PhysicsEarth's mantle helps hunt for fifth force of nature A new long-range force – mediated by curious "unparticles" – could be detected by letting electrons in the mantle affect particles at ground level ¿ìè¶ÌÊÓÆµ
PhysicsMost fundamental clock ever could redefine kilogram Physicists have created the first clock with a tick that depends on the hyper-regular frequency of matter itself ¿ìè¶ÌÊÓÆµ