Quantum computers are assisting researchers in scouting the universe in search of life outside of our planet -- and although it's far from certain they'll find actual aliens, the outcomes of the experiment could be almost as exciting.
During the eight-week program, quantum resources will be combined with classical computing tools to resolve complex calculations with better accuracy, with the end goal of finding out whether quantum computing could provide a useful boost to the work of astrophysicists, despite the technology's current limitations.
Detecting life in space is as tricky a task as it sounds. It all comes down to finding evidence of molecules that have the potential to create and sustain life -- and because scientists don't have the means to go out and observe the molecules for themselves, they have to rely on alternative methods.
Typically, astrophysicists pay attention to light, which can be analyzed through telescopes. This is because light -- for example, infrared radiation generated by nearby stars -- often interacts with molecules in outer space. And when it does, the particles vibrate, rotate, and absorb some of the light, leaving a specific signature on the spectral data that can be picked up by scientists back on Earth.
Therefore, for researchers, all that is left to do is detect those signatures and trace back to which molecules they correspond.
The problem? MIT researchers have previously established that over 14,000 molecules could indicate signs of life in exoplanets' atmospheres. In other words, there is still a long way to go before astrophysicists have drawn a database of all the different ways that those molecules might interact with light -- of all the signatures that they should be looking for when pointing their telescopes to other planets.
That's the challenge that the University of Hull has set for itself: the institution's Centre for Astrophysics is effectively hoping to generate a database of detectable biological signatures.
For over two decades, explains David Benoit, senior lecturer in molecular physics and astrochemistry at the University of Hull, researchers have been using classical means to try and predict those signatures. Still, the method is rapidly running out of steam.
The calculations carried out by the researchers at the center in Hull involve describing exactly how electrons interact with each other within a molecule of interest -- think hydrogen, oxygen, nitrogen and so on. "On classical computers, we can describe the interactions, but the problem is this is a factorial algorithm, meaning that the more electrons you have, the faster your problem is going to grow," Benoit tells ZDNet.
"We can do it with two hydrogen atoms, for example, but by the time you have something much bigger, like CO2, you're starting to lose your nerve a little bit because you're using a supercomputer, and even they don't have enough memory or computing power to do that exactly."
Simulating these interactions with classical means, therefore, ultimately comes at the cost of accuracy. But as Benoit says, you don't want to be the one claiming to have detected life on an exo-planet when it was actually something else.
Unlike classical computers, however, quantum systems are built on the principles of quantum mechanics -- those that govern the behavior of particles when they are taken at their smallest scale: the same principles as those that underlie the behavior of electrons and atoms in a molecule.
This prompted Benoit to approach Zapata with a "crazy idea": to use quantum computers to solve the quantum problem of life in space.
"The system is quantum, so instead of taking a classical computer that has to simulate all of the quantum things, you can take a quantum thing and measure it instead to try and extract the quantum data we want," explains Benoit.
Quantum computers, by nature, could therefore allow for accurate calculations of the patterns that define the behavior of complex quantum systems like molecules without calling for the huge compute power that a classical simulation would require.
The data that is extracted from the quantum calculation about the behavior of electrons can then be combined with classical methods to simulate the signature of molecules of interest in space when they come into contact with light.
It remains true that the quantum computers that are currently available to carry out this type of calculation are limited: most systems don't break the 100-qubit count, which is not enough to model very complex molecules.
Benoit explains that this has not put off the center's researchers. "We are going to take something small and extrapolate the quantum behavior from that small system to the real one," says Benoit. "We can already use the data we get from a few qubits, because we know the data is exact. Then, we can extrapolate."
That is not to say that the time has come to get rid of the center's supercomputers, continues Benoit. The program is only starting, and over the course of the next eight weeks, the researchers will be finding out whether it is possible at all to extract those exact physics on a small scale, thanks to a quantum computer, in order to assist large-scale calculations.
"It's trying to see how far we can push quantum computing," says Benoit, "and see if it really works, if it's really as good as we think it is."
If the project succeeds, it could constitute an early use case for quantum computers -- one that could demonstrate the usefulness of the technology despite its current technical limitations. That in itself is a pretty good achievement; the next milestone could be the discovery of our exo-planet neighbors.