Rotational force and some questions about flat earth.
« on: December 12, 2017, 05:39:22 AM »
so I may not be a true flat earth believer, but I have a question that I hope the answer may prove my belief in globe earth wrong. It may be a series of questions, but they are based on one idea: acceleration.
So here is my question: if the planet rotates in a circular motion, why would people not fly off the edge of the planet or die of the rapid changes in acceleration? It’s obvious that this effect applies to small things like those play sets in the park where you spin and feel the forces try to throw you off of it, so why wouldn’t we feel these forces on the flat earth? And if it is the sun and moon that are moving, how is it that the sun and moon end up in specific paths? Wouldn’t that require gravity or rope or some sort of movement based machine? How is it that things we put in space end up going in a perfect circular path when they got up to space? How do they keep spacecraft up in space for such long periods of time if they have a limited amount of fuel?

« Last Edit: December 12, 2017, 05:56:41 AM by CometStreak »

Offline rgr331

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Re: Rotational force
« Reply #1 on: December 12, 2017, 06:07:36 AM »
so I may not be a true flat earth believer, but I have a question that I hope the answer may prove my belief in globe earth wrong. It may be a series of questions, but they are based on one idea: acceleration.
So here is my question: if the planet rotates in a circular motion, why would people not fly off the edge of the planet or die of the rapid changes in acceleration? It’s obvious that this effect applies to small things like those play sets in the park where you spin and feel the forces try to throw you off of it, so why wouldn’t we feel these forces on the flat earth? And if it is the sun and moon that are moving, how is it that the sun and moon end up in specific paths? Wouldn’t that require gravity or rope or some sort of movement based machine?

Seems like you would feel it, but in actuality, that force is very very small relative to what you experience say in a car going around a turn. 

Flat earthers like to say “if the earth is round they we must be blazing around in a circle at 1000 miles per hour.” Well we are, but that doesn’t mean we can feel it.  On a plane, you are flying at 550 mph, can you feel that?

Fact is, what you are really feeling when you drive a car around a corner is your change in direction.  Acceleration is the change in velocity and velocity is a vector defined by both magnitude (speed) and direction (N S E W). So a body can experience acceleration even when the speed stays constant.

So, how much change in direction are we feeling in a car going around a corner. Assuming a 90 degree turn that takes 3 seconds (fairly typical for an automobile), your change in direction is 30 degrees per second.

Now let’s take a look at the rotation of the earth. It takes 24 hours for your body to experience 360 degrees of change (1 rotation of the earth). So your body is experiencing 0.0041 degrees per second.  That is 0.0041=360/24/60/60.

The magnitude is about 7200 times greater in the 90 degree turn in a car.
« Last Edit: December 12, 2017, 03:41:46 PM by rgr331 »

Re: Rotational force
« Reply #2 on: December 12, 2017, 06:17:17 AM »
If you were on one of those toys at the park and it were spinning one revolution per day, would you notice?

That's how fast the earth is spinning, not very much.

You can, however, measure the centrifugal force if you have a sensitive enough scale.

That's why, for example, when weighing things very delicately for things like the pharmaceutical industry you have to correct the weight on your scale based on your latitude.

https://www.pharmamanufacturing.com/articles/2016/mass-measurement-precision-small-objects-pharmaceutical-production/

See especially this image:

Offline Scroogie

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Re: Rotational force and some questions about flat earth.
« Reply #3 on: December 12, 2017, 07:30:17 AM »
so I may not be a true flat earth believer, but I have a question that I hope the answer may prove my belief in globe earth wrong. It may be a series of questions, but they are based on one idea: acceleration.
So here is my question: if the planet rotates in a circular motion, why would people not fly off the edge of the planet or die of the rapid changes in acceleration? It’s obvious that this effect applies to small things like those play sets in the park where you spin and feel the forces try to throw you off of it, so why wouldn’t we feel these forces on the flat earth? And if it is the sun and moon that are moving, how is it that the sun and moon end up in specific paths? Wouldn’t that require gravity or rope or some sort of movement based machine? How is it that things we put in space end up going in a perfect circular path when they got up to space? How do they keep spacecraft up in space for such long periods of time if they have a limited amount of fuel?

Simply put, the centrifugal force of the rotation of the earth is substantially less than what people commonly expect it to be without having actually calculated it. From the graph above it can be seen that the difference in gravity (G) from the poles to the equator, which is created by that very rotation, amounts to only .05G, or 5% of the of the centripetal, or inward, force created by the earth's gravity. Zero centrifugal force at the poles, .05G of centrifugal force at the equator.

As for rockets satellites and fuel use, once an "object" attains a sufficient velocity in a (more or less) circular path around a (usually, but not always) larger body (such as the earth), the centrifugal force created by the radial acceleration within that circular path will equal the centripetal force of the larger body's gravity. At that point the "object" will be able to remain suspended above the larger body while following its  (more or less) circular path around that body. (I say"more or less" because the orbit of a body around another body can vary from perfectly circular to highly elliptical). Since upward force equals downward force, no fuel need be expended to maintain orbit.

The "specific paths" you mention are the result of highly complex interactions among the bodies which are able to exert gravitational forces on other, relatively nearby, bodies. For example, the orbits of all the bodies in the solar system, from tiny asteroids to Jupiter, have been influenced to a greater or lesser extent by most, if not all, of the other bodies in the system. While a small asteroid will be incapable of measurably influencing the orbit of Jupiter, for example, the reverse case is exactly the opposite, with Jupiter having a large influence on the orbits of small asteroids.

devils advocate

Re: Rotational force and some questions about flat earth.
« Reply #4 on: December 12, 2017, 09:34:14 AM »
How do they keep spacecraft up in space for such long periods of time if they have a limited amount of fuel?

Don't be confused by direction in space, there is no up/down. Space craft use the most amount of fuel taking off (those huge fuel tanks on the sides of the rocket that fall off). Once in space as it is a vacuum there is no friction so all you need is one thrust in any direction and the craft will continue to move in that direction as there is no force to slow it down.

Offline ShowmetheProof

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Re: Rotational force and some questions about flat earth.
« Reply #5 on: December 12, 2017, 06:45:01 PM »
So here is my question: if the planet rotates in a circular motion, why would people not fly off the edge of the planet or die of the rapid changes in acceleration?
We wouldn't, because of gravity.  On the flat earth, what happens to the poor people on the bottom of the disk?:)

Offline Scroogie

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Re: Rotational force and some questions about flat earth.
« Reply #6 on: December 13, 2017, 02:49:54 AM »
How do they keep spacecraft up in space for such long periods of time if they have a limited amount of fuel?

Don't be confused by direction in space, there is no up/down. Space craft use the most amount of fuel taking off (those huge fuel tanks on the sides of the rocket that fall off). Once in space as it is a vacuum there is no friction so all you need is one thrust in any direction and the craft will continue to move in that direction as there is no force to slow it down.

Yes. Thank you DA. I neglected to mention the lack of an atmosphere "up" there. ;)

Re: Rotational force and some questions about flat earth.
« Reply #7 on: December 20, 2017, 01:03:09 AM »
So what I’m hearing is that there is gravity.

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Offline Tom Haws

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Re: Rotational force and some questions about flat earth.
« Reply #8 on: December 20, 2017, 08:56:40 PM »
So here is my question: if the planet rotates in a circular motion, why would people not fly off the edge of the planet?

Gravity vastly overwhelms centrifugal force, or in more orthodox language, provides vastly more force than required for centripetal acceleration. I'll give you numbers if you want.

or die of the rapid changes in acceleration?

If there were any changes in acceleration, you would feel them indeed! Why do you think that anybody is suggesting changes in acceleration? Mainstream physicists are not proposing this.
Civil Engineer (professional mapper)

Thanks to Tom Bishop for his courtesy.

No flat map can predict commercial airline flight times among New York, Paris, Cape Town, & Buenos Aires.

The FAQ Sun animation does not work with sundials. And it has the equinox sun set toward Seattle (well N of NW) at my house in Mesa, AZ.

Re: Rotational force and some questions about flat earth.
« Reply #9 on: December 22, 2017, 04:42:17 PM »
So what I’m hearing is that there is gravity.

There is a force of attraction between any 2 bodies. The force is dependent on the mass of both bodies and the distance between both bodies. This force of attraction has been calculated and measured multiple times over multiple centuries ever since Newton got bonked on the head by that apple. (Note, his getting hit on the head is actually a myth).

Now there are a number of theories as to why that force exists and to my knowledge, right now, no one knows why it happens.

That force of attraction is called gravity. It is not an invention of NASA or the illuminati. We feel gravity on our earth mostly as an attractive force towards the center of the earth. The earth feels an attractive force towards each and every single item on it's surface. But compared to everything on our dear planet, the size of the earth is humongous and gargantuan (just wanted to get that word in) and so we feel drawn more towards the earth than the earth feels drawn towards us. That force of attraction can be and has been measured.

So, yes. There is gravity. Not universal acceleration (which should tear a flat earth to bits) and not denspressure (which can't explain why things go "down" and not "left" or "right")
« Last Edit: December 22, 2017, 04:44:07 PM by SpaceCadet »