Scientists have built world’s first ‘time machine’ in experiment which defies the laws of physics
QUANTUM TIME Scientists have built world’s first ‘time
machine’ in experiment which defies the laws of physics
Lead researcher Dr Gordey Lesovik said by putting
scattered electrons back into their original shape they had effectively created
a state which went against the 'direction of time'
By Greg Wilford 13th March 2019, 3:07 pm
SCIENTISTS have built the world’s first time machine —
sort of.
Working with electrons in the bizarre realm of quantum
mechanics, they first created the equivalent of a break for a game of pool.
The “balls” scattered and, according to the laws of
physics, should have appeared to split in a haphazard way.
But researchers managed to make them reform in their
original order — looking as if they were turning back time.
Lead researcher Dr Gordey Lesovik, of Moscow’s Laboratory
of the Physics of Quantum Information, said: “We have artificially created a
state that evolves in a direction opposite to that of the thermodynamic arrow
of time.”
His team used a rudimentary quantum computer, which
carries information on subatomic particles. He hopes their findings, in journal
Scientific Reports, will help improve processing power.
Not quite Dr Who, but even Time Lords had to start
somewhere . . .
So how does it work? Well the time machine is actually a
rudimentary quantum computer made up of electron qubits.
A qubit is a the basic unit of quantum information – a
unit that represents one, zero, and both one and zero at the same time.
Researchers ran an "evolution program", which
caused the qubits to enter a complicated changing pattern of ones and zeroes.
And during this process, the order was lost – like
hitting balls at the start of a game of pool.
A separate program then modified the state of this
quantum computer so that it evolved backwards, returning from chaos to order.
This allowed the qubits to return to their original
starting point.
Scientists were able to perform this so-called "time
reversal" successfully 85 per cent of the time with two qubits, and had a
50 per cent success rate with three qubits.
The idea was to test out a theory about whether time can
reverse itself – at least for a single particle for a fraction of a second.
When scientists observe an electron, they can't figure
out its exact position, but can determine where it's roughly located.
But over time, it becomes more difficult to tell where
that electron is, because the region of space containing it "spreads
out". Or rather, it becomes more "chaotic".
This increases the uncertainty of the electron's position
– a core principle of Schrodinger's equation.
The team were able to then calculate the probability of a
"smeared out" electron spontaneously "localising" back to
its recent past – travelling through time, in effect.
And it turns out that if you observe 10billion freshly
localised electrons every second for 13.7billion years, you'd only see this
happen once.
And even then, the electron would only travel no more
than a ten-billionth of a second into the past.
That's not ideal, because not being able to predict
time-reversal makes the system useless to scientists.
That's why it's so important that scientists were able to
successfully "reverse time on demand" with a quantum computer.
What is quantum computing?
Quantum computing could use interactive photons, but what
actually is it?
·
Computer chips are getting smaller and faster,
but there's a limit to how small we can go
·
Quantum computing is a way to keep making
computers faster once we hit the limit of normal computer chips
·
It's based on the idea of using tiny particles
that can exist in multiple random "states" at any one time
·
Quantum bits (or qubits) in a quantum computer
could be a one, a zero, or both at the same time
·
Think of a giant pole running through the centre
of the earth
·
The pole would be in the middle, but also at
both ends of the planet, simultaneously
·
In this example, a qubit could be at any point
of the planet, and at all points of the planet, at any given time
·
That means a qubit could store huge amounts of
information, because it has millions of possible "states"
·
This means that a quantum computer would be able
to perform complex tasks very quickly by utilising qubits
·
Sadly, quantum computers are still very much a
work-in-progress
·
But scientists hope that by using tiny particles
like photons, it would be possible to advance quantum computing research
QUANTUM TIME Scientists have built world’s first ‘time
machine’ in experiment which defies the laws of physics
Lead researcher Dr Gordey Lesovik said by putting
scattered electrons back into their original shape they had effectively created
a state which went against the 'direction of time'
By Greg Wilford 13th March 2019, 3:07 pm
SCIENTISTS have built the world’s first time machine —
sort of.
Working with electrons in the bizarre realm of quantum
mechanics, they first created the equivalent of a break for a game of pool.
The “balls” scattered and, according to the laws of
physics, should have appeared to split in a haphazard way.
But researchers managed to make them reform in their
original order — looking as if they were turning back time.
Lead researcher Dr Gordey Lesovik, of Moscow’s Laboratory
of the Physics of Quantum Information, said: “We have artificially created a
state that evolves in a direction opposite to that of the thermodynamic arrow
of time.”
His team used a rudimentary quantum computer, which
carries information on subatomic particles. He hopes their findings, in journal
Scientific Reports, will help improve processing power.
Not quite Dr Who, but even Time Lords had to start
somewhere . . .
So how does it work? Well the time machine is actually a
rudimentary quantum computer made up of electron qubits.
A qubit is a the basic unit of quantum information – a
unit that represents one, zero, and both one and zero at the same time.
Researchers ran an "evolution program", which
caused the qubits to enter a complicated changing pattern of ones and zeroes.
And during this process, the order was lost – like
hitting balls at the start of a game of pool.
A separate program then modified the state of this
quantum computer so that it evolved backwards, returning from chaos to order.
This allowed the qubits to return to their original
starting point.
Scientists were able to perform this so-called "time
reversal" successfully 85 per cent of the time with two qubits, and had a
50 per cent success rate with three qubits.
The idea was to test out a theory about whether time can
reverse itself – at least for a single particle for a fraction of a second.
When scientists observe an electron, they can't figure
out its exact position, but can determine where it's roughly located.
But over time, it becomes more difficult to tell where
that electron is, because the region of space containing it "spreads
out". Or rather, it becomes more "chaotic".
This increases the uncertainty of the electron's position
– a core principle of Schrodinger's equation.
The team were able to then calculate the probability of a
"smeared out" electron spontaneously "localising" back to
its recent past – travelling through time, in effect.
And it turns out that if you observe 10billion freshly
localised electrons every second for 13.7billion years, you'd only see this
happen once.
And even then, the electron would only travel no more
than a ten-billionth of a second into the past.
That's not ideal, because not being able to predict
time-reversal makes the system useless to scientists.
That's why it's so important that scientists were able to
successfully "reverse time on demand" with a quantum computer.
What is quantum computing?
Quantum computing could use interactive photons, but what
actually is it?
·
Computer chips are getting smaller and faster,
but there's a limit to how small we can go
·
Quantum computing is a way to keep making
computers faster once we hit the limit of normal computer chips
·
It's based on the idea of using tiny particles
that can exist in multiple random "states" at any one time
·
Quantum bits (or qubits) in a quantum computer
could be a one, a zero, or both at the same time
·
Think of a giant pole running through the centre
of the earth
·
The pole would be in the middle, but also at
both ends of the planet, simultaneously
·
In this example, a qubit could be at any point
of the planet, and at all points of the planet, at any given time
·
That means a qubit could store huge amounts of
information, because it has millions of possible "states"
·
This means that a quantum computer would be able
to perform complex tasks very quickly by utilising qubits
·
Sadly, quantum computers are still very much a
work-in-progress
·
But scientists hope that by using tiny particles
like photons, it would be possible to advance quantum computing research
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