The final project for my ATDP 2019 Astronomy and Astrophysics Course revolved around wormholes and the possibility of their existence. I probably invested half of June in this project, not only because I wanted it to be good, but also because it was just so interesting and engaging. I used each and any book I could lay my hands on at the UC Berkeley Library, watched videos searched the web and even asked some grad students for their opinion.
A wormhole is a structure joining separate points in spacetime. It is most often visualised as a tunnel connecting two different points in the four-dimensional region of spacetime.
I elaborated on the three main kinds of wormholes, their structure and the possibility of their existence with the help of models as follows:
Einstein-Rosen bridges: These are connections between areas of space that can be modelled as vacuum solutions to the Einstein field equations. Einstein-Rosen bridges work on the principles of a black hole, and its complete opposite, a white hole. The black hole takes matter in, as it normally does in the universe. A white hole is the exact opposite of a black hole(which means no matter can enter it), so it spews matter outwards. These are unlikely to exist since there are no possible processes that may form white holes.
An Einstein-Rosen Bridge
String Theory Wormholes: String theory wormholes are said to connect through strings called cosmic strings, which also keep them open. String theory wormholes were (probably) made during the Big Bang when quantum fluctuations (the temporary change in the amount of energy in a point in space) at the smallest scale (the Planck length- 1035 m) created many traversable wormholes. Then, by cosmic inflation, which was the rapid expansion of the universe just after the Big Bang, these wormholes increased in size, to the macroscopic scale, and were cast light-years apart in the interstellar medium.
String Theory Wormhole
Manmade Wormholes: Man-made wormholes are created by propping open holes in spacetime, and keeping them open. This is done using exotic matter (matter with negative mass). So, instead of the attractive force of gravity, it will exert a repulsive force which could prop open wormholes.
I had a lot of fun working on this project since it involved a lot of research, cross-referencing and comparing different information. Since this is a debatable topic, I enjoyed sharing opinions with others and getting to know what thoughts others have on this subject. I almost felt sad when my presentation ended since I knew my excuse to pursue this topic had just been exhausted.