Through the looking glass

One of the things I love about physics is how it changes the way one sees the world. As one starts to think about some basic things very differently. Then even such a simple act as measurement is a complicated process which can even be used to manipulate physical systems.

How to measure time

Precise timekeeping is crucial for many of our daily activities. High-speed communication (on the internet or in a mobile phone network), satellite navigation, and many other tasks require time synchronisation over long distances to work properly. But how is time measured? And can quantum physics help reach better accuracies? The basic idea behind measuring time is …

Of light and springs

Using light, we can achieve more than simply see the world around us. Spectroscopy can be used to find chemical composition of a sample, frequency of light interacting with atoms can be used to measure time. We can even move objects by shining light at them. Such manipulations are far from tractor beams of science fiction, but optical tweezers are commonly used to manipulate small objects in many labs around the world. And there are other ways how to control matter using light.