1929 in science

Estrogen (American English) or oestrogen (Commonwealth English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy.

the metabolic pathway where lactic acid produced in the muscles is converted into glucose in the liver

Styrene-butadiene or styrene-butadiene rubber (SBR) describe families of synthetic rubbers derived from styrene and butadiene (the version developed by Goodyear is called Neolite). These materials have good abrasion resistance and good aging stability when protected by additives. In 2012, more than 5.4 million tonnes of SBR were processed worldwide. About 50% of car tires are made from various types of SBR. The styrene/butadiene ratio influences the properties of the polymer: with high styrene content, the rubbers are harder and less rubbery. SBR is not to be confused with the thermoplastic el

thumb|right|300px thumb|right|350px|Slight timing errors are compensated for by redundancy (engineering)|printing each line twice.

overview of natural science-related events during the year of 1929

hominin fossil

20th-century total solar eclipse

20th-century annular solar eclipse