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Brahe, Tycho

(Encyclopedia)Brahe, Tycho tīˈkō brä [key], 1546–1601, Danish astronomer. The most prominent astronomer of the late 16th cent., he paved the way for future discoveries by improving instruments and by his prec...

Echinodermata

(Encyclopedia)CE5 Internal anatomy of a sea star, representative of the phylum Echinodermata Echinodermata əkīˌnōdûrˈmətə [key] [Gr.,=spiny skin], phylum of exclusively marine bottom-dwelling invertebra...

multiple sclerosis

(Encyclopedia)multiple sclerosis (MS), chronic, slowly progressive autoimmune disease in which the body's immune system attacks the protective myelin sheaths that surround the nerve cells of the brain and spinal co...

Lorentz contraction

(Encyclopedia)Lorentz contraction lôrˈĕnts [key], in physics, contraction or foreshortening of a moving body in the direction of its motion, proposed by H. A. Lorentz on theoretical grounds and based on an earli...

Eton

(Encyclopedia)Eton ēˈtən [key], town, Windsor and Maidenhead, central England, on the Thames River. It i...

Savigny, Friedrich Karl von

(Encyclopedia)Savigny, Friedrich Karl von frēˈdrĭkh kärl fən säˈvĭnyē [key], 1779–1861, German jurist and legal historian, a founder of the historical school of jurisprudence. He taught (1810–42) Roman...

echo sounder

(Encyclopedia)echo sounder, an older instrumentation system for indirectly determining ocean floor depth. Echo sounding is based on the principle that water is an excellent medium for the transmission of sound wave...

peonage

(Encyclopedia)peonage pēˈənĭj [key], system of involuntary servitude based on the indebtedness of the laborer (the peon) to his creditor. It was prevalent in Spanish America, especially in Mexico, Guatemala, Ec...

sharecropping

(Encyclopedia)sharecropping, an agricultural system in which a landowner allows a tenant to use their land in return for a share of the crop produced. In the United S...

radio-frequency identification

(Encyclopedia)radio-frequency identification (RFID), a technology that uses radio waves to transmit data and uniquely identify an animal, person, or thing. An RFID system typically consists of a tag and a reader. T...