‘Extremely odd physics’: Researchers prove a 50-year-old theory that throwing an object into a black hole then retrieving it could generate enough energy ‘to power planets’
- The black hole energy theory was proposed by physicist Roger Penrose in 1969
- He said it would take an advanced alien civilisation to be able to test the theory
- A 1971 idea that twisting light waves on a spinning disc could prove the theory
- The technology doesn’t exist to spin the disc a least a billion times a second
- This new study involved firing sound waves at a slower spinning disc and measuring the response – they found this resulted in the expected increase
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A theory that energy can be created by throwing objects into a black hole has been proved by scientists more than 50 years after it was first proposed.
A team of researchers at the University of Glasgow’s School of Physics and Astronomy set out to validate the 1969 work by British physicist Roger Penrose.
They used sound waves in an attempt to endorse the ‘extremely odd physics’ caused when you drop an object in a black hole and then split the object in two.
He theorised the energy generated from the recoil action of retrieving one half of the object could be stored and used to power entire worlds.
Scientists have been finding ways to test the theory for decades, after Penrose claimed the engineering challenges to test it could only be carried out ‘by an advanced, possibly alien, civilisation’.
A team of researchers at the University of Glasgow’s School of Physics and Astronomy set out to validate the 1969 work by British physicist Roger Penrose
In 1971, physicist Yakov Zeldovich suggested the theory could be tested with twisted light waves projected onto a spinning surface.
To test that, the spinning surface would need to rotate at at least a billion times a second – a feat still not possible due to the limitations of engineering.
Now, the Glasgow researchers have finally found a way to experimentally demonstrate the effect using sound waves.
This works as sound waves require a much slower rotating surface than light.
Using a ring of speakers, the researchers sent a rotating wave of sound towards a spinning foam disk with two microphones attached to the back.
They found that as the sound waves passed through the disk, the pitch was amplified by up to 30 per cent, known as a rotational Doppler effect.
Marion Cromb, the paper’s lead author, said the linear version of the Doppler effect is familiar to most people.
‘The phenomenon occurs as the pitch of an ambulance siren appears to rise as it approaches the listener but drops as it heads away,’ said Cromb.
‘It appears to rise because the sound waves are reaching the listener more frequently as the ambulance nears, then less frequently as it passes.’
The team say the rotational Doppler effect is similar but the effect is confined to a circular space – rather than stretching over a line.
In their experiment they found that the twisted sound waves change their pitch when measures from the point of view of the rotating surface.
‘If the surface rotates fast enough then the sound frequency can do something very strange – it can go from a positive frequency to a negative one, and in doing so steal some energy from the rotation of the surface,’ said Cromb.
They used sound waves in an attempt to endorse the ‘extremely odd physics’ caused when you drop an object in a black hole and then split the object in two
During the experiment, researchers found that as the pitch of the sound wave hits the spinning disk, it dropped until it became too low to hear.
Then, when passing through, it was amplified by up to 30 per cent greater than the original pitch – mimicking the expected effects of dropping an object in a black hole
Professor Daniele Faccio, co-author on the paper, said they were thrilled to be able to experimentally verify some extremely odd physics.
‘It’s strange to think that we’ve been able to confirm a half-century-old theory with cosmic origins here in our lab in the west of Scotland but we think it will open up a lot of new avenues of scientific exploration.
‘We think it will open up a lot of new avenues of scientific exploration. We’re keen to see how we can investigate the effect on different sources such as electromagnetic waves in the near future.’
BLACK HOLES HAVE A GRAVITATIONAL PULL SO STRONG NOT EVEN LIGHT CAN ESCAPE
Black holes are so dense and their gravitational pull is so strong that no form of radiation can escape them – not even light.
They act as intense sources of gravity which hoover up dust and gas around them. Their intense gravitational pull is thought to be what stars in galaxies orbit around.
How they are formed is still poorly understood. Astronomers believe they may form when a large cloud of gas up to 100,000 times bigger than the sun, collapses into a black hole.
Many of these black hole seeds then merge to form much larger supermassive black holes, which are found at the centre of every known massive galaxy.
Alternatively, a supermassive black hole seed could come from a giant star, about 100 times the sun’s mass, that ultimately forms into a black hole after it runs out of fuel and collapses.
When these giant stars die, they also go ‘supernova’, a huge explosion that expels the matter from the outer layers of the star into deep space.