Cosmic Rays Change Composition Midway
Cosmic rays are not light but charged particles bombarding Earth from all directions. Most of them are protons (hydrogen nuclei), but heavier nuclei also show up: helium, nitrogen, iron.
The Earth’s Neutrino Confession: IceCube Reads the Planet in the Language of Weak Interactions
Earth is a closed book for those accustomed to leafing through pages with light. But to neutrinos, the invisible particles born in cosmic rays and barely remembering the prediction of Pauli, our planet is a braille script: each kilometer of depth presses its relief into their…
Neutrino Tomography of Earth: A New Look at the Planet's Interior
For almost a century, seismology has been the planet’s chief X-ray, probing the interior through elastic waves. But neutrinos, ghost particles predicted by Wolfgang Pauli, offer a different perspective.
The Milky Way Speaks the Language of Neutrinos
Deep beneath the ice of the South Pole, nearly two and a half kilometers down, an unusual telescope is at work. It is not pointed at the sky but through the Earth. Its quarry: neutrinos, nearly elusive particles that pass through planets and stars without interacting with anything.