I was so taken up with the strange properties of quantum physics that I wrote my research project on it. It is not easy to find detailed information about this subject, so I contacted people who work at ICFO, who gave me study materials and helped me clear up many of my doubts.

I not only learned a lot about emerging quantum technologies: my project won the high school graduation prize!

A lot of people are concerned about knowing which interpretation of quantum physics is the right one and truly describes the world we live in. I think this issue is really irrelevant, since the success of quantum physics lies in predicting many phenomena that have been tested experimentally.

Ultimately, this is the only thing that is useful to us and that allows us to keep making progress!

I am a biochemist and I research new substances that could become medicines to cure diseases that are currently incurable.

One of the lengthier parts of the process of developing a possible new drug is finding out the effects it would have on organisms.

With the emergence of quantum computers we could significantly improve our simulation programs and this could dramatically reduce the need to experiment on living beings.

Quantum particles behave in a similar way to classical waves, so we could create technologies for material beams (atoms) analogous to those for light.

Examples: matter lasers, atomic interferometers, atomic lenses and mirrors, etc.

The advantage is that these devices would be very sensitive to variations in the gravitational field and inertial effects with applications in the manufacture of accelerometers (sensors that detect position changes, which are found in smartphones and tablets), for example.

In some experiments, the result does not allow us to distinguish which path the particle has taken: it is as if it were traveling along two paths at once! What we can observe is the effect of the interference between the two paths.

If we block one path, we no longer see interference, even though the particle has gone through the open path. It is as if it knew what is happening on the other path without going along it.

Applications: detecting and/or observing objects without interacting.

Thanks to superposition and entanglement, a computer with quantum bits (qubits) is much faster at solving some essential problems such as factorisation (very important for current cryptography!), optimisation problems and simulations, which even with the best computers we currently have would take millions of years to solve. 

There are some quantum computers now, but they do not yet have enough bits to surpass traditional computers.  

It is not possible to measure incompatible observables, such as the position and speed of a particle, at the same time and with arbitrary precision.

This is also known as Heisenberg's uncertainty principle.

The more precise the value of one observable, the more uncertain the other will be. For example, if I know the position of one particle with high precision, then the measurement of its velocity will be highly uncertain (i.e. it will have a large error).

Applications: sensors. We can use this property to obtain ultra-sensitive measurements from magnetic fields or gravity.

On many occasions throughout the history of science a new theory has replaced an older one: heliocentrism supplanted geocentrism, evolution supplanted catastrophic and Lamarckian theories. No-one can be sure this will not happen with quantum physics.

Should we then worry that all the efforts we are making now in this field will one day be in vain? Or can we carry on calmly, given that the current theory works for the moment, that is, it allows us to make predictions and develop new technologies?

We are used to the fact that measuring does not change the properties of objects at all, but at the quantum level, measuring can change the properties of what is being measured. In fact, if the particle is in a superposition of two states, the measurement causes the collapse of the superposition and as a result we observe only one well-defined one state.

If we cannot avoid the effect of our presence as observers on the system, how can we really know anything for sure?

Their applications in all fields of human activity will radically change our lives, just as electricity and electronics once did. We must invest as much as we can in their development, to make them commercially viable as soon as possible. 

We should not be fooled by illusory promises. We have gone very far with traditional technologies and we still have a long way to go: we should keep the current investment in quantum technologies at the same level. Let scientists do their work and continue to research, focusing on maintaining and improving the technologies that we already have. 

Research into quantum physics and its applications is positive, but we currently have other far more important and pressing issues, such as hunger, poverty, wars and terrorism. Let us maintain research, but invest our money to find solutions to the major problems our society has today.  

Quantum technologies are very promising, but if they are to be effective, they require solid knowledge of their foundations. We should invest in fundamental research: a better understanding of the foundations of quantum physics will naturally lead to the development of its applications.