A private physicist from California has written a research paper, which proves the inconsistency in the Einstein's 1934 two blackboard derivation of conservation of energy.
A private physicist from California claims to have mathematically proven that the law of energy conservation of energy and momentum are flawed and incomplete. The PDF of the paper can found here: http://zpointenergy.com/wp-content/uploads/2014/03/ClassicalEnergyProblem_extended.pdf (http://zpointenergy.com/wp-content/uploads/2014/03/ClassicalEnergyProblem_extended.pdf). As per the paper if multiple inertial observers observe a system with conserved energy then the difference/derivative in energy observed between them is also conserved. For example if John is a inertial observer who observes the kinetic energy of a system as 10 Joules conserved between two states "before" and "after". If Mike is another inertial observer moving at a speed 10 miles/sec with respect to John who observes the the kinetic energy of the system as 15 Joules for the same and if there is a statistician who takes data feed from both John and Mark, he will find that the difference of observed energy between John and Mike (5 Joules) is also conserved. If the statistician employees a huge number of observers, he can plot the energies observed by each of them against the velocity they are going. The plot will remain exactly the same for states "before" and "after" as the energy is conserved and all the differentials along the plot will also remain the same. The paper uses the conservation of energy differentials with respect to velocity to prove that conservation of kinetic energy implies conservation of momentum. Furthermore it proves that there are infinite such conservation equations and all of them need to satisfied for any momentum change or energy exchange. Later in the paper an example of Einstein's 1934 2 board derivation is used to prove that the phenomena as used in that derivation cannot even exist.
Shalender, the physicist who wrote the paper says that the infinite conservation equations are contradictory even to the everyday phenomena of striking of 2 billiard balls. He conjectures that the compensation of non-matching higher level derivatives is provided by the space-time itself, which means that the space-time must be composed of particles with energy and mass and thus the space-time is quantized. He further claims that the inertial frames of reference are created by the gravitation of a heavy bodies, which carry the space-time bundle along with them. It means that a lot of energy exists as a space-time gravitation field beyond the mass itself. So the energy of a mass is not mere E=mc^2 but it is the energy in the space-time it carrier + mc^2.
As per Shalender, this has a strong impact in the way we understand the space-time, energy and fields. Once the problem is completely solved and validated people will also find ways to harness the energy from space-time. Once relation between space-time, mass and energy become clearer, energy can also be used to manipulate space and time, allowing things like negative energy and sending of information towards past.