smart cards because the data could be stored without a power source Magnets open the gate to nanoscale logic 8. Neutrons used to measure quantum gravitational effects The quantum properties of the electromagnetic force are seen in many phenomena, such as the electronic orbits in atoms and the structure of nuclei. However, it is extremely difficult to make analogous observations in gravitational fields because the effect of gravity is negligible at the atomic scale However, physicists at the Institute Laue-Langevin(ILL) observed quantized states of motion under the influence of gravity for the first time in 2002. The ILL team used ultra-cold neutrons to make their measurements, and the findings could be used to study the equivalence principle and Neutrons reveal quantum effects of gravity 9. First evidence for tetra-neutrons' It is important to understand the interactions between nucleons to understand the nucleus Physicists already know that pairs of neutrons can exist in an 'almost bound state, and they have spent many years trying to find evidence of these and higher numbers of neutron clusters However, these experiments are difficult because neutrons or clusters of neutrons have no charge In May researchers working at the Ganil accelerator in France reported the first evidence for tetra-neutrons-- nuclear clusters containing four neutrons and no protons. They found six possible candidates for the four-neutron clusters among fragments of neutron-rich beryllium nuclei If confirmed, the findings could greatly help in our understanding of nuclear forces Physicists get a taste of tetra-neutrons 10. Bright times in optics Optical physicists made progress in many directions in 2002. Researchers in Gottingen used conventional optics to image clumps of bacteria just 33 nanometres across--equivalent to a mere 23 of the wavelength of light used to illuminate them. the achievement shows that far-field ptical microscopes can operate well beyond the so-called diffraction limit. Meanwhile physicists in Bielefeld and Vienna continued last year's revolution in the generation of attosecond laser pulses by using such pulses to investigate the dynamics of the electrons in krypton atoms There was also a series of firsts in the realm of quantum optics: the first quantum NOT gates, the storage of two bits of information on a single photon, and the near-perfect cloning of a photon (perfect cloning is forbidden by the laws of quantum mechanics). Physicists in the UK and Germany also set a new distance record for the transmission of a"quantum key"in free space Such keys are essential components of secure communication systems Microscopes move to smaller scales First light for attophysics Quantum logic: to be or Not to be? Single photons to soak up data Photons get the quantum cloning treatment Quantum key travels record distancesmart cards because the data could be stored without a power source. Magnets open the gate to nanoscale logic 8. Neutrons used to measure quantum gravitational effects The quantum properties of the electromagnetic force are seen in many phenomena, such as the electronic orbits in atoms and the structure of nuclei. However, it is extremely difficult to make analogous observations in gravitational fields because the effect of gravity is negligible at the atomic scale. However, physicists at the Institute Laue-Langevin (ILL) observed quantized states of motion under the influence of gravity for the first time in 2002. The ILL team used ultra-cold neutrons to make their measurements, and the findings could be used to study the 'equivalence principle' and other fundamental aspects of physics. Neutrons reveal quantum effects of gravity 9. First evidence for 'tetra-neutrons' It is important to understand the interactions between nucleons to understand the nucleus. Physicists already know that pairs of neutrons can exist in an 'almost bound' state, and they have spent many years trying to find evidence of these and higher numbers of neutron clusters. However, these experiments are difficult because neutrons or clusters of neutrons have no charge. In May researchers working at the GANIL accelerator in France reported the first evidence for 'tetra-neutrons' -- nuclear clusters containing four neutrons and no protons. They found six possible candidates for the four-neutron clusters among fragments of neutron-rich beryllium nuclei. If confirmed, the findings could greatly help in our understanding of nuclear forces. Physicists get a taste of 'tetra-neutrons' 10. Bright times in optics Optical physicists made progress in many directions in 2002. Researchers in Göttingen used conventional optics to image clumps of bacteria just 33 nanometres across -- equivalent to a mere 1/23 of the wavelength of light used to illuminate them. The achievement shows that 'far-field' optical microscopes can operate well beyond the so-called diffraction limit. Meanwhile physicists in Bielefeld and Vienna continued last year's revolution in the generation of attosecond laser pulses by using such pulses to investigate the dynamics of the electrons in krypton atoms. There was also a series of firsts in the realm of quantum optics: the first quantum NOT gates, the storage of two bits of information on a single photon, and the near-perfect cloning of a photon (perfect cloning is forbidden by the laws of quantum mechanics). Physicists in the UK and Germany also set a new distance record for the transmission of a "quantum key" in free space. Such keys are essential components of secure communication systems. Microscopes move to smaller scales First light for attophysics Quantum logic: to be, or NOT to be? Single photons to soak up data Photons get the quantum cloning treatment Quantum key travels record distance