Google’s unveiling of Willow, its latest quantum computing marvel, has sent ripples of excitement and curiosity throughout the world of science and technology. It not only marks a monumental development in quantum computing but also reignites profound questions about the future of computing, artificial intelligence (AI), and even the nature of reality itself.
Will quantum computers like Willow be the key to unlocking AI with unimaginable capabilities? Will they shatter the foundations of Bitcoin and online security? Do they really prove the existence of a multiverse? Will quantum computing change the world? Let’s cut through the hype and dig deeper to find out what all this really means.
What breakthroughs did Google announce?
Google claims Willow has achieved two major breakthroughs. First, it boasts of significantly improved error correction, a crucial step towards building reliable quantum computers. Qubits, the building blocks of quantum computers, are incredibly sensitive to environmental disturbances. Even the slightest noise, like a change in temperature, a stray electromagnetic field, or sometimes even cosmic rays, can cause qubits to lose information introducing errors. Imagine performing a complex calculation on a calculator where the numbers constantly flicker and change – that’s the challenge posed by these fragile qubits.
Now, typically, the more qubits you have, the more errors you encounter. It’s like building a towering and intricate structure with LEGO bricks: the larger it gets, the more unstable it becomes. But Willow defies this trend. Google’s engineers have achieved a remarkable feat – as they build larger and larger grids of qubits, the errors actually decrease exponentially. This is indeed a historic achievement, because it opens up possibilities for building larger and more powerful quantum computers.
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The second breakthrough lies in Willow’s sheer speed. Google claims it performed a benchmark computation task in under five minutes that would take the world’s fastest supercomputer an unfathomable ten septillion (10^25) years to solve. To put this in perspective, the universe itself is estimated to be around 13.8 billion years old.
How could quantum computers change the future of computing?
Taking five minutes for something that would need 10 septillion years isn’t just a speed boost. It is a fundamental shift in what’s possible. It’s like comparing the blink of an eye to the entire history of the universe – a fleeting moment versus billions of years. So, what does this mean for the future of computing?
Imagine simulating molecular interactions with incredible accuracy allowing scientists to design personalised drugs for treating cancer, Alzheimer’s, and other complex diseases. Quantum simulations could help discover new materials like room-temperature superconductors or design stronger, lighter, and more durable materials for use in everything from aircrafts to medical implants. They could analyse complex financial data and model market behaviour with unmatched precision, enabling far superior risk assessment, portfolio optimisation, and fraud detection.
And then there’s AI. Quantum computers could not only train AI models faster using larger datasets, but they could also identify patterns invisible to classical computers leading us to create AI that is far more intelligent, accurate, and insightful.
Why are we talking about multiverses?
Google’s announcement of Willow contained a rather intriguing aside – a suggestion that its development “lends credence to the notion that quantum computation occurs in many parallel universes, in line with the idea that we live in a multiverse.”
This seemingly casual remark touches upon a profound idea championed by David Deutsch, an Oxford physicist and quantum computing pioneer. Deutsch subscribes to the “many-worlds interpretation” of quantum mechanics, a theory proposing that every quantum measurement spawns a multitude of universes, with each possible outcome of the measurement unfolding in a separate reality.
In his 1997 book titled The Fabric of Reality, Deutsch issued an interesting challenge to “all those who still cling to a single-universe worldview”. He points to Shor’s algorithm, one of the earliest quantum algorithms to be developed, which theoretically allows for the factorisation of incredibly large numbers. However, factorising a sufficiently large number in Deutsch’s example would require 10^500 times the computational resources present in our entire universe, which has only about 10^80 atoms.
“So if the visible universe were the extent of physical reality,” writes Deutsch, “physical reality would not even remotely contain the resources required to factorise such a large number. Who did factorise it, then? How, and where, was the computation performed?” His answer: across the multiverse with each parallel universe contributing to the solution.
Google’s offhand remark that Willow lends credence to us living in a multiverse might not be as outlandish as it first appears. Deutsch’s challenge forces us to confront the limitations of our conventional understanding of reality. If our universe simply doesn’t possess the capacity to perform such calculations, then where do they occur? The many-worlds interpretation offers an elegant, albeit radical, solution. While definitive proof of the multiverse remains elusive, the extraordinary capabilities of quantum computers like Willow certainly compel us to consider the possibility that our reality is far stranger than we ever imagined.
A sober look at quantum computing
While it’s easy to get swept up in the excitement surrounding Willow, it’s also important to step back and examine the bigger picture. Back in 2019, Google claimed “quantum supremacy” with their Sycamore processor, stating it solved a problem in 200 seconds that would take a supercomputer 10,000 years. However, this claim was quickly challenged by IBM researchers, who showed a classical computer could solve the same problem in just 2.5 days. Later, Chinese researchers devised a clever technique using multiple GPUs to solve the problem even faster, casting further doubt on Google’s supremacy claim.
IBM, a formidable rival to Google in developing quantum computers, cautions against using terms like “quantum supremacy” or “quantum advantage”. These terms create a misleading narrative of a battle between quantum and classical computers, where one ultimately triumphs over the other. This is simply not the case.
Quantum computers excel at specific types of problems, while classical computers remain superior for many everyday tasks. The future of computing lies in them working together by leveraging their unique strengths. Terms like “supremacy” fuel unrealistic expectations and hype, leading to disappointment and disillusionment when quantum computers don’t immediately revolutionise every aspect of our lives. A more nuanced approach highlighting the specific areas where quantum computers offer a clear advantage and emphasising the collaborative nature of quantum and classical computing can foster a more realistic understanding of this evolving technology.
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While Google’s work is undeniably impressive from a scientific and engineering standpoint, its immediate consequences for our everyday life, as physicist Sabine Hossenfelder points out, are still exactly zero. Practical applications like drug discovery and cryptography will require millions of qubits, while Willow has just 105. As we explored in our 2020 article, The Inconvenient Truth About Quantum Computing, there is a chasm between current quantum capabilities and those needed for practical applications. Bridging it demands multiple breakthroughs. While Willow is a significant milestone, it’s crucial to recognise the long road and formidable challenges ahead in building commercially viable quantum computers.
Every new announcement in quantum computing triggers a new wave of obituaries for Bitcoin. But no, Willow is no threat to Bitcoin. Cracking Bitcoin’s encryption will require millions of qubits, far beyond our current capabilities. Furthermore, Bitcoin developers have been anticipating and addressing the potential quantum threat since the cryptocurrency’s earliest days.
Willow is a testament to human ingenuity and our relentless pursuit of knowledge. While the hype surrounding quantum computing may sometimes outpace reality, the progress being made is irrefutable. From revolutionising medicine and materials science to reshaping AI and perhaps even unlocking the secrets of the multiverse, quantum computers hold the key to a future that strains the limits of our imagination. As we continue to push the boundaries of this extraordinary technology, we may find ourselves not just changing the world but redefining our very understanding of reality itself.
Viraj Kulkarni is a quantum computing researcher, amateur historian and science writer. His twitter handle is: @VirajZero.
