Best,

-joe

Abstract: 

The unification of quantum mechanics and general relativity, two of the most successful

theories in physics, poses immense difficulties, such as the problem of time. Recent works

have started to investigate low energy effects at this interface, probing the quantum nature of

spacetime. This thesis starts with the assumption that a superposition of masses leads to a

superposition of spacetimes. We formalize this notion under the additional assumption of low

velocities. To illustrate these ideas, we simulate the gravitational quantum switch. We then

present a scheme to map out spacetime using signals, as an operational way to distinguish

spacetimes. The second part brings clocks into the picture. We derive a decoherence effect

of a large mass near a clock and a minimal uncertainty for a clock in a gravitational field.