| Important Vocabulary |
| Spacetime-The idea of time as a fourth dimention. Due to the fact that information cannot travel faster than the speed of light, objects at astronomical distances do not exist for us or each other without a time factor.The idea of four- dimensionl spacetime was first introduced by the German physicist Hermann Minkowski in 1908. |
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| Chandrasekhar limit-A calculation stating that if a star has a mass less than 1.4 solar masses, gravity will not overpower the exclusion principle. It will become a white dwarf. This calculation was made by a young Indian physicist, Subrahmanyan Chandrasekhar, at the University of Cambridge in the late 1920s. |
| Exclusion principle-The principle that particles must keep their distance, leaving empty space in atoms. The principle requires that only two electrons can occupy the same region of space at the same time. Electrons moving around the nuclei of atoms are paired together in cells (or orbitals). Electrons build up "electron degeneracy motion" due to their place in these cells. Through this pressure, electrons are not pulled into the nucleus of the atom. |
| Solar mass-The mass of the sun. The term 'Solar mass' is used to measure the mass of other stars and black holes. For example, if something has a mass of "50 solar masses," its mass is 50 times that of the sun. |
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