This is Steve Ember.
And this is Sarah Long with the VOA Special English program,
Explorations. Today we tell about a scientist who changed the
way we understand the universe, Albert Einstein.
In the year Nineteen-Oh-Five, Albert Einstein published some
important papers in a German scientific magazine. They included
one of the most important scientific documents in history. It
was filled with mathematics. It explained what came to be called
his ¡°Special Theory of Relativity.¡±
Ten years later he expanded it to a ¡°General Theory
Albert Einstein¡¯s theories of relativity are about
the basic ideas we use to describe natural happenings. They
are about time, space, mass, movement, and gravity.
Albert Einstein was born in Ulm, Germany, in Eighteen-Seventy-Nine.
His father owned a factory that made electrical devices. His
mother enjoyed music and books. His parents were Jewish but
they did not observe many of the religion¡¯s rules.
Albert was a quiet child who spent much of his time alone.
He was slow to talk and had difficulty learning to read.
When Albert was five years old, his father gave him a compass.
The child was filled with wonder when he discovered that the
compass needle always pointed in the same direction -- to the
north. He asked his father and his uncle what caused the needle
Their answers about magnetism and gravity were difficult for
the boy to understand. Yet he spent a lot of time thinking about
them. He said later that he felt something hidden had to be
Albert did not like school. The German schools of that time
were not pleasant. Students could not ask questions. Albert
said he felt as if he were in prison.
One story says Albert told his Uncle Jacob how much he hated
school, especially mathematics. His uncle told him to solve
mathematical problems by pretending to be a policeman. ¡°You
are looking for someone,¡± he said, ¡°but
you do not know who. Call him X. Find him by using the mathematical
tools of algebra and geometry.¡±
Albert learned to love mathematics. He was studying the complex
mathematics of calculus when all his friends were still studying
simple mathematics. Instead of playing with friends he thought
about things such as: ¡°What would happen if people
could travel at the speed of light?¡±
Albert decided that he wanted to teach mathematics and physics.
He attended the Federal Polytechnic Institute in Zurich, Switzerland.
He graduated with honors, but could not get a teaching job.
So he began working for the Swiss government as an inspector
of patents for new inventions. The job was not demanding. He
had a lot of time to think about some of his scientific theories.
From the time he was a boy, Albert Einstein had performed what
he called ¡°thought experiments¡± to
test his ideas. He used his mind as a laboratory. By Nineteen-Oh-Five,
he had formed his ideas into theories that he published.
In one paper he said that light travels both in waves and in
particles, called photons. This idea is an important part of
what is called the quantum theory.
Another paper was about the motion of small particles suspended
in a liquid or gas. It confirmed the atomic theory of matter.
The most important of Albert Einstein¡¯s theories
published that year became known as his ¡°Special
Theory of Relativity.¡± He said the speed of light
is always the same -- almost three-hundred-thousand kilometers
a second. Where the light is coming from or who is measuring
it does not change the speed. However, he said, time can change.
And mass can change. And length can change. They depend on where
a person is in relation to an object or an event.
Imagine two space vehicles with a scientist travelling in each
one. One spaceship is red. One is blue. Except for color, both
spaceships are exactly alike. They pass one another far out
Neither scientist feels that his ship is moving. To each, it
seems that the other ship is moving, not his. As they pass at
high speed, the scientist in each ship measures how long it
takes a beam of light to travel from the floor to the top of
his spaceship, hit a mirror and return to the floor. Each spaceship
has a window that lets each scientist see the experiment of
They begin their experiments at exactly the same moment. The
scientist in the blue ship sees his beam of light go straight
up and come straight down. But he sees that the light beam in
the red ship does not do this. The red ship is moving so fast
that the beam does not appear to go straight up. It forms a
path up and down that looks like an upside down ¡°V¡±.
The scientist in the red ship would see exactly the same thing
as he watched the experiment by the other scientist. He could
say that time passed more slowly in the other ship. Each scientist
would be correct, because the passing of time is linked to the
position of the observer.
Each scientist also would see that the other spaceship was
shorter than his own. The higher the speeds the spaceships were
travelling, the shorter the other ship would appear. And although
the other ship would seem shorter, its mass would increase.
It would seem to get heavier.
The ideas were difficult to accept. Yet other scientists did
experiments to prove that Einstein¡¯s theory was
Ten years after his paper on the special theory of relativity,
Albert Einstein finished work on another theory. It described
what he called his ¡°General Theory of Relativity.¡±
It expanded his special theory to include the motion of objects
that are gaining speed. This theory offered new ideas about
gravity and the close relationship between matter and energy.
It built on the ideas about mass he had expressed in Nineteen-Oh-Five.
Einstein said that an object loses mass when it gives off light,
which is a kind of energy. He believed that matter and energy
were different forms of the same thing. That was the basis of
his famous mathematical statement E equals m-c squared (energy
equals mass times the speed of light squared). This statement
or formula explained that a great amount of energy could come
from a small piece of matter. It explained how the sun could
give off heat and light for millions of years. This formula
also led to the discovery of atomic energy.
In his general theory of relativity, Einstein said that gravity,
like time, is not always the same. Gravity changes as observers
speed up or slow down. He also said that gravity from very large
objects, such as stars, could turn the path of light waves that
passed nearby. This seemed unbelievable. But in Nineteen-Nineteen,
British scientists confirmed his theory when the sun was completely
blocked during a solar eclipse. Albert Einstein immediately
became famous around the world.
In Nineteen-Twenty-One, he won the Nobel Prize in Physics.
It was given to him, not for his theories of relativity, but
for his discovery of the law of the photoelectric effect. This
scientific law explained how and why some metals give off electrons
after light falls on their surfaces. The discovery led to the
development of modern electronics, including radio and television.
Albert Einstein taught in Switzerland and Germany. He left
Germany when Adolph Hitler came to power in Nineteen-Thirty-Three.He
moved to the United States to continue his research. He worked
at the Institute for Advanced Study in Princeton, New Jersey.
Einstein became a citizen of the United States in Nineteen-Forty.
Einstein was a famous man, but you would not have known that
by looking at him. His white hair was long and wild. He wore
old clothes. He showed an inner joy when he was playing his
violin or talking about his work. Students and friends said
he had a way of explaining difficult ideas using images that
were easy to understand.
Albert Einstein opposed wars. Yet he wrote to President Franklin
Roosevelt in Nineteen-Thirty-Nine to advise him that the United
States should develop an atomic bomb before Germany did.
Einstein spent the last twenty-five years of his life working
on what he called a ¡°unified field theory.¡±
He hoped to find a common mathematical statement that could
tie together all the different parts of physics. He did not
Albert Einstein died in Nineteen-Fifty-Five. He was seventy-six
This Special English program was written by Marilyn Christiano
and produced by Paul Thompson. This is Sarah Long.
And this is Steve Ember. Join us again next week for another
Explorations program on the Voice of America.
This V-O-A Explorations Report is published
courtesy of VOAnews.com