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Light-bending black hole supports Einstein’s theory of relativity

AP, July 30, 2018 7:00PM news.com.au

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This artist's impression shows the path of the star S2 as it passes close to the supermassive black hole at the centre of the Milky Way galaxy. Picture: AP media_cameraThis artist's impression shows the path of the star S2 as it passes close to the supermassive black hole at the centre of the Milky Way galaxy. Picture: AP

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More than a century after Albert Einstein suggested it, his famous theory of general relativity* has passed another test.

With giant telescopes pointed at the centre of our galaxy*, a team of European researchers watched a fast-moving star that got close to a monstrous* black hole. They saw that the black hole distorted* the light waves from the star in a way that agrees with Einstein’s theory.

The result was reported in the journal Astronomy & Astrophysics by a research team led by Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany.

This drawing provided by the European Southern Observatory in July 2018 shows the path of the star S2 as it passes close to the supermassive black hole at the centre of the Milky Way galaxy. As the star gets nearer to the black hole, a very strong gravitational field causes the colour of the star to shift slightly to the red, an effect of Einstein's general theory of relativity. Picture: AP media_cameraThis drawing provided by the European Southern Observatory in July 2018 shows the path of the star S2 as it passes close to the supermassive black hole at the centre of the Milky Way galaxy. As the star gets nearer to the black hole, a very strong gravitational field causes the colour of the star to shift slightly to the red, an effect of Einstein’s general theory of relativity. Picture: AP

Einstein’s theory says the universe is not simply space, but a more complex existence called space-time, which is warped, twisted or bent out of shape by heavy objects.

Black holes offer a good opportunity to test that idea. The black hole in the Milky Way is 4 million times bigger than the sun.

“I, just like every physicist* in the world, would have loved to finally see a crack in Einstein’s relativity,” said Ohio State University astrophysicist Paul Sutter, who wasn’t part of this project. “But he’s outsmarted us.”

Scientists know that the theory still doesn’t explain everything about the universe. So they keep testing it. So far, nobody has been able to replace it with a better theory.

Although the effects of general relativity have been seen before, this was the first detection* made by watching the motion of a star near a supermassive black hole.

“To me, that’s what makes this so cool,” said Clifford Will, a University of Florida physicist who was not part of the research.

Mr Will hopes his fellow scientists will be able to discover stars even closer to the black hole, where the effects of relativity would be stronger. This finding “is really the opening episode*,” he said.

“The future, I think, is going to be very exciting.”

Albert Einstein in 1921. Picture: supplied media_cameraAlbert Einstein in 1921. Picture: supplied

WHO WAS ALBERT EINSTEIN?

A German-born scientist, who was born in 1875 and died in 1955.

He discovered a lot about gravity, light and energy.

He won many awards, including the Nobel prize in Physics in 1921.

Einstein was a genius and if you call someone an “Einstein”, you’re saying that they are very smart.

He wrote the formula that people call the world’s most famous equation. It shows how mass (m, a bit like weight) and energy (e) and the speed of light (c) are related. It is written as e = mc2 and you say it as e equals mc squared.

He wrote the theory of relativity. This is a big, complicated set of maths ideas that help explain light, time and space. It helps explains what the universe looks like to different people, at different places around the universe, who may be moving at different speeds. One part of the relativity theory is that the speed of light is always the same.

GLOSSARY

relativity: things only have importance in comparison to other things

galaxy: system of billions of stars held together by gravity

monstrous: enormous

distorted: bent out of shape or line

physicist: a science of physics to do with energy and matter

detection: observation, noticing

episode: one part of something bigger

LISTEN TO TODAY’S STORY

QUICK QUIZ

1. Where were the telescopes pointed?

2. What did they watch the black hole do?

3. How big is the black hole compared to the sun?

4. Why would it be good to find stars even closer to the black hole?

5. In the theory of relativity, the speed of light is always the …

CLASSROOM ACTIVITIES

1. Close activity

Re-write this paragraph, adding in the missing words from the word bank below.

Albert Einstein was a ________ who lived from 1875 to 1955. He was famous for many __________ and theories, including his theory of general ________. His theory includes the idea that the _________ consists of space-time which can be __________ by heavy objects. When a fast-moving star recently passed by a _____________ black hole, researchers were able to ________ what occurred using giant telescopes. What they saw ______ with Einstein’s theory – the light _______ from the star were ___________ by the force of the black hole. This was the first time that Einstein’s theory had been _________ in this way.

WORD BANK: observe universe waves relativity supermassive scientist warped tested discoveries agreed distorted

2. Extension: If you could ask Albert Einstein 3 questions, what would they be?

Time: Allow 25 minutes

Curriculum links: English, Science

VCOP ACTIVITY

After reading the article, with a partner, highlight all the openers you can find in blue. Discuss if they are powerful and varied openers or not. Why do you think the journalists has used a mix of simple and power openers? Would you change any, and why?

QUESTION: What would you like scientists to look for in space? Why?
Explain your answer using full sentences.

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