Famous Scientists for Kids Trivia Quiz

Answer: Archimedes

Archimedes, who lived in the third century BCE, was one of the greatest scientists of the ancient world. A popular story about him is that a king asked him to find out if a crown that had been made for him was pure gold or had been dishonestly mixed with silver. Archimedes understood that because gold is denser than silver it takes up less space, so if he could measure the volume of the crown, he could determine its purity, but he did not know how to do this.

While getting into a bath, he noticed that the water level rose as he sank in.

He realized that if he placed the crown in water, he could measure the amount of water displaced and compare this to the amount displaced by a block of pure gold of the same weight. If the crown was impure, then it would displace more water. Archimedes is said to have invented many useful devices such as a screw that could pump water out of the hold of a ship, and a giant claw attached to a crane that could lift an enemy ship out of the sea to stop it from attacking his city.

Answer: Calculated the circumference of the Earth

Using the results of land surveys, Eratosthenes calculated the circumference of the Earth with remarkable accuracy for someone living in ancient times. The exact method he used has been lost to history, but a popular account explained that this could be done by calculating the length of shadows cast by the sun in two different cities on the same day that are a known distance apart. Using this information, one could calculate the angle of the sun's rays as a fraction of the 360 degrees in a circle.

Then, multiply the distance between the two cities by the inverse of the fraction. For example, if the angle was calculated to be 1/50th the circumference of a circle, then multiply the distance by 50 to get the circumference of the earth. Eratosthenes was also the first person to calculate the tilt of the Earth's axis, and created a map of the known world. Over this map, he placed grids of overlapping lines over the surface of the Earth, a system which is still used today to create coordinates for any location, in the form of longitude and latitude.

Answer: Heliocentrism

The first person known to have come up with the idea of heliocentrism, that the sun is the centre of the solar system around which the planets revolved, was actually an ancient Greek astronomer named Aristarchus of Samos. However, this idea did not catch on.

Instead, for the next 18 centuries, most people believed in geocentrism, the theory that the earth does not move and is the centre of the universe. Geocentrism as a theory had a few problems, such as explaining why the planets sometimes appear to move backwards when seen from the earth. Copernicus argued that if the earth was actually moving around the sun, then this problem of apparent backward motion would be easier to explain. Copernicus made a few mistakes in his theory - for example, he thought the orbits of the planets were perfect circles, instead of ellipses. Even so, heliocentrism forever changed the way people understand the universe, something which is known as the Copernican Revolution.

Answer: Galileo Galilei

Galileo is today known as the "father of modern science" because of his many important discoveries in astronomy and physics, as well as his contribution to the modern scientific method of understanding the world. Although he did not invent the first telescope, he is one of the first astronomers known to have used one to study the heavens.

His discovery that the moon had mountains and craters on its surface disproved the idea that it was a perfect sphere, contrary to Aristotle, an ancient Greek philosopher. Aristotle had also taught that all heavenly bodies orbited the earth, which Galileo also disproved by his discovery that Jupiter had several moons orbiting around it.

There is a widespread notion that Galileo went blind after looking at the sun through his telescope, but this is not true.

He was actually very careful during his studies of the sun, which he conducted in his forties, and did not go blind until he was 73. (Still, you should not look directly into the sun!) There is also a popular legend that he dropped two iron balls of different sizes from the Leaning Tower of Pisa to test his theory that objects of different weights will fall at the same speed.

He actually tested this by rolling them down inclined planes. Galileo famously got into hot water with the Church for teaching the Copernican theory that the earth moves around the sun. He was forced to recant this theory on pain of death, although there is a legend that he muttered under his breath, "but it does move." Eventually, the Catholic Church admitted the error of its ways and publicly apologized for banning Galileo's teachings - in 1992! So they finally got it right, even if it took them over 350 years!

Answer: Colour

Newton performed pioneering experiments in optics to learn about the nature of light. In a famous demonstration, he showed that sunlight passing through a glass prism would change into the colours of the rainbow. The same coloured ray of light passing through a second prism would change back into white light.

This showed that colour is a fundamental feature of light itself. Before this, some people thought that objects generate their own colours, but Newton showed that colours appear when objects interact with the colours that already exist within light. Newton also invented a reflecting telescope that uses mirrors instead of lenses to magnify images, to produce a clearer image. Reflecting telescopes are still used by astronomers today. Newton made many other contributions to mathematics and science, and is considered one of the most influential scientists ever.

Answer: Radioactivity

Popularly known as Madame Curie, this great scientist lived from 1867 to 1934. She was the first woman to earn a Nobel Prize, and the first person to win the Nobel Prize in two scientific fields, specifically, physics and chemistry. She and her husband Pierre Curie performed pioneering experiments on uranium.

They learned that radioactivity originates within the atom itself and that atoms are themselves made up of smaller particles. Her second Nobel Prize was awarded for the discovery of two new elements: polonium and radium, which she found in minerals containing uranium.

She guided research into using radioactivity to treat cancer, which is still used today. Ironically, she did not to know how dangerous it was to constantly expose herself to radioactive metals like radium, which she carried around in her pockets. Sadly, she died from cancer caused by the radioactivity in her lab. To this day, her lab notes and papers are so radioactive that they are kept in a lead box and people are only allowed to look at them while wearing special protective gear.

Answer: Peas

Mendel discovered many of the rules of heredity that govern how traits of plants and animals are passed on from generation to generation. These findings are called the laws of Mendelian inheritance and are the foundation of the science of genetics. He performed experiments on thousands of pea plants in the garden of the monastery where he lived. By cross-breeding plants with different traits, say, green or yellow peas, he found that the offspring would have either one trait or the other, e.g. were green or yellow, but not a combination of both. Additionally, traits would be passed on from generation to generation in mathematically predictable ways.

Answer: Natural selection

The theory of evolution explains how different species of life have emerged and changed over time. People before Darwin had considered that species might change and evolve over time, but could note explain how evolution works. Darwin's great idea was that evolution works through natural selection.

This means that individuals with "favourable characteristics" - things that help them survive and reproduce - are better at passing on these characteristics to the next generation. Darwin developed many of his ideas while on a voyage to the Galapagos Islands, in which he studied many kinds of unique animals there.

For example, he noticed that birds called finches on different islands had particular features that helped them survive in the unique environments of each island - finches that ate fruit had short beaks like parrots, while finches that ate insects had long thin beaks good for prying between rocks where insects live.

He realized that all the finches came from a common ancestor and must have changed over time. Finches that had useful characteristics that helped them fit in with life on each island were more likely to survive than those that did not.

This survival advantage led them to evolve new forms over vast spans of time.

Answer: Chimpanzees

Jane Goodall went to the Gombe Stream National Park in Tanzania, Africa, in 1960 to study chimpanzees in their natural habitat. She began a study program that has continued to this day that has given the world an in-depth look at how chimpanzees live from birth to old age. Before her work began, people knew very little about what these animals were like.

She discovered that their behaviour is much more like that of humans than anyone had thought. For example, chimpanzees can create simple tools, which people had previously thought only humans could do.

She was also the first person to learn that chimpanzees hunt other animals for meat and sometimes gang up on other members of their own kind, and that groups of chimpanzees will even wage war against neighbouring groups. Chimpanzees are more closely related to humans than other animals, so understanding them can help us understand why humans are the way they are.

Answer: Theory of relativity

Albert Einstein was a German-born theoretical physicist who many see as one of the greatest physicists of all time. His famous theory of relativity is too complex to explain in detail here, but basically it showed that measurement of physical properties is not absolute but depends on one's frame of reference, so that a stationery observer and a moving observer viewing the same event (e.g., the flight of a spaceship) will measure it differently.

This is because time and space are not fixed but can actually contract relative to someone moving at high speeds.

This means that for someone travelling on a spaceship moving at close to the speed of light, time will pass more slowly. So, someone could theoretically go on a long space flight at very high speed and when they return, centuries might have passed for people on earth while the traveller may have aged only a few years! More practically, the theory of relativity has had real-life applications - the Global Positioning System (GPS) that drivers use to navigate makes use of this theory. Time passes slightly faster aboard the satellites used in GPS than it does on the surface of the earth because of relativistic effects, so the computers on board these satellites must take this into account when calculating someone's position on earth, using Einstein's theory.