The extreme weakness of gravitation currently excludes experimentation with gravity in the quantum regime. Here, I will report how high energy makes a quantum process, Compton scattering, sensitive to gravity and how to measure the strength of photon interaction with the Earth's gravitational field. Then, I will demonstrate a dramatic departure from the general relativity's light deflection predictions by exploring existing laser Compton scattering data for high energy photons. Experimental hints for opposite - away from the Earth - deflection from two different accelerator laboratories will be discussed as well. In perspective, dedicated high energy gravity tests could provide an experimental breakthrough for understanding and developing the quantum theory of gravitation.
