corresponding to an effective interparticle attraction, and allowed the gas to equilibrate. Next, they apidly decreased the value of the magnetic field, sweeping it across the Feshbach resonance to the side that supports a weakly bound molecular state. The magnetic field is spatially constant, so it does not change the speed of the centre-of-mass of an atomic pair. The sweep is also sufficiently rapid to avoid any changes in the overall speed of the atoms due to collisions As a result, the initial distribution of the centre-of-mass speeds of the fermionic pairs is the same as the distribution for the molecules after the magnetic sweep. Jin and co-workers then measured this speed distribution and found that it was exactly the type one gets from of a Bose-Einstein condensate. In this way, the JILA result is the"smoking gun"of a fermionic condensate One of the most important consequences of the production of a fermionic condensate is that enables ultracold atoms to be used to study the crossover between conventional superfluidity in the BCs limit and the superfluidity of molecules. This crossover may well be relevant to high-temperature superconductivity. It will also allow us to study strongly interacting many-body systems, such as"Bertsch nuclei"in nuclear physics. With such an exquisite degree of control over ultracold matter, we can also hope that it will ultimately be possible to elucidate the internal structure of the fermionic pairs Autho Krzysztof Goral and Keith Burnett are in the Physics Department of the University of Oxford, UKcorresponding to an effective interparticle attraction, and allowed the gas to equilibrate. Next, they rapidly decreased the value of the magnetic field, sweeping it across the Feshbach resonance to the side that supports a weakly bound molecular state. The magnetic field is spatially constant, so it does not change the speed of the centre-of-mass of an atomic pair. The sweep is also sufficiently rapid to avoid any changes in the overall speed of the atoms due to collisions. As a result, the initial distribution of the centre-of-mass speeds of the fermionic pairs is the same as the distribution for the molecules after the magnetic sweep. Jin and co-workers then measured this speed distribution and found that it was exactly the type one gets from of a Bose-Einstein condensate. In this way, the JILA result is the "smoking gun" of a fermionic condensate. One of the most important consequences of the production of a fermionic condensate is that it enables ultracold atoms to be used to study the crossover between conventional superfluidity in the BCS limit and the superfluidity of molecules. This crossover may well be relevant to high-temperature superconductivity. It will also allow us to study strongly interacting many-body systems, such as "Bertsch nuclei" in nuclear physics. With such an exquisite degree of control over ultracold matter, we can also hope that it will ultimately be possible to elucidate the internal structure of the fermionic pairs. Author Krzysztof Góral and Keith Burnett are in the Physics Department of the University of Oxford, UK