Ok, I was talking to my roommate the other day and he said that in school they taught him that gravity was created by the earth spinning and the earth’s magnetic field. I told him he was wrong, that the reason why we have gravity is one objects mass being less than another, such as the moon has less gravity because it has less mass than the earth. He said that when man landed on the moon (which I question) they had these magnetic plates on the bottom of the moon buggy to keep it from floating away because the moon has no magnetic field. Honestly, I don’t think my friend knows jack about “NEWTON’S LAW” or general relitivity. I gues they did’nt teach either one of those in his school. Not only do I have that one friend that believes this crap, but I have another friend that believes the same way and has never went to the same school and hardly knows my roommate. Do they really teach this B.S. in public schools? I’d really like to know where I can find some article that says that magnetic fields and/or the spin of an object are not what causes gravity. I did a google search, but to no success.
my physics teacher taught me the same thing… an object with more mass has more gravity, e.g black holes have no volume and infinite density, and thier gravitational energy is so strong, that light and even TIME!!!(seen the bit about time in a tv show about black holes) can’t escape its gravitational force. (source)
Now pretty much everyone knows if something has no volume, it can hardly spin, and if it did (somehow) it would not nearly create enough gravity to suck in entire stars!!
just a little thought! 
(BTW, i love this kind of thing!!! )
Yeah, that sounds like a load of crap what your roomie is saying. Just show him this:
F = Gm1m2 / r^2,
where F = gravitational force
m1 = mass of object 1
m2 = mass of object 2
r = distance between objects
But your explanation seems a little off too. Gravity is due to mass and not relative masses. You can have two objects of the same mass and they still experience gravity.
It probibly has something to do with both.
And Mercury spins around the sun really fast, why doesn’t that create a magnetic field? Also, does the sun rotate?
Different layers of the sun rotate at different speeds, so yes.
as far as i know… yeah but6 interestingly, it rotates faster at the equator like jupiter and saturn
the sunspots change from day to day, so this is evidence that the sun does rotate.
(again i can observe this because i like to project the sun through my telescope on a white screen, but i accidentally melted one of my eyepieces because i kept in on the sun for too long…%|)
Well yes if two objects have the same mass then they both have the same amount of gravitational pull. I’m just tryin’ to figure out a way to show him that magentic fields and spinning doesn’t create the gravity. He says that the magnetic gravity thing can be proven cause the magnets attract each other, metal and repel each other. Sometimes I think he’s stupid 
JackBlack maybe your friend isn’t that stupid after all. I saw in a Nat Geo program that Mars doesn’t have a magnetic field either. And thats why scientist believe theres no life on Mars.
And the scary thing is that they said also that the Earth’s magnetic field is shrinking. Apparently in archeology, they can measure how old something is by measuring it’s magnetic field. When something like an ancient piece of pottery was made and fired up, the magnetic field of that time gets locked in. So the more magnetic field some ancient piece of pottery has, the older it is.
Scientists don’t know why the Earth’s magnetic field is shrinking, it could be the end of the world, or they suspect Earth’s magnetic field is getting ready to flip. Apparently it flips every few hundred thousand years.
Just tell your friend to take a basic physics class at a real school (and report that quack teacher to the school he’s in) or get a book from the library.
Anything with mass has gravity. Electrical fields has nothing to do with it.
There are four fundamental forces:
Strong (force that holds the parts of atomic nuclei together)
Electro-magnetic (your friend’s magnets)
Weak (force that causes nuclear decay)
Gravity (force that attracts masses together)
Gravity is (fortunately for existance) the weakest of them all, but its range is infinite. Gravity isn’t caused by difference in mass, but its relative effect (or strength) is directly proportional to the mass. Google “barycenter”.
Hope this helps.
My roommates in college now (HaHaHaHa… oh man), I was homeschooled, so what is the average grade that General Relativity and Newrons Law of Gravity are taught? He went to public school by the way, not a christian or homeschool.
I think that 11th or 12th grade (High School) will touch on gravity, but relativity is usually reserved for college… I could be wrong.
jackblack you are going about this all wrong,
if you want to show your roommate who is boss,
sneak into his room when he is sleeping and bash his face in with one of those metal folding chairs, like on the old WWF wrestling shows.
jackblack you are going about this all wrong,
if you want to show your roommate who is boss,
sneak into his room when he is sleeping and bash his face in with one of those metal folding chairs, like on the old WWF wrestling shows.
Tried that, didn’t work 
(he’s too hard headed).
isnt the magnetic field of the earth due to the core of solid iron/nickel(?) at its center, and when the liquid metals spin around the outside of the core it creates energy?
i also thought that scientists used carbon dating to check how old things were, not by measuring the magnetic field, because wouldnt an object have to contain at least some iron or magnetic content to have a magnetic field?
Your right
My physics is crap so I ain’t joining this debate.
To my knowledge, a lot of what Newton did is present other peoples ideas (people who had been ridiculed and in some cases persecuted) in a slightly different way so that they would be more acceptable.
hydravien had it right - Earth’s magnetic field is generated by a spinning solid metal core at the centre of a superheated flud. In fact, they made use of this in the fictional movie “The Core”.
The other planets (With one or two notable exceptions) do not have the same spinning core, so no magnetic field. (Although, Jupiter’s magnetic field is so vast, if we could see it, it would take up as much of the sky as the sun and caused NASA to redesign Voyager from the ground up with more shielding!)
This has nothing to do with Gravity, which is a seperate force created by the masses of objects.
Although magnetic and gravitational forces appear similar because the strength of the force varies inversley with the square of the distance between the objects (ie: x times distance = 1/x^2 times force) gravitation is entirely attraction from mass while magnetic fields can be attraction or repulsion and rely on either the positioning of feric ions in a substance, or the movement of electrons.
(And - yes, Einstien freaks, I’m using Newton’s gravitational theory here because I’m on my lunch break and don’t want to have to go into speacial relativity! Those crazy enough can try Relativity in Four Letter Words)
Um… in a nutshell - Your room mate’s wrong.
i also thought that scientists used carbon dating to check how old things were, not by measuring the magnetic field, because wouldnt an object have to contain at least some iron or magnetic content to have a magnetic field?[/quote]
Ozo - yes that is what they suspect will happen - the magnetic poles are currently accelerating and, at the current rate, the North magnetic pole will be in Alaska in just a few decades. The worrying thing is that when (or if!) they decide to flip, there will be a period in which the Earth has no magnetic field, and therefore no protection against cosmic radiation, meaning we’d all turn into lumps of cancer pretty darn quick.
Hydravien - they also use magnetic dating, especially for things such as seabeds and such like - they contain small ferrous deposits that align to the direction of the magnetic field.
Although in practice this technique is usually used in reverse - the mid-ocean ridges are formed where tectonic plates are moving apart and magma fills the gap, and as it cools the magma’s ferrous deposits align themselves to the direction of the magnetic field. It was scientists investigating this that discovered that the Earth’s magnetic field regularly flipped - they discovered bands of rock that had alternating directions of magnetic field.
Wow! Very interesting. How the heck can you know there is a magnetic field inside a planet, much less a sun, if you haven’t been there?
there are ways to view the magnetic field (i would assume) and you would also notice that magnetic objects (asteroids) are there when they wouldnt normally be. there are also ways to pulse sound into the earth and by doing so, you can tell what material it is made out of. that is how they know that the earth is in layers.
science is fun