46&2's Globe Earth Experiment

[46AND2]

The discussion was brought up in another thread that if the earth is a spinning globe, then the weight of objects should vary at different latitudes. This is because centrifugal force is stronger when closer to the equator than the poles, a reaction counter to the force of gravity.

To illustrate why the centrifugal force is stronger, consider a person standing in the northern most part of Siberia. If you measure the circle created at that latitude, that's how far one travels/spins in one day. Now consider somebody standing at the equator. The circle created at the equator is much larger, indeed, the whole circumference of the earth. But someone standing on that circle still has to travel the entire circumference in the same amount of time as the person in Siberia has to travel around the circumference of their circle.

This means that the person at the equator must be travelling faster than the person in Siberia. So the force acting against gravity is stronger at the equator, making the person standing there weigh less.

This, of course, has been tested and confirmed (I will add links soon). But I thought it would be fun to actually perform an experiment of my own and document it.

I have selected a reasonably priced scale that has a sufficient accuracy to document the small changes that would be incurred:

My Weigh iBalance 401 (i401)

It has good reviews, and is supposed to be accurate to within 5 millligrams. The difference I expect to see will be in the couple hundred milligram range (I'll calculate an actual prediction prior to the experiment).

Of course, there is virtually no way to convince you flat earthers that I won't cheat. To that I say, THEN DO IT YOURSELF.

That said, I will attempt to minimize shadiness by adhering to a few guidelines, and am open to other suggestions for these guidelines that I have not considered; no reasonable condition will be denied. Here they are (so far):

1. I will video the unpackaging of the box the scale comes in
2. I will video the unpackaging of the calibration weights
3. I will document the serial number of the scale
4. Hopefully, I can find some weights that have their own serial numbers, but if not, I will figure out how to mark them in some way, so all can see I am using the same ones.
5. I will document my GPS coordinates for each weighing location
6. I will provide video proof that I am at the locations I say I am.
7. I will select locations that are approximately the same elevation. I will be travelling to Phoenix, AZ from Vancouver, WA. Phoenix is substantially higher elevation, so I will have to find a suitable location near Vancouver on a hill or mountain.
8. Tests will occur indoors (at ground level) to minimize potential temperature and artificial elevation effects, with ample "warm-up" time for the scale.
9. Scale will be plugged in, rather than use of batteries, to ensure it is fully powered.
10. I will go back to my Washington location after the trip to confirm the calibration of the scale has not been thrown out of whack during travel. I will do my best to treat it gently along the way.
11. New batteries will be installed (while plugged in) prior to each journey, in case it won't save settings without them (though this shouldn't be a problem, anyway). And it will remain plugged in for the duration of my stay in Phoenix.
12. The limit of the scale is 400 grams. However, scales are typically less accurate in the top and bottom 25% of their ranges (at least this was true 20 years ago when I had to calibrate them in the Army). So the test will be conducted with a 300 gram weight.
13. Scale will be boxed up and sealed on camera between measurements, and reopened on camera when measurement is to be performed.

I will add conditions as deemed necessary in the coming weeks. The trip should take place over the Christmas holidays this year.

Please offer any suggestions for improvement or things to consider.

Your condition suggestions will be highlighted in red.

 

[Of the Kingdom]

It could be that some flat Earth models would allow for weight to vary. My understanding of plane thinking is that *bouyancy* is the explanation for things falling or rising, and that *gravity* doesn't exist. To a plane thinker, presumably *gravity* implies Newton's idea that all masses attract each other.

Obviously we can't think of every possible interpretation, but it makes sense to ask the question if anyone sees a reason on a disk Earth for weights to vary.

 

[46AND2]

It could be that some flat Earth models would allow for weight to vary. My understanding of plane thinking is that *bouyancy* is the explanation for things falling or rising, and that *gravity* doesn't exist. To a plane thinker, presumably *gravity* implies Newton's idea that all masses attract each other.

Obviously we can't think of every possible interpretation, but it makes sense to ask the question if anyone sees a reason on a disk Earth for weights to vary.

And to vary in such a way consistent with the globe explanation:

Two cities at the same latitude but different longitude should read approximately equally.
Two cities equidistant from, and on opposite sides of, the equator should read approximately the same.

And, I should be able to calculate the approximate difference with math and make a prediction of what the difference will be in my experiment, based on the globe model.

 

[The IbanezerScrooge]

couple of questions:

1. Is that enough of a latitudinal distance to make that much difference in weight? Both places are still quite far from the equator. I suppose even if the difference is small if you can replicate that difference consistently at the same latitudes then the size of the difference doesn't really matter.

2. Does the altitude itself determine gravity's tug or would you need to factor in the surrounding mass as well? IOW, if you're sitting in a wooden fire tower 50 feet off the ground at 1000 feet elevation (total of 1050 feet above sea level) on a relatively flat plain, is that the same as standing on top of a hill at 1050 feet above sea level that gradually slopes away for a few miles around you resulting in many, many more tons of earth mass in the immediate area? Would the difference be significant?

 

[46AND2]

couple of questions:

1. Is that enough of a latitudinal distance to make that much difference in weight? Both places are still quite far from the equator. I suppose even if the difference is small if you can replicate that difference consistently at the same latitudes then the size of the difference doesn't really matter.

2. Does the altitude itself determine gravity's tug or would you need to factor in the surrounding mass as well? IOW, if you're sitting in a wooden fire tower 50 feet off the ground at 1000 feet elevation (total of 1050 feet above sea level) on a relatively flat plain, is that the same as standing on top of a hill at 1050 feet above sea level that gradually slopes away for a few miles around you resulting in many, many more tons of earth mass in the immediate area? Would the difference be significant?

1. Yes, it's enough of a difference. The poles are about 6000-ish miles from the equator. The difference in weight between the two is about .5%. With a 300 gram weight, this would be 1.5 grams.

The difference in distance from the equator for the two cities I'll be testing is about 1100 miles, or about 1/6th the distance between equator and poles. On a perfect sphere, this would equate to about 250 milligrams, and I selected a scale that is accurate to about 5 milligrams. I'll do more robust calculations when I have more time.

2. The difference should be negligible due to the fact that even that much rock mass is very tiny compared to the mass of the earth's center. Even so, I would not use artificial means such as that to increase my elevation. I added that as part of condition 8 in the OP.

 

[46AND2]

couple of questions:

1. Is that enough of a latitudinal distance to make that much difference in weight? Both places are still quite far from the equator. I suppose even if the difference is small if you can replicate that difference consistently at the same latitudes then the size of the difference doesn't really matter.

2. Does the altitude itself determine gravity's tug or would you need to factor in the surrounding mass as well? IOW, if you're sitting in a wooden fire tower 50 feet off the ground at 1000 feet elevation (total of 1050 feet above sea level) on a relatively flat plain, is that the same as standing on top of a hill at 1050 feet above sea level that gradually slopes away for a few miles around you resulting in many, many more tons of earth mass in the immediate area? Would the difference be significant?

Concerning #1, I'm also considering performing the 1st and 3rd measurements at my brother's house in Tacoma, WA. That's a couple hundred miles further from Phoenix, and he lives up on a hill which may be (haven't checked yet; need to get his actual address) comparable to Phoenix elevation.

 

[46AND2]

Interestingly, Phoenix is about the same distance (2311 miles) north of the equator as Sydney, Australia is (2340 miles) south of the equator. So the weight should weigh about the same in these two cities.

I have a lot of family in Sydney, and have been planning to take a trip there in the next year or two. So, I may just hold on to the scale (as opposed to reselling it after this experiment), to perform it again when I go there.

 

[The IbanezerScrooge]

Interestingly, Phoenix is about the same distance (2311 miles) north of the equator as Sydney, Australia is (2340 miles) south of the equator. So the weight should weigh about the same in these two cities.

I have a lot of family in Sydney, and have been planning to take a trip there in the next year or two. So, I may just hold on to the scale (as opposed to reselling it after this experiment), to perform it again when I go there.

Oh that would be cool.

 

[Anguspure]

The discussion was brought up in another thread that if the earth is a spinning globe, then the weight of objects should vary at different latitudes. This is because centrifugal force is stronger when closer to the equator than the poles, a reaction counter to the force of gravity.

To illustrate why the centrifugal force is stronger, consider a person standing in the northern most part of Siberia. If you measure the circle created at that latitude, that's how far one travels/spins in one day. Now consider somebody standing at the equator. The circle created at the equator is much larger, indeed, the whole circumference of the earth. But someone standing on that circle still has to travel the entire circumference in the same amount of time as the person in Siberia has to travel around the circumference of their circle.

This means that the person at the equator must be travelling faster than the person in Siberia. So the force acting against gravity is stronger at the equator, making the person standing there weigh less.

This, of course, has been tested and confirmed (I will add links soon). But I thought it would be fun to actually perform an experiment of my own and document it.

I have selected a reasonably priced scale that has a sufficient accuracy to document the small changes that would be incurred:

My Weigh iBalance 401 (i401)

It has good reviews, and is supposed to be accurate to within 5 millligrams. The difference I expect to see will be in the couple hundred milligram range (I'll calculate an actual prediction prior to the experiment).

Of course, there is virtually no way to convince you flat earthers that I won't cheat. To that I say, THEN DO IT YOURSELF.

That said, I will attempt to minimize shadiness by adhering to a few guidelines, and am open to other suggestions for these guidelines that I have not considered; no reasonable condition will be denied. Here they are (so far):

1. I will video the unpackaging of the box the scale comes in
2. I will video the unpackaging of the calibration weights
3. I will document the serial number of the scale
4. Hopefully, I can find some weights that have their own serial numbers, but if not, I will figure out how to mark them in some way, so all can see I am using the same ones.
5. I will document my GPS coordinates for each weighing location
6. I will provide video proof that I am at the locations I say I am.
7. I will select locations that are approximately the same elevation. I will be travelling to Phoenix, AZ from Vancouver, WA. Phoenix is substantially higher elevation, so I will have to find a suitable location near Vancouver on a hill or mountain.
8. Tests will occur indoors (at ground level) to minimize potential temperature and artificial elevation effects, with ample "warm-up" time for the scale.
9. Scale will be plugged in, rather than use of batteries, to ensure it is fully powered.
10. I will go back to my Washington location after the trip to confirm the calibration of the scale has not been thrown out of whack during travel. I will do my best to treat it gently along the way.
11. New batteries will be installed (while plugged in) prior to each journey, in case it won't save settings without them (though this shouldn't be a problem, anyway). And it will remain plugged in for the duration of my stay in Phoenix.
12. The limit of the scale is 400 grams. However, scales are typically less accurate in the top and bottom 25% of their ranges (at least this was true 20 years ago when I had to calibrate them in the Army). So the test will be conducted with a 300 gram weight.

I will add conditions as deemed necessary in the coming weeks. The trip should take place over the Christmas holidays this year.

Please offer any suggestions for improvement or things to consider.

Your condition suggestions will be highlighted in red.

To be more accurate you will also need to take into account the gravitational variation at the different locations you are visiting.
Matter in Motion: Earth's Changing Gravity | Earthdata
Gravity map reveals Earth's extremes

 

[46AND2]

To be more accurate you will also need to take into account the gravitational variation at the different locations you are visiting.
Matter in Motion: Earth's Changing Gravity | Earthdata
Gravity map reveals Earth's extremes

Thank you, yes. I had planned to try to incorporate that into my calculation. The two cities are on top of very different types of rock, so it could be a fairly significant difference. More so than I had originally thought.

 

[46AND2]

couple of questions:

1. Is that enough of a latitudinal distance to make that much difference in weight? Both places are still quite far from the equator. I suppose even if the difference is small if you can replicate that difference consistently at the same latitudes then the size of the difference doesn't really matter.

2. Does the altitude itself determine gravity's tug or would you need to factor in the surrounding mass as well? IOW, if you're sitting in a wooden fire tower 50 feet off the ground at 1000 feet elevation (total of 1050 feet above sea level) on a relatively flat plain, is that the same as standing on top of a hill at 1050 feet above sea level that gradually slopes away for a few miles around you resulting in many, many more tons of earth mass in the immediate area? Would the difference be significant?

Re: #2:

After reading up a bit more, they actually even have corrections for whether you are measuring on a hill or flat land. It might be easier to just incorporate an elevation correction and measure on flat land in both cities, rather than finding a hilly location in Vancouver.

 

[Strathos]

Do you really think this will convince any of them?

 

[essentialsaltes]

"Of course, there is virtually no way to convince you flat earthers that I won't cheat."

The most obvious (to me) way to cheat would be to jigger the calibration. As you say, there's no way to be absolutely convincing, but consider boxing and unboxing the scale so that your entire interaction with it is filmed. Possibly adding some tape with a hard to reproduce squiggle on it, or some other way to demonstrate that the scale hasnt been touched in the interim.

 

[46AND2]

"Of course, there is virtually no way to convince you flat earthers that I won't cheat."

The most obvious (to me) way to cheat would be to jigger the calibration. As you say, there's no way to be absolutely convincing, but consider boxing and unboxing the scale so that your entire interaction with it is filmed. Possibly adding some tape with a hard to reproduce squiggle on it, or some other way to demonstrate that the scale hasnt been touched in the interim.

Funny. That is the exact thing I had in mind, right down to the hard to reproduce squiggle.

 

[46AND2]

Do you really think this will convince any of them?

No, of course not. It's a fun cheap experiment I can do on my own, and I get to learn some things, particularly in trying to come up with a good prediction.

 

[The IbanezerScrooge]

Funny. That is the exact thing I had in mind, right down to the hard to reproduce squiggle.

Assuming you're using a cardboard box and box tape, you could draw a symbol or write the date and time on the top of the box and then cover it with the box tape in view of the camera. Then during your next interaction with it rip off that tape which should damage the marking. Then write the new date time and cover it again.

If you did that on a part that would have to be cut or ripped in order to open the box then any tampering would be evident and/or difficult to conceal.

Of course nothing is going to be perfectly fool-proof and acceptable to everyone. :-/

 

[46AND2]

"Of course, there is virtually no way to convince you flat earthers that I won't cheat."

The most obvious (to me) way to cheat would be to jigger the calibration. As you say, there's no way to be absolutely convincing, but consider boxing and unboxing the scale so that your entire interaction with it is filmed. Possibly adding some tape with a hard to reproduce squiggle on it, or some other way to demonstrate that the scale hasnt been touched in the interim.

One issue with this, though, is that the recommended "warm-up" period for some scales (I have not read the manual for this one yet) is several hours. That would mean a particularly long video to confirm no tampering has been performed during this time.

Edit: Nevermind, this scale only has a warm-up period of "several minutes" according to the user manual.

 

[Tinker Grey]

Looking forward to this. Very cool.

 

[FrumiousBandersnatch]

What are the chances he comes back a flat Earther?

 

[pgp_protector]

What are the chances he comes back a flat Earther?

I'd say about 0.00%