säteilypainetta

Säteilypainetta is a Finnish term that translates to radiation pressure in English. It refers to the mechanical pressure exerted by electromagnetic radiation, such as light, when it is absorbed or reflected by a surface. This pressure arises from the transfer of momentum from photons to the absorbing or reflecting object.

Although often small in everyday experience, radiation pressure is a significant factor in various astrophysical phenomena. For instance, it plays a crucial role in the formation and evolution of stars and planetary systems. The intense radiation from a star can push away gas and dust, influencing the accretion disk and the eventual composition of planets. In the case of stars themselves, the outward radiation pressure counteracts the inward force of gravity, helping to maintain their stability.

On a smaller scale, radiation pressure can be observed in laboratory settings. Lasers can be used to trap and manipulate microscopic particles through this effect, a technique known as optical tweezers. While the force is tiny, the ability to precisely control these particles has opened up new avenues in fields like nanotechnology and biological research. The concept of radiation pressure is fundamental to understanding the interaction of light with matter across a wide range of scales, from the subatomic to the cosmic.