Artificial intelligence could already exist elsewhere in the universe and may have been around for billions of years, according to a leading expert.

Susan Schneider of the University of Connecticut believes other civilisations could rely on forms of alien super-intelligence we haven't yet created on Earth.

She claims these life-forms could be 'post-biological' and not driven by the propagation of genes like creatures on Earth but powered by technology - meaning they could be immortal too.

Such alien AI civilisations could be super-intelligent and already spying on Earth.

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Artificial intelligence could already exist elsewhere in the universe and may have been around for billions of years, according to a leading expert (stock image)

POSTBIOLOGICAL LIFE Dr Schneider believes in 'the short window observation' which states that by the time a society has created the technology to put them into the cosmos they are just hundreds of years away from being postbiological. This means as biologically-based organisms we are currently living in a 'short window' and possible aliens we encounter would be more likely to be in the postbiological phase. They could be vastly more intelligent than us and therefore much more likely to be in the postbiological phase. She also believes they will be non carbon-based and could survive in much harsher conditions than carbon-based life forms. Advertisement

'There many be lots of life in the cosmos but the greatest alien intelligences will probably be postbiological having grown out of biological civilisations', Dr Schneider of the University of Connecticut and the Institute for Advanced Studies at Princeton said at the IdeaFestival in Louisville.

Dr Schneider believes in 'the short window observation' which states that by the time a society has created the technology to put them into the cosmos they are just hundreds of years away from being postbiological, writes Daily Galaxy.

This means as biologically-based organisms we are currently living in a 'short window'.

Possible aliens we could encounter in the cosmos would be more likely to be in the post-biological phase, Dr Schneider claims.

'Other civilisations may be vastly older than us - earthlings are galactic babies', she said.

Dr Schneider also believes in 'the greater age of alien civilisations.'

She says evidence suggests alien civilisations are likely to be older than our own - somewhere between the range of 1.7 billion and 8 billion years old.

These life-forms could be 'postbiological' and not driven by the propagation of genes like creatures on Earth but powered by technology (stock image)

This means they could be vastly more intelligent than us and therefore even more likely to be in the postbiological phase.

Uploading onto machines means silicon-based life could survive in harsher conditions than carbon-based life forms.

Experts also believe silicon-brains could be smarter as information passes faster along plastic neurons than in the brain itself.

Dr Schneider said there are many advantages to being silicon-based.

'It's easier for instance to survive space travel. There's tremendous computational power available and there are no physical limitations like the skull and a machine could in principle reach super-intelligence quicker than a human', she said.

'There would be near-immortality and reliability'.

However, she did not believe there necessarily was life on other planets.

'The universe could be a lonely place, we still do not know the conditions that created life on this planet', she said.