This article was originally published in Finnish in issue 3/2026 of Yliopisto magazine.
When
However, the child could not go on the trip and see friends at the same time. At the atomic level, the perspective is different. When electrons are in a superposition, they are everywhere at the same time. This is just one of the peculiarities of quantum mechanics.
Why does quantum mechanics seem so irrational? Does nature not comply with its own laws?
“Common sense stems from our sensory perception and what our senses communicate to our brain. Quantum mechanics deals with phenomena at extremely small scales and low temperatures, which humans cannot directly observe,” Keski-Vakkuri explains.
In other words, the laws of nature persist, but manifest differently at different scales.
Atomic messages
Even if our common sense cannot grasp quantum mechanics, it is present in our everyday lives. Among other things, it underpins smartphones and computers, solar panels and nuclear power, GPS navigation and brain imaging.
“Modern life is based on our having learned to utilise quantum mechanics,” Keski-Vakkuri says.
Quantum theory is also one of the most rigorously tested scientific theories. Albert Einstein called it repulsive, but the theory nevertheless works.
Atoms can exchange messages and energy only in packages of a certain size known as quanta. Related phenomena can be controlled and managed, which opens up many technical application opportunities. One of them is quantum computing.
Between states
Regular computers perform calculations by manipulating binary digits (0 or 1) known as bits. In contrast, quantum computers use quantum bits, or qubits. When they are in a superposition, they exist simultaneously in the states of 0 and 1, or rather between these states.
When qubits are in a superposition, quantum computers calculate all possible results simultaneously, possibly accelerating computing exponentially. They also consume less energy than regular computers.
The problem is that the superposition, or the quantum state, collapses extremely easily due to any disturbance, including measurement. The collapse turns qubits into regular bits, which can only be either 0 or 1.
“The biggest mystery of the quantum state is how and why it collapses. No one knows,” says Keski-Vakkuri.
Quantum magic
In addition to the superposition, quantum computing entails other special characteristics. Qubits can become entangled to form a single quantum system that can be controlled simultaneously, regardless of the distance between the qubits.
“Let’s assume that I have two entangled quantum coins that produce either heads or tails at a certain probability when tossed, and I give one of them to you. You travel to Rovaniemi. I’m looking at my coin and see that it’s tails. In that case, your coin in Rovaniemi will also show tails.”
Many quantum algorithms exploit entanglement. It and the superposition are often considered the reason for the effectiveness of quantum computing, but they alone are not enough. In addition, special quantum logic gates are used. They create a clever structure for calculations necessary to speed up computing. This is what physicists call magic.
Alleviating mistakes
A lot of expectations have been placed on quantum computers. They could potentially be used to discover new drugs, carbon-binding molecules and substitutes for plastic and rare-earth elements. They could optimise routes and stock portfolios, and produce fertilisers while consuming less energy.
Current quantum computers are not there yet. They are what are known as noisy devices that make a lot of mistakes. The aim is to both prevent errors during computing and mitigate them afterwards.
Among other things, additional information can be used to this end.
“If I spell out my name on the phone using a phonetic alphabet (E for echo, S for Sierra, K for Kilo, O for Oscar), I use a great deal of information to make sure that the four letters are correct. This is the same thing,” Keski-Vakkuri explains.
Disruptions can be reduced by cooling and isolation. Physical qubits can also be combined into logical qubits, where they fix each other’s errors. In such cases, as many as millions of physical qubits are needed. In Finland, IQM and VTT Technical Research Centre of Finland are currently building a 300-qubit quantum computer.
“The quantum computers we are pursuing would be error-proof, but there’s still ways to go.”
Precision
Current quantum computers can nevertheless be effective for learning how such devices function and practising quantum computing. In fact, they are primarily used in teaching and research.
Developing algorithms for quantum computers is difficult. First you have to design an algorithm based on the rules of quantum mechanics, then you have to prove that it functions more efficiently than algorithms on classical computers.
Regular computers can quickly close the quantum advantage gained, as their programming languages make software coding easier, something currently absent in quantum computing.
One of the first things that Keski-Vakkuri believes quantum computers are suited for is the simulation of physical models and materials research. Quantum computing can also improve measurement precision, for example, in thermometers and microscopes.
Dynamite
Quantum computers are also associated with risks. After all, a sufficiently powerful quantum computer would be capable of breaking currently used encryption systems, earning the description of a stick of dynamite placed at the door to the bank vault.
The most common encryption currently in use is based on the product of two prime numbers, and it is slow for regular computers to divide a sufficiently large number of up to 50 digits into its factors. However, as early as 1994 Peter Shor developed an algorithm that enables quantum computers to quickly divide even large numbers into their factors.
Shor’s algorithm does not run on current quantum computers, but future machines may have the required capacity. Moreover, spies and criminals can collect encrypted data now and decrypt them later.
In addition to banks, people’s health details as well as governmental defence and intelligence data are under threat. Traffic control and energy and water supply systems could also suffer.
Securing data
The International Monetary Fund has urged banks to prepare for threats, and in Finland, the National Emergency Supply Agency has also issued warnings. Quantum-secure encryption methods must be deployed.
Such solutions already exist: in 2024, the National Institute of Standards and Technology (NIST) in the United States standardised four cryptographic algorithms that quantum computers cannot break.
However, the global transition is slow and costs billions of euros.
A couple of years ago, a survey conducted by VTT indicated that only a small share of businesses in Finland had taken concrete measures to adopt quantum-secure encryption techniques, even though three-quarters were aware of the threat.
“There is time for the transition. Quantum computers capable of breaking encryptions are unlikely to arrive soon. My guess is that it will take ten years or so. However, new data should be encrypted in a quantum-secure manner in advance,” Keski-Vakkuri estimates.
In the future, quanta may enable even more effective encryption. Quantum states cannot be copied without destroying them. In other words, quantum communication cannot be spied on without exposing yourself. A quantum communication network between countries is already being established in Europe.
What kind of qubit?
There are several ways to create qubits. Quantum computers in Finland use superconducting circuits. These are electrical circuits cooled to near absolute zero, easy to manufacture and fast to operate. The downside is their susceptibility to collapsing out of superposition, and they are also quite prone to errors
Other options include trapped atoms and ions, which remain longer in a superposition, but are slower to use. In some quantum computers, photons are also used as qubits.
“Each option has its pros and cons,” Keski-Vakkuri muses.
Quantum machine learning combines two hot fields, artificial intelligence and quantum computing. Both are hindered by errors and difficult comprehensibility. Could they boost each other?
“Quantum machine learning involves a lot of hype. Time will tell how effective it is. Having said that, the Finnish startup Qutwo has made a good start.”
According to the physicist, uncertainty is a fundamental characteristic of quantum mechanics. However, the uncertainty of machine learning stems from a lack of understanding of how artificial intelligence functions.
A brain twister
Should everyone try to grasp quantum mechanics in spite of its complexity?
“At this stage, quantum computing does not really concern ordinary citizens. But if you want to tie your brain in a knot, this is one way to do it. Quantum mechanics also provides excellent questions for pub quizzes. For example, it explains why things do not fall off the table.”
Perhaps quantum science can be better understood through fiction. Everywhere All at Once, a science fiction comedy released in 2022, thrillingly used the many-worlds theory of quantum physics. In the superhero film Ant-Man (2015), the protagonist, shrunken to microscopically small stature, ventures to the quantum realm.
Quantum mechanics is full of paradoxes. For example, Keski-Vakkuri has wondered whether the quantum state is ontological or epistemic, or, in plain language, whether it is real or dependent on knowledge.
“Physicists think the quantum state is real. But the longer you consider quantum mechanics, the more you start to suspect that it might be epistemic after all. We can’t see the quantum state. The moment we look, it collapses.”
Quantum mechanics has traditionally been taught by telling students to shut up and concentrate on calculations, which amuses Keski-Vakkuri.
“I’m already 60 and at the point where physicists start going scatterbrained and wondering what quantum mechanics actually means.”
Tommi Tenkanen’s book entitled Kvanttikilpajuoksu (Tammi, 2025) was used a source for this article.
Yliopisto is a popular science magazine published by the University of Helsinki and committed to the journalistic guidelines of the Council for Mass Media in Finland.
Trying to explain the quantum realm in terms of classical physics often leads to false notions. According to
“Spoken language does not describe quantum mechanics very well. It should be preferably conceptualised by way of mathematics. You have to accept that it does not fit your everyday logic and learn to live with the fact that the whole thing feels strange.”
Palmgren investigated how first-year students of the physical sciences learned quantum mechanics and how proficient they felt they were in it. An abstract mathematical approach that supports intellectual development better than traditional teaching in quantum mechanics was chosen as the teaching method.
“The approach promoted learning effectively, but it must have been a shock to students at the beginning, as their self-efficacy beliefs went down a notch. Groupwork, among other things, proved to be a successful course correction.”
Quantum mechanics is also taught in general upper secondary school, but Palmgren believes that the math approach is probably too technical in that context.
While not everyone has to understand quantum science, quantum computers can have a societal impact. Palmgren believes that this is why everyone should understand their functioning enough to take part in the discussion.
“Quantum computers may need regulation or cause contention among the great powers. In addition, a range of jobs are available in the field.”
Palmgren works at
“In addition to quantum physicists, we need representatives from many fields, including lawyers and policymakers, who understand the societal effects of quantum technology,” Palmgren says.