Our Earth is continuously being bombarded by particles from outer space. A small fraction of these particles was unexpectedly found to carry a lot of energy. To discover where such particles, and the source of their energy, come from, new particle detectors are needed that are suitable for observing neutrinos and protons with a very high energy. That is difficult because the particles concerned are very rare and, moreover, they normally fly unnoticed through detectors.

Gravitational waves are ripples in space-time. Using the equations from Einstein's general theory of relativity, we can calculate the gravitational radiation of, for example, two black holes that swallow each other. Ultra-sensitive interferometers are searching for gravitational signals from the Universe.

• Jo van den Brand
• Chris Van Den Broeck
• Piet Mulders
• Rob van der Meer
• Wijnanda de Haan