An Electron Orbits An Atom's Nucleus (IMAGE) Northwestern University Caption In this artist's representation, an electron orbits an atom's nucleus, spinning about its axis as a cloud of other subatomic particles are constantly emitted and reabsorbed. Several hypotheses predict particles, as yet undetected, would cause the cloud to appear slightly pear-shaped. ACME researchers peered at the shape with unprecedented, extreme precision. To the limits of their experiment, they saw a perfectly round sphere, implying that certain types of new particles -- if they exist at all -- have properties different from those theorists expected. Credit Nicolle R. Fuller, National Science Foundation Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.