Scientific American Magazine

Although such testimony is frequently challenged, it is still widely assumed to be more reliable than other kinds of evidence. Numerous experiments show, however, that it is remarkably subject to error

Observations at the wavelengths of light, radio waves and X rays indicate that the X-ray source Cygnus X-1 is probably a black hole in orbit around a massive star

Cells isolated from this freshwater polyp can aggregate and form a complete new animal. Experiments with the system lend support to a physico-chemical scheme for the creation of biological pattern

The first steps in photosynthesis are the absorption of light by a pigment molecule and the delivery of the absorbed energy to other molecules capable of entering into chemical reactions

Many properties of a cast metal part arise from events that take place as the molten metal solidifies in the mold. Advances in understanding of these events make it possible to control them

Recent findings have upset previous explanations of how pigeons fnd their way home from distant locations. It appears that they have more than one compass system for determining direction

The recent experimental discovery of a hitherto unobserved class of elementary-particle interactions supports the view that a deep link exists between the weak force and the electromagnetic force

A runaway inflation in the third century debased the value of coins and drove out of circulation the coins whose value was not debased. The need for exchange then gave rise to widespread counterfeiting