A newly discovered way for oxygen to form in carbon-dioxide-rich atmospheres of exoplanets could help guide scientists' ...

but no mass while traveling in a different direction. Known as semi-Dirac fermions, particles with this bizarre behavior were first predicted 16 years ago. The discovery was made in a semi-metal ...

For the first time, scientists have observed a collection of particles ... move like they have mass and sometimes move like they have none." A particle can have no mass when its energy is entirely ...