EMDrives are claimed to be propellentless space propulsion systems. If propellentless propulsion is possible it could enable fast human travel throughout the solar system and possible interstellar ...

The gravitational field on Earth varies not only with latitude, but also with altitude and in other ways, particularly due to crustal thickness and the fact that the Earth's crust effectively floats ...

The last 30 years of his life were spent on a fruitless search for a unified field theory, but as John Ellis explains, Einstein put this "holy grail" of modern physics on the theoretical map. The ...

According to general relativity, black holes are incomplete, which prevents developing a complete physical description of their dynamical formation and evolution once quantum effects are taken into ...