Present and past, simultaneous

Did you ever thought to see an evolution in time needs to wait this time? People from the university of Heidelberg (in Germany) saw a pulsar under five different time perspectives at the same time. How to understand this? The explanation is the gravitational lensing.


In 10th April 2008 Nature you can find a short article about this and also in the HubbleSite you can find a good images about this. The source article is from The Astrophysical Journal, but only the abstract is accessible.

As far as I understand, the point is the galaxy in the middle. It curves the light from the quasar that cannot come directly to as (because something is in the middle) an it came from five different paths. The light travels different distances to arrives here, and it means each ways has differences on time scale. They arrive here at the same time, but then they need to start the trip on different moments.