# The Flat Earth Society

## Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: buddha on April 23, 2021, 10:47:16 PM

Post by: buddha on April 23, 2021, 10:47:16 PM
It sounds silly at first. but what is your weight?
take your weight at the equatore then the pole.
They shoud Not be the same.

The earth is spining? so at the equatore you
are moving faster and with centrifugal force.
so you are being thrown up and away.

If I tell you how fast you will not belive me so,
The Earth is spining at speed, but what is it?
find out how much the earth is from one side to the other side.
times this by Pi 3.14159.  24 hours in a day,

so divied what you got by 24.
that is how fast you are moving at the equatore!
stand at the pole! you have no centrifugal force?

So you are heavy at the pole and um! you may fly off at the equatore!

No grammar police. its off topic!

Title: Re: what is your weight?
Post by: scomato on April 23, 2021, 10:51:36 PM
https://wtamu.edu/~cbaird/sq/2014/01/07/do-i-weigh-less-on-the-equator-than-at-the-north-pole/
https://www.sciencefocus.com/planet-earth/why-dont-we-weigh-more-at-the-poles-than-we-do-at-the-equator/

Yes, you weigh less on the equator than at the North or South Pole, but the difference is small. Note that your body itself does not change. Rather it is the force of gravity and other forces that change as you approach the poles.

You weigh about 1% less at the equator than at the poles. If you weigh 200 pounds (90.7 kg) at the North Pole, you will weigh 198 pounds (89.8 kg) at the equator.
Title: Re: what is your weight?
Post by: Toddler Thork on April 23, 2021, 11:02:44 PM
https://wtamu.edu/~cbaird/sq/2014/01/07/do-i-weigh-less-on-the-equator-than-at-the-north-pole/
https://www.sciencefocus.com/planet-earth/why-dont-we-weigh-more-at-the-poles-than-we-do-at-the-equator/

Yes, you weigh less on the equator than at the North or South Pole, but the difference is small. Note that your body itself does not change. Rather it is the force of gravity and other forces that change as you approach the poles.

You weigh about 1% less at the equator than at the poles. If you weigh 200 pounds (90.7 kg) at the North Pole, you will weigh 198 pounds (89.8 kg) at the equator.
Preposterous.

Step 1. Buy 100 tons of gold at equator.
Step 2. Sell 101 tons of gold at North Pole.
Step 3. ???
Step 4. Profit.
Title: Re: what is your weight?
Post by: SteelyBob on April 23, 2021, 11:36:49 PM
https://wtamu.edu/~cbaird/sq/2014/01/07/do-i-weigh-less-on-the-equator-than-at-the-north-pole/
https://www.sciencefocus.com/planet-earth/why-dont-we-weigh-more-at-the-poles-than-we-do-at-the-equator/

Yes, you weigh less on the equator than at the North or South Pole, but the difference is small. Note that your body itself does not change. Rather it is the force of gravity and other forces that change as you approach the poles.

You weigh about 1% less at the equator than at the poles. If you weigh 200 pounds (90.7 kg) at the North Pole, you will weigh 198 pounds (89.8 kg) at the equator.
Preposterous.

Step 1. Buy 100 tons of gold at equator.
Step 2. Sell 101 tons of gold at North Pole.
Step 3. ???
Step 4. Profit.

Why is it preposterous? It’s true. Weight does change at different latitudes.

To be technically correct, there’s so such thing as centrifugal force, although it’s a commonly used phrase to help explain and understand what is actually a  centripetal force.

To your point on profiting...it’s been suggested on numerous occasions. Two points to understand though:

- weight and mass are not the same thing. 100kg of gold will always be 100kg of gold, wherever it is. North Pole, equator, in orbit, on the moon - the same. Mass doesn’t change. Its weight, however, does. Weight is a force, measured in Newtons. We measure weight and use it to calculate mass, because measuring mass directly is quite hard to do.

- you would find the scales used to measure your gold in both locations actually read the same. This is because in applications where accuracy is important, reference weights are used to calibrate the scales, thereby correcting for local g variations.
Title: Re: what is your weight?
Post by: Toddler Thork on April 24, 2021, 12:03:57 AM
- you would find the scales used to measure your gold in both locations actually read the same.

This is because in applications where accuracy is important, reference weights are used to calibrate the scales, thereby correcting for local g variations.

Well that's some fine circular reasoning. 'The scales would read the same ... if you calibrated them to read the same'. Thank you very much, Sir Isaac.  ::)
Title: Re: what is your weight?
Post by: buddha on April 24, 2021, 12:35:22 AM
I am for a not ball earth.
I was trying to put it in a way to get you to think about it.

as I get it, the earth is spining at 831.9KM a hour?
from the link it says 0.4 percent differences!
that seems to small?
Title: Re: what is your weight?
Post by: SteelyBob on April 24, 2021, 07:19:41 AM
- you would find the scales used to measure your gold in both locations actually read the same.

This is because in applications where accuracy is important, reference weights are used to calibrate the scales, thereby correcting for local g variations.

Well that's some fine circular reasoning. 'The scales would read the same ... if you calibrated them to read the same'. Thank you very much, Sir Isaac.  ::)

No, it's not. You have an agreed set of reference weights (which should, more correctly, be called 'masses') made and calibrated for the task. Like these:
Quote
https://www.cleaverscientific.com/electrophoresis-products/oiml-weights-f1-100g-calibration-weight/

If you're going to trade on a unknown amount of gold, both parties are going to want assurance that the amount being bought and sol is accurate, so you use calibrated scales, benchmarked using reference weights/masses. That way your equatorial gold will measure the same at the your point of sale in the arctic. That's why scales have a 'legal for trade' mark on them if they have been calibrated for that purpose. It's not just gravity, or the correction needed for centripetal acceleration, there lots of other error sources too. The mass never changes though - it's just the challenge of measuring it.

It's not clear what you are disputing - are you saying that things don't weigh slightly less as they get closer to the equator?

Title: Re: what is your weight?
Post by: fisherman on April 24, 2021, 03:53:03 PM
What we perceive as weight is nothing more than the normal force pushing up.

Disclaimer: I'm sticking with Newtonian concepts of gravity/RE concepts to avoid confusion.

On an RE with gravity, gravity is pulling you down onto the ground.  According to the action reaction principle, the force of your feet pushing on the ground causes the ground to push back up.  That's what you perceive  as your weight.

As long as you are perfectly perpendicular to the ground, the two forces will be equal.  The force of gravity pulling you down onto the ground will be equal to the force pushing you back up.  As long as those two forces are equal you remain stationary.

You don't "fly off" at the equator, because no matter where you are on the earth, gravity and the normal force will "equalize" in response to one another, keeping you on the ground.

If you aren't perfectly perpendicular, and the gravitational force and normal force aren't exactly equal, you don't fly off, but you will fall down, again equalizing the two forces, keeping you in place.
Title: Re: what is your weight?
Post by: SteelyBob on April 24, 2021, 05:07:10 PM
I am for a not ball earth.
I was trying to put it in a way to get you to think about it.

as I get it, the earth is spining at 831.9KM a hour?
from the link it says 0.4 percent differences!
that seems to small?

Things don't spin at a speed - that's the wrong unit of measure. Things spin at angular rates, like degrees per second, or perhaps revolutions per unit of time, like rpm. Earth spins at 15 degrees per hour, which is barely perceptible. Yes, at the equator that equates to a fast speed, but that means little on its own when calculating the implications for the change in weight.

The equation we want for this is the one describing centripetal force and circular motion : a = v2 / r

Earth's equatorial radius is around 6371km, or 6,371,000m

So our 'v' at the equator is the circumference of the equator (the distance) divided by the time it takes to travel that distance - one day. 24 hours is  86400 seconds, so v = 6371000 * pi * 2 / 86400 = 463 m/s, or 1667 km/h, which is about 1000mph.

Then we plug in our v and r figures into the equation and we get a = 4632 / 6371000 = 0.0336 m/s2

So, if our typical 'g' is 9.81 m/s2, then our figure at the equator will be 9.81 - 0.0336 = 9.776

So, not really much of a difference, although measurable with reasonable accurate scales, and significant if you are trying to achieve a world record in an event of some kind. It's worth bearing in mind though that other factors influence gravity itself around the globe, so the exact figure won't be this simple.