Blog of Veikko M.O.T. Nyfors, Hybrid Quantum ICT consultant
Quantum Mechanics demystified, a try
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Gravity
Aristotle
One of the earliest attempts to explain gravity, e.g. why things fall to the ground, was that of the Greek philosopher Aristotle’s. He explained things were willing to move to their natural places. Apples to ground, air to up, fire even higher and water in between. Quite a good explanation, isn’t it? For that age.
Galileo
It was Galileo Galilei who figured it out that an object will carry on moving with a steady velocity along a straight line. Unless a force is effecting it to take a turn from the line into force’s direction. Why does the object carry on straight, that’s a bit of a mystery.
Or has been. Actually, you see, each and every object just stands still at it’s own spot. That is when we look the case from the object’s own frame of reference. Having two objects standing still in their own frames of references, each object perceive the other moving along a straight line. Just as Galileo had put it.
When one is stationary at 3D frame, it is still that the time is moving. We’ll come to that down there.
Newton
Isaac Newton then said, that two objects attract each other with a force relative to their masses and counter relatively to the square of their distance. Ok, the apple is falling to the ground! Gravity!
But again, this is the hunch we get when we look at it from our own frame of reference, which is more or less the same as for the earth, i.e. ground. If we look it from the frame of reference of the apple, the ground is moving towards the apple. From a passing by bee’s frame of reference, earth and apple are both moving towards each other.
So, the apple is not falling to the ground in anywhere else than in our minds.
But the attraction between those two is there, just as Newton said. But not necessarily exactly as Newton thought.
Einstein
As Einstein game, Newton’s reckoning got into doubt. It appeared to be only part of the thruth.
Einstein said gravity is due to bended space-time. Space-time near masses get warped. This approach held good on scales beyond Newtonian ones also, e.g. near to the speed of light.
Here again we meet the affair of time moving in distinct frames of references. The two objects, Earth and the apple, are just standing still on their own frames of reference. But they are approaching each other, nevertheless. The time is flowing though. In the curved space time. Time is just another dimension in our universe’s space. Us humans are able to comprehend space only in 3D (+time), but there most certainly are even more dimensions. Curving is likely to take place over other dimensions as well. Whatever it means in the end.
As space-time is curved, i.e. time is non-linearly related to other dimensions in space, two objects apparently moving linearly to each other in time are not doing so in the end. In Earth-apple case they get closer and closer to each other, colliding in the end.
The warp of space-time due to masses makes the objects possessing the mass get closer to each other when the time passes. That’s the kind of a warp it is.
Analogous to two persons starting from equator straight towards north, some distance away from each other. It appears they are moving along parallel lines, but instead they will get closer to each other on the way, eventually getting together at North Pole. Apparently linear lines get closer and collide in the end on non-euclidean, ‘warped’ flat space.
Mathematically Einstein’s described gravity in exact formulas. Like
It says curvature of the space-time is equal to the amount of mass-stress-energy in space-time.
These formulas have held true so far, so they must be correct to at least some degree better than Newton’s.
Intuitively this stuff is harder to catch than mathematically. Common images and animations where a marble is rolling on a rubber sheet bent by a bowling ball in the middle, make it no easier. That scene might just be too close to our reality. I have it hard at least to relate the rolling of the marble actually describes the time flowing.
QED
Below Quantum electrodynamical interpretation is based on gravitons. Graviton field is a permeative particle field spreading out from and to every direction of the universe in the speed of light.
Earth absorbs and apple absorbs gravitons. Ending up on less gravitons speeding between earth and apple.
Causing gravitons from other directions pushing apple and earth towards each other.
Some say this can’t be causing gravitation, as there would be below described flaw in above idea.
Earth is rotating around the sun with tremendous speed of 107000 km/h. Earth should therefore hit more gravitons from the front than from the back. Making orbital speed to slow down, causing earth’s orbit to drop eventually down towards sun.
Haven’t happened in 4*109 years. Contradiction! This theory can’t hold, they say.
But, there is a flaw on that deduction, instead.
You see, graviton field is spreading from and to every direction, with speed of light. Thus earth is hitting as many gravitons on the front as on the back.
Us humans just so easily conceive this scenario in sun’s frame of the reference. Assuming graviton field is somehow attached to that.
As we always tend to see things in the frame of reference of the most massive object around.
Let’s still have a look on the falling apple. If it would clarify this a bit more.
Earth is rotating round it’s axis at about 1600km/h at equator. As is the apple in the tree there. Once it drops from the tree, there is no (electric) force keeping the apple at the same vertical spot any more.
Now that the apple is speeding the 1600km/h, if graviton field would be attached to earth’s frame, it should be hitting more gravitons from the frontside than from the back side. Thus the rotating speed of apple should decrease and it should drop a bit east from the spot directly under. Unfortunately we do not have accurate enough equipment to measure this. However, if we did, we could see the apple is dropping directly to the ground, not any amount east.
Gravitons are hitting the apple evenly from front and back in this case also.
But less from down than up. That’s gravity!
