2.5 OTHER LIFTS EXPERIMENT AND EQUIVALENCE PRINCIPLE
Background and actual explanation
The equivalence principle:
to an observer inside the elevator, without possibility to observe the external
world, there is no physical experiment that it could be performed to
differentiate between an gravitational field and an
accelerated motion.
Working with light is quite
difficult because its high speed. The original Einstein experiment can be
performed, but requires a special attention and enough amount of money. In
order to convince anyone about absurdities of actual general relativity, simple
experiments, able to be interpreted even by unskilled people are developed.
first experiment
Two lifts
one situated in gravitational field and another one in an acceleration field
are considered like in fig. 2.9.

Figure2.9 Ball throwing in gravitational and
accelerated field
On every
lift a golf player having a device for ball throwing is considered.
In case of gravitational
field when the device throws the ball with an angle α, the trajectory of
ball is a known parabola. After the y axis the ball moves for a time upward and
after that downwards related to the floor of lift considered as reference.
In second
case, when the machine throws the ball with the same angle α, the
trajectory of ball is always upwards. The observer having already an idea of
the place where the ball must fall will observe the curios trajectory of ball.
Without applying any mathematical formula he will deduce a simple and logical
conclusion. There is a fundamental difference between a gravitational field and
an acceleration field and is impossible to have an equivalence of them. It is
possible in some cases to have the same effect in both cases, but theoretically
an infinity of causes can produce the same effect.
second experiment
The same
frame with two lifts is considered like in fig 2.10 but in every lift there is
a hunter having a fire arm and there is a possibility to measure the impact
energy of bullets.
In every
case, for every lift, the hunter will measure this impact energy for a
horizontal bullet (E1) and for a vertical bullet (E2).
After that, the observer from every lift, compare the impact
energy of bullets thrown in vertical direction with the energy for a bullet
thrown in horizontal direction.
In case of a
gravitational field, there will be a significant difference between this
energies and ΔE = E2 - E1 will be different of zero, due to the
fact that gravitational field modify the kinetic energy of bullet with
different amounts in up presented cases.
In case of
accelerating field, the observer will measure the same impact energy in both
cases, more precisely E1=E2.
In case of
closed observer, the throwing a bullet in this field means a
action of gravitation in a specific manner of moving bullets. In case of a accelerated field of force the energy in both cases
(vertical and horizontal) is the same, only the trajectory of bullets is
apparent modified by accelerated field.
Again there
is impossible to make the assumption of equivalence between an accelerated field and a gravitational filed.

Figure
12. Bullet energy in
gravitational and accelerated field