Is this another limit for Newtonian Gravity?

  • 0 Replies

0 Members and 1 Guest are viewing this topic.


Offline MikeS

  • Neilep Level Member
  • ******
  • 1044
  • The Devils Advocate
    • View Profile
Is this another limit for Newtonian Gravity?
« on: 02/08/2011 09:17:54 »
"Newton's law has since been superseded by Einstein's theory of general relativity, but it continues to be used as an excellent approximation of the effects of gravity. Relativity is required only when there is a need for extreme precision, or when dealing with gravitation for extremely massive and dense objects."'s_law_of_universal_gravitation

According to Newtonian gravity, a photon gains energy when falling within a gravitational field.
According to General Relativity  the photons does not actually gain energy, it just appears to as it is viewed from a different reference frame deeper within the gravity well.

The aim of this post is to show that Newtonian gravity is inadequate in this situation and should not be used when considering photons.

Consider this experiment.
We have a high tower, at the top of which there is a device for converting electricity into pair particles.  (let’s assume that matter and antimatter particles are both gravitationally attractive)   We drop the particles and catch them in buckets at the bottom of the tower.  The buckets are essentially like a water wheel.  The wheel turns a generator producing electricity.  The electricity is sent back to the top of the tower to produce more pair particles.  Let’s assume the apparatus is all lossless.  There is no loss of energy in the ‘wheel’, generator or wires.

Let us look, in more detail at what is happening:-
In the ‘downward’ leg of the loop.
A pair particle is produced at the top of the tower and falls down the tower and in so doing converts some of its gravitational potential energy (PE) into kinetic energy (KE).  The wheel and generator convert that KE into electricity.  The electricity is sent back to the top of the tower.

Let us look more closely at what is happening in the electrical circuit. 
The ‘upward’ leg of the loop.
It is a simple two wire circuit.  Electricity flows up one wire and down the other.  Gravity is effecting all of the electrons equally, trying to pull them all downwards.  Any potential gain in energy of the descending electrons is cancelled by the potential loss of energy in the ascending electrons.  The current in the circuit ‘should’ be the same regardless of where measured.  Overall, it would appear there is no loss or gain of energy due to gravity.

What has happened in one cycle:-
The downward leg has gained energy.
The upward leg has neither loss nor gain.
Therefore, there is a surplus of energy over.

This surplus of energy is used to create more particles which gain more energy and so on.
In every cycle there is an increase in energy.  Not just perpetual motion but a continuous production of usable power .

Obviously, the above experiment cannot work as it would defeat the first and second laws of thermodynamics. 

How does Newtonian gravity explain the apparent discrepancy in energy in the above experiment.  As far as I can see, it doesn’t.  All it can offer is that energy must be conserved and ‘it takes energy to lift something into a higher gravitational potential’.  None of which explains what is actually happening in the above experiment.

GR time dilation fully and simply does explain the mechanism for why  energy is conserved in the above experiment.

The question is why can’t Newtonian gravity account for the energy discrepancy?  It can’t because it is being applied to electricity which in a sence ‘flows’ at the speed of light.  If it shouldn’t be applied to electricity because electricity travels at the speed of light then it should not be applied to light itself.

Photons do not gain energy when ‘falling’ within a gravitational field.  They only ‘appear to’ when observed from the perspective of Newtonian gravity which itself is inadequate to explain what is really happening.

Edit added 01-09-11
"An object in free-fall is in actuality inertial, but as it approaches the planetary object the time scale stretches at an accelerated rate, giving the appearance that it is accelerating towards the planetary object when, in fact, the falling body really isn't accelerating at all. This is why an accelerometer in free-fall doesn't register any acceleration; there isn't any."

This is why a photon does not gain energy 'falling'within a gravitational field.  A free falling accelerator proves it.

« Last Edit: 01/09/2011 07:44:01 by MikeS »