DNA ‘tweezers’ take shape
Bernard Yurke from Lucent Technologies in the US, Andrew Turberfield from Oxford University in the UK and Lucent, and co-workers constructed the tweezers from three separate strands of DNA. DNA molecu...
Microscopy: two lasers are better than one
Stefan Hell and co-workers at Gottingen have adapted a technique known as fluorescence microscopy. In this form of microscopy the specimen is irradiated at a wavelength which excites either natural or...
New materials stretch the imagination
The Poisson’s ratio of a material is defined as nij = –ej/ ei, where ej is the lateral strain in the j direction that is caused when a strain ei is applied in the longitudinal i direction....
Physics, polymers and pesticides
Physicists have studied the interaction of water with surfaces for centuries. Felix Savart, for instance, first studied shocks in shallow water in 1833. It is now well known that the maximum diameter ...
Turbulence turns elastic
Polymer films are used in to make many mass-produced products, such as compact discs. It has been known for some time that the flow rate of liquid polymers can become irregular during the manufacturin...
Read article: Science and the Stradivarius
Science and the Stradivarius
Is there a secret that makes a Stradivarius sound so good, and can modern violins match the wonderful tonal quality of this great Italian instrument, asks Colin Gough
Double first for superfluids
Helium-3 flows without friction when it is cooled below the superfluid transition temperature of 2.6 millikelvin. In the superfluid state the helium-3 atoms, which are fermions and therefore obey the ...
Physics in a bubble
The MIT team injected small quantities of air into a highly viscous liquid to stimulate the formation of air bubbles. As the bubbles reached the surface, da Silveira and colleagues punctured them with...
Conductivity measurements made on a single strand of DNA
The Delft group fabricated the electrodes by making a slit in a silicon nitride film with standard lithography. A series of platinum layers were then sputtered across the slit until the gap was reduce...
Helium beam moves into sharper focus
Physicists have tried for years to develop a beam of atoms that could be focused as easily as electrons and photons. The helium atoms are fired at 1 km/s through a micron diameter nozzle past a set of...
