Context and question: The infrared portion of the spectrum has several useful benefits for astronomers. Cold, dark molecular clouds of gas and dust in our galaxy will glow with radiated heat as they are irradiated by imbedded stars. Infrared can also be used to detect protostars before they begin to emit visible light. Stars emit a smaller portion of their energy in the infrared spectrum, so nearby cool objects such as planets can be more readily detected. (In the visible light spectrum, the glare from the star will drown out the reflected light from a planet.)
What irradiates clouds of gas in the galaxy and makes them glow?
Answer: imbedded stars
Context and question: The most important source after Polybius is Diodorus Siculus who wrote his Bibliotheca historica between 60 and 30 BCE and reproduced some important earlier sources such as Hieronymus, but his account of the Hellenistic period breaks off after the battle of Ipsus (301). Another important source, Plutarch's (c.50—c.120) Parallel Lives though more preoccupied with issues of personal character and morality, outlines the history of important Hellenistic figures. Appian of Alexandria (late first century CE-before 165 CE) wrote a history of the Roman empire that includes information of some Hellenistic kingdoms.
What battle marks the end of Diodorus Siculus' work?
Answer: battle of Ipsus
Context and question: In 1996, Billboard created a new chart called Adult Top 40, which reflects programming on radio stations that exists somewhere between "adult contemporary" music and "pop" music. Although they are sometimes mistaken for each other, the Adult Contemporary chart and the Adult Top 40 chart are separate charts, and songs reaching one chart might not reach the other. In addition, hot AC is another subgenre of radio programming that is distinct from the Hot Adult Contemporary Tracks chart as it exists today, despite the apparent similarity in name.
Adult Top 40 represented a midpoint between what two radio formats?
Answer:
"adult contemporary" music and "pop" music