Albert Einstein was known for his theory of relativity, which changed how scientists understand space, time and gravity, and for the equation E = mc². In 1905 he also showed that light comes in tiny packets and helped prove atoms are real. He won the Nobel Prize in Physics for 1921 for explaining the photoelectric effect.
Albert Einstein quick facts
- Einstein did his famous 1905 work while working at a patent office.
- A 1919 eclipse showed starlight bending just as he predicted.
- His Nobel Prize was for the photoelectric effect, not relativity.
- GPS satellite clocks run 38 microseconds a day fast, and his theories fix this.
- Gravitational waves he predicted were first detected in 2015.
Albert Einstein at a glance
Albert Einstein is probably the most famous scientist who ever lived. His name has become another word for genius. But what did he actually discover, and why does it still matter today?
This guide explains his big ideas in plain words: light, atoms, E = mc², relativity and gravity. It also shows how his ideas help your phone find its way. The facts come from ETH Zurich, the American Institute of Physics, the Royal Society, NIST, NASA and the US National Science Foundation.
| Albert Einstein at a glance | |
|---|---|
| Born | 14 March 1879, Ulm, Germany |
| Died | 18 April 1955, Princeton, USA |
| Famous for | Relativity, E = mc² and the photoelectric effect |
| “Miracle year” | 1905 |
| General relativity | Completed in 1915 |
| Nobel Prize | Physics, for 1921, for the photoelectric effect |
| Everyday use | GPS clocks are corrected using his theories |
What was Einstein known for?
Einstein was known for changing how scientists think about space, time, light and gravity. ETH Zurich, where he studied, says his most famous work was the theory of relativity.
He also showed that light comes in tiny packets of energy, and helped prove that atoms are real. His equation E = mc² is the most famous equation in the world.
Many of his ideas were strange when he first shared them. More than a century later, scientists are still finding new evidence that he was right.
Einstein as a child
Albert Einstein was born in Ulm, Germany, on 14 March 1879. ETH Zurich says he grew up in Munich.
When he was 4 or 5, a magnetic compass amazed him. The American Institute of Physics (AIP) says he wondered what invisible force moved the needle. At 12 he fell in love with geometry, because its proofs gave certain answers.
He was excellent at maths. But he hated his strict Munich school, which valued memorising and obeying. The AIP says he left at 15 and taught himself maths, physics and philosophy from books at home.
A clerk with big ideas
In 1895, Einstein failed the entrance exam for the Zurich Polytechnic. ETH Zurich says he then finished school in Aarau, Switzerland. From 1896 to 1900 he studied at the Polytechnic, now called ETH Zurich.
Finding a university job was hard. In 1902 he became a “technical expert, third class” at the Swiss patent office in Bern. His job was to check other people’s inventions.
ETH Zurich says he did his most famous early work while working at the patent office.
1905: the miracle year
In 1905, Einstein published a string of papers that changed physics. ETH Zurich says this is often called his “miracle year”. The AIP describes the four most famous papers.
| Month (1905) | Idea | What it showed |
|---|---|---|
| March | Light quanta | Light comes in tiny packets of energy |
| May | Brownian motion | Jiggling specks in water are pushed by atoms |
| June | Special relativity | Space and time depend on how you move |
| September | E = mc² | Mass and energy are linked |
Any one of these papers would have made a scientist famous. Einstein wrote all four in a single year, while still working as a clerk.
Light comes in packets
In March 1905, Einstein suggested that light comes in tiny packets of energy. He called them light quanta. The AIP says this explained a puzzle called the photoelectric effect.
The photoelectric effect happens when light knocks electrons out of a metal. Einstein’s idea of light packets solved it.
This work won him the Nobel Prize, as you will see below.
Proving atoms are real
In 1905, some scientists still doubted that atoms existed. They were far too small to see.
In May 1905, Einstein explained Brownian motion. This is the jiggling of tiny specks floating in water. The AIP says he showed that the specks jiggle because invisible atoms and molecules keep bumping into them. His work helped prove that atoms are real.
Special relativity
In June 1905, Einstein published his theory of special relativity. It changed how scientists think about space and time.
One of its strangest ideas is about time. NIST, the US measurement laboratory, explains that the faster you move, the slower time passes for you compared with someone standing still.
At everyday speeds the difference is far too small to notice. But it is real, and it has been measured with very accurate clocks.
What does E = mc² mean?
In September 1905, Einstein showed that mass and energy are linked. He wrote it as E = mc². The AIP explains what the letters mean.
E stands for energy. M stands for mass, which is roughly how much stuff something contains. C stands for the speed of light, which is a very large number.
Because the speed of light is so large, E = mc² means that a small amount of mass holds a huge amount of energy.
General relativity and gravity
Einstein was not finished. ETH Zurich says he completed his theory of general relativity in 1915.
General relativity explains gravity in a new way. The Royal Society describes it as the bending, or warping, of space and time. A heavy object such as the Sun curves the space around it, and other things follow that curve.
NIST adds that strong gravity also makes time run slower. A clock closer to the ground ticks very slightly more slowly than one higher up. In 2010, NIST scientists showed this with two clocks only about 30 cm (1 ft) apart in height.
The 1919 eclipse that made him famous
General relativity made a bold prediction. NASA explains that the Sun‘s gravity should bend light from distant stars. Einstein’s 1915 theory said the bend should be twice as big as his earlier estimate.
Normally the Sun is too bright to see stars near it. But during a total solar eclipse, the sky goes dark. The Royal Society says two British teams watched the eclipse of 29 May 1919 to test the idea.
Arthur Eddington went to the island of Príncipe, off West Africa. A second team went to Sobral in Brazil. Their photographs showed starlight bent by the amount Einstein had predicted.
The results were announced on 6 November 1919. The Royal Society says Einstein became world-famous almost overnight. NASA adds that many later, more precise tests have confirmed the result.
His Nobel Prize
Einstein won the Nobel Prize in Physics for 1921. ETH Zurich says it was for his discovery of the law of the photoelectric effect.
Many people assume he won it for relativity. He did not.
Moving to America
ETH Zurich says Einstein worked as a professor in Zurich, Prague and Berlin. When the Nazis took power in Germany in 1933, he moved to Princeton in the USA.
He feared what Hitler’s Germany might do, and the AIP says he gave up his strict pacifism because of it. That fear came before the Second World War spread across the world. The AIP says he signed a letter to President Franklin D. Roosevelt in 1939, warning that powerful new bombs might be possible. The AIP says he played no other part in building the atomic bomb.
ETH Zurich says Einstein died in Princeton on 18 April 1955, aged 76.
Still being proved right
Einstein’s theory predicted gravitational waves. These are tiny ripples in space and time. NASA’s Jet Propulsion Laboratory says the LIGO detectors in the USA picked them up for the first time on 14 September 2015.
The waves came from two black holes colliding 1.3 billion years ago. Each LIGO detector has laser tubes 4 km (2.5 miles) long. Three LIGO scientists won the 2017 Nobel Prize in Physics.
On 10 April 2019, the Event Horizon Telescope showed the first-ever picture of a black hole. The US National Science Foundation says the image shows light bent by the black hole’s gravity, just as Einstein’s theory predicts.
How Einstein helps your phone
Einstein’s ideas are hidden in your pocket. GPS, the system phones use to find their position, relies on clocks in satellites. NIST says those clocks must be corrected using both of his theories.
Because the satellites move fast, their clocks lose about 7 millionths of a second a day. Because gravity is weaker up there, they gain about 45 millionths of a second a day.
Overall, NIST says, GPS satellite clocks run 38 microseconds a day fast. Engineers correct them. Without Einstein’s physics, GPS would soon give the wrong position.
Einstein built on ideas from earlier scientists, especially Isaac Newton, whose laws of gravity still work well for everyday life.
Three things people get wrong
Myth: Einstein failed maths. The AIP says he was excellent at maths. ETH Zurich says he did fail a university entrance exam in 1895, but he was only 16, younger than most students taking it.
Myth: Einstein won the Nobel Prize for relativity. ETH Zurich says his Nobel Prize for 1921 was for the law of the photoelectric effect, not for relativity.
Myth: relativity has nothing to do with everyday life. NIST says GPS satellite clocks run 38 microseconds a day fast. Engineers correct them using Einstein’s theories, so phone maps can work.
Did you know? A compass amazed Einstein when he was 4 or 5. He wondered what invisible force moved the needle.
Try it
Look up where you are on a map app. Then explain to someone how Einstein’s theories help the satellites give the right answer.
Knowledge check
What did Einstein win the Nobel Prize for?
Show answer
For the law of the photoelectric effect, not for relativity.
What does E = mc² mean?
Show answer
Mass and energy are linked: a small amount of mass holds a huge amount of energy.
Frequently asked questions
What was Albert Einstein most famous for?
Albert Einstein was most famous for his theory of relativity and the equation E = mc². His ideas changed how scientists understand space, time, light and gravity.
What did Einstein win the Nobel Prize for?
Einstein won the Nobel Prize in Physics for 1921. ETH Zurich says it was for discovering the law of the photoelectric effect, not for relativity.
What is Einstein’s miracle year?
Einstein’s miracle year was 1905. He published papers on light quanta, Brownian motion, special relativity and E = mc² while working at a patent office.
How was general relativity proved?
British teams photographed a total solar eclipse on 29 May 1919. The Royal Society says starlight bent by the amount Einstein’s 1915 theory predicted.
Did Albert Einstein fail maths?
No. The American Institute of Physics says Einstein was excellent at maths. He failed a university entrance exam at 16, younger than usual.
How does Einstein’s work help GPS?
NIST says GPS satellite clocks run 38 microseconds a day fast because of speed and gravity. Engineers correct them using Einstein’s theories.
Sources
- ETH Zurich Library: Albert Einstein — his life, schooling, patent office work, Nobel Prize and death
- American Institute of Physics: Einstein, the great works — the 1905 papers; its childhood, fame and nuclear pages were also used
- Royal Society: observing relativity — the 1919 eclipse expeditions
- NIST: putting Einstein to the test — time slowing with speed and gravity, and GPS clocks
- NASA JPL: gravitational waves detected — the 2015 LIGO detection; NASA’s page on bending starlight was also used
- US National Science Foundation: Event Horizon Telescope — the first images of black holes
