proper+sphere
131Star catalogue — An illustration of the Perseus constellation (after Perseus from Greek mythology) from the star catalogue published by the German astronomer Johannes Hevelius in 1690 A star catalogue, or star catalog, is an astronomical catalogue that lists… …
132Modulated neutron initiator — A modulated neutron initiator is a neutron source capable of producing a burst of neutrons on activation. It is a crucial part of some nuclear weapons, as its role is to kick start the chain reaction at the optimal moment when the configuration… …
