If earth is round then why dont we slip...or fall out

Thread Starter

Himanshoo

Joined Apr 3, 2015
265
If we think earth to be round(sphere) then how are we able to stand over it ...i mean imagine yourself standing on a big ball..and if you pour water over it ...it should flow off...so according to this theory we must not have any ponds or stagnant water bodies on earth...but any how we have..... why???

please bear with my imagination..:)
 

djsfantasi

Joined Apr 11, 2010
9,163
Gr
If we take gravity into context...and suppose we start moving ..then by the time we reach the bottom of earth we should feel dizzy..just as the boys in pink and yellow shirt would be feeling right now in the picture....
Gravity (illustrated by the white arrows) is aligned with their bodies in the same way as the boy in the green shirt. So, from their perspective they are in the same position as the boy in the green shirt. It's all relative so no dizziness.
 

Thread Starter

Himanshoo

Joined Apr 3, 2015
265
Does gravity have any thing to do with flow of liquid on earth...of course it prevents it from hanging up...or anything beyond that
 

djsfantasi

Joined Apr 11, 2010
9,163
But all three people are in "direction 'up'". Up is relative to the direction of the force of gravity, which is down. That direction is represented by the white arrows.
 

GopherT

Joined Nov 23, 2012
8,009
If we think earth to be round(sphere) then how are we able to stand over it ...i mean imagine yourself standing on a big ball..and if you pour water over it ...it should flow off...so according to this theory we must not have any ponds or stagnant water bodies on earth...but any how we have..... why???

please bear with my imagination..:)

If things would work that way, discussing of toilets flushing in the Southern Hemisphere causing a vortex that is clockwise vs counter-clockwise would be a minor issue compared to the direction of water flow (up vs down).
 

Wendy

Joined Mar 24, 2008
23,429
I have to wonder if this thread is serious, or some sort of joke. I would like to ask the OP what education level he is at?

I see from the profile he is 25 years old, and I looked up where the post is coming from (no need for others to know).

I'm discussing with the other moderators why this is in the Physics Forum, it really does read like a joke. If it is a serious question then we'll treat this as a serious thread.

1. How big do you think the earth is? It is big enough you can not see the curvature from walking or driving. Even flying it is hard to spot.

2. Local gravity is created by the earth, gravity is not outside the earth (as the question would imply). It always points to the center of the earth.
 
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Thread Starter

Himanshoo

Joined Apr 3, 2015
265
I have to wonder if this thread is serious, or some sort of joke. I would like to ask the OP what education level he is at?

I see from the profile he is 25 years old, and I looked up where the post is coming from (no need for others to know).

I'm discussing with the other moderators why this is in the Physics Forum, it really does read like a joke. If it is a serious question then we'll treat this as a serious thread.

1. How big do you think the earth is? It is big enough you can not see the curvature from walking or driving. Even flying it is hard to spot.

2. Local gravity is created by the earth, gravity is not outside the earth (as the question would imply). It always points to the center of the earth.
My point of query is quite simple...---> It is part of the natural physics of water and other fluids to always find their level and remain flat.If disturbed in any way, motion continues until the flat level is regained.since the nature of all liquids is to quickly flood outwards taking the easiest course towards finding its new level.Hence the upper surface of fluid at rest is a horizontal plane..If earth is a sphere then all earth's water (oceans and all)should maintain some degree of convexity....but this is against the fundamental physical nature of water to be always be and remain level at a horizontal plane.... what should i infer then...
 

Wendy

Joined Mar 24, 2008
23,429
But the earth is not flat. The oceans are curved around the earth. You are confusing a macro phenomena with a micro phenomenon. The very big and the very small act differently.

Even a glass of water on your desk has the curvature of the earth, but it is so tiny I suspect it can not be measured.

With surveying (measuring plots of land ) and map making you can not escape this fundamental fact. We approximate because we can, it works. But on a global scale you can not evade it any longer.

I would still like to know your education level. This sort of stuff should have been sorted out in your head at a very young age.
 

MrChips

Joined Oct 2, 2009
30,824
My point of query is quite simple...---> It is part of the natural physics of water and other fluids to always find their level and remain flat.If disturbed in any way, motion continues until the flat level is regained.since the nature of all liquids is to quickly flood outwards taking the easiest course towards finding its new level.Hence the upper surface of fluid at rest is a horizontal plane..If earth is a sphere then all earth's water (oceans and all)should maintain some degree of convexity....but this is against the fundamental physical nature of water to be always be and remain level at a horizontal plane.... what should i infer then...
What is "the fundamental physical nature of water"? If you think it is to remain level at a horizontal plane then you are mistaken. The "fundamental physical nature" of any fluid is to assume the shape of a sphere. Have you ever noticed the shape of raindrops?

A tiny blob of water, oil, molten metal, mercury, etc. will be spherical. What happens to the shape of the blob as the amount of material increases?

Why do you think a mass of water on the planet wants to remain level on a horizontal plane?
 
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Thread Starter

Himanshoo

Joined Apr 3, 2015
265
But the earth is not flat. The oceans are curved around the earth. You are confusing a macro phenomena with a micro phenomenon. The very big and the very small act differently.

Even a glass of water on your desk has the curvature of the earth, but it is so tiny I suspect it can not be measured.

With surveying (measuring plots of land ) and map making you can not escape this fundamental fact. We approximate because we can, it works. But on a global scale you can not evade it any longer.

I would still like to know your education level. This sort of stuff should have been sorted out in your head at a very young age.
Ok if human size would be this as seen in the pic and then ignoring force of friction and gravity for a moment..would it be obvious that we would slip around the curves...
upload_2015-5-9_23-39-27.png
 

MrChips

Joined Oct 2, 2009
30,824
There is no friction.
Why would you slide? There is no force to pull you sideways. All of the force is downwards from your head to your feet as shown by the arrows in the diagram.
You cannot ignore gravity because so far all your questions can be explained by one force, gravity.

Why do you think the earth is spherical?
If it were not for gravity, there would be no planet and we wouldn't be sitting here discussing this.
 

Thread Starter

Himanshoo

Joined Apr 3, 2015
265
There is no friction.
Why would you slide? There is no force to pull you sideways. All of the force is downwards from your head to your feet as shown by the arrows in the diagram.
You cannot ignore gravity because so far all your questions can be explained by one force, gravity.

Why do you think the earth is spherical?
If it were not for gravity, there would be no planet and we wouldn't be sitting here discussing this.
The curve of earth is approx 8 inch per mile..which is almost negligible to experience since the size of human is very small in comparison to earth...micro phenomenon as Bill discussed earlier ....and now considering human size to be very-2 large in comparison to earth ...and considering gravity also...would then we experience the curve of earth...??
 
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