Question from a physicist
« on: May 16, 2017, 12:57:56 PM »
Hello everyone. 

I have a question for you all.  I've been through the FAQ and, although the concept of gravity is discussed, I couldn't see any reference to this particular point.

Imagine that you're travelling around with an accurate accelerometer (a device which measures acceleration).  At various places you stop and take a measurement, and after a while start to notice that these measurements differ from each other by a small amount.  This shows that the strength of gravity is different at different places on the planet. 

In classical physics this is well documented and can be explained by a number of different phenomena.  For example, according to Newton's law of gravitation [F=G(Mm)/r^2] if you are at the top of a mountain, gravity should be slightly weaker than if you were at sea level.  Also, the non-uniform mass density of the planet can account for some considerable variation, even if measurements are taken at the same altitude.  In fact, the measurement you take can vary by as much as 0.7% from place to place.

Now, as I understand it (and do please correct me if I've got the wrong idea) you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Thanks for taking the time to read this, and I look forward to hearing what you have to say.  Please note, I'm not here as a troll, I just find the whole topic fascinating.

Thanks!

F

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Offline Dither

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Re: Question from a physicist
« Reply #1 on: May 17, 2017, 04:54:01 AM »
you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Not every FE believes this, some work by density alone.

I'm a bit out of my league now so I'll await someone else's response.
A lie will make it around the world before the truth has time to put on its shoes.

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Offline rabinoz

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Re: Question from a physicist
« Reply #2 on: May 17, 2017, 06:23:55 AM »
Hello everyone. 

I have a question for you all.  I've been through the FAQ and, although the concept of gravity is discussed, I couldn't see any reference to this particular point.

Imagine that you're travelling around with an accurate accelerometer (a device which measures acceleration).  At various places you stop and take a measurement, and after a while start to notice that these measurements differ from each other by a small amount.  This shows that the strength of gravity is different at different places on the planet. 

In classical physics this is well documented and can be explained by a number of different phenomena.  For example, according to Newton's law of gravitation [F=G(Mm)/r^2] if you are at the top of a mountain, gravity should be slightly weaker than if you were at sea level.  Also, the non-uniform mass density of the planet can account for some considerable variation, even if measurements are taken at the same altitude.  In fact, the measurement you take can vary by as much as 0.7% from place to place.

Now, as I understand it (and do please correct me if I've got the wrong idea) you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Thanks for taking the time to read this, and I look forward to hearing what you have to say.  Please note, I'm not here as a troll, I just find the whole topic fascinating.

Thanks!

F
Junker advises us
"Please make sure to check out these resources to ensure that your time at tfes.org is enjoyable and productive."
so we do that and find:
  • The Rules: not relevant here.

  • The FAQ and under "Physics and Cosmology", that contains:
    Quote
    Why doesn't gravity pull the earth into a spherical shape?
    The earth isn't pulled into a sphere because the force known as gravity doesn't exist or at least exists in a greatly diminished form than is commonly taught. The earth is constantly accelerating up at a rate of 32 feet per second squared (or 9.8 meters per second squared). This constant acceleration causes what you think of as gravity. Imagine sitting in a car that never stops speeding up. You will be forever pushed into your seat. The earth works much the same way. It is constantly accelerating upwards being pushed by a universal accelerator (UA) known as dark energy or aetheric wind.

    There are also other theories of flat earth thought that maintain that the earth sits on an infinite plane, with the sun moving overhead. Gravity works much like it does in a round-earth model, and the earth will never form into a sphere because the plane is endless.

  • The Wiki
    Searching "the Wiki" for "gravity" leads to: Universal Acceleration where this is particularly relevant to your query
    Quote
    Tidal Effects
    In the FE universe, gravitation (not gravity) exists in other celestial bodies. The gravitational pull of the stars, for example, causes observable tidal effects on Earth.
    Q: Why does gravity vary with altitude?
    A: The moon and stars have a slight gravitational pull.
I still query:
  • How the "gravitation" can exist between "other celestial bodies" and objects on earth
    and not between the massive earth and objects on earth.
  • What explains the variation of gravity with latitude, north and south of the equator.
  • How Einstein's Special Relativity can be accepted,
    but not General Relativity, which reduces to Newton's Laws of Motion and Gravitation.

I'd like to hear your ideas.

İntikam

Re: Question from a physicist
« Reply #3 on: May 17, 2017, 08:14:47 AM »
Hello everyone. 

I have a question for you all.  I've been through the FAQ and, although the concept of gravity is discussed, I couldn't see any reference to this particular point.

Imagine that you're travelling around with an accurate accelerometer (a device which measures acceleration).  At various places you stop and take a measurement, and after a while start to notice that these measurements differ from each other by a small amount.  This shows that the strength of gravity is different at different places on the planet. 

In classical physics this is well documented and can be explained by a number of different phenomena.  For example, according to Newton's law of gravitation [F=G(Mm)/r^2] if you are at the top of a mountain, gravity should be slightly weaker than if you were at sea level.  Also, the non-uniform mass density of the planet can account for some considerable variation, even if measurements are taken at the same altitude.  In fact, the measurement you take can vary by as much as 0.7% from place to place.

Now, as I understand it (and do please correct me if I've got the wrong idea) you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Thanks for taking the time to read this, and I look forward to hearing what you have to say.  Please note, I'm not here as a troll, I just find the whole topic fascinating.

Thanks!

F

Hello.

Firstly, the earth is stationary and doesn't move to anywhere. That knowledge is "old theory" and debunked several times, also by ourselves.

Most part believers accept the "gravity effect" as caused by atmospheric stringency. You may think it as atmospheric pressure. They are not same by phsically but are about same as effective.

In nature, everything pushes others, including atmospher. So when you are on a mountain, there is less atmospher upper side of you and so, it causes less force to down you. So the gravity is less.

In ground level, the atmospher on your upper side is more than the mountain level, so the gravity effect increases. Thats all.

You can explain every type of gravity effects by changing the atmospheric weight/or hight which effect to the object.

PS: I'm an engineer from 20 years.

Offline Flatout

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Re: Question from a physicist
« Reply #4 on: May 17, 2017, 09:28:32 AM »
Hello everyone. 

I have a question for you all.  I've been through the FAQ and, although the concept of gravity is discussed, I couldn't see any reference to this particular point.

Imagine that you're travelling around with an accurate accelerometer (a device which measures acceleration).  At various places you stop and take a measurement, and after a while start to notice that these measurements differ from each other by a small amount.  This shows that the strength of gravity is different at different places on the planet. 

In classical physics this is well documented and can be explained by a number of different phenomena.  For example, according to Newton's law of gravitation [F=G(Mm)/r^2] if you are at the top of a mountain, gravity should be slightly weaker than if you were at sea level.  Also, the non-uniform mass density of the planet can account for some considerable variation, even if measurements are taken at the same altitude.  In fact, the measurement you take can vary by as much as 0.7% from place to place.

Now, as I understand it (and do please correct me if I've got the wrong idea) you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Thanks for taking the time to read this, and I look forward to hearing what you have to say.  Please note, I'm not here as a troll, I just find the whole topic fascinating.

Thanks!

F

Hello.

Firstly, the earth is stationary and doesn't move to anywhere. That knowledge is "old theory" and debunked several times, also by ourselves.

Most part believers accept the "gravity effect" as caused by atmospheric stringency. You may think it as atmospheric pressure. They are not same by phsically but are about same as effective.

In nature, everything pushes others, including atmospher. So when you are on a mountain, there is less atmospher upper side of you and so, it causes less force to down you. So the gravity is less.

In ground level, the atmospher on your upper side is more than the mountain level, so the gravity effect increases. Thats all.

You can explain every type of gravity effects by changing the atmospheric weight/or hight which effect to the object.

PS: I'm an engineer from 20 years.
You are incorrect in your understanding of the role of atmospheric pressure and the measured weight of a object.  An object of constant density and volume will weigh more when the air pressure decreases.  The phenomenon is known as air buoyancy.  There are correction formulas established to accommodate for this effect when doing mass calibrations.  The less dense the object is the more pronounced the weight increase will be as elevation increases.

http://metrology.burtini.ca/grav_air.html

http://www.npl.co.uk/reference/faqs/how-do-i-calculate-and-apply-air-buoyancy-corrections-(faq-mass-and-density)



« Last Edit: May 17, 2017, 09:40:56 AM by Flatout »

İntikam

Re: Question from a physicist
« Reply #5 on: May 17, 2017, 09:30:34 AM »
Hello everyone. 

I have a question for you all.  I've been through the FAQ and, although the concept of gravity is discussed, I couldn't see any reference to this particular point.

Imagine that you're travelling around with an accurate accelerometer (a device which measures acceleration).  At various places you stop and take a measurement, and after a while start to notice that these measurements differ from each other by a small amount.  This shows that the strength of gravity is different at different places on the planet. 

In classical physics this is well documented and can be explained by a number of different phenomena.  For example, according to Newton's law of gravitation [F=G(Mm)/r^2] if you are at the top of a mountain, gravity should be slightly weaker than if you were at sea level.  Also, the non-uniform mass density of the planet can account for some considerable variation, even if measurements are taken at the same altitude.  In fact, the measurement you take can vary by as much as 0.7% from place to place.

Now, as I understand it (and do please correct me if I've got the wrong idea) you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Thanks for taking the time to read this, and I look forward to hearing what you have to say.  Please note, I'm not here as a troll, I just find the whole topic fascinating.

Thanks!

F

Hello.

Firstly, the earth is stationary and doesn't move to anywhere. That knowledge is "old theory" and debunked several times, also by ourselves.

Most part believers accept the "gravity effect" as caused by atmospheric stringency. You may think it as atmospheric pressure. They are not same by phsically but are about same as effective.

In nature, everything pushes others, including atmospher. So when you are on a mountain, there is less atmospher upper side of you and so, it causes less force to down you. So the gravity is less.

In ground level, the atmospher on your upper side is more than the mountain level, so the gravity effect increases. Thats all.

You can explain every type of gravity effects by changing the atmospheric weight/or hight which effect to the object.

PS: I'm an engineer from 20 years.
You are incorrect in your understanding of the role of atmospheric pressure and the measured weight of a object.  An object of constant density and volume will weigh more when the air pressure decreases.  The phenomenon is known as air buoyancy.  There are correction formulas established to accommodate for this effect when doing mass calibrations.

http://metrology.burtini.ca/grav_air.html

http://www.npl.co.uk/reference/faqs/how-do-i-calculate-and-apply-air-buoyancy-corrections-(faq-mass-and-density)



I am correct and your post is completely an hoax. You are already an anti flat earth fascist. You have none of reliablity.

Offline Flatout

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« Last Edit: May 17, 2017, 10:27:54 AM by Flatout »

Re: Question from a physicist
« Reply #7 on: May 17, 2017, 03:50:38 PM »
Dear all,

Thank you for the replies that have come in so far, they have been interesting to read.  As a scientist, one universal truth I've come to understand is that answering one question creates innumerable additional questions.  So, I hope you'll permit me to keep this conversation going.  Please try to keep it civil and respectful though, it's important (and extremely interesting) that everyone has a chance to express their opinion. 

I'd like to address some specific points:

Searching "the Wiki" for "gravity" leads to: Universal Acceleration where this is particularly relevant to your query
Quote
Tidal Effects
In the FE universe, gravitation (not gravity) exists in other celestial bodies. The gravitational pull of the stars, for example, causes observable tidal effects on Earth.
Q: Why does gravity vary with altitude?
A: The moon and stars have a slight gravitational pull.

Thanks, Rabinoz, for finding that for me.  Looks like I must have missed it when I was reading the FAQ.

This point has lead me down a whole path of questions; far too many for this conversation.  I guess the thing that really sticks out to me though is this:  surely that would mean any two locations which have the same altitude would have an identical gravitational force, but this is demonstrably untrue.  Perhaps I'm missing something.

Rabinoz also said:

I still query:
  • How the "gravitation" can exist between "other celestial bodies" and objects on earth
    and not between the massive earth and objects on earth.
  • What explains the variation of gravity with latitude, north and south of the equator.
  • How Einstein's Special Relativity can be accepted,
    but not General Relativity, which reduces to Newton's Laws of Motion and Gravitation.

These are all interesting questions, and I'd like to play devil's advocate here (if you'll pardon the expression) with your first point.  I suppose that, if we assume the flat Earth is an infinite plane of limited depth, then (in classical physics) the main pull of gravity will be in all directions horizontally.  The net effect would be a very slight downward acceleration (caused by the depth of the plane), but nothing like the 9.8m/s^2 we experience.  Hmmm... I'm far from convinced about this, but it's going to be a fun thing to think about later!  Thanks again, Rabinoz, your questions are very interesting and I'd love to hear what others have to say about them.

Most part believers accept the "gravity effect" as caused by atmospheric stringency.

Thanks, İntikam.  Your explanation leads me to two questions/observations:
  • What is a "part believer"?  Do you accept some parts of the flat Earth theory but not others?
  • If what we feel as gravity is actually the pressure of the air above us pressing us down, and we can accurately measure the mass of air, we can calculate how much air is above us, pressing us down.  In your model, do you think that the air pressure is constant between the ground and the dome above us (or whatever it is)?  Or does air pressure reduce as our elevation increases?

An object of constant density and volume will weigh more when the air pressure decreases.  The phenomenon is known as air buoyancy.  There are correction formulas established to accommodate for this effect when doing mass calibrations.  The less dense the object is the more pronounced the weight increase will be as elevation increases.

Thanks, Flatout.  The videos you attached were a good example of this phenomenon and I enjoyed watching them.  Now, I'm being a bit pedantic here, but I think I see a problem with this explanation.  Imagine we've got a buoyant object (for example a boat) floating in a fluid medium (like water).  If the density of the fluid increases (maybe you change it for liquid mercury) then the boat will be raised higher, making it appear to have a lower weight.  In fact the weight of the boat remains constant (please note, I'm using the word "weight" as being synonymous with "mass" here.  I understand this is inaccurate, but it keeps things simple.) The apparent mass is what changes here.

So, after saying that, the question I have is this:  In flat Earth theory, what is the difference between weight and mass?  In classical physics weight is the force of an object due to its mass and the acceleration of gravity.  How would it be described in the absence of gravity?

You are already an anti flat earth fascist. You have none of reliablity.

İntikam, please don't say things like that.  It is disrespectful and upsetting.

Thank you all very much for your replies.  As a research physicist I often encounter people with views that are different from my own, and I very much enjoy trying to understand them.  If you have any questions for me, I'll be happy to try to answer them.

F

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Offline TomInAustin

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Re: Question from a physicist
« Reply #8 on: May 17, 2017, 06:54:45 PM »
Hello everyone. 

I have a question for you all.  I've been through the FAQ and, although the concept of gravity is discussed, I couldn't see any reference to this particular point.

Imagine that you're travelling around with an accurate accelerometer (a device which measures acceleration).  At various places you stop and take a measurement, and after a while start to notice that these measurements differ from each other by a small amount.  This shows that the strength of gravity is different at different places on the planet. 

In classical physics this is well documented and can be explained by a number of different phenomena.  For example, according to Newton's law of gravitation [F=G(Mm)/r^2] if you are at the top of a mountain, gravity should be slightly weaker than if you were at sea level.  Also, the non-uniform mass density of the planet can account for some considerable variation, even if measurements are taken at the same altitude.  In fact, the measurement you take can vary by as much as 0.7% from place to place.

Now, as I understand it (and do please correct me if I've got the wrong idea) you suggest that the flat Earth is being accelerated upwards at a constant 9.8m/s^2.  Surely, if that were the case, the acceleration measured at any point on the planet would be exactly the same.

Thanks for taking the time to read this, and I look forward to hearing what you have to say.  Please note, I'm not here as a troll, I just find the whole topic fascinating.

Thanks!

F

Hello.

Firstly, the earth is stationary and doesn't move to anywhere. That knowledge is "old theory" and debunked several times, also by ourselves.

Most part believers accept the "gravity effect" as caused by atmospheric stringency. You may think it as atmospheric pressure. They are not same by phsically but are about same as effective.

In nature, everything pushes others, including atmospher. So when you are on a mountain, there is less atmospher upper side of you and so, it causes less force to down you. So the gravity is less.

In ground level, the atmospher on your upper side is more than the mountain level, so the gravity effect increases. Thats all.

You can explain every type of gravity effects by changing the atmospheric weight/or hight which effect to the object.

PS: I'm an engineer from 20 years.

Then why does an object not float in a vacuum?  Surely you took a few physics courses in your engineering curriculum?
The distance from New York to Paris is unknown.

Offline 3DGeek

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Re: Question from a physicist
« Reply #9 on: May 17, 2017, 09:46:16 PM »
So from what I've been reading, there are at least three FE theories for why things fall to the floor when you drop them? (What RE calls "gravity").

1) The Earth is accelerating upwards at 9.8 m/s/s.
2) That the air presses down on things to make them fall.
3) That there actually is gravity (like in RE) but the earth is infinite in extent.

Then maybe some people believe combinations of these - so accelerating upwards AND air pressing downwards...or that AND that the sun, moon and stars do have actual gravity and pull upwards to make things lighter on mountain tops.

My problem is that I don't see how any of these - in any combination - explains the observation that gravity is less at the equator than at the poles.

It's very difficult to discuss FE theories when there are so many of them, and they are (frankly) contradictory.

It would be nice to have some kind of clarification of all of them.  The Wiki doesn't really lay them all out clearly.

Offline Flatout

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Re: Question from a physicist
« Reply #10 on: May 17, 2017, 10:27:52 PM »
The effects of gravity are also different when objects are in motion going east vs West and in motion at different latitudes.

Offline 3DGeek

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Re: Question from a physicist
« Reply #11 on: May 18, 2017, 12:28:34 PM »
The effects of gravity are also different when objects are in motion going east vs West and in motion at different latitudes.

Oh!?   That's odd.   What is the cause and effect of that one?

Offline Flatout

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Re: Question from a physicist
« Reply #12 on: May 18, 2017, 12:46:08 PM »
The effects of gravity are also different when objects are in motion going east vs West and in motion at different latitudes.

Oh!?   That's odd.   What is the cause and effect of that one?
When traveling east your total velocity (velocity plus earth spin) is greater than when traveling due west (earth spin minus velocity).   The centripetal acceleration is greater when traveling east resulting in lower measured weight. It's called the Eotvos Effect.

 http://www.cleonis.nl/physics/phys256/eotvos.php

« Last Edit: May 18, 2017, 12:51:16 PM by Flatout »

Offline 3DGeek

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Re: Question from a physicist
« Reply #13 on: May 18, 2017, 03:54:06 PM »

When traveling east your total velocity (velocity plus earth spin) is greater than when traveling due west (earth spin minus velocity).   The centripetal acceleration is greater when traveling east resulting in lower measured weight. It's called the Eotvos Effect.

 http://www.cleonis.nl/physics/phys256/eotvos.php

Oh - yeah - I'd forgotten about that result.  Weird.  Makes sense in RE - but less so in FE.

It's almost like the laws of FE physics cunningly conspire to make it seem like the Earth is round!

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Offline Pete Svarrior

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Re: Question from a physicist
« Reply #14 on: May 18, 2017, 05:00:04 PM »
    I still query:
    • How the "gravitation" can exist between "other celestial bodies" and objects on earth
      and not between the massive earth and objects on earth.
    You assume without evidence that there is a correlation between mass and gravitational pull.

    • How Einstein's Special Relativity can be accepted,
      but not General Relativity, which reduces to Newton's Laws of Motion and Gravitation.
    Given that the two are entirely separate, I don't see why you would necessarily expect anyone to either accept or reject both. It's like saying that all vegetarians must be left-wingers.
    Read the FAQ before asking your question - chances are we've already addressed it.
    Follow the Flat Earth Society on Facebook and Twitter!

    Offline Flatout

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    Re: Question from a physicist
    « Reply #15 on: May 19, 2017, 12:47:28 PM »
      I still query:
      • How the "gravitation" can exist between "other celestial bodies" and objects on earth
        and not between the massive earth and objects on earth.
      You assume without evidence that there is a correlation between mass and gravitational pull.
      You assume that science just makes stuff up.  We have been doing measured mass attraction experiments since the mid 1800's.   Our present understanding of gravity and mass were derived from those experiments. 
        [/list]