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Physics, Astronomy & Cosmology / Equivalence principle´s roots: are they that strong and clear?
« on: 09/11/2017 07:56:38 »
Recently I´ve been trying to convey the idea that what we feel in a gravity field isn´t actually gravity itself, but internal stresses originated by both the fraction of gravity somehow not allowed to make each part of our body accelerate (acc. to Newton´s 2nd Law), and the push and/or pull exerted on us by the "obstacle" that avoids our fully free fall (and the subsequent "chain" of reaction forces of each part of our body (acc. to Newton´s 3rd Law).
Whatever the deep nature of gravity, that´s quite clear, as far as I can understand.
But "apparently" (?) this Einstein´s journey first steps (before bringing up the idea of relativity), didn´t keep that in mind. "To be "politically correct", I have to say I must be wrong !! … Please kindly help me "ruminate" it over, in order to try and find where my error could be.
It´s better to go step by step, not to jump the gun (and possible errors …)
From an Einstein specialized site I´ve taken:
"...We, the crew of the spaceship shown on the right, are floating freely in space, far away from all major sources of gravity. Now imagine that there is another observer in a spaceship, shown on the left: The rocket engine of that observer's spaceship is firing and produces an acceleration of 9.8 meters (32 feet) per square second. This accelerated observer feels as heavy as we would feel on earth, since the gravitational acceleration with which an object on earth falls to the ground has that exact same value".
So far, so good. But, any further comments? Or ... any nuances to bring up? (for now, better if only directly about what said above …)
Whatever the deep nature of gravity, that´s quite clear, as far as I can understand.
But "apparently" (?) this Einstein´s journey first steps (before bringing up the idea of relativity), didn´t keep that in mind. "To be "politically correct", I have to say I must be wrong !! … Please kindly help me "ruminate" it over, in order to try and find where my error could be.
It´s better to go step by step, not to jump the gun (and possible errors …)
From an Einstein specialized site I´ve taken:
"...We, the crew of the spaceship shown on the right, are floating freely in space, far away from all major sources of gravity. Now imagine that there is another observer in a spaceship, shown on the left: The rocket engine of that observer's spaceship is firing and produces an acceleration of 9.8 meters (32 feet) per square second. This accelerated observer feels as heavy as we would feel on earth, since the gravitational acceleration with which an object on earth falls to the ground has that exact same value".
So far, so good. But, any further comments? Or ... any nuances to bring up? (for now, better if only directly about what said above …)