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Well, actually, no, we don't really understand the mechanism underlying force at a distance (gravity and magnetism). We have very accurately quantified the effects. But the best explanation to date of HOW gravity acts at a distance with no intervening medium (sorry, no luminiferous aethyr) is Einstein's concept that mass creates a warpage in space-time, which means that objects with mass move toward positions of lower gravitational potential. His quantification of this effect was proven when astronomical observations demonstrated the bending of light rays around the sun, but the underlying explanation still remains unsatisfying.
Of course everyone learns the inverse square law of gravitational attraction in high school, and many learn the related laws of magnetic fields in college (Maxwell), but no, the actual fundamental mechanism by which these forces act, at a distance, in a vacuum, is NOT truly understood in the way we understand how water boils or a beam bends under load.
This is exactly what I'm trying to drive home. Most humans aren't scientific-minded. Striking a match in front of people of primitive tribes would seem like witchcraft to them.
How does a magnet move a steel ball without touching it?
Why would it have to touch it? It moves it because of the magnetic qualities of the ball. A magnet doesn't move a brass, aluminum or gold ball. Why not, OP? Mystery?
If it wasn't for gravity, those Aussies would float up and hit their heads on the ceiling.
Despite 4 years of physics in HS/college, I still don't believe in magnetism. Something is missing in the explanation, or something.
I believe that some things in nature are never meant for human minds to fully grasp. The world wouldn't be so fun or exciting if all secrets of nature were revealed to man.
I understand why gravity is important, though. It holds the earth together. It, combined with opposing centrifugal force, keeps us a certain distance from the sun for enough vital energy to live without burning to death. It keeps us from floating away into space. It is one of several nature's tools for law and order in the universe. I have a gun to end my misery should the earth get too close to the sun and things get horribly hot here on earth. Gravity between the earth and sun would prevail if the earth slowed down on its orbital travels and the orbit decayed and we spiraled toward a great ball of flames. Conversely, the earth might speed up and escape the sun's field of gravity and things might get quite cold here. What can change the earth's velocity of orbit? A nuclear blast? Collisions with space junk or big extraterrestrial rocks?
This is exactly what I'm trying to drive home. Most humans aren't scientific-minded. Striking a match in front of people of primitive tribes would seem like witchcraft to them.
Who says witchcraft doesn't operate according to scientific laws? Maybe if someone actually bothered to research aspects of it, they might be surprised. Science is still in its infancy, in some ways.
Who says witchcraft doesn't operate according to scientific laws? Maybe if someone actually bothered to research aspects of it, they might be surprised. Science is still in its infancy, in some ways.
The supernatural has no place in physics, biology, modern medicine, chemistry or mathematics. I don't believe in magic. I believe stage magicians conjure illusions according to certain natural laws. The human eye can be fooled in certain conditions.
Stage magicians violate no laws of physics. They merely create illusions that the human mind might incorrectly presume to be something of reality. The eye sees something, a stimulus, light, but the mind repaints the whole picture differently.
Man doesn't know what causes it or how it works. We can only observe and measure its effects. Gravity, like another natural non-contact force, magnetism, seems to have no perceivable direct mechanical (material) connection between the two bodies being attracted to one another or repelled from one another.
I can tie a rope to a box and pull the box toward me over the ground. The rope in question is the material means which binds the force exerted by my body with the box. It's a force communication component. A car's transmission communicates force or driving energy through a mass, or a drive shaft, to the rear axle.
Gravity and magnetism both have no apparent ropes, wires, strings or shafts attached between two masses to cause movement between them.
How does the earth move the apple from a tree branch toward the ground without actually touching the fruit?
How does a magnet move a steel ball without touching it?
Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Magnetism is one aspect of the combined phenomenon of electromagnetism.
Well, as I noted above, it's a good explanation of how to calculate the effects of gravity (the good old inverse-square law), but it sluffs over the mechanism of gravity by using the same words I used above "Einstein determined that mass creates a warpage in the space-time continuum which leads objects of mass to move from regions of higher gravitational potential to those of lower gravitational potential" - which strikes me as yet another analogy rather than a true explanation of the detailed mechanism. We know Einstein's calculations are correct as per observations of the bending of light, but it's still not clear HOW gravity acts at a distance. The existence (proposed) of gravitons may be an approach to a detailed mechanism.
Keep in mind that Isaac Newton's great contribution to science was not the inverse square law of gravitation or the theory of light and color or the Principia Mathematica; it was the mental leap that you don't have to understand the detailed mechanism to calculate its effects with great accuracy. Prior to Newton, "scientists" spent immense amounts of time cogitating and theorizing about the mechanisms of the things they observed (almost always fruitlessly as they didn't have the instrumentation to discover them) and very little time quantifying them and establishing the equations governing their behavior. Once, with Newton, people realized that you could take a bunch of data, curve fit the data to fairly simple equations, and successfully use those equations to predict the behavior of physical systems, even though you didn't understand the detailed mechanism, that's when science took off, became experimental rather than purely theoretical, and led directly to the Industrial Revolution and all its results including the computer I'm typing this on.
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Maybe if someone actually bothered to research aspects of it, they might be surprised. Science is still in its infancy, in some ways.
