In computing, Extract, Transform and Load (ETL) refers to a process in database usage and especially in data warehousing that performs: Data extraction â extracts data from homogeneous or heterogeneous data sources.
(Beginner) Reading astronomy books, I've come up with the word singularity a lot, but I can't figure out what it exactly means. A singularity means a point where some property is infinite. For example, at the center of a black hole, according to classical theory, the density is infinite (because a finite mass is compressed to a zero volume). Hence it is a singularity.
For the purposes of proving the PenroseâHawking singularity theorems, a spacetime with a singularity is defined to be one that contains geodesics that cannot be extended in a smooth manner. The end of such a geodesic is considered to be the singularity. This is a different definition, useful for proving theorems. The two most important types of spacetime singularities are curvature singularities and conical singularities.