- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
18 December 1997 8:00 pm
The father of FM radio was born on this day in 1890. In the 1920s, radio broadcasting used only amplitude modulation (AM), in which a signal is transmitted by variations in the amplitude of a radio wave. Such signals were susceptible to the crackle of static from storms and electrical disturbances. In 1933, electronics engineer Edwin Armstrong introduced radio broadcasting by frequency modulation (FM), in which the signal is transmitted by variations in the frequency of the radio wave over a wide waveband. This method, which now dominates radio, television, microwave, and satellite transmissions, is unaffected by static, although it is limited to line-of-sight distances. Armstrong is also known for his invention of the superheterodyne receiving circuit, which was used during World War I to detect enemy aircraft by the radio waves given off by the ignition systems of their engines.
[Source: Roy Porter, Ed. The Biographical Dictionary of Scientists, Second Edition. Oxford University Press. 1994.]