WelcomeUser Guide
ToSPrivacyCanary
DonateBugsLicense

©2026 Poal.co

1.5K

Anyone got anything other than the stupid Cavendish experiment?

Prove gravity is real. Please and thank you.

Anyone got anything other than the stupid Cavendish experiment? Prove gravity is real. Please and thank you.

(post is archived)

[–] 0 pt

If the jet stream is caused at least partially by the rotation of the earth, wouldn't the oceans move the same way as clouds, in currents; and also not be affected by that tiny bit of gravity from the moon that we can't reliably measure?

[–] 0 pt

Interesting question.

Do you ever drive with water or coffee in your car?

How does the little tiny cup of orange juice sit so flat on the little tray table of a plane?

The answer is inertia and friction.

The ocean is liquid water which has a very strong bond to itself, and has gotten used to rotating at 1000mph

The air is way less dense, and isn't very good at sticking together (it can be felt as air resistance, but doesn't do a really good job of holding together) allowing the earth to rotate under it. Even though the air wants to stay mostly where it is, it still tags along.

I'm sure there are weather people that can explain the jet stream very scientifically. I usually just reference people to cars and planes as they can relate to those.

Water for sure can be very stable - think rowing a canoe. If you drag the paddle slow enough through the water, there is very little movement of the water but the canoe will move forward/backward. The water holds together and allows the paddle to press against it. Trying to move the paddle fast will create splashes.

Even though 1000mph sounds fast, the earth is very very huge, and 1000mph rotation isn't much, relatively speaking. Do you feel yourself moving at 1000mph when you jump up? no, because of inertia and a relative frame of reference to everything around you.

Look up the 'throwing a ball up in a truck" and then the "shooting a ball out of a cannon" video by mythbusters.

The shooting the ball out one is awesome because they drive the truck at 50mph or whatever, then shoot the ball out the back of the truck at 50mph and the ball just drops straight down.

[–] 0 pt

Rotation at 1000mph is different that a straight line. If you got up to 1000mph in a car, and turned even slightly (rotation of the earth)...you would feel it, and perhaps spill your coffee if it was too full.

They say the air / atmosphere is locked to the earths rotation due to gravity. Which is why you don't see the ground move below you when you are hovering in a helicopter.

I still see no reason why gravity from the moon can affect the tides, but not affect air.

[–] 0 pt

Helicopter hovering is not "stationary" with respect to a point on the ground - the pilot has to control the movement to keep the helicopter stationary, not just because of the rotation but because of winds.

Because of the atmosphere and winds there are no real experiments that can be done to test rotation.

Here's a thought experiment for tides and air:

consider a pool table with all of the pool balls magnetic and the bumpers also slightly magnetic.

for water, one side of the pool table is jam packed with pool balls, and the other side is empty. This represents water having to live in the ocean.

now take a magnet and put it at end of the 'air' side of the pool table. Each pool ball feels the magnet, just a little bit, and wants to move upwards, with the bottom ones pushing those above it a little closer, and each row pushing the one on top of it a bit more.

Over the course of a few hours, the topmost balls will have moved closer because they want to get closer, but also the other balls have pushed them.

Now for air, take away most of the balls, leaving say 20 on the table, and also, start them bouncing around.

The motion of the balls is the kinetic energy of the air. Temperature is defined scientifically as the "average random molecular kinetic energy of a substance." What that means is air is bouncing all around - giving it kinetic energy, and the particles hit each other and go faster or slower or stop, but on average, all the balls have a constant speed.

Now put that magnet at one end of the table. Do the balls change their behavior? No. Because the magnetic force is very weak, and their velocities outstrip the magnetic force by a huge amount. Huge!

So the air see the force, and as a whole might not hit the far end of the table as often, but their velocity/kinetic energy overrides all of the magnetic force.

Why doesn't water bounce around? because liquids have energy due to vibrations and rotations, not kinetic energy like bouncing balls do. So the entire liquid feels the force and with no bouncing, that magnetic force can slowly build up a displacement.

[–] 0 pt

But water isn't the only thing spinning at 1000mph, why does nothing else get affected by the moon?

Have you heard of land tides?

[–] 0 pt

I think I might have briefly heard of them.

I don't think they matter much, because will your house expand and contract upwards?

The answer is that solids are much less affected by the 0.0003% change, and any other earthly forces are much much greater.

Tree branches and leaves should be affected by gravity, but the strength of the branch itself keeps it from moving. Can a toddler handle 0.3grams of force? yeah, probably wouldn't even tip over. So a solid tree branch will not be impacted much from the moon.

Also any wind would definitely cancel out anything that even approached a moon effect.

To see results things have to be huge - ocean huge or lake huge.