Version 2.2, published 20220810
Some people argue that if the Earth was indeed spinning at the speed science tells us, it could not possibly keep all the water (and basically everything else) sticking to the planet, and that we should all be hurled out into space.
The intention of the calculations done on this page is to prove those people wrong.
We will do this by comparing the Earth to a Basketball, and to a Basketballsized solid piece of Lead.
Let's first take a look at some basic facts, and then give an explanation for the given numbers.
Earth  Basketball  Leadball  Earthball  

Equatorial radius 
6 378 137.000  0.121  0.121  0.121  m 
Equatorial circumference 
40 075 017.000  0.760  0.760  0.760  m 
Volume  1 083 210 000 000 000 000 000.000  0.007  0.007  0.007  m³ 
Density  5 513.585  80.855  11 340.000  804 825 976 624 924 000 000 000 000.000  kg/m³ 
Mass  5 972 370 000 000 000 000 000 000.000  0.600  84.151  5 972 370 000 000 000 000 000 000.000  kg 
Gravitational acceleration 
9.799  0.000  0.000  27 244 885 125 074 200.000  m/s² 
The Gravitational Acceleration is the acceleration of an object in free fall, and is the steady gain in speed caused exclusively by the force of gravitational attraction.
To calculate it, we need to use the gravitational constant of 6.67430×10^{11} N×m²×kg^{–2}
The formula is: (Gravitational constant × Mass) / (Equatorial radius)²
As a result, we get the rather wellknown 9.8 m/s² for the Earth, and really small numbers for the Basketball and the ball of lead. This huge difference simply comes from the huge difference in mass of our objects.
And as a side note: Since our calculation of the gravitational acceleration is based the equatorial radius of the Earth, this number will differ slightly if your are not on the equator, or not at sea level.
Obviously, some of these number are either too large or too small to be handled with ease. So from here on, let's write them in scientific notation.
Earth  Basketball  Leadball  Earthball  

Equatorial radius  6.378×10^{6}  1.210×10^{1}  1.210×10^{1}  1.210×10^{1}  m 
Equatorial circumference  4.008×10^{7}  7.600×10^{1}  7.600×10^{1}  7.600×10^{1}  m 
Volume  1.083×10^{21}  7.421×10^{3}  7.421×10^{3}  7.421×10^{3}  m³ 
Density  5.514×10^{3}  8.085×10^{1}  1.134×10^{4}  8.048×10^{26}  kg/m³ 
Mass  5.972×10^{24}  6.000×10^{1}  8.415×10^{1}  5.972×10^{24}  kg 
Gravitational acceleration  9.799×10^{0}  2.737×10^{9}  3.839×10^{7}  2.724×10^{16}  m/s² 
Now, before we start comparing the ability to hold water, some general remarks:
Let's assume our objects are all spinning at the same "speed" (rotation period) as the Earth, spinning around once each day.
Rotation period 
Rotational speed 
Rotations per day 


Earth  8.640×10^{4}  4.638×10^{2}  m/s  1 
Basketball  8.640×10^{4}  8.796×10^{6}  m/s  1 
Leadball  8.640×10^{4}  8.796×10^{6}  m/s  1 
Earthball  8.640×10^{4}  8.796×10^{6}  m/s  1 
Please note that 463.8 m/s equals 1 669.8 km/h or 1 037.6 mph, which is the source of the "spinning at 1000 miles per hour" claim that is often made for shock value.
The rotational speed of all the Basketballsized objects is of course identical, as they have the same diameter and the same rotation period.
Let's calculate the force that is trying to hurl things at the surface ob our objects out into space. This is represented the centrifugal acceleration.
The formula for this is (Rotational speed)² / (Equatorial radius) (speed is important).
Since the centrifugal acceleration and gravitational acceleration directly work against each other, we can also immediately compare them to see if surface matter sticks, or if it goes flying.
Centrifugal acceleration 
Gravitational acceleration 
Difference  Factor  

Earth  3.373×10^{2}  9.799×10^{0}  9.765×10^{0}  m/s²  290.495 
Basketball  6.397×10^{10}  2.737×10^{9}  2.097×10^{9}  m/s²  4.279 
Leadball  6.397×10^{10}  3.839×10^{7}  3.832×10^{7}  m/s²  600.109 
Earthball  6.397×10^{10}  2.724×10^{16}  2.724×10^{16}  m/s²  4.259×10^{25} 
As you can see, the gravitational acceleration is (far) larger than the centrifugal acceleration for all of our objects. Therefore, at the Earth's rotation period, water (or other stuff) will "stick" to the surface of all of them.
If you want to see it in plain numbers: Earth's gravitational acceleration is 9.799 m/s² and the centrifugal acceleration is only 0.034 m/s², which leads to a factor of 290.495 in favor of gravity.
So let's speed things up. In fact, let's assume our Basketballsized objects are spinning at the same rotational speed (not period) as the Earth.
The rotation period is now calculated by Circumference / (Rotational speed).
The number of rotations per day is calculated by 86 400 s / (Rotation period).
Rotation period 
Rotational speed 
Rotations per day 


Earth  8.640×10^{4}  4.638×10^{2}  m/s  1 
Basketball  1.639×10^{3}  4.638×10^{2}  m/s  5.273×10^{7} 
Leadball  1.639×10^{3}  4.638×10^{2}  m/s  5.273×10^{7} 
Earthball  1.639×10^{3}  4.638×10^{2}  m/s  5.273×10^{7} 
Our small objects are spinning fast now. Over 52 million times a day. 610 rotations per second. All that just to match the equatorial rotational speed of the Earth  all because of the huge size difference.
So let's see if things still stick to the surface.
Centrifugal acceleration 
Gravitational acceleration 
Difference  Factor  

Earth  3.373×10^{2}  9.799×10^{0}  9.765×10^{0}  m/s²  290.495 
Basketball  1.779×10^{6}  2.737×10^{9}  1.779×10^{6}  m/s²  0.000 
Leadball  1.779×10^{6}  3.839×10^{7}  1.779×10^{6}  m/s²  0.000 
Earthball  1.779×10^{6}  2.724×10^{16}  2.724×10^{16}  m/s²  1.532×10^{10} 
For the Earth, of course nothing has changed  we haven't touched it.
But for the "lightweight" balls, the tides have turned. At this rotational speed, and resulting centrifugal acceleration, they can now no longer keep stuff at their surface.
And the different in centrifugal to gravitational acceleration is not trivial, either: The centrifugal acceleration is almost 1.8 million m/s² larger than the gravitational acceleration. So all the stuff will leave fast.
What we've seen so far is that at a rather pedestrian rate of one revolution every day, all of our objects can keep hold of things at their surface. But if we spin up the rotation, lighter objects will lose grip and fling things that are on their surface out into space.
Which leaves one quesion open: At which rate do our objects have to spin for the centrifugal and gravitational acceleration to cancel each other out?
Since the gravitational acceleration is dictated only by mass and diameter of the object, we have to calculate the rotational speed, and thereby rotation period, at which the resulting centrifugal acceleration exactly matches that gravitational acceleration.
(Rotational speed) = sqrt((Centrifugal acceleration) × (Equatorial radius))
(Rotation period) = (Equatorial circumference) / (Rotational speed)
Centrifugal & Gravitational acceleration 
Rotational speed 
Rotation period 
Rotations per day 


Earth  9.799×10^{0} m/s²  7.905×10^{3} m/s  5.069×10^{3} s  17.044 
Basketball  2.737×10^{9} m/s²  1.820×10^{5} m/s  4.177×10^{4} s  2.069 
Leadball  3.839×10^{7} m/s²  2.155×10^{4} m/s  3.527×10^{3} s  24.497 
Earthball  2.724×10^{16} m/s²  5.741×10^{7} m/s  1.324×10^{8} s  6.526×10^{12} 
As you can see, if the Earth's rotation sped up 17 times, we'd run into a problem.
Meanwhile the much lighter Basketball only needs to rotate more than 2 times a day, and it will not be able to keep anything on its surface.
Even with the claim of "spinning at 1000 miled per hour", the Earth's rotation is still rather slow. Think about it: Spinning anything at only one revolution per day will not strike anyone as being fast. What makes the rotational speed number look so big is the fact that compared to any spinning object we interact with every day, the Earth is really, really big. It has a large radius, therefore the surface at the end of that radius is moving faster than the surface at the end of a smaller radius when rotating with the same period.
Big mass means big gravitional forces. Although the gravitational pull reduces quickly when moving away from the center of mass, at only one revolution per day it is still enough to overcome the centrifugal force, which is mostly dependend on rotational speed.
Put a Basketball into space, give it a spin of one revolution per day, and water will "stick to the surface".
If someone shows you a YouTube video of someone wetting a Basketball (or any other ball, for that matter), spinning it, and showing the water flinging off in all directions  that is simply because a) the ball is spinning at much more than one revolution per day and b) the ball is inside the Earth's gravitational influence, and atmosphere.