Last updated February 8, 2018 at 10:37 am
An ambitious experiment is set to test why the quantum world plays by different rules.
Scientists from across Europe are gearing up for an ambitious test of one of the fundamental laws of quantum physics. Together, they’ll test the limits of one of the core principles of quantum mechanics – the mind-boggling physical law that allows particles such as atoms and electrons to be in two places at once.
Newton vs Quantum
The vast majority of things that we see and interact with every day obey Isaac Newton’s laws of physics. However, the subatomic world obeys the laws of quantum mechanics, which are so strange that they seem counter-intuitive.
Just why the subatomic world exists using these different set of rules, for which there is significant evidence, while objects on the larger scale do not, has been baffling. If atoms can exist in quantum superposition, why do everyday objects such as cars, trees and people not behave in a quantum mechanical manner and exist in two places at once?
Some unproven theories suggest there could be some kind of universal background ‘noise’ that destroys QSP of larger objects. (When quantum physicists talk about larger objects, they are referring to particles the size that can be seen using an optical microscope.)
Testing on quantum scales
The experiment they have planned will involve a tiny particle of glass, one-thousandth of the width of a human hair, being levitated by an electric field in a vacuum, at a temperature close to absolute zero (-273°C). A laser will be shot at the particle, and the scattering of the laser’s light measured for signs of movement of the glass. If there is no movement, it means that quantum mechanics still apply at this scale and there is no universal background noise.
However, if movement is detected, it indicates the existence of a noise that prevents QSP applying at this scale.
Should they detect movement of the glass particle, it would represent the first failure of quantum theory, setting a limit on the scale at which quantum mechanics apply and having implications for large-scale applications of any physical system based on quantum principles.
In effect, quantum theory would need to be largely rewritten to deal with size limitations.
However, should there be no movement of the glass, it will have incredible implications for future technology.
“Our research programme could prove that we do not have to deal with extremely small systems in order to see quantum effects, which is currently the main limitation of quantum technology,” said Mauro Paternostro from Queen’s University Belfast, who will be involved in the experiment.
A lead-in to the future
“If you can prove that quantum theory extends to larger systems, it will offer a much more robust way of processing information: all the chips and integrated systems in computers could be shrunk to a much smaller scale and we would be able to manage quantum for daily applications.”
And that, he says, could revolutionise computing and communications. “This would mean larger data-processing rates, larger memories and larger transmission rates of data across these larger networks.”
Proving quantum superposition is possible at larger scales will also open up new possibilities for physics research, allowing the developed of ultra-sensitive measuring devices to measure the effects of gravity on a scale far finer than anything we have currently.
This is one experiment we will definitely be keeping an eye on as it happens – whatever result comes out will change how we view physics.
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