What is gravity?

How does science work? And what's all this about quantum mechanics?

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Re: What is gravity?

Post by gaffo »

RCSaunders wrote: Fri Jul 17, 2020 7:19 pm
commonsense wrote: Thu Jul 16, 2020 11:24 pm Gravity is the force generated by the electromagnetic attraction between objects.
You are joking aren't you?

Gravity and magnetism are totally different phenomena. All mass is accelerated toward other masses and the rate of acceleration is always directly proportional to the mass and inversely proportional to the distance. That acceleration is described as a force of attraction. Gravity has no poles.

Magnetic force is totally independent of mass (except for the mass of the electrons involved) and there is no relationship between mass and the force which may either attract or repel. Ferromagnetic materials are attracted to a magnetic field, diamagnetic material is repelled by a magnetic field, and for all magnetic fields, like poles always repel.

There is no gravitation repulsion, and no magnetic attraction between most physical bodies.
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Re: What is gravity?

Post by RCSaunders »

gaffo wrote: Sun Aug 02, 2020 4:27 am
RCSaunders wrote: Wed Jul 15, 2020 1:30 am
seeds wrote: Mon Apr 16, 2018 11:37 pm ... gravity?
Gravity is not a thing or even an attribute. It is only an observed phenomena of entities which have momentum. All such entities accelerate towards each other, and that phenomenon is called gravity. If you are going to ask, what is gravity, you have to ask what is mometum--why do bodies remain in motion (at the same speed and direction) unless accelerated? And, since no entity is totally isolated, all entities are constantly accelerated.
Gravity is a Force, and it it depends upon MASS, not momentum.
Of course, but you cannot actually measure mass. You can measure acceleration and mass is described in terms of that. I used momentum because only that which can have momentum is mass. I have no idea why physics has dropped the fact that momentum is defined as mass times velocity, the fact a mass must be accelerated to have a velocity has simply been dropped. It is a mistake.
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Re: What is gravity?

Post by Impenitent »

gaffo wrote: Sun Aug 02, 2020 5:15 am
Impenitent wrote: Fri Jul 17, 2020 4:47 pm
uwot wrote: Fri Jul 17, 2020 4:33 pm Impenitent, what the fuck are you doing asking serious questions all of a sudden? Meh. In order:

Well the honest answer is I don't know, having only ever been on one planet, but I would be surprised if a few million miles made a huge difference to the laws of physics. The assumption is that the rules are universal, so it is simply a matter that the more massive the planet, the close the magnet has to be to win.
Could, for example, aluminium be magnetic on Mars? Well never say never, but never.

That's the test isn't it? Good question. I don't know the answer, but I really think if it were shown that magnets do weird shit in outer space we would have heard about it.
thanks, the conversation just struck me so I asked ...

I thought that the gravitational pull from larger planets was greater than that on Earth so I thought magnetism on the larger planets may differ accordingly...
um no. there is the Electromagnetic Force, Gravity, the Weak Force, and the Strong Force (the last two are related to the atomic nucliuos and radioactive decay. - when the weak force is not longer able to counteract the strong force, we have fission/radioactive elements - and why all elements after/from Bismuth - now we now Bismuth is a radioactive element - though half live is 1-percent of the universe's age), and why all heavier elements are not able to keep there nuclous - shit together, and eventually fly apart.

- this may in fact apply to the proton itself - to date we still do not know - 40 yrs now and counting - if so (proton decays - to someting/and a photon) - then all mater is radioactive and will eventually decay into energy.

though we are talking in timelines much longer than the lifetime to date of the universe.

Impenitent wrote: Fri Jul 17, 2020 4:47 pm if magnetism on the larger planet is different, perhaps a denser or "heavier" metal would be more magnetic...
Magnetism is a property of an element - not the mass of .

so say Lead, a heavy element is not magnetic - be it here on Earth or on Mars or on Jupter or in space.

Iron, a middle weight element is magnetic - be it here on Earth or on mars etc.........

Aluminum/Magnesium are light weight and are not magnetic -be they on earth mars........etc.........

all about the element in question - not were that brick of iron is in the universe.

Impenitent wrote: Fri Jul 17, 2020 4:47 pm perhaps if the magnet was far enough away from a gravitational source it would do weird stuff...
nope. EM force is a force outside and unrelated to gravity or position in space.


Impenitent wrote: Fri Jul 17, 2020 4:47 pm a compass on the moon doesn't point north does it?
nope, the compass will not point north because the moon has not magnetic field.
Impenitent wrote: Fri Jul 17, 2020 4:47 pm (then again, north on the moon is different than north on the Earth isn't it?)
um, nope, "north is north" - be it on the moon earth or mars or where-ever.
thanks for the responses- north is north if it is the top of the spinning generic globe...

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