Dark Matter – Dark matter can not be detected by any current means. It is theorized to exist to make up for gravitational discrepancies, and is said to account for about 80% of the universe. Scientists believe that it might be made up of some kind of subatomic particle.


Dark Energy – Dark energy is said to exist throughout space and accelerates the expansion of the universe. It is said to makeup about 26% of the universe, but like dark matter it remains a matter of speculation. It also does not seem to interact with any other fundamental forces.


Space Roar – The space roar is a loud radio signal from somewhere in outer space. Scientists say it is six times louder than what is expected from normal sources, and they have yet to determine its source. It is so “loud” that it is currently limiting the study of the earliest stars.


Cold Fusion – Normally the fusion of two atoms requires extremely high temperatures, but you could also hypothetically get the same reaction at room temperature. Although early  claims of cold fusion have been discredited, there are still scientists working on the idea.


The Mpemba Effect – This is the notion that under certain circumstances warmer water can freeze faster than colder water. There is no agreement on what exactly the effect is, although there are several theories explaining what might be happening.