# The ISOLDE LEGO® Robot: Playing with nuclear physics or The ISOLDE LEGO® Robot: Building interest in nuclear physics ?

Abstract

An outreach programme centred around nuclear physics making use of a LEGO® Mindstorm® kit is presented. It consists in a presentation given by trained undergraduate students as science ambassadors followed by a workshop where the target audience manipulates the LEGO® Mindstorm® robots to familiarise themselves with the concepts in an interactive and exciting way. This programme has been coupled to the CERN-ISOLDE $$50^{th}$$ anniversary and the launch of the CERN-MEDICIS facility in Geneva, Switzerland. The modular aspect of the programme readily allows its application to other topics.

## The perception of nuclear physics in the society

Nuclear science bares the stigma of its most visible outcomes of the 20$${}^{th}$$ century, such as the bombing of Hiroshima and Nagasaki in 1945, or the explosion at the Chernobyle nuclear reactor in 1986. Behind those very visible events, many more activities have contributed to the bad reputation of nuclear research, such as the decades of environmental nuclear military testing or minor civil nuclear incidents around the globe. Altogether, the threat of nuclear disaster added to the very visible impact of some dramatic events has swayed the public opinion and convinced the environmental movements to oppose all forms of nuclear activities.

Nuclear science is however different from nuclear engineering. The main focus is the deep understanding of the forces of nature through the study of the atomic nucleus. The nucleus itself carries more than $$99.9\%$$ of the mass of the atom, while it only occupies $$0.0000000000001\%$$ of its volume; as matter, we are full of nothing, filled mostly with empty space. The nucleus is constituted of chargeless neutrons and positively-charge protons: how can these charged particles hold together against the Coulomb force at such close range? The answer lies with the strong force, named in part for holding against the Coulomb force, which action is sufficient to overcome the repulsion of the protons from one another. And this question is only the surface of how fascinating the nuclear medium can be in the study of fundamental properties.

If one now turns to the stars, those giant balls of gas that light our way and enthrall our fascination, one may wonder at how they are powered. The answer lies again in nuclear science: stars are giant fusion reactors, where nuclear energy is released continuously until there is no more energy left. After that point, a star collapses upon itself with gravity, until it blows out in a supernova explosion, during which many nuclear reactions occur, leading to the balance of elements as we know them in our solar system. While this story of the life cycle of a star takes here but a few lines, it occurs over billion of years, and involves countless nuclear reactions, not all of which are yet fully understood. Extensive work is thus performed in many worldwide facilities in order to better understand how a star lives, breathes, and comes to pass, as well as all other forms of exotic galactic events that might be powered by the nuclear force.