World History
This empire, ruled by Julius Caesar and Augustus, controlled much of Europe around 2,000 years ago.
What is the Roman Empire?
This is the only even prime number.
What is 2?
This language family includes English, Spanish, Hindi, and Russian.
What is Indo-European?
These two brothers are credited with the first successful powered airplane flight in 1903.
Who are the Wright Brothers?
These structures inside cells contain genetic material in the form of DNA.
What are chromosomes?
This Chinese dynasty built much of the present-day Great Wall and sent out the treasure fleets of Zheng He.
What is the Ming Dynasty?
A statement that can be proven true using logic and previously established results is called this.
What is a theorem?
The system of symbols used to represent sounds in spoken language is known by these three initials.
What is the IPA (International Phonetic Alphabet)?
This force keeps planets in orbit around the Sun and satellites in orbit around Earth.
What is gravity?
This process allows plants to convert sunlight into chemical energy.
What is photosynthesis?
This 11th-century Norman ruler defeated King Harold II at the Battle of Hastings and became King of England.
Who is William the Conqueror?
This Greek mathematician is credited with writing Elements, one of history’s most influential geometry texts.
Who is Euclid?
This dead language of ancient Rome became the ancestor of Spanish, French, Italian, Portuguese, and Romanian.
What is Latin?
This principle explains how an airplane wing creates lift by causing faster-moving air above the wing to have lower pressure than the air below it.
What is Bernoulli’s principle?
This scientist proposed the theory of natural selection in On the Origin of Species.
This West African empire became wealthy through trans-Saharan gold trade and was ruled by Mansa Musa in the 14th century.
What is the Mali Empire?
This branch of mathematics studies objects such as vertices and edges and is used to analyze networks, routes, and connections.
In linguistics, this term refers to a word borrowed from another language, such as “karaoke” in English.
What is a loanword?
This line, located 100 kilometers above Earth’s surface, is commonly used to define the boundary of space.
What is the Kármán line?
This type of immune cell produces antibodies that help the body recognize and neutralize pathogens.
What are B cells?
This 1815 meeting of European powers, led in part by Klemens von Metternich, attempted to restore stability after the Napoleonic Wars.
What is the Congress of Vienna?
This Austrian logician proved in 1931 that any sufficiently powerful formal mathematical system contains true statements that cannot be proven within the system itself.
Who is Kurt Gödel?
This proposed proto-language is believed to be the common ancestor of Indo-European, though no written records of it exist.
What is Proto-Indo-European?
In orbital mechanics, this effect causes a spacecraft traveling extremely fast near a massive body to experience slower passage of time relative to observers farther away.
What is gravitational time dilation?
This hypothesis proposes that mitochondria and chloroplasts originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells.
What is the endosymbiotic theory?