You are currently browsing the tag archive for the ‘Spaß’ tag.

Dies ist ein kurzer Follow-up Post zur und soll euch meinen Finalbeitrag zeigen. Viel Spaß!

Editorial: Bevor ihr auf das unten stehende Video klickt, muss ich zunächst noch einen Fehler korrigieren, der mir im Zuge der Aufzeichnung des Vorspanns unterlaufen ist: Der erste Gammablitz wurde im Jahre 1963 entdeckt (die entsprechende Publikation dann im Jahre 1967 veröffentlicht). Somit sind seit ihrer Entdeckung 48 Jahre vergangen (und nicht 40, wie von mir fälschlicherweise behauptet).

Here’s the english translation in case you’re not saddle-fast in german:

Each and everyone of you has experienced in your life an earthquake at least once. Besides the terrifying shaking of the Earth and the catastrophic consequences that such an earthquake can have it can be, scientifically speaking, quite interesting. Using the waves caused by the quake which penetrate the Earth we can understand how the Earth is built up inside: Core, Mantle, Crust. This is very similar how you can determine the difference between a clarinet and a contrabass according to their acoustic waves.
The science that makes use of these kind of waves is called seismology.

But seismology is not limited to the Earth. Because stars tremble as well. ‚How can we possibly know that‘, you might ask, ’nobody has ever been on the surface of a star‘. This is very true. But what astronomers do: we observe the light of a star over a long period of time: days, weeks, months and even years. And what we see in such a dataset is the cyclic and periodic change of the luminosity of a star. These changes in brightness are caused by the periodic expansion and contraction of the stellar surface [This is the time where I try to visualize the radial pulsation mode of the star]. Similarly to earthquakes, these stellar quakes can help us to determine the inner build-up and structure of a star. This kind of science is called astroseismology.

In my diploma thesis, I investigated the so called ’slowly pulsating B stars‘. These stars are very hot and massive stars, which are in the midst of their lives and pulsate very slowly, with about one to two cycles per day.

There is yet another way to understand and picture stellar quakes. Sound is nothing else than the overlap of many waves. One can shift the observed oscillations of a star by a few octaves to the range where they than can be heard by us humans. Here’s one star where this has been done. Ladies and gentleman, without further ado I give you one of the many musicians of the cosmic orchestra: [I hold up the roundish thing which hangs around my neck] the star DO Eridani.

[sound plays]

Thank you very much.