A world of new questions
Between about 1830 and 1920, steam power, electricity, railways, telegraph and photography spread. Cities grew. Newspapers and cheap books reached many more people. Old beliefs were tested, and many thinkers said: "Let us look at evidence." This time is often called the age of modern science and culture.
This lesson shows three fields side by side: science, literature and art. Look for one question in each: how do living things change, how do people live, and how do we see?
Darwin and natural selection
Charles Darwin (1809–1882) sailed around the world on the ship Beagle (1831–1836). He noticed that animals on islands, such as the Galapagos finches, had different beak shapes that suited the food of each island.
In 1859 he published On the Origin of Species. His main idea is natural selection:
- Animals of one kind are not all the same. Some have small differences (a longer beak, a darker colour).
- Many young are born, but not all survive.
- Those whose differences help them survive in their place live longer and have more young.
- They pass the helpful traits on, so after many generations the group changes.
This means that species are not fixed; they change slowly over very long times. Many people, including some religious leaders, disagreed at first. Today the idea of evolution is the base of biology. Notice the careful words: natural selection is not an animal 'trying' to change, it is nature 'keeping' helpful traits.
Other science: Mendel, the Curies and Einstein
- Gregor Mendel (a monk) grew thousands of pea plants and found that traits pass from parents to young in fixed patterns. He published in 1866, but his work was noticed only around 1900. He is called the father of genetics.
- Louis Pasteur showed in the 1860s that tiny living things (germs) cause many diseases. This led to vaccines and cleaner medicine.
- Marie and Pierre Curie studied radioactivity and discovered the elements polonium and radium (1898). Marie Curie won two Nobel Prizes in different sciences.
- Albert Einstein (1879–1955): in 1905 he explained light as packets of energy (the photoelectric effect), and showed in special relativity that the speed of light is the same for everyone and that mass and energy are linked by E = mc². In 1915 his general relativity said that big masses bend space and time, which we feel as gravity.
In E = mc², c is the speed of light, a huge number, and it is squared. That is why a tiny mass can match a huge amount of energy. This idea helps explain how the Sun shines and how nuclear power works.
Literature: books about real life
Earlier, many famous stories were about kings or heroes. In the 1800s a new style called realism showed ordinary people, work, money and unfairness.
- Charles Dickens (England): Oliver Twist (1838) showed hungry children in city workhouses and made readers care about poverty.
- Victor Hugo (France): Les Miserables (1862) is about justice, mercy and the struggles of poor people.
- Leo Tolstoy (Russia): War and Peace (1869) tells how war touches families.
- Rabindranath Tagore (India): poet, writer and song-maker. His poems Gitanjali earned him the 1913 Nobel Prize in Literature, making him the first Asian winner.
- In many countries writers began writing in everyday languages, not only in the language of courts and scholars.
Cheap printing and rising literacy made readers of the working and middle classes, who wanted stories about their own lives.
Art: new ways of seeing
Photography (1839) could copy a face or a street exactly. Painters asked: "What can paint do that a camera cannot?" Their answers:
- Impressionism (first group show in Paris, 1874): painters like Claude Monet painted light and a passing moment, using quick brush strokes and bright colour, often outdoors.
- Post-Impressionists such as Vincent van Gogh and Paul Cezanne used colour and shape to show feeling and structure.
- Cubism (about 1907, Pablo Picasso and Georges Braque): an object is shown from many sides at once, in broken shapes.
- In India, artists like Raja Ravi Varma mixed European oil painting with Indian stories; later artists of the Bengal School, such as Abanindranath Tagore, looked back to Indian styles.
Try it: your own three lanes
Draw three lines on paper: science, literature, art. Place the years 1831, 1859, 1874, 1905, 1913 on them. Then try a mini experiment: put 12 counters in a bowl, 3 green (strong beak) and 9 red (weak beak). Each round, take out 3 red counters (they could not eat) and put in 3 green ones (the strong birds had chicks). After 3 rounds the bowl is 12 green. This is a tiny model of natural selection. Say in one sentence why the green ones increased.
Key formulas and definitions
- Natural selection: the process by which helpful traits become more common over generations
- Evolution: slow change of living things over many generations
- Heredity: passing of traits from parents to young (Mendel)
- Radioactivity: the giving out of energy from the centre of some atoms (Curies)
- E = mc²: energy equals mass times the speed of light squared (Einstein, 1905)
- Realism: writing or art that shows ordinary life as it is
- Impressionism: painting of light and the feeling of a moment (1870s)
- Cubism: showing an object from many sides at once (about 1907)
Worked examples
1. Using the bird demo: if 3 of 12 birds have strong beaks and food becomes hard, why do strong beaks become more common?
Birds with strong beaks can crack the seeds and survive, so they have more chicks. Their chicks inherit strong beaks. After a few generations, more birds in the group have strong beaks.
2. Why did photography change painting?
Photographs could copy real faces and places exactly. Painters then turned to things a camera could not show easily, such as light, feeling and new ways of looking at shapes.
3. In E = mc², what happens to the energy if the mass becomes twice as large?
The energy also becomes twice as large, because E is directly proportional to m (c stays the same).
4. Why is Rabindranath Tagore's 1913 prize a landmark?
He was the first Asian to win the Nobel Prize in Literature. It showed the world that great literature was also written in Indian languages (he wrote in Bengali).
5. Match: Mendel, Darwin, Einstein with 'heredity', 'natural selection', 'relativity'.
Mendel: heredity. Darwin: natural selection. Einstein: relativity.
Common mistakes
- Saying Darwin said humans came from monkeys. He said that humans and apes share common ancestors that lived long ago.
- Thinking animals change on purpose. Natural selection keeps helpful traits that already exist; it is not wishing or trying.
- Mixing E = mc² with Newton's ideas. It comes from Einstein's relativity in 1905.
- Thinking Impressionist painting is blurry because of poor skill. The artists chose quick strokes to catch light.