The Moon

Joe_Soap

Well-Known Member
Joined
Apr 21, 2013
Messages
199
Reaction score
0
Ok, I don't know exactly where this thread should be, so move if need be

But what would happen to the earth if the moon got destroyed, say by a massive object?
What would change on planet earth? How would our lives change?
 
On the subject of the moon, how is its gravitational pull generated? Does it also have a molten core?
 
On the subject of the moon, how is its gravitational pull generated? Does it also have a molten core?

Gravitation = Mass
Magnetic field = Iron in molten core.

Moon doesn't have a magnetic field.

Common misunderstanding I hear from some people during discussions about gravity.

My favourite one is: "If the earth or core stops spinning we'll fall off"

???
 
I understand it also keeps our axis relatively fixed in our trip around the sun. So our climate and seasons would become unstable without a moon. It was very important for the development of advanced life to have a stable climate. This is probably in one of the links above.
 
Gravitation = Mass
Magnetic field = Iron in molten core.

Moon doesn't have a magnetic field.

Ok help me. Why does the earth (or any planet/oid for that matter) draw things toward it when everything else forces it away?
 
Ok help me. Why does the earth (or any planet/oid for that matter) draw things toward it when everything else forces it away?

Two marbles attract via gravity when placed anywhere in the Universe. The force of gravity is just very weak compared to the other fundamental interactions. Matter curves space-time. Why exactly? If I have to tell you I have to Ki... erm share my Nobal prize with you?
 
Ok help me. Why does the earth (or any planet/oid for that matter) draw things toward it when everything else forces it away?

Explain what this everything else is?

If you talking about things in orbit, they still attracted and falling towards earth, they just missing. The moon for one is coming closer and will eventually hit the earth... just not within the next couple of billions years from now: still has to much momentum.
If you talking about particles they like solar winds, they electrically charged and we know what happens when N & S on magnets meet.
 
Last edited:
Explain what this everything else is?

sorry, maybe not everything else. If you spin some thing around, the force pushes things away from the centre.

IE: a ball on the end of a string will go to the end of the string and stay there while you are spinning it.
a bucket of water spun around will keep the water inside the bucket while it is being spun around.
 
O
sorry, maybe not everything else. If you spin some thing around, the force pushes things away from the centre.

IE: a ball on the end of a string will go to the end of the string and stay there while you are spinning it.
a bucket of water spun around will keep the water inside the bucket while it is being spun around.

That is thanks to momentum/acceleration, different force.

Will explain it when back on PC

Edit: As promised here we go vs This one

Centripetal force (from Latin centrum "center" and petere "to seek") is a force that makes a body follow a curved path: its direction is always orthogonal to the velocity of the body, toward the fixed point of the instantaneous center of curvature of the path. Centripetal force is generally the cause of circular motion.
In simple terms, centripetal force is defined as a force which keeps a body moving with a uniform speed along a circular path and is directed along the radius towards the centre. The mathematical description was derived in 1659 by Dutch physicist Christiaan Huygens. Isaac Newton's description was: "A centripetal force is that by which bodies are drawn or impelled, or in any way tend, towards a point as to a centre.

vs

Centrifugal force (from Latin centrum, meaning "center", and fugere, meaning "to flee") is the apparent outward force that draws a rotating body away from the center of rotation. It is caused by the inertia of the body as the body's path is continually redirected. In Newtonian mechanics, the term centrifugal force is used to refer to one of two distinct concepts: an inertial force (also called a "fictitious" force) observed in a non-inertial reference frame, and a reaction force corresponding to a centripetal force.
The term is also sometimes used in Lagrangian mechanics to describe certain terms in the generalized force that depend on the choice of generalized coordinates.
The concept of centrifugal force is applied in rotating devices such as centrifuges, centrifugal pumps, centrifugal governors, centrifugal clutches, etc., as well as in centrifugal railways, planetary orbits, banked curves, etc. These devices and situations can be analyzed either in terms of the fictitious force in the rotating coordinate system of the motion relative to a center, or in terms of the centripetal and reactive centrifugal forces seen from a non-rotating frame of reference; these different forces are equal in magnitude, but centrifugal and reactive centrifugal forces are opposite in direction to the centripetal force.

So simply put the Centrifugal force caused by the moons speed is just high enough to negate most of the Centripetal force caused by gravity so that it "miss" earth. As it slows down the Centrifugal force becomes weaker and orbits closer. But thanx to the lack of resistance in space this speed loss is not something we have to worry about. Oh and the same things happens to all the planets vs the sun and all the sun's vs the center of the galaxy where a certain black hole wanna suck us in.

Another fun fact: Outer planets travel slower than internal ones but because of the weaker force gravity has at greater distance, and man made satellites use rocket boosters to keep its speed constant so that they do not spin off or fall to earth. That is why they eventually "fall" when fuel is spent.
 
Last edited:
Ok, I have now learned about Centripetal force.
What causes it tho? Centrifugal force is caused by the momentum involved in the energy used in pushing it away, and the string on the ball or the arm on the bucket keeps it from flying away.

What is the energy that causes Centripetal force?
 
Top
Sign up to the MyBroadband newsletter
X