. What makes you think that they cannot?

Rowbotham's examples are of objects moving with a constant velocity

Then I expect that you will be able to quote where the horse, ship, or train are specified to be moving at a "constant velocity."

[edby]

Horses can accelerate. What makes you think that they cannot?

Rowbotham's examples are of objects moving with a constant velocity

Then I expect that you will be able to quote where the horse, ship, or train are specified to be moving at a "constant velocity."

Very interesting. Let's suppose he does mean 'acceleration' rather than 'rapid motion', although he does not say so.

Then suppose R's arguments concern accelerating objects only? How is this relevant to the movement of the earth, then?

[Tom Bishop]

Then suppose R's arguments concern accelerating objects only? How is this relevant to the movement of the earth, then?

Rotating bodies exhibit acceleration. See the merry-go-round example.

[edby]

Then suppose R's arguments concern accelerating objects only? How is this relevant to the movement of the earth, then?

Rotating bodies exhibit acceleration. See the merry-go-round example.

Why is the rotation of the earth relevant to the merry go round?

[Rama Set]

Then suppose R's arguments concern accelerating objects only? How is this relevant to the movement of the earth, then?

Rotating bodies exhibit acceleration. See the merry-go-round example.

Now slow the merry go round to making one rotation every day and see what the ball does. Do it again, but only throw the ball 1/100,000th of the diameter and see what happens.

[Pete Svarrior]

If there anyone appears, to have a "particularly egregious misunderstanding of classical mechanics" than it's Mr. R..

You misunderstood literally every word of what I said. I agreed that Rowbotham is misunderstanding Newtonian mechanics, and yet you felt the need to try to explain the same to me.

You also proceeded to respond to my point on why we need to consider more than just the conservation of momentum... by stating what the conservation of momentum is.

Buddy. Take a deep breath. I already agreed with the RET side in this thread. There's no need for you to present bad arguments for RET.

[edby]

Now slow the merry go round to making one rotation every day and see what the ball does. Do it again, but only throw the ball 1/100,000th of the diameter and see what happens.

But this is not a precise analogy. If I throw a ball into the air, I am throwing it along its radius. If I throw it up from a merry go round, I am throwing it perpendicular to the radius.

What you say is also true, of course.

[Tom Bishop]

Then suppose R's arguments concern accelerating objects only? How is this relevant to the movement of the earth, then?

Rotating bodies exhibit acceleration. See the merry-go-round example.

Now slow the merry go round to making one rotation every day and see what the ball does. Do it again, but only throw the ball 1/100,000th of the diameter and see what happens.

The earth should have some kind of measurable deflection. See the works of Tycho Brahe, an astronomer, one of the greatest in history in fact, who concluded with various cannon experiments that the earth was stationary.

The astronomer Giovanni Riccioli describes the experiments and agrees that astronomers who are trying to downplay or deny the results of such experiments are providing a weak explanation.

http://arxiv.org/ftp/arxiv/papers/1012/1012.3642.pdf

VIII. Tycho also argues that if the cannon experiment were performed at the
poles of the Earth, where the ground speed produced by the diurnal motion is
diminished, then the result of the experiment would be the same regardless of
toward which part of the horizon the cannon was fired. However, if the experiment
were performed near the equator, where the ground speed is greatest, the result
would be different when the ball is hurled East or West, than when hurled North or
South.

The form of the argument is thus: If Earth is moved with diurnal motion, a ball fired
from a cannon in a consistent manner would pass through a different trajectory when hurled
near the poles or toward the poles, than when hurled along the parallels nearer to the Equator,
or when hurled into the South or North. But this is contrary to experience. Therefore, Earth is
not moved by diurnal motion.

If Tycho is to be believed, experiments have shown this to be correct. Moreover,
if a ball is fired along a Meridian toward the pole (rather than toward the East or
West), diurnal motion will cause the ball to be carried off [i.e. the trajectory of the
ball is deflected], all things being equal: for on parallels nearer the poles, the ground
moves more slowly, whereas on parallels nearer the equator, the ground moves more
rapidly.7

The Copernican response to this argument is to deny it, or to concede it but claim that the differences in trajectory fall below our ability to measure. But in fact the argument is strong, and this response is not.

See the bolded above.

Riccioli concludes in the pdf with:

None of the above examples of what should happen if the Earth moves are in accord with what we see. Therefore, the Earth does not move with diurnal, much less annual, motion.

[edby]

The earth should have some kind of measurable deflection.

But not measurable by crude experiments with cannon balls and horses.

Riccioli concludes in the pdf with:

None of the above examples of what should happen if the Earth moves are in accord with what we see. Therefore, the Earth does not move with diurnal, much less annual, motion.

But Riccioli was wrong, correct?

[edby]

Now, they were wrong about the effect not existing.  The effect exists, but it is much harder to observe than one might expect.  Indeed, even Isaac Newton and Robert Hooke in 1679-1680 tried, without success, to use the effect to prove Earth’s rotation. https://www.vofoundation.org/blog/frs-riccioli-dechales-science-shows-earth-rest-coriolis-effect/

I believe we have discussed this before, Tom.

[edby]

Ah yes - before my time, but here we are:

The Coriolis Effect is caused by the stars, which are moving at a rate of one rotation per 24 hours.

So there is a small and very difficult to detect phenomenon, and it is caused by the stars. Why all the stuff about cannon balls and horses then?

[Tom Bishop]

Ah yes - before my time, but here we are:

The Coriolis Effect is caused by the stars, which are moving at a rate of one rotation per 24 hours.

So there is a small and very difficult to detect phenomenon, and it is caused by the stars. Why all the stuff about cannon balls and horses then?

The Coriolis Effect is a slight effect, but it does not really describe what the rotating earth should predict.

Look into Airy's Failure, the Sagnac Experiment, et all. There are a ton of experiments which suggests that that the earth does not rotate.

Curious Squirrel posted a good link:

.

Try looking up any calculation of the matter. But in particular relevance I'll just link this again as perhaps you missed my edit earlier with it.

http://adsabs.harvard.edu/full/1913PA.....21..208R

I read through this article. The commentary tends to assert that the object motion experiments did not perform so well in matching the predictions made by astronomers for their (downplayed) Copernican calculations of how the rotational force should operate.

The author even states that there has never been experimental proof for the theories on the meridional deviation of falling bodies:



"Universally admitted" but "never met with an experimental proof."

[edby]

The Coriolis Effect is a slight effect, but it does not really describe what the rotating earth should predict.

OK we agree on that then. Phew. But this thread is about R's 'experiment in Zetetic Astronomy', which tried to measure the effect by throwing tennis balls in the air, jumping off horses or whatnot. He concluded there was no such effect, because he couldn't see one. But (a) the effect is 'so slight' that it could exist without him observing it through such crude experiments and (b) it does exist anyway, as we now both agree, as so he was wrong.

[BillO]

Rowbotham is describing movement between points in space in his text and the illustrator from the book company, George Davies, drew lines between the points described.

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 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.

No, clearly he says: "but because the two motions act conjointly, the ball will take the diagonal direction, A, D." This is why the illustrator drew it that way.

Next he states that the ball's forward motion will come to an abrupt stop at D: "the ball will begin to fall, by the force of gravity alone, in the vertical direction, D, B, H" and state this is because the: "two forces will have been expended".  What is 'expending' the two forces?  The force of gravity is always acting on the ball, the net force that launched it in the first place was done once the ball was in flight and traveling with momentum.  What would suddenly reduce it's forward momentum to zero at D?  This would and does not happen.  Rowbotham is wrong!

Rowbotham is talking about acceleration. The ship is accelerating, and leaves the ball behind. The same happens with the next example.

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


FIG. 48.

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.

Look at the spacing of the trains. Accelerating. The ball is left behind. True.

The illustrator also made it look like the ball hit the train again, but if you read the text it is clearly conveyed what Rowbotham is describing.

So, the illustrator can't get the other drawings right, but he get's this 'acceleration' (that is never mentioned by Rowbotham), just right perfect - maybe because now his ineptness supports your point?  LOL!

Get onto a merry-go-round that is rotating at a 'constant speed' and see if you can throw a ball up straight into the air and get it to fall back into its same position with you.

...

If the merry-go-round was in space, and the floor of the merry-go-round was as attractive as the earth would be, I don't see how the ball would behave any differently.

A merry-go-round is not the same situation as throwing something up from the surface of the spherical earth, as you know well enough.  However, it would be similar to what would happen on a flat earth (like in your 2nd comment above), and since what happens on a merry-go-round is not what we see when we toss a ball in the air form the surface, the the earth can't be flat, can it?

[Rama Set]

WhThe Coriolis Effect is a slight effect, but it does not really describe what the rotating earth should predict.

Look into Airy's Failure, the Sagnac Experiment, et all. There are a ton of experiments which suggests that that the earth does not rotate.

These are experiments looking for the Luminiferous Ether. What do they have to do with the Coriolis effect?

[Tom Bishop]

Experiments should have been able to pick it up. Did you think that measuring tools and math was invented in the last fifty years or something?

It says right there on the Harvard / NASA library link in my last post. The rotation of the earth has never been met with an experimental proof.

[Rama Set]

Experiments should have been able to pick it up. Did you think that measuring tools and math was invented in the last fifty years or something?

It says right there on the Harvard / NASA library link in my last post. The rotation of the earth has never been met with an experimental proof.

That's not what it says and unfortunately for you, the rotation of the earth needs no experiment to show its existence, it has been observed directly.