2004

	10.12.2004
	Equivalence principle also valid for atoms
	In the 16th century Galileo Galilei dropped leaden, golden and wooden objects off the leaning tower in Pisa. He found that all objects reached the ground at the same time. This illustrates the more general result that in a gravitational field the motion of all bodies is the same independent of their mass and composition. ...

	25.11.2004
	Quantum memory for light
	In the macroscopic classical world, it is possible to copy information from one device into another. We do this everyday, when, for example, we copy files in a computer or we tape a conversation. In the microscopic world, however, it is not possible to copy the quantum information from one system into another one. ...

	28.10.2004
	Photons under Control
	By using a tightly trapped single calcium ion, localized between two ultra-high reflectivity mirrors, and subjecting it to an external laser pulse, the scientists could emit photons one by one. The emission time and the pulse shape of each photon were completely user-controlled. ...

	27.08.2004
	Light oscillations become visibler
	The human eye can detect changes in the intensity of light, not however the wavelength because light oscillates too fast (approximately 1000 trillion times per second). An international collaboration led by Ferenc Krausz and made up of researchers from the Vienna University of Technology, ...

	20.05.2004
	When Bosons become Fermions
	There are two fundamentally distinct families of particles in nature: bosons and fermions. Being a boson or a fermion has profound consequences on the ‘social behaviour’ of a particle when it meets other partners. Whereas bosons tend to socialize and want to be as close to each other as possible, fermions are very independent and like to be on their own. ...

	26.02.2004
	The fastest stopwatch in the world
	The electromagnetic field of visible light changes direction approx. one thousand trillion (10 up 15) times per second, so that the intensity of the light field varies from zero to maximum faster than a femtosecond (1 femtosecond being one thousandth of a trillionth of a second)....