# Calculating the mass of a wormhole

What would for an observer be the mass of an isolated wormhole (meaning that there is no gas and no mass of stars around it) if the wormhole mouth opposite to the observer reflects the light of a region from the galaxy it opens into.

Wormholes per definition require negative energy in the form of exotic matter so as to have their mouths open. Would this negative mass be the only mass of the wormhole object or for an observer in the isolated wormhole also include the light reflected of stars and gases visible through the wormhole of another galaxy.

Wormholes connect two systems for only a short time, and collapse when too much time has passed, or too much mass has passed through them. My question would be for wormholes that can have their mouths connected either naturally or artificially for a reasonable length of time.

• This is a qood question, initially I would have believed that it would take the apparent mass based on distance from and size of mass on the opposite side of the wormhole. This would be similar to how much light gets through a hole on a piece of paper. However the negative energy piece I have not thought of. I know this doesn't help. I just really like the question.
– Joe
Jan 30, 2015 at 12:43
• Some papers, and this suggest that the dacay mode of the energy through a gravitational wave might be influenced from the local geometry(metric). The object might be a star, black hole, wormhole, ...etc even not having a spherical symmetry. Jan 17, 2016 at 23:27
• Is the wormhole asymptotically flat and stationary? Then it has a Komar or ADM mass like anything else does. Otherwise, it's nontrivial how to define the notion of mass.
– user21299
Feb 15, 2020 at 21:59