The World Quantum Day aims at engaging the general public in the understanding and discussion of Quantum Science and Technology, namely:

  • how it helps us understand Nature at its most fundamental level,
  • how it helped us develop technologies that are crucial for our life today,
  • and how it can lead to future scientific and technological revolutions, and how these can impact our society.

The World Quantum Day is an initiative from quantum scientists around the World, launched on 14 April 2021 as the countdown towards the first global celebration on 14 April 2022.

It is a decentralized and bottom-up initiative, inviting all quantum scientists, engineers, educators, communicators, entrepreneurs, technologists, and their institutions, to organize their own activities, such as outreach talks, lab tours, debates, interviews, etc., to celebrate the World Quantum Day around the World.

Join us!

What is quantum physics?

Quantum physics is the most fundamental theory we have to describe Nature, namely at the level of the elementary particles and forces that constitute the Universe.

Furthermore, quantum physics is at the origin of transformational technological developments that helped shape the society of today, such as the transistor, the laser, medical imaging, to name just a few.

And, over the last decades, quantum science expanded beyond physics, and has been transforming our understanding of Information and opening the prospect for new and revolutionary information technologies, such as quantum computers and a quantum internet.

However, the foundations of quantum physics remain a source of scientific and philosophical debate.

Why April 14?

The World Quantum Day is celebrated on April 14, a reference to 4.14, the rounded first digits of Planck’s constant: 4.135667696×10−15 eV.s = 0,000 000 000 000 004 135667696 electronvolt second, a product of energy and time that is the fundamental constant governing quantum physics.

Why is Planck’s constant so important? Did you know it is used to define the kilogram? And, otherwise, how does it affect our lives? These are some of the questions, among many others, that will be addressed by the World Quantum Day activities. As well as by this web site, in the run up to 2022.

And what other dates and numbers do you consider important for Quantum Science and Technology? When was quantum physics first taught in your country? And in your university/school?

Send us your suggestions to

and these will be used in the preparation of future activities!